Series comparison

target-arm queue. The big thing here is the landing of the 3-phase
reset patches...

-- PMM

The following changes since commit 204aa60b37c23a89e690d418f49787d274303ca7:

Merge remote-tracking branch 'remotes/amarkovic/tags/mips-queue-jan-29-2020' into staging (2020-01-30 14:18:45 +0000)

are available in the Git repository at:

https://git.linaro.org/people/pmaydell/qemu-arm.git tags/pull-target-arm-20200130

for you to fetch changes up to dea101a1ae9968c9fec6ab0291489dad7c49f36f:

target/arm/cpu: Add the kvm-no-adjvtime CPU property (2020-01-30 16:02:06 +0000)

----------------------------------------------------------------
target-arm queue:
 * hw/core/or-irq: Fix incorrect assert forbidding num-lines == MAX_OR_LINES
 * target/arm/arm-semi: Don't let the guest close stdin/stdout/stderr
 * aspeed: some minor bugfixes
 * aspeed: add eMMC controller model for AST2600 SoC
 * hw/arm/raspi: Remove obsolete use of -smp to set the soc 'enabled-cpus'
 * New 3-phase reset API for device models
 * hw/intc/arm_gicv3_kvm: Stop wrongly programming GICR_PENDBASER.PTZ bit
 * Arm KVM: stop/restart the guest counter when the VM is stopped and started

----------------------------------------------------------------
Andrew Jeffery (2):
      hw/sd: Configure number of slots exposed by the ASPEED SDHCI model
      hw/arm: ast2600: Wire up the eMMC controller

Andrew Jones (6):
      target/arm/kvm: trivial: Clean up header documentation
      hw/arm/virt: Add missing 5.0 options call to 4.2 options
      target/arm/kvm64: kvm64 cpus have timer registers
      tests/arm-cpu-features: Check feature default values
      target/arm/kvm: Implement virtual time adjustment
      target/arm/cpu: Add the kvm-no-adjvtime CPU property

Cédric Le Goater (2):
      ftgmac100: check RX and TX buffer alignment
      hw/arm/aspeed: add a 'execute-in-place' property to boot directly from CE0

Damien Hedde (11):
      add device_legacy_reset function to prepare for reset api change
      hw/core/qdev: add trace events to help with resettable transition
      hw/core: create Resettable QOM interface
      hw/core: add Resettable support to BusClass and DeviceClass
      hw/core/resettable: add support for changing parent
      hw/core/qdev: handle parent bus change regarding resettable
      hw/core/qdev: update hotplug reset regarding resettable
      hw/core: deprecate old reset functions and introduce new ones
      docs/devel/reset.rst: add doc about Resettable interface
      vl: replace deprecated qbus_reset_all registration
      hw/s390x/ipl: replace deprecated qdev_reset_all registration

Joel Stanley (1):
      misc/pca9552: Add qom set and get

Peter Maydell (2):
      hw/core/or-irq: Fix incorrect assert forbidding num-lines == MAX_OR_LINES
      target/arm/arm-semi: Don't let the guest close stdin/stdout/stderr

Philippe Mathieu-Daudé (1):
      hw/arm/raspi: Remove obsolete use of -smp to set the soc 'enabled-cpus'

Zenghui Yu (1):
      hw/intc/arm_gicv3_kvm: Stop wrongly programming GICR_PENDBASER.PTZ bit

The num-lines property of the TYPE_OR_GATE device sets the number
of input lines it has. An assert() in or_irq_realize() restricts
this to the maximum supported by the implementation. However we
got the condition in the assert wrong: it should be using <=,
because num-lines == MAX_OR_LINES is permitted, and means that
all entries from 0 to MAX_OR_LINES-1 in the s->levels[] array
are used.

We didn't notice this previously because no user has so far
needed that many input lines.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20200120142235.10432-1-peter.maydell@linaro.org
---
 hw/core/or-irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/core/or-irq.c b/hw/core/or-irq.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/or-irq.c
+++ b/hw/core/or-irq.c
@@ -XXX,XX +XXX,XX @@ static void or_irq_realize(DeviceState *dev, Error **errp)
 {
     qemu_or_irq *s = OR_IRQ(dev);
 
-    assert(s->num_lines < MAX_OR_LINES);
+    assert(s->num_lines <= MAX_OR_LINES);
 
     qdev_init_gpio_in(dev, or_irq_handler, s->num_lines);
 }
-- 
2.20.1

The guest can use the semihosting API to open a handle
corresponding to QEMU's own stdin, stdout, or stderr.
When the guest closes this handle, we should not
close the underlying host stdin/stdout/stderr
the way we would do if the handle corresponded to
a host fd we'd opened on behalf of the guest in SYS_OPEN.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200124172954.28481-1-peter.maydell@linaro.org
---
 target/arm/arm-semi.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/arm-semi.c
+++ b/target/arm/arm-semi.c
@@ -XXX,XX +XXX,XX @@ static uint32_t host_closefn(ARMCPU *cpu, GuestFD *gf)
 {
     CPUARMState *env = &cpu->env;
 
+    /*
+     * Only close the underlying host fd if it's one we opened on behalf
+     * of the guest in SYS_OPEN.
+     */
+    if (gf->hostfd == STDIN_FILENO ||
+        gf->hostfd == STDOUT_FILENO ||
+        gf->hostfd == STDERR_FILENO) {
+        return 0;
+    }
     return set_swi_errno(env, close(gf->hostfd));
 }
 
-- 
2.20.1

From: Andrew Jeffery <andrew@aj.id.au>

The AST2600 includes a second cut-down version of the SD/MMC controller
found in the AST2500, named the eMMC controller. It's cut down in the
sense that it only supports one slot rather than two, but it brings the
total number of slots supported by the AST2600 to three.

The existing code assumed that the SD controller always provided two
slots. Rework the SDHCI object to expose the number of slots as a
property to be set by the SoC configuration.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20200114103433.30534-2-clg@kaod.org
[PMM: fixed up to use device_class_set_props()]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/sd/aspeed_sdhci.h |  1 +
 hw/arm/aspeed.c              |  2 +-
 hw/arm/aspeed_ast2600.c      |  2 ++
 hw/arm/aspeed_soc.c          |  2 ++
 hw/sd/aspeed_sdhci.c         | 11 +++++++++--
 5 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/hw/sd/aspeed_sdhci.h b/include/hw/sd/aspeed_sdhci.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/sd/aspeed_sdhci.h
+++ b/include/hw/sd/aspeed_sdhci.h
@@ -XXX,XX +XXX,XX @@ typedef struct AspeedSDHCIState {
     SysBusDevice parent;
 
     SDHCIState slots[ASPEED_SDHCI_NUM_SLOTS];
+    uint8_t num_slots;
 
     MemoryRegion iomem;
     qemu_irq irq;
diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -XXX,XX +XXX,XX @@ static void aspeed_machine_init(MachineState *machine)
         amc->i2c_init(bmc);
     }
 
-    for (i = 0; i < ARRAY_SIZE(bmc->soc.sdhci.slots); i++) {
+    for (i = 0; i < bmc->soc.sdhci.num_slots; i++) {
         SDHCIState *sdhci = &bmc->soc.sdhci.slots[i];
         DriveInfo *dinfo = drive_get_next(IF_SD);
         BlockBackend *blk;
diff --git a/hw/arm/aspeed_ast2600.c b/hw/arm/aspeed_ast2600.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed_ast2600.c
+++ b/hw/arm/aspeed_ast2600.c
@@ -XXX,XX +XXX,XX @@ static void aspeed_soc_ast2600_init(Object *obj)
     sysbus_init_child_obj(obj, "sdc", OBJECT(&s->sdhci), sizeof(s->sdhci),
                           TYPE_ASPEED_SDHCI);
 
+    object_property_set_int(OBJECT(&s->sdhci), 2, "num-slots", &error_abort);
+
     /* Init sd card slot class here so that they're under the correct parent */
     for (i = 0; i < ASPEED_SDHCI_NUM_SLOTS; ++i) {
         sysbus_init_child_obj(obj, "sdhci[*]", OBJECT(&s->sdhci.slots[i]),
diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed_soc.c
+++ b/hw/arm/aspeed_soc.c
@@ -XXX,XX +XXX,XX @@ static void aspeed_soc_init(Object *obj)
     sysbus_init_child_obj(obj, "sdc", OBJECT(&s->sdhci), sizeof(s->sdhci),
                           TYPE_ASPEED_SDHCI);
 
+    object_property_set_int(OBJECT(&s->sdhci), 2, "num-slots", &error_abort);
+
     /* Init sd card slot class here so that they're under the correct parent */
     for (i = 0; i < ASPEED_SDHCI_NUM_SLOTS; ++i) {
         sysbus_init_child_obj(obj, "sdhci[*]", OBJECT(&s->sdhci.slots[i]),
diff --git a/hw/sd/aspeed_sdhci.c b/hw/sd/aspeed_sdhci.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/sd/aspeed_sdhci.c
+++ b/hw/sd/aspeed_sdhci.c
@@ -XXX,XX +XXX,XX @@
 #include "qapi/error.h"
 #include "hw/irq.h"
 #include "migration/vmstate.h"
+#include "hw/qdev-properties.h"
 
 #define ASPEED_SDHCI_INFO            0x00
 #define  ASPEED_SDHCI_INFO_RESET     0x00030000
@@ -XXX,XX +XXX,XX @@ static void aspeed_sdhci_realize(DeviceState *dev, Error **errp)
 
     /* Create input irqs for the slots */
     qdev_init_gpio_in_named_with_opaque(DEVICE(sbd), aspeed_sdhci_set_irq,
-                                        sdhci, NULL, ASPEED_SDHCI_NUM_SLOTS);
+                                        sdhci, NULL, sdhci->num_slots);
 
     sysbus_init_irq(sbd, &sdhci->irq);
     memory_region_init_io(&sdhci->iomem, OBJECT(sdhci), &aspeed_sdhci_ops,
                           sdhci, TYPE_ASPEED_SDHCI, 0x1000);
     sysbus_init_mmio(sbd, &sdhci->iomem);
 
-    for (int i = 0; i < ASPEED_SDHCI_NUM_SLOTS; ++i) {
+    for (int i = 0; i < sdhci->num_slots; ++i) {
         Object *sdhci_slot = OBJECT(&sdhci->slots[i]);
         SysBusDevice *sbd_slot = SYS_BUS_DEVICE(&sdhci->slots[i]);
 
@@ -XXX,XX +XXX,XX @@ static const VMStateDescription vmstate_aspeed_sdhci = {
     },
 };
 
+static Property aspeed_sdhci_properties[] = {
+    DEFINE_PROP_UINT8("num-slots", AspeedSDHCIState, num_slots, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void aspeed_sdhci_class_init(ObjectClass *classp, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(classp);
@@ -XXX,XX +XXX,XX @@ static void aspeed_sdhci_class_init(ObjectClass *classp, void *data)
     dc->realize = aspeed_sdhci_realize;
     dc->reset = aspeed_sdhci_reset;
     dc->vmsd = &vmstate_aspeed_sdhci;
+    device_class_set_props(dc, aspeed_sdhci_properties);
 }
 
 static TypeInfo aspeed_sdhci_info = {
-- 
2.20.1

From: Andrew Jeffery <andrew@aj.id.au>

Initialise another SDHCI model instance for the AST2600's eMMC
controller and use the SDHCI's num_slots value introduced previously to
determine whether we should create an SD card instance for the new slot.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20200114103433.30534-3-clg@kaod.org
[ clg : - removed ternary operator from sdhci_attach_drive()
        - renamed SDHCI objects with a '-controller' prefix ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/arm/aspeed_soc.h |  2 ++
 hw/arm/aspeed.c             | 26 +++++++++++++++++---------
 hw/arm/aspeed_ast2600.c     | 29 ++++++++++++++++++++++++++---
 3 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/include/hw/arm/aspeed_soc.h b/include/hw/arm/aspeed_soc.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/arm/aspeed_soc.h
+++ b/include/hw/arm/aspeed_soc.h
@@ -XXX,XX +XXX,XX @@ typedef struct AspeedSoCState {
     AspeedGPIOState gpio;
     AspeedGPIOState gpio_1_8v;
     AspeedSDHCIState sdhci;
+    AspeedSDHCIState emmc;
 } AspeedSoCState;
 
 #define TYPE_ASPEED_SOC "aspeed-soc"
@@ -XXX,XX +XXX,XX @@ enum {
     ASPEED_MII4,
     ASPEED_SDRAM,
     ASPEED_XDMA,
+    ASPEED_EMMC,
 };
 
 #endif /* ASPEED_SOC_H */
diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -XXX,XX +XXX,XX @@ static void aspeed_board_init_flashes(AspeedSMCState *s, const char *flashtype,
     }
 }
 
+static void sdhci_attach_drive(SDHCIState *sdhci, DriveInfo *dinfo)
+{
+        DeviceState *card;
+
+        card = qdev_create(qdev_get_child_bus(DEVICE(sdhci), "sd-bus"),
+                           TYPE_SD_CARD);
+        if (dinfo) {
+            qdev_prop_set_drive(card, "drive", blk_by_legacy_dinfo(dinfo),
+                                &error_fatal);
+        }
+        object_property_set_bool(OBJECT(card), true, "realized", &error_fatal);
+}
+
 static void aspeed_machine_init(MachineState *machine)
 {
     AspeedBoardState *bmc;
@@ -XXX,XX +XXX,XX @@ static void aspeed_machine_init(MachineState *machine)
     }
 
     for (i = 0; i < bmc->soc.sdhci.num_slots; i++) {
-        SDHCIState *sdhci = &bmc->soc.sdhci.slots[i];
-        DriveInfo *dinfo = drive_get_next(IF_SD);
-        BlockBackend *blk;
-        DeviceState *card;
+        sdhci_attach_drive(&bmc->soc.sdhci.slots[i], drive_get_next(IF_SD));
+    }
 
-        blk = dinfo ? blk_by_legacy_dinfo(dinfo) : NULL;
-        card = qdev_create(qdev_get_child_bus(DEVICE(sdhci), "sd-bus"),
-                           TYPE_SD_CARD);
-        qdev_prop_set_drive(card, "drive", blk, &error_fatal);
-        object_property_set_bool(OBJECT(card), true, "realized", &error_fatal);
+    if (bmc->soc.emmc.num_slots) {
+        sdhci_attach_drive(&bmc->soc.emmc.slots[0], drive_get_next(IF_SD));
     }
 
     arm_load_kernel(ARM_CPU(first_cpu), machine, &aspeed_board_binfo);
diff --git a/hw/arm/aspeed_ast2600.c b/hw/arm/aspeed_ast2600.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed_ast2600.c
+++ b/hw/arm/aspeed_ast2600.c
@@ -XXX,XX +XXX,XX @@ static const hwaddr aspeed_soc_ast2600_memmap[] = {
     [ASPEED_ADC]       = 0x1E6E9000,
     [ASPEED_VIDEO]     = 0x1E700000,
     [ASPEED_SDHCI]     = 0x1E740000,
+    [ASPEED_EMMC]      = 0x1E750000,
     [ASPEED_GPIO]      = 0x1E780000,
     [ASPEED_GPIO_1_8V] = 0x1E780800,
     [ASPEED_RTC]       = 0x1E781000,
@@ -XXX,XX +XXX,XX @@ static const hwaddr aspeed_soc_ast2600_memmap[] = {
 
 #define ASPEED_SOC_AST2600_MAX_IRQ 128
 
+/* Shared Peripheral Interrupt values below are offset by -32 from datasheet */
 static const int aspeed_soc_ast2600_irqmap[] = {
     [ASPEED_UART1]     = 47,
     [ASPEED_UART2]     = 48,
@@ -XXX,XX +XXX,XX @@ static const int aspeed_soc_ast2600_irqmap[] = {
     [ASPEED_ADC]       = 78,
     [ASPEED_XDMA]      = 6,
     [ASPEED_SDHCI]     = 43,
+    [ASPEED_EMMC]      = 15,
     [ASPEED_GPIO]      = 40,
     [ASPEED_GPIO_1_8V] = 11,
     [ASPEED_RTC]       = 13,
@@ -XXX,XX +XXX,XX @@ static void aspeed_soc_ast2600_init(Object *obj)
     sysbus_init_child_obj(obj, "gpio_1_8v", OBJECT(&s->gpio_1_8v),
                           sizeof(s->gpio_1_8v), typename);
 
-    sysbus_init_child_obj(obj, "sdc", OBJECT(&s->sdhci), sizeof(s->sdhci),
-                          TYPE_ASPEED_SDHCI);
+    sysbus_init_child_obj(obj, "sd-controller", OBJECT(&s->sdhci),
+                          sizeof(s->sdhci), TYPE_ASPEED_SDHCI);
 
     object_property_set_int(OBJECT(&s->sdhci), 2, "num-slots", &error_abort);
 
     /* Init sd card slot class here so that they're under the correct parent */
     for (i = 0; i < ASPEED_SDHCI_NUM_SLOTS; ++i) {
-        sysbus_init_child_obj(obj, "sdhci[*]", OBJECT(&s->sdhci.slots[i]),
+        sysbus_init_child_obj(obj, "sd-controller.sdhci[*]",
+                              OBJECT(&s->sdhci.slots[i]),
                               sizeof(s->sdhci.slots[i]), TYPE_SYSBUS_SDHCI);
     }
+
+    sysbus_init_child_obj(obj, "emmc-controller", OBJECT(&s->emmc),
+                          sizeof(s->emmc), TYPE_ASPEED_SDHCI);
+
+    object_property_set_int(OBJECT(&s->emmc), 1, "num-slots", &error_abort);
+
+    sysbus_init_child_obj(obj, "emmc-controller.sdhci",
+                          OBJECT(&s->emmc.slots[0]), sizeof(s->emmc.slots[0]),
+                          TYPE_SYSBUS_SDHCI);
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ static void aspeed_soc_ast2600_realize(DeviceState *dev, Error **errp)
                     sc->memmap[ASPEED_SDHCI]);
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->sdhci), 0,
                        aspeed_soc_get_irq(s, ASPEED_SDHCI));
+
+    /* eMMC */
+    object_property_set_bool(OBJECT(&s->emmc), true, "realized", &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+    sysbus_mmio_map(SYS_BUS_DEVICE(&s->emmc), 0, sc->memmap[ASPEED_EMMC]);
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->emmc), 0,
+                       aspeed_soc_get_irq(s, ASPEED_EMMC));
 }
 
 static void aspeed_soc_ast2600_class_init(ObjectClass *oc, void *data)
-- 
2.20.1

From: Cédric Le Goater <clg@kaod.org>

These buffers should be aligned on 16 bytes.

Ignore invalid RX and TX buffer addresses and log an error. All
incoming and outgoing traffic will be dropped because no valid RX or
TX descriptors will be available.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20200114103433.30534-4-clg@kaod.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/net/ftgmac100.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/net/ftgmac100.c b/hw/net/ftgmac100.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/net/ftgmac100.c
+++ b/hw/net/ftgmac100.c
@@ -XXX,XX +XXX,XX @@ typedef struct {
     uint32_t        des3;
 } FTGMAC100Desc;
 
+#define FTGMAC100_DESC_ALIGNMENT 16
+
 /*
  * Specific RTL8211E MII Registers
  */
@@ -XXX,XX +XXX,XX @@ static void ftgmac100_write(void *opaque, hwaddr addr,
         s->itc = value;
         break;
     case FTGMAC100_RXR_BADR: /* Ring buffer address */
+        if (!QEMU_IS_ALIGNED(value, FTGMAC100_DESC_ALIGNMENT)) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad RX buffer alignment 0x%"
+                          HWADDR_PRIx "\n", __func__, value);
+            return;
+        }
+
         s->rx_ring = value;
         s->rx_descriptor = s->rx_ring;
         break;
@@ -XXX,XX +XXX,XX @@ static void ftgmac100_write(void *opaque, hwaddr addr,
         break;
 
     case FTGMAC100_NPTXR_BADR: /* Transmit buffer address */
+        if (!QEMU_IS_ALIGNED(value, FTGMAC100_DESC_ALIGNMENT)) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad TX buffer alignment 0x%"
+                          HWADDR_PRIx "\n", __func__, value);
+            return;
+        }
         s->tx_ring = value;
         s->tx_descriptor = s->tx_ring;
         break;
-- 
2.20.1

From: Cédric Le Goater <clg@kaod.org>

The overhead for the OpenBMC firmware images using the a custom U-Boot
is around 2 seconds, which is fine, but with a U-Boot from mainline,
it takes an extra 50 seconds or so to reach Linux. A quick survey on
the number of reads performed on the flash memory region gives the
following figures :

OpenBMC U-Boot      922478 (~ 3.5 MBytes)
  Mainline U-Boot   20569977 (~ 80  MBytes)

QEMU must be trashing the TCG TBs and reloading text very often. Some
addresses are read more than 250.000 times. Until we find a solution
to improve boot time, execution from MMIO is not activated by default.

Setting this option also breaks migration compatibility.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200114103433.30534-5-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/arm/aspeed.h |  2 ++
 hw/arm/aspeed.c         | 44 ++++++++++++++++++++++++++++++++++++-----
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/include/hw/arm/aspeed.h b/include/hw/arm/aspeed.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/arm/aspeed.h
+++ b/include/hw/arm/aspeed.h
@@ -XXX,XX +XXX,XX @@ typedef struct AspeedBoardState AspeedBoardState;
 
 typedef struct AspeedMachine {
     MachineState parent_obj;
+
+    bool mmio_exec;
 } AspeedMachine;
 
 #define ASPEED_MACHINE_CLASS(klass) \
diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -XXX,XX +XXX,XX @@ static void aspeed_machine_init(MachineState *machine)
          * SoC and 128MB for the AST2500 SoC, which is twice as big as
          * needed by the flash modules of the Aspeed machines.
          */
-        memory_region_init_rom(boot_rom, OBJECT(bmc), "aspeed.boot_rom",
-                               fl->size, &error_abort);
-        memory_region_add_subregion(get_system_memory(), FIRMWARE_ADDR,
-                                    boot_rom);
-        write_boot_rom(drive0, FIRMWARE_ADDR, fl->size, &error_abort);
+        if (ASPEED_MACHINE(machine)->mmio_exec) {
+            memory_region_init_alias(boot_rom, OBJECT(bmc), "aspeed.boot_rom",
+                                     &fl->mmio, 0, fl->size);
+            memory_region_add_subregion(get_system_memory(), FIRMWARE_ADDR,
+                                        boot_rom);
+        } else {
+            memory_region_init_rom(boot_rom, OBJECT(bmc), "aspeed.boot_rom",
+                                   fl->size, &error_abort);
+            memory_region_add_subregion(get_system_memory(), FIRMWARE_ADDR,
+                                        boot_rom);
+            write_boot_rom(drive0, FIRMWARE_ADDR, fl->size, &error_abort);
+        }
     }
 
     aspeed_board_binfo.ram_size = ram_size;
@@ -XXX,XX +XXX,XX @@ static void witherspoon_bmc_i2c_init(AspeedBoardState *bmc)
     /* Bus 11: TODO ucd90160@64 */
 }
 
+static bool aspeed_get_mmio_exec(Object *obj, Error **errp)
+{
+    return ASPEED_MACHINE(obj)->mmio_exec;
+}
+
+static void aspeed_set_mmio_exec(Object *obj, bool value, Error **errp)
+{
+    ASPEED_MACHINE(obj)->mmio_exec = value;
+}
+
+static void aspeed_machine_instance_init(Object *obj)
+{
+    ASPEED_MACHINE(obj)->mmio_exec = false;
+}
+
+static void aspeed_machine_class_props_init(ObjectClass *oc)
+{
+    object_class_property_add_bool(oc, "execute-in-place",
+                                   aspeed_get_mmio_exec,
+                                   aspeed_set_mmio_exec, &error_abort);
+    object_class_property_set_description(oc, "execute-in-place",
+                           "boot directly from CE0 flash device", &error_abort);
+}
+
 static void aspeed_machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -XXX,XX +XXX,XX @@ static void aspeed_machine_class_init(ObjectClass *oc, void *data)
     mc->no_floppy = 1;
     mc->no_cdrom = 1;
     mc->no_parallel = 1;
+
+    aspeed_machine_class_props_init(oc);
 }
 
 static void aspeed_machine_palmetto_class_init(ObjectClass *oc, void *data)
@@ -XXX,XX +XXX,XX @@ static const TypeInfo aspeed_machine_types[] = {
         .name          = TYPE_ASPEED_MACHINE,
         .parent        = TYPE_MACHINE,
         .instance_size = sizeof(AspeedMachine),
+        .instance_init = aspeed_machine_instance_init,
         .class_size    = sizeof(AspeedMachineClass),
         .class_init    = aspeed_machine_class_init,
         .abstract      = true,
-- 
2.20.1

From: Joel Stanley <joel@jms.id.au>

Following the pattern of the work recently done with the ASPEED GPIO
model, this adds support for inspecting and modifying the PCA9552 LEDs
from the monitor.

(qemu) qom-set  /machine/unattached/device[17] led0 on
 (qemu) qom-set  /machine/unattached/device[17] led0 off
 (qemu) qom-set  /machine/unattached/device[17] led0 pwm0
 (qemu) qom-set  /machine/unattached/device[17] led0 pwm1

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20200114103433.30534-6-clg@kaod.org
[clg: - removed the "qom-get" examples from the commit log
      - merged memory leak fixes from Joel ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/misc/pca9552.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/misc/pca9552.c
+++ b/hw/misc/pca9552.c
@@ -XXX,XX +XXX,XX @@
 #include "hw/misc/pca9552.h"
 #include "hw/misc/pca9552_regs.h"
 #include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
 
 #define PCA9552_LED_ON   0x0
 #define PCA9552_LED_OFF  0x1
 #define PCA9552_LED_PWM0 0x2
 #define PCA9552_LED_PWM1 0x3
 
+static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
+
 static uint8_t pca9552_pin_get_config(PCA9552State *s, int pin)
 {
     uint8_t reg   = PCA9552_LS0 + (pin / 4);
@@ -XXX,XX +XXX,XX @@ static int pca9552_event(I2CSlave *i2c, enum i2c_event event)
     return 0;
 }
 
+static void pca9552_get_led(Object *obj, Visitor *v, const char *name,
+                            void *opaque, Error **errp)
+{
+    PCA9552State *s = PCA9552(obj);
+    int led, rc, reg;
+    uint8_t state;
+
+    rc = sscanf(name, "led%2d", &led);
+    if (rc != 1) {
+        error_setg(errp, "%s: error reading %s", __func__, name);
+        return;
+    }
+    if (led < 0 || led > s->nr_leds) {
+        error_setg(errp, "%s invalid led %s", __func__, name);
+        return;
+    }
+    /*
+     * Get the LSx register as the qom interface should expose the device
+     * state, not the modeled 'input line' behaviour which would come from
+     * reading the INPUTx reg
+     */
+    reg = PCA9552_LS0 + led / 4;
+    state = (pca9552_read(s, reg) >> (led % 8)) & 0x3;
+    visit_type_str(v, name, (char **)&led_state[state], errp);
+}
+
+/*
+ * Return an LED selector register value based on an existing one, with
+ * the appropriate 2-bit state value set for the given LED number (0-3).
+ */
+static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state)
+{
+        return (oldval & (~(0x3 << (led_num << 1)))) |
+                ((state & 0x3) << (led_num << 1));
+}
+
+static void pca9552_set_led(Object *obj, Visitor *v, const char *name,
+                            void *opaque, Error **errp)
+{
+    PCA9552State *s = PCA9552(obj);
+    Error *local_err = NULL;
+    int led, rc, reg, val;
+    uint8_t state;
+    char *state_str;
+
+    visit_type_str(v, name, &state_str, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    rc = sscanf(name, "led%2d", &led);
+    if (rc != 1) {
+        error_setg(errp, "%s: error reading %s", __func__, name);
+        return;
+    }
+    if (led < 0 || led > s->nr_leds) {
+        error_setg(errp, "%s invalid led %s", __func__, name);
+        return;
+    }
+
+    for (state = 0; state < ARRAY_SIZE(led_state); state++) {
+        if (!strcmp(state_str, led_state[state])) {
+            break;
+        }
+    }
+    if (state >= ARRAY_SIZE(led_state)) {
+        error_setg(errp, "%s invalid led state %s", __func__, state_str);
+        return;
+    }
+
+    reg = PCA9552_LS0 + led / 4;
+    val = pca9552_read(s, reg);
+    val = pca955x_ledsel(val, led % 4, state);
+    pca9552_write(s, reg, val);
+}
+
 static const VMStateDescription pca9552_vmstate = {
     .name = "PCA9552",
     .version_id = 0,
@@ -XXX,XX +XXX,XX @@ static void pca9552_reset(DeviceState *dev)
 static void pca9552_initfn(Object *obj)
 {
     PCA9552State *s = PCA9552(obj);
+    int led;
 
     /* If support for the other PCA955X devices are implemented, these
      * constant values might be part of class structure describing the
@@ -XXX,XX +XXX,XX @@ static void pca9552_initfn(Object *obj)
      */
     s->max_reg = PCA9552_LS3;
     s->nr_leds = 16;
+
+    for (led = 0; led < s->nr_leds; led++) {
+        char *name;
+
+        name = g_strdup_printf("led%d", led);
+        object_property_add(obj, name, "bool", pca9552_get_led, pca9552_set_led,
+                            NULL, NULL, NULL);
+        g_free(name);
+    }
 }
 
 static void pca9552_class_init(ObjectClass *klass, void *data)
-- 
2.20.1

From: Philippe Mathieu-Daudé <f4bug@amsat.org>

Since we enabled parallel TCG code generation for softmmu (see
commit 3468b59 "tcg: enable multiple TCG contexts in softmmu")
and its subsequent fix (commit 72649619 "add .min_cpus and
.default_cpus fields to machine_class"), the raspi machines are
restricted to always use their 4 cores:

See in hw/arm/raspi2 (with BCM283X_NCPUS set to 4):

222 static void raspi2_machine_init(MachineClass *mc)
  223 {
  224     mc->desc = "Raspberry Pi 2";
  230     mc->max_cpus = BCM283X_NCPUS;
  231     mc->min_cpus = BCM283X_NCPUS;
  232     mc->default_cpus = BCM283X_NCPUS;
  235 };
  236 DEFINE_MACHINE("raspi2", raspi2_machine_init)

We can no longer use the -smp option, as we get:

$ qemu-system-arm -M raspi2 -smp 1
  qemu-system-arm: Invalid SMP CPUs 1. The min CPUs supported by machine 'raspi2' is 4

Since we can not set the TYPE_BCM283x SOC "enabled-cpus" with -smp,
remove the unuseful code.

We can achieve the same by using the '-global bcm2836.enabled-cpus=1'
option.

Reported-by: Laurent Bonnans <laurent.bonnans@here.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20200120235159.18510-2-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/raspi.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/raspi.c
+++ b/hw/arm/raspi.c
@@ -XXX,XX +XXX,XX @@ static void raspi_init(MachineState *machine, int version)
     /* Setup the SOC */
     object_property_add_const_link(OBJECT(&s->soc), "ram", OBJECT(&s->ram),
                                    &error_abort);
-    object_property_set_int(OBJECT(&s->soc), machine->smp.cpus, "enabled-cpus",
-                            &error_abort);
     int board_rev = version == 3 ? 0xa02082 : 0xa21041;
     object_property_set_int(OBJECT(&s->soc), board_rev, "board-rev",
                             &error_abort);
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Provide a temporary device_legacy_reset function doing what
device_reset does to prepare for the transition with Resettable
API.

All occurrence of device_reset in the code tree are also replaced
by device_legacy_reset.

The new resettable API has different prototype and semantics
(resetting child buses as well as the specified device). Subsequent
commits will make the changeover for each call site individually; once
that is complete device_legacy_reset() will be removed.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-2-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/qdev-core.h   | 4 ++--
 hw/audio/intel-hda.c     | 2 +-
 hw/core/qdev.c           | 6 +++---
 hw/hyperv/hyperv.c       | 2 +-
 hw/i386/microvm.c        | 2 +-
 hw/i386/pc.c             | 2 +-
 hw/ide/microdrive.c      | 8 ++++----
 hw/intc/spapr_xive.c     | 2 +-
 hw/ppc/pnv_psi.c         | 4 ++--
 hw/ppc/spapr_pci.c       | 2 +-
 hw/ppc/spapr_vio.c       | 2 +-
 hw/s390x/s390-pci-inst.c | 2 +-
 hw/scsi/vmw_pvscsi.c     | 2 +-
 hw/sd/omap_mmc.c         | 2 +-
 hw/sd/pl181.c            | 2 +-
 15 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -XXX,XX +XXX,XX @@ char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, DeviceState *dev);
 void qdev_machine_init(void);
 
 /**
- * @device_reset
+ * device_legacy_reset:
  *
  * Reset a single device (by calling the reset method).
  */
-void device_reset(DeviceState *dev);
+void device_legacy_reset(DeviceState *dev);
 
 void device_class_set_props(DeviceClass *dc, Property *props);
 
diff --git a/hw/audio/intel-hda.c b/hw/audio/intel-hda.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/audio/intel-hda.c
+++ b/hw/audio/intel-hda.c
@@ -XXX,XX +XXX,XX @@ static void intel_hda_reset(DeviceState *dev)
     QTAILQ_FOREACH(kid, &d->codecs.qbus.children, sibling) {
         DeviceState *qdev = kid->child;
         cdev = HDA_CODEC_DEVICE(qdev);
-        device_reset(DEVICE(cdev));
+        device_legacy_reset(DEVICE(cdev));
         d->state_sts |= (1 << cdev->cad);
     }
     intel_hda_update_irq(d);
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@ HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
 
 static int qdev_reset_one(DeviceState *dev, void *opaque)
 {
-    device_reset(dev);
+    device_legacy_reset(dev);
 
     return 0;
 }
@@ -XXX,XX +XXX,XX @@ static void device_set_realized(Object *obj, bool value, Error **errp)
             }
         }
         if (dev->hotplugged) {
-            device_reset(dev);
+            device_legacy_reset(dev);
         }
         dev->pending_deleted_event = false;
 
@@ -XXX,XX +XXX,XX @@ void device_class_set_parent_unrealize(DeviceClass *dc,
     dc->unrealize = dev_unrealize;
 }
 
-void device_reset(DeviceState *dev)
+void device_legacy_reset(DeviceState *dev)
 {
     DeviceClass *klass = DEVICE_GET_CLASS(dev);
 
diff --git a/hw/hyperv/hyperv.c b/hw/hyperv/hyperv.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/hyperv/hyperv.c
+++ b/hw/hyperv/hyperv.c
@@ -XXX,XX +XXX,XX @@ void hyperv_synic_reset(CPUState *cs)
     SynICState *synic = get_synic(cs);
 
     if (synic) {
-        device_reset(DEVICE(synic));
+        device_legacy_reset(DEVICE(synic));
     }
 }
 
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -XXX,XX +XXX,XX @@ static void microvm_machine_reset(MachineState *machine)
         cpu = X86_CPU(cs);
 
         if (cpu->apic_state) {
-            device_reset(cpu->apic_state);
+            device_legacy_reset(cpu->apic_state);
         }
     }
 }
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -XXX,XX +XXX,XX @@ static void pc_machine_reset(MachineState *machine)
         cpu = X86_CPU(cs);
 
         if (cpu->apic_state) {
-            device_reset(cpu->apic_state);
+            device_legacy_reset(cpu->apic_state);
         }
     }
 }
diff --git a/hw/ide/microdrive.c b/hw/ide/microdrive.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ide/microdrive.c
+++ b/hw/ide/microdrive.c
@@ -XXX,XX +XXX,XX @@ static void md_attr_write(PCMCIACardState *card, uint32_t at, uint8_t value)
     case 0x00:	/* Configuration Option Register */
         s->opt = value & 0xcf;
         if (value & OPT_SRESET) {
-            device_reset(DEVICE(s));
+            device_legacy_reset(DEVICE(s));
         }
         md_interrupt_update(s);
         break;
@@ -XXX,XX +XXX,XX @@ static void md_common_write(PCMCIACardState *card, uint32_t at, uint16_t value)
     case 0xe:	/* Device Control */
         s->ctrl = value;
         if (value & CTRL_SRST) {
-            device_reset(DEVICE(s));
+            device_legacy_reset(DEVICE(s));
         }
         md_interrupt_update(s);
         break;
@@ -XXX,XX +XXX,XX @@ static int dscm1xxxx_attach(PCMCIACardState *card)
     md->attr_base = pcc->cis[0x74] | (pcc->cis[0x76] << 8);
     md->io_base = 0x0;
 
-    device_reset(DEVICE(md));
+    device_legacy_reset(DEVICE(md));
     md_interrupt_update(md);
 
     return 0;
@@ -XXX,XX +XXX,XX @@ static int dscm1xxxx_detach(PCMCIACardState *card)
 {
     MicroDriveState *md = MICRODRIVE(card);
 
-    device_reset(DEVICE(md));
+    device_legacy_reset(DEVICE(md));
     return 0;
 }
 
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -XXX,XX +XXX,XX @@ static target_ulong h_int_reset(PowerPCCPU *cpu,
         return H_PARAMETER;
     }
 
-    device_reset(DEVICE(xive));
+    device_legacy_reset(DEVICE(xive));
 
     if (kvm_irqchip_in_kernel()) {
         Error *local_err = NULL;
diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/pnv_psi.c
+++ b/hw/ppc/pnv_psi.c
@@ -XXX,XX +XXX,XX @@ static void pnv_psi_reset(DeviceState *dev)
 
 static void pnv_psi_reset_handler(void *dev)
 {
-    device_reset(DEVICE(dev));
+    device_legacy_reset(DEVICE(dev));
 }
 
 static void pnv_psi_realize(DeviceState *dev, Error **errp)
@@ -XXX,XX +XXX,XX @@ static void pnv_psi_p9_mmio_write(void *opaque, hwaddr addr,
         break;
     case PSIHB9_INTERRUPT_CONTROL:
         if (val & PSIHB9_IRQ_RESET) {
-            device_reset(DEVICE(&psi9->source));
+            device_legacy_reset(DEVICE(&psi9->source));
         }
         psi->regs[reg] = val;
         break;
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -XXX,XX +XXX,XX @@ static int spapr_phb_children_reset(Object *child, void *opaque)
     DeviceState *dev = (DeviceState *) object_dynamic_cast(child, TYPE_DEVICE);
 
     if (dev) {
-        device_reset(dev);
+        device_legacy_reset(dev);
     }
 
     return 0;
diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr_vio.c
+++ b/hw/ppc/spapr_vio.c
@@ -XXX,XX +XXX,XX @@ int spapr_vio_send_crq(SpaprVioDevice *dev, uint8_t *crq)
 static void spapr_vio_quiesce_one(SpaprVioDevice *dev)
 {
     if (dev->tcet) {
-        device_reset(DEVICE(dev->tcet));
+        device_legacy_reset(DEVICE(dev->tcet));
     }
     free_crq(dev);
 }
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -XXX,XX +XXX,XX @@ int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra)
                 stw_p(&ressetpci->hdr.rsp, CLP_RC_SETPCIFN_FHOP);
                 goto out;
             }
-            device_reset(DEVICE(pbdev));
+            device_legacy_reset(DEVICE(pbdev));
             pbdev->fh &= ~FH_MASK_ENABLE;
             pbdev->state = ZPCI_FS_DISABLED;
             stl_p(&ressetpci->fh, pbdev->fh);
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -XXX,XX +XXX,XX @@ pvscsi_on_cmd_reset_device(PVSCSIState *s)
 
     if (sdev != NULL) {
         s->resetting++;
-        device_reset(&sdev->qdev);
+        device_legacy_reset(&sdev->qdev);
         s->resetting--;
         return PVSCSI_COMMAND_PROCESSING_SUCCEEDED;
     }
diff --git a/hw/sd/omap_mmc.c b/hw/sd/omap_mmc.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/sd/omap_mmc.c
+++ b/hw/sd/omap_mmc.c
@@ -XXX,XX +XXX,XX @@ void omap_mmc_reset(struct omap_mmc_s *host)
      * into any bus, and we must reset it manually. When omap_mmc is
      * QOMified this must move into the QOM reset function.
      */
-    device_reset(DEVICE(host->card));
+    device_legacy_reset(DEVICE(host->card));
 }
 
 static uint64_t omap_mmc_read(void *opaque, hwaddr offset,
diff --git a/hw/sd/pl181.c b/hw/sd/pl181.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/sd/pl181.c
+++ b/hw/sd/pl181.c
@@ -XXX,XX +XXX,XX @@ static void pl181_reset(DeviceState *d)
     /* Since we're still using the legacy SD API the card is not plugged
      * into any bus, and we must reset it manually.
      */
-    device_reset(DEVICE(s->card));
+    device_legacy_reset(DEVICE(s->card));
 }
 
 static void pl181_init(Object *obj)
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Adds trace events to reset procedure and when updating the parent
bus of a device.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-3-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/core/qdev.c       | 29 ++++++++++++++++++++++++++---
 hw/core/trace-events |  9 +++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@
 #include "hw/boards.h"
 #include "hw/sysbus.h"
 #include "migration/vmstate.h"
+#include "trace.h"
 
 bool qdev_hotplug = false;
 static bool qdev_hot_added = false;
@@ -XXX,XX +XXX,XX @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
     bool replugging = dev->parent_bus != NULL;
 
     if (replugging) {
-        /* Keep a reference to the device while it's not plugged into
+        trace_qdev_update_parent_bus(dev, object_get_typename(OBJECT(dev)),
+            dev->parent_bus, object_get_typename(OBJECT(dev->parent_bus)),
+            OBJECT(bus), object_get_typename(OBJECT(bus)));
+        /*
+         * Keep a reference to the device while it's not plugged into
          * any bus, to avoid it potentially evaporating when it is
          * dereffed in bus_remove_child().
          */
@@ -XXX,XX +XXX,XX @@ HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
     return hotplug_ctrl;
 }
 
+static int qdev_prereset(DeviceState *dev, void *opaque)
+{
+    trace_qdev_reset_tree(dev, object_get_typename(OBJECT(dev)));
+    return 0;
+}
+
+static int qbus_prereset(BusState *bus, void *opaque)
+{
+    trace_qbus_reset_tree(bus, object_get_typename(OBJECT(bus)));
+    return 0;
+}
+
 static int qdev_reset_one(DeviceState *dev, void *opaque)
 {
     device_legacy_reset(dev);
@@ -XXX,XX +XXX,XX @@ static int qdev_reset_one(DeviceState *dev, void *opaque)
 static int qbus_reset_one(BusState *bus, void *opaque)
 {
     BusClass *bc = BUS_GET_CLASS(bus);
+    trace_qbus_reset(bus, object_get_typename(OBJECT(bus)));
     if (bc->reset) {
         bc->reset(bus);
     }
@@ -XXX,XX +XXX,XX @@ static int qbus_reset_one(BusState *bus, void *opaque)
 
 void qdev_reset_all(DeviceState *dev)
 {
-    qdev_walk_children(dev, NULL, NULL, qdev_reset_one, qbus_reset_one, NULL);
+    trace_qdev_reset_all(dev, object_get_typename(OBJECT(dev)));
+    qdev_walk_children(dev, qdev_prereset, qbus_prereset,
+                       qdev_reset_one, qbus_reset_one, NULL);
 }
 
 void qdev_reset_all_fn(void *opaque)
@@ -XXX,XX +XXX,XX @@ void qdev_reset_all_fn(void *opaque)
 
 void qbus_reset_all(BusState *bus)
 {
-    qbus_walk_children(bus, NULL, NULL, qdev_reset_one, qbus_reset_one, NULL);
+    trace_qbus_reset_all(bus, object_get_typename(OBJECT(bus)));
+    qbus_walk_children(bus, qdev_prereset, qbus_prereset,
+                       qdev_reset_one, qbus_reset_one, NULL);
 }
 
 void qbus_reset_all_fn(void *opaque)
@@ -XXX,XX +XXX,XX @@ void device_legacy_reset(DeviceState *dev)
 {
     DeviceClass *klass = DEVICE_GET_CLASS(dev);
 
+    trace_qdev_reset(dev, object_get_typename(OBJECT(dev)));
     if (klass->reset) {
         klass->reset(dev);
     }
diff --git a/hw/core/trace-events b/hw/core/trace-events
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/trace-events
+++ b/hw/core/trace-events
@@ -XXX,XX +XXX,XX @@
 # loader.c
 loader_write_rom(const char *name, uint64_t gpa, uint64_t size, bool isrom) "%s: @0x%"PRIx64" size=0x%"PRIx64" ROM=%d"
+
+# qdev.c
+qdev_reset(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_reset_all(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_reset_tree(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset_all(void *obj, const char *objtype) "obj=%p(%s)"
+qbus_reset_tree(void *obj, const char *objtype) "obj=%p(%s)"
+qdev_update_parent_bus(void *obj, const char *objtype, void *oldp, const char *oldptype, void *newp, const char *newptype) "obj=%p(%s) old_parent=%p(%s) new_parent=%p(%s)"
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

This commit defines an interface allowing multi-phase reset. This aims
to solve a problem of the actual single-phase reset (built in
DeviceClass and BusClass): reset behavior is dependent on the order
in which reset handlers are called. In particular doing external
side-effect (like setting an qemu_irq) is problematic because receiving
object may not be reset yet.

The Resettable interface divides the reset in 3 well defined phases.
To reset an object tree, all 1st phases are executed then all 2nd then
all 3rd. See the comments in include/hw/resettable.h for a more complete
description. The interface defines 3 phases to let the future
possibility of holding an object into reset for some time.

The qdev/qbus reset in DeviceClass and BusClass will be modified in
following commits to use this interface. A mechanism is provided
to allow executing a transitional reset handler in place of the 2nd
phase which is executed in children-then-parent order inside a tree.
This will allow to transition devices and buses smoothly while
keeping the exact current qdev/qbus reset behavior for now.

Documentation will be added in a following commit.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-4-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/core/Makefile.objs   |   1 +
 include/hw/resettable.h | 211 +++++++++++++++++++++++++++++++++++
 hw/core/resettable.c    | 238 ++++++++++++++++++++++++++++++++++++++++
 hw/core/trace-events    |  17 +++
 4 files changed, 467 insertions(+)
 create mode 100644 include/hw/resettable.h
 create mode 100644 hw/core/resettable.c

diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -XXX,XX +XXX,XX @@
 common-obj-y += qdev.o qdev-properties.o
 common-obj-y += bus.o
 common-obj-y += cpu.o
+common-obj-y += resettable.o
 common-obj-y += hotplug.o
 common-obj-y += vmstate-if.o
 # irq.o needed for qdev GPIO handling:
diff --git a/include/hw/resettable.h b/include/hw/resettable.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/resettable.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Resettable interface header.
+ *
+ * Copyright (c) 2019 GreenSocs SAS
+ *
+ * Authors:
+ *   Damien Hedde
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_RESETTABLE_H
+#define HW_RESETTABLE_H
+
+#include "qom/object.h"
+
+#define TYPE_RESETTABLE_INTERFACE "resettable"
+
+#define RESETTABLE_CLASS(class) \
+    OBJECT_CLASS_CHECK(ResettableClass, (class), TYPE_RESETTABLE_INTERFACE)
+
+#define RESETTABLE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(ResettableClass, (obj), TYPE_RESETTABLE_INTERFACE)
+
+typedef struct ResettableState ResettableState;
+
+/**
+ * ResetType:
+ * Types of reset.
+ *
+ * + Cold: reset resulting from a power cycle of the object.
+ *
+ * TODO: Support has to be added to handle more types. In particular,
+ * ResettableState structure needs to be expanded.
+ */
+typedef enum ResetType {
+    RESET_TYPE_COLD,
+} ResetType;
+
+/*
+ * ResettableClass:
+ * Interface for resettable objects.
+ *
+ * See docs/devel/reset.rst for more detailed information about how QEMU models
+ * reset. This whole API must only be used when holding the iothread mutex.
+ *
+ * All objects which can be reset must implement this interface;
+ * it is usually provided by a base class such as DeviceClass or BusClass.
+ * Every Resettable object must maintain some state tracking the
+ * progress of a reset operation by providing a ResettableState structure.
+ * The functions defined in this module take care of updating the
+ * state of the reset.
+ * The base class implementation of the interface provides this
+ * state and implements the associated method: get_state.
+ *
+ * Concrete object implementations (typically specific devices
+ * such as a UART model) should provide the functions
+ * for the phases.enter, phases.hold and phases.exit methods, which
+ * they can set in their class init function, either directly or
+ * by calling resettable_class_set_parent_phases().
+ * The phase methods are guaranteed to only only ever be called once
+ * for any reset event, in the order 'enter', 'hold', 'exit'.
+ * An object will always move quickly from 'enter' to 'hold'
+ * but might remain in 'hold' for an arbitrary period of time
+ * before eventually reset is deasserted and the 'exit' phase is called.
+ * Object implementations should be prepared for functions handling
+ * inbound connections from other devices (such as qemu_irq handler
+ * functions) to be called at any point during reset after their
+ * 'enter' method has been called.
+ *
+ * Users of a resettable object should not call these methods
+ * directly, but instead use the function resettable_reset().
+ *
+ * @phases.enter: This phase is called when the object enters reset. It
+ * should reset local state of the object, but it must not do anything that
+ * has a side-effect on other objects, such as raising or lowering a qemu_irq
+ * line or reading or writing guest memory. It takes the reset's type as
+ * argument.
+ *
+ * @phases.hold: This phase is called for entry into reset, once every object
+ * in the system which is being reset has had its @phases.enter method called.
+ * At this point devices can do actions that affect other objects.
+ *
+ * @phases.exit: This phase is called when the object leaves the reset state.
+ * Actions affecting other objects are permitted.
+ *
+ * @get_state: Mandatory method which must return a pointer to a
+ * ResettableState.
+ *
+ * @get_transitional_function: transitional method to handle Resettable objects
+ * not yet fully moved to this interface. It will be removed as soon as it is
+ * not needed anymore. This method is optional and may return a pointer to a
+ * function to be used instead of the phases. If the method exists and returns
+ * a non-NULL function pointer then that function is executed as a replacement
+ * of the 'hold' phase method taking the object as argument. The two other phase
+ * methods are not executed.
+ *
+ * @child_foreach: Executes a given callback on every Resettable child. Child
+ * in this context means a child in the qbus tree, so the children of a qbus
+ * are the devices on it, and the children of a device are all the buses it
+ * owns. This is not the same as the QOM object hierarchy. The function takes
+ * additional opaque and ResetType arguments which must be passed unmodified to
+ * the callback.
+ */
+typedef void (*ResettableEnterPhase)(Object *obj, ResetType type);
+typedef void (*ResettableHoldPhase)(Object *obj);
+typedef void (*ResettableExitPhase)(Object *obj);
+typedef ResettableState * (*ResettableGetState)(Object *obj);
+typedef void (*ResettableTrFunction)(Object *obj);
+typedef ResettableTrFunction (*ResettableGetTrFunction)(Object *obj);
+typedef void (*ResettableChildCallback)(Object *, void *opaque,
+                                        ResetType type);
+typedef void (*ResettableChildForeach)(Object *obj,
+                                       ResettableChildCallback cb,
+                                       void *opaque, ResetType type);
+typedef struct ResettablePhases {
+    ResettableEnterPhase enter;
+    ResettableHoldPhase hold;
+    ResettableExitPhase exit;
+} ResettablePhases;
+typedef struct ResettableClass {
+    InterfaceClass parent_class;
+
+    /* Phase methods */
+    ResettablePhases phases;
+
+    /* State access method */
+    ResettableGetState get_state;
+
+    /* Transitional method for legacy reset compatibility */
+    ResettableGetTrFunction get_transitional_function;
+
+    /* Hierarchy handling method */
+    ResettableChildForeach child_foreach;
+} ResettableClass;
+
+/**
+ * ResettableState:
+ * Structure holding reset related state. The fields should not be accessed
+ * directly; the definition is here to allow further inclusion into other
+ * objects.
+ *
+ * @count: Number of reset level the object is into. It is incremented when
+ * the reset operation starts and decremented when it finishes.
+ * @hold_phase_pending: flag which indicates that we need to invoke the 'hold'
+ * phase handler for this object.
+ * @exit_phase_in_progress: true if we are currently in the exit phase
+ */
+struct ResettableState {
+    unsigned count;
+    bool hold_phase_pending;
+    bool exit_phase_in_progress;
+};
+
+/**
+ * resettable_reset:
+ * Trigger a reset on an object @obj of type @type. @obj must implement
+ * Resettable interface.
+ *
+ * Calling this function is equivalent to calling @resettable_assert_reset()
+ * then @resettable_release_reset().
+ */
+void resettable_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_assert_reset:
+ * Put an object @obj into reset. @obj must implement Resettable interface.
+ *
+ * @resettable_release_reset() must eventually be called after this call.
+ * There must be one call to @resettable_release_reset() per call of
+ * @resettable_assert_reset(), with the same type argument.
+ *
+ * NOTE: Until support for migration is added, the @resettable_release_reset()
+ * must not be delayed. It must occur just after @resettable_assert_reset() so
+ * that migration cannot be triggered in between. Prefer using
+ * @resettable_reset() for now.
+ */
+void resettable_assert_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_release_reset:
+ * Release the object @obj from reset. @obj must implement Resettable interface.
+ *
+ * See @resettable_assert_reset() description for details.
+ */
+void resettable_release_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_is_in_reset:
+ * Return true if @obj is under reset.
+ *
+ * @obj must implement Resettable interface.
+ */
+bool resettable_is_in_reset(Object *obj);
+
+/**
+ * resettable_class_set_parent_phases:
+ *
+ * Save @rc current reset phases into @parent_phases and override @rc phases
+ * by the given new methods (@enter, @hold and @exit).
+ * Each phase is overridden only if the new one is not NULL allowing to
+ * override a subset of phases.
+ */
+void resettable_class_set_parent_phases(ResettableClass *rc,
+                                        ResettableEnterPhase enter,
+                                        ResettableHoldPhase hold,
+                                        ResettableExitPhase exit,
+                                        ResettablePhases *parent_phases);
+
+#endif
diff --git a/hw/core/resettable.c b/hw/core/resettable.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/core/resettable.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Resettable interface.
+ *
+ * Copyright (c) 2019 GreenSocs SAS
+ *
+ * Authors:
+ *   Damien Hedde
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/module.h"
+#include "hw/resettable.h"
+#include "trace.h"
+
+/**
+ * resettable_phase_enter/hold/exit:
+ * Function executing a phase recursively in a resettable object and its
+ * children.
+ */
+static void resettable_phase_enter(Object *obj, void *opaque, ResetType type);
+static void resettable_phase_hold(Object *obj, void *opaque, ResetType type);
+static void resettable_phase_exit(Object *obj, void *opaque, ResetType type);
+
+/**
+ * enter_phase_in_progress:
+ * True if we are currently in reset enter phase.
+ *
+ * Note: This flag is only used to guarantee (using asserts) that the reset
+ * API is used correctly. We can use a global variable because we rely on the
+ * iothread mutex to ensure only one reset operation is in a progress at a
+ * given time.
+ */
+static bool enter_phase_in_progress;
+
+void resettable_reset(Object *obj, ResetType type)
+{
+    trace_resettable_reset(obj, type);
+    resettable_assert_reset(obj, type);
+    resettable_release_reset(obj, type);
+}
+
+void resettable_assert_reset(Object *obj, ResetType type)
+{
+    /* TODO: change this assert when adding support for other reset types */
+    assert(type == RESET_TYPE_COLD);
+    trace_resettable_reset_assert_begin(obj, type);
+    assert(!enter_phase_in_progress);
+
+    enter_phase_in_progress = true;
+    resettable_phase_enter(obj, NULL, type);
+    enter_phase_in_progress = false;
+
+    resettable_phase_hold(obj, NULL, type);
+
+    trace_resettable_reset_assert_end(obj);
+}
+
+void resettable_release_reset(Object *obj, ResetType type)
+{
+    /* TODO: change this assert when adding support for other reset types */
+    assert(type == RESET_TYPE_COLD);
+    trace_resettable_reset_release_begin(obj, type);
+    assert(!enter_phase_in_progress);
+
+    resettable_phase_exit(obj, NULL, type);
+
+    trace_resettable_reset_release_end(obj);
+}
+
+bool resettable_is_in_reset(Object *obj)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+    ResettableState *s = rc->get_state(obj);
+
+    return s->count > 0;
+}
+
+/**
+ * resettable_child_foreach:
+ * helper to avoid checking the existence of the method.
+ */
+static void resettable_child_foreach(ResettableClass *rc, Object *obj,
+                                     ResettableChildCallback cb,
+                                     void *opaque, ResetType type)
+{
+    if (rc->child_foreach) {
+        rc->child_foreach(obj, cb, opaque, type);
+    }
+}
+
+/**
+ * resettable_get_tr_func:
+ * helper to fetch transitional reset callback if any.
+ */
+static ResettableTrFunction resettable_get_tr_func(ResettableClass *rc,
+                                                   Object *obj)
+{
+    ResettableTrFunction tr_func = NULL;
+    if (rc->get_transitional_function) {
+        tr_func = rc->get_transitional_function(obj);
+    }
+    return tr_func;
+}
+
+static void resettable_phase_enter(Object *obj, void *opaque, ResetType type)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+    ResettableState *s = rc->get_state(obj);
+    const char *obj_typename = object_get_typename(obj);
+    bool action_needed = false;
+
+    /* exit phase has to finish properly before entering back in reset */
+    assert(!s->exit_phase_in_progress);
+
+    trace_resettable_phase_enter_begin(obj, obj_typename, s->count, type);
+
+    /* Only take action if we really enter reset for the 1st time. */
+    /*
+     * TODO: if adding more ResetType support, some additional checks
+     * are probably needed here.
+     */
+    if (s->count++ == 0) {
+        action_needed = true;
+    }
+    /*
+     * We limit the count to an arbitrary "big" value. The value is big
+     * enough not to be triggered normally.
+     * The assert will stop an infinite loop if there is a cycle in the
+     * reset tree. The loop goes through resettable_foreach_child below
+     * which at some point will call us again.
+     */
+    assert(s->count <= 50);
+
+    /*
+     * handle the children even if action_needed is at false so that
+     * child counts are incremented too
+     */
+    resettable_child_foreach(rc, obj, resettable_phase_enter, NULL, type);
+
+    /* execute enter phase for the object if needed */
+    if (action_needed) {
+        trace_resettable_phase_enter_exec(obj, obj_typename, type,
+                                          !!rc->phases.enter);
+        if (rc->phases.enter && !resettable_get_tr_func(rc, obj)) {
+            rc->phases.enter(obj, type);
+        }
+        s->hold_phase_pending = true;
+    }
+    trace_resettable_phase_enter_end(obj, obj_typename, s->count);
+}
+
+static void resettable_phase_hold(Object *obj, void *opaque, ResetType type)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+    ResettableState *s = rc->get_state(obj);
+    const char *obj_typename = object_get_typename(obj);
+
+    /* exit phase has to finish properly before entering back in reset */
+    assert(!s->exit_phase_in_progress);
+
+    trace_resettable_phase_hold_begin(obj, obj_typename, s->count, type);
+
+    /* handle children first */
+    resettable_child_foreach(rc, obj, resettable_phase_hold, NULL, type);
+
+    /* exec hold phase */
+    if (s->hold_phase_pending) {
+        s->hold_phase_pending = false;
+        ResettableTrFunction tr_func = resettable_get_tr_func(rc, obj);
+        trace_resettable_phase_hold_exec(obj, obj_typename, !!rc->phases.hold);
+        if (tr_func) {
+            trace_resettable_transitional_function(obj, obj_typename);
+            tr_func(obj);
+        } else if (rc->phases.hold) {
+            rc->phases.hold(obj);
+        }
+    }
+    trace_resettable_phase_hold_end(obj, obj_typename, s->count);
+}
+
+static void resettable_phase_exit(Object *obj, void *opaque, ResetType type)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+    ResettableState *s = rc->get_state(obj);
+    const char *obj_typename = object_get_typename(obj);
+
+    assert(!s->exit_phase_in_progress);
+    trace_resettable_phase_exit_begin(obj, obj_typename, s->count, type);
+
+    /* exit_phase_in_progress ensures this phase is 'atomic' */
+    s->exit_phase_in_progress = true;
+    resettable_child_foreach(rc, obj, resettable_phase_exit, NULL, type);
+
+    assert(s->count > 0);
+    if (s->count == 1) {
+        trace_resettable_phase_exit_exec(obj, obj_typename, !!rc->phases.exit);
+        if (rc->phases.exit && !resettable_get_tr_func(rc, obj)) {
+            rc->phases.exit(obj);
+        }
+        s->count = 0;
+    }
+    s->exit_phase_in_progress = false;
+    trace_resettable_phase_exit_end(obj, obj_typename, s->count);
+}
+
+void resettable_class_set_parent_phases(ResettableClass *rc,
+                                        ResettableEnterPhase enter,
+                                        ResettableHoldPhase hold,
+                                        ResettableExitPhase exit,
+                                        ResettablePhases *parent_phases)
+{
+    *parent_phases = rc->phases;
+    if (enter) {
+        rc->phases.enter = enter;
+    }
+    if (hold) {
+        rc->phases.hold = hold;
+    }
+    if (exit) {
+        rc->phases.exit = exit;
+    }
+}
+
+static const TypeInfo resettable_interface_info = {
+    .name       = TYPE_RESETTABLE_INTERFACE,
+    .parent     = TYPE_INTERFACE,
+    .class_size = sizeof(ResettableClass),
+};
+
+static void reset_register_types(void)
+{
+    type_register_static(&resettable_interface_info);
+}
+
+type_init(reset_register_types)
diff --git a/hw/core/trace-events b/hw/core/trace-events
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/trace-events
+++ b/hw/core/trace-events
@@ -XXX,XX +XXX,XX @@ qbus_reset(void *obj, const char *objtype) "obj=%p(%s)"
 qbus_reset_all(void *obj, const char *objtype) "obj=%p(%s)"
 qbus_reset_tree(void *obj, const char *objtype) "obj=%p(%s)"
 qdev_update_parent_bus(void *obj, const char *objtype, void *oldp, const char *oldptype, void *newp, const char *newptype) "obj=%p(%s) old_parent=%p(%s) new_parent=%p(%s)"
+
+# resettable.c
+resettable_reset(void *obj, int cold) "obj=%p cold=%d"
+resettable_reset_assert_begin(void *obj, int cold) "obj=%p cold=%d"
+resettable_reset_assert_end(void *obj) "obj=%p"
+resettable_reset_release_begin(void *obj, int cold) "obj=%p cold=%d"
+resettable_reset_release_end(void *obj) "obj=%p"
+resettable_phase_enter_begin(void *obj, const char *objtype, unsigned count, int type) "obj=%p(%s) count=%d type=%d"
+resettable_phase_enter_exec(void *obj, const char *objtype, int type, int has_method) "obj=%p(%s) type=%d method=%d"
+resettable_phase_enter_end(void *obj, const char *objtype, unsigned count) "obj=%p(%s) count=%d"
+resettable_phase_hold_begin(void *obj, const char *objtype, unsigned count, int type) "obj=%p(%s) count=%d type=%d"
+resettable_phase_hold_exec(void *obj, const char *objtype, int has_method) "obj=%p(%s) method=%d"
+resettable_phase_hold_end(void *obj, const char *objtype, unsigned count) "obj=%p(%s) count=%d"
+resettable_phase_exit_begin(void *obj, const char *objtype, unsigned count, int type) "obj=%p(%s) count=%d type=%d"
+resettable_phase_exit_exec(void *obj, const char *objtype, int has_method) "obj=%p(%s) method=%d"
+resettable_phase_exit_end(void *obj, const char *objtype, unsigned count) "obj=%p(%s) count=%d"
+resettable_transitional_function(void *obj, const char *objtype) "obj=%p(%s)"
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

This commit adds support of Resettable interface to buses and devices:
+ ResettableState structure is added in the Bus/Device state
+ Resettable methods are implemented.
+ device/bus_is_in_reset function defined

This commit allows to transition the objects to the new
multi-phase interface without changing the reset behavior at all.
Object single reset method can be split into the 3 different phases
but the 3 phases are still executed in a row for a given object.
From the qdev/qbus reset api point of view, nothing is changed.
qdev_reset_all() and qbus_reset_all() are not modified as well as
device_legacy_reset().

Transition of an object must be done from parent class to child class.
Care has been taken to allow the transition of a parent class
without requiring the child classes to be transitioned at the same
time. Note that SysBus and SysBusDevice class do not need any transition
because they do not override the legacy reset method.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-5-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 tests/Makefile.include |  1 +
 include/hw/qdev-core.h | 27 ++++++++++++
 hw/core/bus.c          | 97 ++++++++++++++++++++++++++++++++++++++++++
 hw/core/qdev.c         | 93 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 218 insertions(+)

diff --git a/tests/Makefile.include b/tests/Makefile.include
index XXXXXXX..XXXXXXX 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -XXX,XX +XXX,XX @@ tests/fp/%:
 tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
 	hw/core/qdev.o hw/core/qdev-properties.o hw/core/hotplug.o\
 	hw/core/bus.o \
+	hw/core/resettable.o \
 	hw/core/irq.o \
 	hw/core/fw-path-provider.o \
 	hw/core/reset.o \
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -XXX,XX +XXX,XX @@
 #include "qemu/bitmap.h"
 #include "qom/object.h"
 #include "hw/hotplug.h"
+#include "hw/resettable.h"
 
 enum {
     DEV_NVECTORS_UNSPECIFIED = -1,
@@ -XXX,XX +XXX,XX @@ typedef struct DeviceClass {
     bool hotpluggable;
 
     /* callbacks */
+    /*
+     * Reset method here is deprecated and replaced by methods in the
+     * resettable class interface to implement a multi-phase reset.
+     * TODO: remove once every reset callback is unused
+     */
     DeviceReset reset;
     DeviceRealize realize;
     DeviceUnrealize unrealize;
@@ -XXX,XX +XXX,XX @@ struct NamedGPIOList {
 /**
  * DeviceState:
  * @realized: Indicates whether the device has been fully constructed.
+ * @reset: ResettableState for the device; handled by Resettable interface.
  *
  * This structure should not be accessed directly.  We declare it here
  * so that it can be embedded in individual device state structures.
@@ -XXX,XX +XXX,XX @@ struct DeviceState {
     int num_child_bus;
     int instance_id_alias;
     int alias_required_for_version;
+    ResettableState reset;
 };
 
 struct DeviceListener {
@@ -XXX,XX +XXX,XX @@ typedef struct BusChild {
 /**
  * BusState:
  * @hotplug_handler: link to a hotplug handler associated with bus.
+ * @reset: ResettableState for the bus; handled by Resettable interface.
  */
 struct BusState {
     Object obj;
@@ -XXX,XX +XXX,XX @@ struct BusState {
     int num_children;
     QTAILQ_HEAD(, BusChild) children;
     QLIST_ENTRY(BusState) sibling;
+    ResettableState reset;
 };
 
 /**
@@ -XXX,XX +XXX,XX @@ void qdev_reset_all_fn(void *opaque);
 void qbus_reset_all(BusState *bus);
 void qbus_reset_all_fn(void *opaque);
 
+/**
+ * device_is_in_reset:
+ * Return true if the device @dev is currently being reset.
+ */
+bool device_is_in_reset(DeviceState *dev);
+
+/**
+ * bus_is_in_reset:
+ * Return true if the bus @bus is currently being reset.
+ */
+bool bus_is_in_reset(BusState *bus);
+
 /* This should go away once we get rid of the NULL bus hack */
 BusState *sysbus_get_default(void);
 
@@ -XXX,XX +XXX,XX @@ void device_legacy_reset(DeviceState *dev);
 
 void device_class_set_props(DeviceClass *dc, Property *props);
 
+/**
+ * device_class_set_parent_reset:
+ * TODO: remove the function when DeviceClass's reset method
+ * is not used anymore.
+ */
 void device_class_set_parent_reset(DeviceClass *dc,
                                    DeviceReset dev_reset,
                                    DeviceReset *parent_reset);
diff --git a/hw/core/bus.c b/hw/core/bus.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/bus.c
+++ b/hw/core/bus.c
@@ -XXX,XX +XXX,XX @@ int qbus_walk_children(BusState *bus,
     return 0;
 }
 
+bool bus_is_in_reset(BusState *bus)
+{
+    return resettable_is_in_reset(OBJECT(bus));
+}
+
+static ResettableState *bus_get_reset_state(Object *obj)
+{
+    BusState *bus = BUS(obj);
+    return &bus->reset;
+}
+
+static void bus_reset_child_foreach(Object *obj, ResettableChildCallback cb,
+                                    void *opaque, ResetType type)
+{
+    BusState *bus = BUS(obj);
+    BusChild *kid;
+
+    QTAILQ_FOREACH(kid, &bus->children, sibling) {
+        cb(OBJECT(kid->child), opaque, type);
+    }
+}
+
 static void qbus_realize(BusState *bus, DeviceState *parent, const char *name)
 {
     const char *typename = object_get_typename(OBJECT(bus));
@@ -XXX,XX +XXX,XX @@ static char *default_bus_get_fw_dev_path(DeviceState *dev)
     return g_strdup(object_get_typename(OBJECT(dev)));
 }
 
+/**
+ * bus_phases_reset:
+ * Transition reset method for buses to allow moving
+ * smoothly from legacy reset method to multi-phases
+ */
+static void bus_phases_reset(BusState *bus)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(bus);
+
+    if (rc->phases.enter) {
+        rc->phases.enter(OBJECT(bus), RESET_TYPE_COLD);
+    }
+    if (rc->phases.hold) {
+        rc->phases.hold(OBJECT(bus));
+    }
+    if (rc->phases.exit) {
+        rc->phases.exit(OBJECT(bus));
+    }
+}
+
+static void bus_transitional_reset(Object *obj)
+{
+    BusClass *bc = BUS_GET_CLASS(obj);
+
+    /*
+     * This will call either @bus_phases_reset (for multi-phases transitioned
+     * buses) or a bus's specific method for not-yet transitioned buses.
+     * In both case, it does not reset children.
+     */
+    if (bc->reset) {
+        bc->reset(BUS(obj));
+    }
+}
+
+/**
+ * bus_get_transitional_reset:
+ * check if the bus's class is ready for multi-phase
+ */
+static ResettableTrFunction bus_get_transitional_reset(Object *obj)
+{
+    BusClass *dc = BUS_GET_CLASS(obj);
+    if (dc->reset != bus_phases_reset) {
+        /*
+         * dc->reset has been overridden by a subclass,
+         * the bus is not ready for multi phase yet.
+         */
+        return bus_transitional_reset;
+    }
+    return NULL;
+}
+
 static void bus_class_init(ObjectClass *class, void *data)
 {
     BusClass *bc = BUS_CLASS(class);
+    ResettableClass *rc = RESETTABLE_CLASS(class);
 
     class->unparent = bus_unparent;
     bc->get_fw_dev_path = default_bus_get_fw_dev_path;
+
+    rc->get_state = bus_get_reset_state;
+    rc->child_foreach = bus_reset_child_foreach;
+
+    /*
+     * @bus_phases_reset is put as the default reset method below, allowing
+     * to do the multi-phase transition from base classes to leaf classes. It
+     * allows a legacy-reset Bus class to extend a multi-phases-reset
+     * Bus class for the following reason:
+     * + If a base class B has been moved to multi-phase, then it does not
+     *   override this default reset method and may have defined phase methods.
+     * + A child class C (extending class B) which uses
+     *   bus_class_set_parent_reset() (or similar means) to override the
+     *   reset method will still work as expected. @bus_phases_reset function
+     *   will be registered as the parent reset method and effectively call
+     *   parent reset phases.
+     */
+    bc->reset = bus_phases_reset;
+    rc->get_transitional_function = bus_get_transitional_reset;
 }
 
 static void qbus_finalize(Object *obj)
@@ -XXX,XX +XXX,XX @@ static const TypeInfo bus_info = {
     .instance_init = qbus_initfn,
     .instance_finalize = qbus_finalize,
     .class_init = bus_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_RESETTABLE_INTERFACE },
+        { }
+    },
 };
 
 static void bus_register_types(void)
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@ void qbus_reset_all_fn(void *opaque)
     qbus_reset_all(bus);
 }
 
+bool device_is_in_reset(DeviceState *dev)
+{
+    return resettable_is_in_reset(OBJECT(dev));
+}
+
+static ResettableState *device_get_reset_state(Object *obj)
+{
+    DeviceState *dev = DEVICE(obj);
+    return &dev->reset;
+}
+
+static void device_reset_child_foreach(Object *obj, ResettableChildCallback cb,
+                                       void *opaque, ResetType type)
+{
+    DeviceState *dev = DEVICE(obj);
+    BusState *bus;
+
+    QLIST_FOREACH(bus, &dev->child_bus, sibling) {
+        cb(OBJECT(bus), opaque, type);
+    }
+}
+
 /* can be used as ->unplug() callback for the simple cases */
 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,
                                   DeviceState *dev, Error **errp)
@@ -XXX,XX +XXX,XX @@ device_vmstate_if_get_id(VMStateIf *obj)
     return qdev_get_dev_path(dev);
 }
 
+/**
+ * device_phases_reset:
+ * Transition reset method for devices to allow moving
+ * smoothly from legacy reset method to multi-phases
+ */
+static void device_phases_reset(DeviceState *dev)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(dev);
+
+    if (rc->phases.enter) {
+        rc->phases.enter(OBJECT(dev), RESET_TYPE_COLD);
+    }
+    if (rc->phases.hold) {
+        rc->phases.hold(OBJECT(dev));
+    }
+    if (rc->phases.exit) {
+        rc->phases.exit(OBJECT(dev));
+    }
+}
+
+static void device_transitional_reset(Object *obj)
+{
+    DeviceClass *dc = DEVICE_GET_CLASS(obj);
+
+    /*
+     * This will call either @device_phases_reset (for multi-phases transitioned
+     * devices) or a device's specific method for not-yet transitioned devices.
+     * In both case, it does not reset children.
+     */
+    if (dc->reset) {
+        dc->reset(DEVICE(obj));
+    }
+}
+
+/**
+ * device_get_transitional_reset:
+ * check if the device's class is ready for multi-phase
+ */
+static ResettableTrFunction device_get_transitional_reset(Object *obj)
+{
+    DeviceClass *dc = DEVICE_GET_CLASS(obj);
+    if (dc->reset != device_phases_reset) {
+        /*
+         * dc->reset has been overridden by a subclass,
+         * the device is not ready for multi phase yet.
+         */
+        return device_transitional_reset;
+    }
+    return NULL;
+}
+
 static void device_class_init(ObjectClass *class, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(class);
     VMStateIfClass *vc = VMSTATE_IF_CLASS(class);
+    ResettableClass *rc = RESETTABLE_CLASS(class);
 
     class->unparent = device_unparent;
 
@@ -XXX,XX +XXX,XX @@ static void device_class_init(ObjectClass *class, void *data)
     dc->hotpluggable = true;
     dc->user_creatable = true;
     vc->get_id = device_vmstate_if_get_id;
+    rc->get_state = device_get_reset_state;
+    rc->child_foreach = device_reset_child_foreach;
+
+    /*
+     * @device_phases_reset is put as the default reset method below, allowing
+     * to do the multi-phase transition from base classes to leaf classes. It
+     * allows a legacy-reset Device class to extend a multi-phases-reset
+     * Device class for the following reason:
+     * + If a base class B has been moved to multi-phase, then it does not
+     *   override this default reset method and may have defined phase methods.
+     * + A child class C (extending class B) which uses
+     *   device_class_set_parent_reset() (or similar means) to override the
+     *   reset method will still work as expected. @device_phases_reset function
+     *   will be registered as the parent reset method and effectively call
+     *   parent reset phases.
+     */
+    dc->reset = device_phases_reset;
+    rc->get_transitional_function = device_get_transitional_reset;
 
     object_class_property_add_bool(class, "realized",
                                    device_get_realized, device_set_realized,
@@ -XXX,XX +XXX,XX @@ static const TypeInfo device_type_info = {
     .class_size = sizeof(DeviceClass),
     .interfaces = (InterfaceInfo[]) {
         { TYPE_VMSTATE_IF },
+        { TYPE_RESETTABLE_INTERFACE },
         { }
     }
 };
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Add a function resettable_change_parent() to do the required
plumbing when changing the parent a of Resettable object.

We need to make sure that the reset state of the object remains
coherent with the reset state of the new parent.

We make the 2 following hypothesis:
+ when an object is put in a parent under reset, the object goes in
reset.
+ when an object is removed from a parent under reset, the object
leaves reset.

The added function avoids any glitch if both old and new parent are
already in reset.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-6-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/resettable.h | 16 +++++++++++
 hw/core/resettable.c    | 62 +++++++++++++++++++++++++++++++++++++++--
 hw/core/trace-events    |  1 +
 3 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/include/hw/resettable.h b/include/hw/resettable.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/resettable.h
+++ b/include/hw/resettable.h
@@ -XXX,XX +XXX,XX @@ void resettable_release_reset(Object *obj, ResetType type);
  */
 bool resettable_is_in_reset(Object *obj);
 
+/**
+ * resettable_change_parent:
+ * Indicate that the parent of Ressettable @obj is changing from @oldp to @newp.
+ * All 3 objects must implement resettable interface. @oldp or @newp may be
+ * NULL.
+ *
+ * This function will adapt the reset state of @obj so that it is coherent
+ * with the reset state of @newp. It may trigger @resettable_assert_reset()
+ * or @resettable_release_reset(). It will do such things only if the reset
+ * state of @newp and @oldp are different.
+ *
+ * When using this function during reset, it must only be called during
+ * a hold phase method. Calling this during enter or exit phase is an error.
+ */
+void resettable_change_parent(Object *obj, Object *newp, Object *oldp);
+
 /**
  * resettable_class_set_parent_phases:
  *
diff --git a/hw/core/resettable.c b/hw/core/resettable.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/resettable.c
+++ b/hw/core/resettable.c
@@ -XXX,XX +XXX,XX @@ static void resettable_phase_exit(Object *obj, void *opaque, ResetType type);
  * enter_phase_in_progress:
  * True if we are currently in reset enter phase.
  *
- * Note: This flag is only used to guarantee (using asserts) that the reset
- * API is used correctly. We can use a global variable because we rely on the
+ * exit_phase_in_progress:
+ * count the number of exit phase we are in.
+ *
+ * Note: These flags are only used to guarantee (using asserts) that the reset
+ * API is used correctly. We can use global variables because we rely on the
  * iothread mutex to ensure only one reset operation is in a progress at a
  * given time.
  */
 static bool enter_phase_in_progress;
+static unsigned exit_phase_in_progress;
 
 void resettable_reset(Object *obj, ResetType type)
 {
@@ -XXX,XX +XXX,XX @@ void resettable_release_reset(Object *obj, ResetType type)
     trace_resettable_reset_release_begin(obj, type);
     assert(!enter_phase_in_progress);
 
+    exit_phase_in_progress += 1;
     resettable_phase_exit(obj, NULL, type);
+    exit_phase_in_progress -= 1;
 
     trace_resettable_reset_release_end(obj);
 }
@@ -XXX,XX +XXX,XX @@ static void resettable_phase_exit(Object *obj, void *opaque, ResetType type)
     trace_resettable_phase_exit_end(obj, obj_typename, s->count);
 }
 
+/*
+ * resettable_get_count:
+ * Get the count of the Resettable object @obj. Return 0 if @obj is NULL.
+ */
+static unsigned resettable_get_count(Object *obj)
+{
+    if (obj) {
+        ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+        return rc->get_state(obj)->count;
+    }
+    return 0;
+}
+
+void resettable_change_parent(Object *obj, Object *newp, Object *oldp)
+{
+    ResettableClass *rc = RESETTABLE_GET_CLASS(obj);
+    ResettableState *s = rc->get_state(obj);
+    unsigned newp_count = resettable_get_count(newp);
+    unsigned oldp_count = resettable_get_count(oldp);
+
+    /*
+     * Ensure we do not change parent when in enter or exit phase.
+     * During these phases, the reset subtree being updated is partly in reset
+     * and partly not in reset (it depends on the actual position in
+     * resettable_child_foreach()s). We are not able to tell in which part is a
+     * leaving or arriving device. Thus we cannot set the reset count of the
+     * moving device to the proper value.
+     */
+    assert(!enter_phase_in_progress && !exit_phase_in_progress);
+    trace_resettable_change_parent(obj, oldp, oldp_count, newp, newp_count);
+
+    /*
+     * At most one of the two 'for' loops will be executed below
+     * in order to cope with the difference between the two counts.
+     */
+    /* if newp is more reset than oldp */
+    for (unsigned i = oldp_count; i < newp_count; i++) {
+        resettable_assert_reset(obj, RESET_TYPE_COLD);
+    }
+    /*
+     * if obj is leaving a bus under reset, we need to ensure
+     * hold phase is not pending.
+     */
+    if (oldp_count && s->hold_phase_pending) {
+        resettable_phase_hold(obj, NULL, RESET_TYPE_COLD);
+    }
+    /* if oldp is more reset than newp */
+    for (unsigned i = newp_count; i < oldp_count; i++) {
+        resettable_release_reset(obj, RESET_TYPE_COLD);
+    }
+}
+
 void resettable_class_set_parent_phases(ResettableClass *rc,
                                         ResettableEnterPhase enter,
                                         ResettableHoldPhase hold,
diff --git a/hw/core/trace-events b/hw/core/trace-events
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/trace-events
+++ b/hw/core/trace-events
@@ -XXX,XX +XXX,XX @@ resettable_reset_assert_begin(void *obj, int cold) "obj=%p cold=%d"
 resettable_reset_assert_end(void *obj) "obj=%p"
 resettable_reset_release_begin(void *obj, int cold) "obj=%p cold=%d"
 resettable_reset_release_end(void *obj) "obj=%p"
+resettable_change_parent(void *obj, void *o, unsigned oc, void *n, unsigned nc) "obj=%p from=%p(%d) to=%p(%d)"
 resettable_phase_enter_begin(void *obj, const char *objtype, unsigned count, int type) "obj=%p(%s) count=%d type=%d"
 resettable_phase_enter_exec(void *obj, const char *objtype, int type, int has_method) "obj=%p(%s) type=%d method=%d"
 resettable_phase_enter_end(void *obj, const char *objtype, unsigned count) "obj=%p(%s) count=%d"
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

In qdev_set_parent_bus(), when changing the parent bus of a
realized device, if the source and destination buses are not in the
same reset state, some adaptations are required. This patch adds
needed call to resettable_change_parent() to make sure a device reset
state stays coherent with its parent bus.

The addition is a no-op if:
1. the device being parented is not realized.
2. the device is realized, but both buses are not under reset.

Case 2 means that as long as qdev_set_parent_bus() is called
during the machine realization procedure (which is before the
machine reset so nothing is in reset), it is a no op.

There are 52 call sites of qdev_set_parent_bus(). All but one fall
into the no-op case:
+ 29 trivial calls related to virtio (in hw/{s390x,display,virtio}/
  {vhost,virtio}-xxx.c) to set a vdev(or vgpu) composing device
  parent bus just before realizing the same vdev(vgpu).
+ hw/core/qdev.c: when creating a device in qdev_try_create()
+ hw/core/sysbus.c: when initializing a device in the sysbus
+ hw/i386/amd_iommu.c: before realizing AMDVIState/pci
+ hw/isa/piix4.c: before realizing PIIX4State/rtc
+ hw/misc/auxbus.c: when creating an AUXBus
+ hw/misc/auxbus.c: when creating an AUXBus child
+ hw/misc/macio/macio.c: when initializing a MACIOState child
+ hw/misc/macio/macio.c: before realizing NewWorldMacIOState/pmu
+ hw/misc/macio/macio.c: before realizing NewWorldMacIOState/cuda
+ hw/net/virtio-net.c: Used for migration when using the failover
                       mechanism to migration a vfio-pci/net. It is
                       a no-op because at this point the device is
                       already on the bus.
+ hw/pci-host/designware.c: before realizing DesignwarePCIEHost/root
+ hw/pci-host/gpex.c: before realizing GPEXHost/root
+ hw/pci-host/prep.c: when initialiazing PREPPCIState/pci_dev
+ hw/pci-host/q35.c: before realizing Q35PCIHost/mch
+ hw/pci-host/versatile.c: when initializing PCIVPBState/pci_dev
+ hw/pci-host/xilinx-pcie.c: before realizing XilinxPCIEHost/root
+ hw/s390x/event-facility.c: when creating SCLPEventFacility/
                             TYPE_SCLP_QUIESCE
+ hw/s390x/event-facility.c: ditto with SCLPEventFacility/
                             TYPE_SCLP_CPU_HOTPLUG
+ hw/s390x/sclp.c: Not trivial because it is called on a SLCPDevice
  just after realizing it. Ok because at this point the destination
  bus (sysbus) is not in reset; the realize step is before the
  machine reset.
+ hw/sd/core.c: Not OK. Used in sdbus_reparent_card(). See below.
+ hw/ssi/ssi.c: Used to put spi slave on spi bus and connect the cs
  line in ssi_auto_connect_slave(). Ok because this function is only
  used in realize step in hw/ssi/aspeed_smc.ci, hw/ssi/imx_spi.c,
  hw/ssi/mss-spi.c, hw/ssi/xilinx_spi.c and hw/ssi/xilinx_spips.c.
+ hw/xen/xen-legacy-backend.c: when creating a XenLegacyDevice device
+ qdev-monitor.c: in device hotplug creation procedure before realize

Note that this commit alone will have no effect, right now there is no
use of resettable API to reset anything. So a bus will never be tagged
as in-reset by this same API.

The one place where side-effect will occurs is in hw/sd/core.c in
sdbus_reparent_card(). This function is only used in the raspi machines,
including during the sysbus reset procedure. This case will be
carrefully handled when doing the multiple phase reset transition.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-7-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/core/qdev.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@ static void bus_add_child(BusState *bus, DeviceState *child)
 
 void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
 {
-    bool replugging = dev->parent_bus != NULL;
+    BusState *old_parent_bus = dev->parent_bus;
 
-    if (replugging) {
+    if (old_parent_bus) {
         trace_qdev_update_parent_bus(dev, object_get_typename(OBJECT(dev)),
-            dev->parent_bus, object_get_typename(OBJECT(dev->parent_bus)),
+            old_parent_bus, object_get_typename(OBJECT(old_parent_bus)),
             OBJECT(bus), object_get_typename(OBJECT(bus)));
         /*
          * Keep a reference to the device while it's not plugged into
          * any bus, to avoid it potentially evaporating when it is
          * dereffed in bus_remove_child().
+         * Also keep the ref of the parent bus until the end, so that
+         * we can safely call resettable_change_parent() below.
          */
         object_ref(OBJECT(dev));
         bus_remove_child(dev->parent_bus, dev);
-        object_unref(OBJECT(dev->parent_bus));
     }
     dev->parent_bus = bus;
     object_ref(OBJECT(bus));
     bus_add_child(bus, dev);
-    if (replugging) {
+    if (dev->realized) {
+        resettable_change_parent(OBJECT(dev), OBJECT(bus),
+                                 OBJECT(old_parent_bus));
+    }
+    if (old_parent_bus) {
+        object_unref(OBJECT(old_parent_bus));
         object_unref(OBJECT(dev));
     }
 }
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

This commit make use of the resettable API to reset the device being
hotplugged when it is realized. Also it ensures it is put in a reset
state coherent with the parent it is plugged into.

Note that there is a difference in the reset. Instead of resetting
only the hotplugged device, we reset also its subtree (switch to
resettable API). This is not expected to be a problem because
sub-buses are just realized too. If a hotplugged device has any
sub-buses it is logical to reset them too at this point.

The recently added should_be_hidden and PCI's partially_hotplugged
mechanisms do not interfere with realize operation:
+ In the should_be_hidden use case, device creation is
delayed.
+ The partially_hotplugged mechanism prevents a device to be
unplugged and unrealized from qdev POV and unrealized.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-8-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/resettable.h | 11 +++++++++++
 hw/core/qdev.c          | 15 ++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/hw/resettable.h b/include/hw/resettable.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/resettable.h
+++ b/include/hw/resettable.h
@@ -XXX,XX +XXX,XX @@ struct ResettableState {
     bool exit_phase_in_progress;
 };
 
+/**
+ * resettable_state_clear:
+ * Clear the state. It puts the state to the initial (zeroed) state required
+ * to reuse an object. Typically used in realize step of base classes
+ * implementing the interface.
+ */
+static inline void resettable_state_clear(ResettableState *state)
+{
+    memset(state, 0, sizeof(ResettableState));
+}
+
 /**
  * resettable_reset:
  * Trigger a reset on an object @obj of type @type. @obj must implement
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@ static void device_set_realized(Object *obj, bool value, Error **errp)
             }
         }
 
+        /*
+         * Clear the reset state, in case the object was previously unrealized
+         * with a dirty state.
+         */
+        resettable_state_clear(&dev->reset);
+
         QLIST_FOREACH(bus, &dev->child_bus, sibling) {
             object_property_set_bool(OBJECT(bus), true, "realized",
                                          &local_err);
@@ -XXX,XX +XXX,XX @@ static void device_set_realized(Object *obj, bool value, Error **errp)
             }
         }
         if (dev->hotplugged) {
-            device_legacy_reset(dev);
+            /*
+             * Reset the device, as well as its subtree which, at this point,
+             * should be realized too.
+             */
+            resettable_assert_reset(OBJECT(dev), RESET_TYPE_COLD);
+            resettable_change_parent(OBJECT(dev), OBJECT(dev->parent_bus),
+                                     NULL);
+            resettable_release_reset(OBJECT(dev), RESET_TYPE_COLD);
         }
         dev->pending_deleted_event = false;
 
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Deprecate device_legacy_reset(), qdev_reset_all() and
qbus_reset_all() to be replaced by new functions
device_cold_reset() and bus_cold_reset() which uses resettable API.

Also introduce resettable_cold_reset_fn() which may be used as a
replacement for qdev_reset_all_fn and qbus_reset_all_fn().

Following patches will be needed to look at legacy reset call sites
and switch to resettable api. The legacy functions will be removed
when unused.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-9-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/qdev-core.h  | 27 +++++++++++++++++++++++++++
 include/hw/resettable.h |  9 +++++++++
 hw/core/bus.c           |  5 +++++
 hw/core/qdev.c          |  5 +++++
 hw/core/resettable.c    |  5 +++++
 5 files changed, 51 insertions(+)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -XXX,XX +XXX,XX @@ int qdev_walk_children(DeviceState *dev,
                        qdev_walkerfn *post_devfn, qbus_walkerfn *post_busfn,
                        void *opaque);
 
+/**
+ * @qdev_reset_all:
+ * Reset @dev. See @qbus_reset_all() for more details.
+ *
+ * Note: This function is deprecated and will be removed when it becomes unused.
+ * Please use device_cold_reset() now.
+ */
 void qdev_reset_all(DeviceState *dev);
 void qdev_reset_all_fn(void *opaque);
 
@@ -XXX,XX +XXX,XX @@ void qdev_reset_all_fn(void *opaque);
  * hard reset means that qbus_reset_all will reset all state of the device.
  * For PCI devices, for example, this will include the base address registers
  * or configuration space.
+ *
+ * Note: This function is deprecated and will be removed when it becomes unused.
+ * Please use bus_cold_reset() now.
  */
 void qbus_reset_all(BusState *bus);
 void qbus_reset_all_fn(void *opaque);
 
+/**
+ * device_cold_reset:
+ * Reset device @dev and perform a recursive processing using the resettable
+ * interface. It triggers a RESET_TYPE_COLD.
+ */
+void device_cold_reset(DeviceState *dev);
+
+/**
+ * bus_cold_reset:
+ *
+ * Reset bus @bus and perform a recursive processing using the resettable
+ * interface. It triggers a RESET_TYPE_COLD.
+ */
+void bus_cold_reset(BusState *bus);
+
 /**
  * device_is_in_reset:
  * Return true if the device @dev is currently being reset.
@@ -XXX,XX +XXX,XX @@ void qdev_machine_init(void);
  * device_legacy_reset:
  *
  * Reset a single device (by calling the reset method).
+ * Note: This function is deprecated and will be removed when it becomes unused.
+ * Please use device_cold_reset() now.
  */
 void device_legacy_reset(DeviceState *dev);
 
diff --git a/include/hw/resettable.h b/include/hw/resettable.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/resettable.h
+++ b/include/hw/resettable.h
@@ -XXX,XX +XXX,XX @@ bool resettable_is_in_reset(Object *obj);
  */
 void resettable_change_parent(Object *obj, Object *newp, Object *oldp);
 
+/**
+ * resettable_cold_reset_fn:
+ * Helper to call resettable_reset((Object *) opaque, RESET_TYPE_COLD).
+ *
+ * This function is typically useful to register a reset handler with
+ * qemu_register_reset.
+ */
+void resettable_cold_reset_fn(void *opaque);
+
 /**
  * resettable_class_set_parent_phases:
  *
diff --git a/hw/core/bus.c b/hw/core/bus.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/bus.c
+++ b/hw/core/bus.c
@@ -XXX,XX +XXX,XX @@ int qbus_walk_children(BusState *bus,
     return 0;
 }
 
+void bus_cold_reset(BusState *bus)
+{
+    resettable_reset(OBJECT(bus), RESET_TYPE_COLD);
+}
+
 bool bus_is_in_reset(BusState *bus)
 {
     return resettable_is_in_reset(OBJECT(bus));
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -XXX,XX +XXX,XX @@ void qbus_reset_all_fn(void *opaque)
     qbus_reset_all(bus);
 }
 
+void device_cold_reset(DeviceState *dev)
+{
+    resettable_reset(OBJECT(dev), RESET_TYPE_COLD);
+}
+
 bool device_is_in_reset(DeviceState *dev)
 {
     return resettable_is_in_reset(OBJECT(dev));
diff --git a/hw/core/resettable.c b/hw/core/resettable.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/resettable.c
+++ b/hw/core/resettable.c
@@ -XXX,XX +XXX,XX @@ void resettable_change_parent(Object *obj, Object *newp, Object *oldp)
     }
 }
 
+void resettable_cold_reset_fn(void *opaque)
+{
+    resettable_reset((Object *) opaque, RESET_TYPE_COLD);
+}
+
 void resettable_class_set_parent_phases(ResettableClass *rc,
                                         ResettableEnterPhase enter,
                                         ResettableHoldPhase hold,
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200123132823.1117486-10-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/devel/index.rst |   1 +
 docs/devel/reset.rst | 289 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 290 insertions(+)
 create mode 100644 docs/devel/reset.rst

diff --git a/docs/devel/index.rst b/docs/devel/index.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/index.rst
+++ b/docs/devel/index.rst
@@ -XXX,XX +XXX,XX @@ Contents:
    tcg
    tcg-plugins
    bitops
+   reset
diff --git a/docs/devel/reset.rst b/docs/devel/reset.rst
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/docs/devel/reset.rst
@@ -XXX,XX +XXX,XX @@
+
+=======================================
+Reset in QEMU: the Resettable interface
+=======================================
+
+The reset of qemu objects is handled using the resettable interface declared
+in ``include/hw/resettable.h``.
+
+This interface allows objects to be grouped (on a tree basis); so that the
+whole group can be reset consistently. Each individual member object does not
+have to care about others; in particular, problems of order (which object is
+reset first) are addressed.
+
+As of now DeviceClass and BusClass implement this interface.
+
+
+Triggering reset
+----------------
+
+This section documents the APIs which "users" of a resettable object should use
+to control it. All resettable control functions must be called while holding
+the iothread lock.
+
+You can apply a reset to an object using ``resettable_assert_reset()``. You need
+to call ``resettable_release_reset()`` to release the object from reset. To
+instantly reset an object, without keeping it in reset state, just call
+``resettable_reset()``. These functions take two parameters: a pointer to the
+object to reset and a reset type.
+
+Several types of reset will be supported. For now only cold reset is defined;
+others may be added later. The Resettable interface handles reset types with an
+enum:
+
+``RESET_TYPE_COLD``
+  Cold reset is supported by every resettable object. In QEMU, it means we reset
+  to the initial state corresponding to the start of QEMU; this might differ
+  from what is a real hardware cold reset. It differs from other resets (like
+  warm or bus resets) which may keep certain parts untouched.
+
+Calling ``resettable_reset()`` is equivalent to calling
+``resettable_assert_reset()`` then ``resettable_release_reset()``. It is
+possible to interleave multiple calls to these three functions. There may
+be several reset sources/controllers of a given object. The interface handles
+everything and the different reset controllers do not need to know anything
+about each others. The object will leave reset state only when each other
+controllers end their reset operation. This point is handled internally by
+maintaining a count of in-progress resets; it is crucial to call
+``resettable_release_reset()`` one time and only one time per
+``resettable_assert_reset()`` call.
+
+For now migration of a device or bus in reset is not supported. Care must be
+taken not to delay ``resettable_release_reset()`` after its
+``resettable_assert_reset()`` counterpart.
+
+Note that, since resettable is an interface, the API takes a simple Object as
+parameter. Still, it is a programming error to call a resettable function on a
+non-resettable object and it will trigger a run time assert error. Since most
+calls to resettable interface are done through base class functions, such an
+error is not likely to happen.
+
+For Devices and Buses, the following helper functions exist:
+
+- ``device_cold_reset()``
+- ``bus_cold_reset()``
+
+These are simple wrappers around resettable_reset() function; they only cast the
+Device or Bus into an Object and pass the cold reset type. When possible
+prefer to use these functions instead of ``resettable_reset()``.
+
+Device and bus functions co-exist because there can be semantic differences
+between resetting a bus and resetting the controller bridge which owns it.
+For example, consider a SCSI controller. Resetting the controller puts all
+its registers back to what reset state was as well as reset everything on the
+SCSI bus, whereas resetting just the SCSI bus only resets everything that's on
+it but not the controller.
+
+
+Multi-phase mechanism
+---------------------
+
+This section documents the internals of the resettable interface.
+
+The resettable interface uses a multi-phase system to relieve objects and
+machines from reset ordering problems. To address this, the reset operation
+of an object is split into three well defined phases.
+
+When resetting several objects (for example the whole machine at simulation
+startup), all first phases of all objects are executed, then all second phases
+and then all third phases.
+
+The three phases are:
+
+1. The **enter** phase is executed when the object enters reset. It resets only
+   local state of the object; it must not do anything that has a side-effect
+   on other objects, such as raising or lowering a qemu_irq line or reading or
+   writing guest memory.
+
+2. The **hold** phase is executed for entry into reset, once every object in the
+   group which is being reset has had its *enter* phase executed. At this point
+   devices can do actions that affect other objects.
+
+3. The **exit** phase is executed when the object leaves the reset state.
+   Actions affecting other objects are permitted.
+
+As said in previous section, the interface maintains a count of reset. This
+count is used to ensure phases are executed only when required. *enter* and
+*hold* phases are executed only when asserting reset for the first time
+(if an object is already in reset state when calling
+``resettable_assert_reset()`` or ``resettable_reset()``, they are not
+executed).
+The *exit* phase is executed only when the last reset operation ends. Therefore
+the object does not need to care how many of reset controllers it has and how
+many of them have started a reset.
+
+
+Handling reset in a resettable object
+-------------------------------------
+
+This section documents the APIs that an implementation of a resettable object
+must provide and what functions it has access to. It is intended for people
+who want to implement or convert a class which has the resettable interface;
+for example when specializing an existing device or bus.
+
+Methods to implement
+....................
+
+Three methods should be defined or left empty. Each method corresponds to a
+phase of the reset; they are name ``phases.enter()``, ``phases.hold()`` and
+``phases.exit()``. They all take the object as parameter. The *enter* method
+also take the reset type as second parameter.
+
+When extending an existing class, these methods may need to be extended too.
+The ``resettable_class_set_parent_phases()`` class function may be used to
+backup parent class methods.
+
+Here follows an example to implement reset for a Device which sets an IO while
+in reset.
+
+::
+
+    static void mydev_reset_enter(Object *obj, ResetType type)
+    {
+        MyDevClass *myclass = MYDEV_GET_CLASS(obj);
+        MyDevState *mydev = MYDEV(obj);
+        /* call parent class enter phase */
+        if (myclass->parent_phases.enter) {
+            myclass->parent_phases.enter(obj, type);
+        }
+        /* initialize local state only */
+        mydev->var = 0;
+    }
+
+    static void mydev_reset_hold(Object *obj)
+    {
+        MyDevClass *myclass = MYDEV_GET_CLASS(obj);
+        MyDevState *mydev = MYDEV(obj);
+        /* call parent class hold phase */
+        if (myclass->parent_phases.hold) {
+            myclass->parent_phases.hold(obj);
+        }
+        /* set an IO */
+        qemu_set_irq(mydev->irq, 1);
+    }
+
+    static void mydev_reset_exit(Object *obj)
+    {
+        MyDevClass *myclass = MYDEV_GET_CLASS(obj);
+        MyDevState *mydev = MYDEV(obj);
+        /* call parent class exit phase */
+        if (myclass->parent_phases.exit) {
+            myclass->parent_phases.exit(obj);
+        }
+        /* clear an IO */
+        qemu_set_irq(mydev->irq, 0);
+    }
+
+    typedef struct MyDevClass {
+        MyParentClass parent_class;
+        /* to store eventual parent reset methods */
+        ResettablePhases parent_phases;
+    } MyDevClass;
+
+    static void mydev_class_init(ObjectClass *class, void *data)
+    {
+        MyDevClass *myclass = MYDEV_CLASS(class);
+        ResettableClass *rc = RESETTABLE_CLASS(class);
+        resettable_class_set_parent_reset_phases(rc,
+                                                 mydev_reset_enter,
+                                                 mydev_reset_hold,
+                                                 mydev_reset_exit,
+                                                 &myclass->parent_phases);
+    }
+
+In the above example, we override all three phases. It is possible to override
+only some of them by passing NULL instead of a function pointer to
+``resettable_class_set_parent_reset_phases()``. For example, the following will
+only override the *enter* phase and leave *hold* and *exit* untouched::
+
+    resettable_class_set_parent_reset_phases(rc, mydev_reset_enter,
+                                             NULL, NULL,
+                                             &myclass->parent_phases);
+
+This is equivalent to providing a trivial implementation of the hold and exit
+phases which does nothing but call the parent class's implementation of the
+phase.
+
+Polling the reset state
+.......................
+
+Resettable interface provides the ``resettable_is_in_reset()`` function.
+This function returns true if the object parameter is currently under reset.
+
+An object is under reset from the beginning of the *init* phase to the end of
+the *exit* phase. During all three phases, the function will return that the
+object is in reset.
+
+This function may be used if the object behavior has to be adapted
+while in reset state. For example if a device has an irq input,
+it will probably need to ignore it while in reset; then it can for
+example check the reset state at the beginning of the irq callback.
+
+Note that until migration of the reset state is supported, an object
+should not be left in reset. So apart from being currently executing
+one of the reset phases, the only cases when this function will return
+true is if an external interaction (like changing an io) is made during
+*hold* or *exit* phase of another object in the same reset group.
+
+Helpers ``device_is_in_reset()`` and ``bus_is_in_reset()`` are also provided
+for devices and buses and should be preferred.
+
+
+Base class handling of reset
+----------------------------
+
+This section documents parts of the reset mechanism that you only need to know
+about if you are extending it to work with a new base class other than
+DeviceClass or BusClass, or maintaining the existing code in those classes. Most
+people can ignore it.
+
+Methods to implement
+....................
+
+There are two other methods that need to exist in a class implementing the
+interface: ``get_state()`` and ``child_foreach()``.
+
+``get_state()`` is simple. *resettable* is an interface and, as a consequence,
+does not have any class state structure. But in order to factorize the code, we
+need one. This method must return a pointer to ``ResettableState`` structure.
+The structure must be allocated by the base class; preferably it should be
+located inside the object instance structure.
+
+``child_foreach()`` is more complex. It should execute the given callback on
+every reset child of the given resettable object. All children must be
+resettable too. Additional parameters (a reset type and an opaque pointer) must
+be passed to the callback too.
+
+In ``DeviceClass`` and ``BusClass`` the ``ResettableState`` is located
+``DeviceState`` and ``BusState`` structure. ``child_foreach()`` is implemented
+to follow the bus hierarchy; for a bus, it calls the function on every child
+device; for a device, it calls the function on every bus child. When we reset
+the main system bus, we reset the whole machine bus tree.
+
+Changing a resettable parent
+............................
+
+One thing which should be taken care of by the base class is handling reset
+hierarchy changes.
+
+The reset hierarchy is supposed to be static and built during machine creation.
+But there are actually some exceptions. To cope with this, the resettable API
+provides ``resettable_change_parent()``. This function allows to set, update or
+remove the parent of a resettable object after machine creation is done. As
+parameters, it takes the object being moved, the old parent if any and the new
+parent if any.
+
+This function can be used at any time when not in a reset operation. During
+a reset operation it must be used only in *hold* phase. Using it in *enter* or
+*exit* phase is an error.
+Also it should not be used during machine creation, although it is harmless to
+do so: the function is a no-op as long as old and new parent are NULL or not
+in reset.
+
+There is currently 2 cases where this function is used:
+
+1. *device hotplug*; it means a new device is introduced on a live bus.
+
+2. *hot bus change*; it means an existing live device is added, moved or
+   removed in the bus hierarchy. At the moment, it occurs only in the raspi
+   machines for changing the sdbus used by sd card.
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Replace deprecated qbus_reset_all by resettable_cold_reset_fn for
the sysbus reset registration.

Apart for the raspi machines, this does not impact the behavior
because:
+ at this point resettable just calls the old reset methods of devices
  and buses in the same order as qdev/qbus.
+ resettable handlers registered with qemu_register_reset are
  serialized; there is no interleaving.
+ eventual explicit calls to legacy reset API (device_reset or
  qdev/qbus_reset) inside this reset handler will not be masked out
  by resettable mechanism; they do not go through resettable api.

For the raspi machines, during the sysbus reset the sd-card is not
reset twice anymore but only once. This is a consequence of switching
both sysbus reset and changing parent to resettable; it detects the
second reset is not needed. This has no impact on the state after
reset; the sd-card reset method only reset local state and query
information from the block backend.

The raspi reset change can be observed by using the following command
(reset will occurs, then do Ctrl-C to end qemu; no firmware is
given here).
qemu-system-aarch64 -M raspi3 \
    -trace resettable_phase_hold_exec \
    -trace qdev_update_parent_bus \
    -trace resettable_change_parent \
    -trace qdev_reset -trace qbus_reset

Before the patch, the qdev/qbus_reset traces show when reset method are
called. After the patch, the resettable_phase_hold_exec show when reset
method are called.

The traced reset order of the raspi3 is listed below. I've added empty
lines and the tree structure.

+->bcm2835-peripherals reset
 |
 |       +->sd-card reset
 |   +->sd-bus reset
 +->bcm2835_gpio reset
 |      -> dev_update_parent_bus (move the sd-card on the sdhci-bus)
 |      -> resettable_change_parent
 |
 +->bcm2835-dma reset
 |
 |   +->bcm2835-sdhost-bus reset
 +->bcm2835-sdhost reset
 |
 |       +->sd-card (reset ONLY BEFORE BEFORE THE PATCH)
 |   +->sdhci-bus reset
 +->generic-sdhci reset
 |
 +->bcm2835-rng reset
 +->bcm2835-property reset
 +->bcm2835-fb reset
 +->bcm2835-mbox reset
 +->bcm2835-aux reset
 +->pl011 reset
 +->bcm2835-ic reset
 +->bcm2836-control reset
System reset

In both case, the sd-card is reset (being on bcm2835_gpio/sd-bus) then moved
to generic-sdhci/sdhci-bus by the bcm2835_gpio reset method.

Before the patch, it is then reset again being part of generic-sdhci/sdhci-bus.
After the patch, it considered again for reset but its reset method is not
called because it is already flagged as reset.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200123132823.1117486-11-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 vl.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/vl.c b/vl.c
index XXXXXXX..XXXXXXX 100644
--- a/vl.c
+++ b/vl.c
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv, char **envp)
 
     /* TODO: once all bus devices are qdevified, this should be done
      * when bus is created by qdev.c */
-    qemu_register_reset(qbus_reset_all_fn, sysbus_get_default());
+    /*
+     * TODO: If we had a main 'reset container' that the whole system
+     * lived in, we could reset that using the multi-phase reset
+     * APIs. For the moment, we just reset the sysbus, which will cause
+     * all devices hanging off it (and all their child buses, recursively)
+     * to be reset. Note that this will *not* reset any Device objects
+     * which are not attached to some part of the qbus tree!
+     */
+    qemu_register_reset(resettable_cold_reset_fn, sysbus_get_default());
     qemu_run_machine_init_done_notifiers();
 
     if (rom_check_and_register_reset() != 0) {
-- 
2.20.1

From: Damien Hedde <damien.hedde@greensocs.com>

Replace deprecated qdev_reset_all by resettable_cold_reset_fn for
the ipl registration in the main reset handlers.

This does not impact the behavior for the following reasons:
+ at this point resettable just call the old reset methods of devices
  and buses in the same order than qdev/qbus.
+ resettable handlers registered with qemu_register_reset are
  serialized; there is no interleaving.
+ eventual explicit calls to legacy reset API (device_reset or
  qdev/qbus_reset) inside this reset handler will not be masked out
  by resettable mechanism; they do not go through resettable api.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200123132823.1117486-12-damien.hedde@greensocs.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/s390x/ipl.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -XXX,XX +XXX,XX @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
      */
     ipl->compat_start_addr = ipl->start_addr;
     ipl->compat_bios_start_addr = ipl->bios_start_addr;
-    qemu_register_reset(qdev_reset_all_fn, dev);
+    /*
+     * Because this Device is not on any bus in the qbus tree (it is
+     * not a sysbus device and it's not on some other bus like a PCI
+     * bus) it will not be automatically reset by the 'reset the
+     * sysbus' hook registered by vl.c like most devices. So we must
+     * manually register a reset hook for it.
+     * TODO: there should be a better way to do this.
+     */
+    qemu_register_reset(resettable_cold_reset_fn, dev);
 error:
     error_propagate(errp, err);
 }
-- 
2.20.1

From: Zenghui Yu <yuzenghui@huawei.com>

If LPIs are disabled, KVM will just ignore the GICR_PENDBASER.PTZ bit when
restoring GICR_CTLR.  Setting PTZ here makes littlt sense in "reduce GIC
initialization time".

And what's worse, PTZ is generally programmed by guest to indicate to the
Redistributor whether the LPI Pending table is zero when enabling LPIs.
If migration is triggered when the PTZ has just been cleared by guest (and
before enabling LPIs), we will see PTZ==1 on the destination side, which
is not as expected.  Let's just drop this hackish userspace behavior.

Also take this chance to refine the comment a bit.

Fixes: 367b9f527bec ("hw/intc/arm_gicv3_kvm: Implement get/put functions")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Message-id: 20200119133051.642-1-yuzenghui@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/intc/arm_gicv3_kvm.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/intc/arm_gicv3_kvm.c
+++ b/hw/intc/arm_gicv3_kvm.c
@@ -XXX,XX +XXX,XX @@ static void kvm_arm_gicv3_put(GICv3State *s)
     kvm_gicd_access(s, GICD_CTLR, &reg, true);
 
     if (redist_typer & GICR_TYPER_PLPIS) {
-        /* Set base addresses before LPIs are enabled by GICR_CTLR write */
+        /*
+         * Restore base addresses before LPIs are potentially enabled by
+         * GICR_CTLR write
+         */
         for (ncpu = 0; ncpu < s->num_cpu; ncpu++) {
             GICv3CPUState *c = &s->cpu[ncpu];
 
@@ -XXX,XX +XXX,XX @@ static void kvm_arm_gicv3_put(GICv3State *s)
             kvm_gicr_access(s, GICR_PROPBASER + 4, ncpu, &regh, true);
 
             reg64 = c->gicr_pendbaser;
-            if (!(c->gicr_ctlr & GICR_CTLR_ENABLE_LPIS)) {
-                /* Setting PTZ is advised if LPIs are disabled, to reduce
-                 * GIC initialization time.
-                 */
-                reg64 |= GICR_PENDBASER_PTZ;
-            }
             regl = (uint32_t)reg64;
             kvm_gicr_access(s, GICR_PENDBASER, ncpu, &regl, true);
             regh = (uint32_t)(reg64 >> 32);
-- 
2.20.1

From: Andrew Jones <drjones@redhat.com>

Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-2-drjones@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/kvm_arm.h | 46 ++++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -XXX,XX +XXX,XX @@
 int kvm_arm_vcpu_init(CPUState *cs);
 
 /**
- * kvm_arm_vcpu_finalize
+ * kvm_arm_vcpu_finalize:
  * @cs: CPUState
- * @feature: int
+ * @feature: feature to finalize
  *
  * Finalizes the configuration of the specified VCPU feature by
  * invoking the KVM_ARM_VCPU_FINALIZE ioctl. Features requiring
@@ -XXX,XX +XXX,XX @@ void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
 int kvm_arm_init_cpreg_list(ARMCPU *cpu);
 
 /**
- * kvm_arm_reg_syncs_via_cpreg_list
- * regidx: KVM register index
+ * kvm_arm_reg_syncs_via_cpreg_list:
+ * @regidx: KVM register index
  *
  * Return true if this KVM register should be synchronized via the
  * cpreg list of arbitrary system registers, false if it is synchronized
@@ -XXX,XX +XXX,XX @@ int kvm_arm_init_cpreg_list(ARMCPU *cpu);
 bool kvm_arm_reg_syncs_via_cpreg_list(uint64_t regidx);
 
 /**
- * kvm_arm_cpreg_level
- * regidx: KVM register index
+ * kvm_arm_cpreg_level:
+ * @regidx: KVM register index
  *
  * Return the level of this coprocessor/system register.  Return value is
  * either KVM_PUT_RUNTIME_STATE, KVM_PUT_RESET_STATE, or KVM_PUT_FULL_STATE.
@@ -XXX,XX +XXX,XX @@ void kvm_arm_init_serror_injection(CPUState *cs);
  * @cpu: ARMCPU
  *
  * Get VCPU related state from kvm.
+ *
+ * Returns: 0 if success else < 0 error code
  */
 int kvm_get_vcpu_events(ARMCPU *cpu);
 
@@ -XXX,XX +XXX,XX @@ int kvm_get_vcpu_events(ARMCPU *cpu);
  * @cpu: ARMCPU
  *
  * Put VCPU related state to kvm.
+ *
+ * Returns: 0 if success else < 0 error code
  */
 int kvm_put_vcpu_events(ARMCPU *cpu);
 
@@ -XXX,XX +XXX,XX @@ typedef struct ARMHostCPUFeatures {
 
 /**
  * kvm_arm_get_host_cpu_features:
- * @ahcc: ARMHostCPUClass to fill in
+ * @ahcf: ARMHostCPUClass to fill in
  *
  * Probe the capabilities of the host kernel's preferred CPU and fill
  * in the ARMHostCPUClass struct accordingly.
+ *
+ * Returns true on success and false otherwise.
  */
 bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf);
 
@@ -XXX,XX +XXX,XX @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu);
 bool kvm_arm_aarch32_supported(CPUState *cs);
 
 /**
- * bool kvm_arm_pmu_supported:
+ * kvm_arm_pmu_supported:
  * @cs: CPUState
  *
  * Returns: true if the KVM VCPU can enable its PMU
@@ -XXX,XX +XXX,XX @@ bool kvm_arm_aarch32_supported(CPUState *cs);
 bool kvm_arm_pmu_supported(CPUState *cs);
 
 /**
- * bool kvm_arm_sve_supported:
+ * kvm_arm_sve_supported:
  * @cs: CPUState
  *
  * Returns true if the KVM VCPU can enable SVE and false otherwise.
@@ -XXX,XX +XXX,XX @@ bool kvm_arm_pmu_supported(CPUState *cs);
 bool kvm_arm_sve_supported(CPUState *cs);
 
 /**
- * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the
- * IPA address space supported by KVM
- *
+ * kvm_arm_get_max_vm_ipa_size:
  * @ms: Machine state handle
+ *
+ * Returns the number of bits in the IPA address space supported by KVM
  */
 int kvm_arm_get_max_vm_ipa_size(MachineState *ms);
 
 /**
- * kvm_arm_sync_mpstate_to_kvm
+ * kvm_arm_sync_mpstate_to_kvm:
  * @cpu: ARMCPU
  *
  * If supported set the KVM MP_STATE based on QEMU's model.
+ *
+ * Returns 0 on success and -1 on failure.
  */
 int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu);
 
 /**
- * kvm_arm_sync_mpstate_to_qemu
+ * kvm_arm_sync_mpstate_to_qemu:
  * @cpu: ARMCPU
  *
  * If supported get the MP_STATE from KVM and store in QEMU's model.
+ *
+ * Returns 0 on success and aborts on failure.
  */
 int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu);
 
@@ -XXX,XX +XXX,XX @@ int kvm_arm_set_irq(int cpu, int irqtype, int irq, int level);
 
 static inline void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
 {
-    /* This should never actually be called in the "not KVM" case,
+    /*
+     * This should never actually be called in the "not KVM" case,
      * but set up the fields to indicate an error anyway.
      */
     cpu->kvm_target = QEMU_KVM_ARM_TARGET_NONE;
@@ -XXX,XX +XXX,XX @@ bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit);
  *
  * Return: TRUE if any hardware breakpoints in use.
  */
-
 bool kvm_arm_hw_debug_active(CPUState *cs);
 
 /**
  * kvm_arm_copy_hw_debug_data:
- *
  * @ptr: kvm_guest_debug_arch structure
  *
  * Copy the architecture specific debug registers into the
  * kvm_guest_debug ioctl structure.
  */
 struct kvm_guest_debug_arch;
-
 void kvm_arm_copy_hw_debug_data(struct kvm_guest_debug_arch *ptr);
 
 /**
- * its_class_name
+ * its_class_name:
  *
  * Return the ITS class name to use depending on whether KVM acceleration
  * and KVM CAP_SIGNAL_MSI are supported
-- 
2.20.1

From: Andrew Jones <drjones@redhat.com>

Add the missing GENERIC_TIMER feature to kvm64 cpus.

We don't currently use these registers when KVM is enabled, but it's
probably best we add the feature flag for consistency and potential
future use. There's also precedent, as we add the PMU feature flag to
KVM enabled guests, even though we don't use those registers either.

This change was originally posted as a hunk of a different, never
merged patch from Bijan Mottahedeh.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200120101023.16030-4-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/kvm64.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -XXX,XX +XXX,XX @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     set_feature(&features, ARM_FEATURE_NEON);
     set_feature(&features, ARM_FEATURE_AARCH64);
     set_feature(&features, ARM_FEATURE_PMU);
+    set_feature(&features, ARM_FEATURE_GENERIC_TIMER);
 
     ahcf->features = features;
 
-- 
2.20.1

From: Andrew Jones <drjones@redhat.com>

If we know what the default value should be then we can test for
that as well as the feature existence.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200120101023.16030-5-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 tests/qtest/arm-cpu-features.c | 37 +++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/qtest/arm-cpu-features.c
+++ b/tests/qtest/arm-cpu-features.c
@@ -XXX,XX +XXX,XX @@ static bool resp_get_feature(QDict *resp, const char *feature)
     qobject_unref(_resp);                                              \
 })
 
+#define assert_feature(qts, cpu_type, feature, expected_value)         \
+({                                                                     \
+    QDict *_resp, *_props;                                             \
+                                                                       \
+    _resp = do_query_no_props(qts, cpu_type);                          \
+    g_assert(_resp);                                                   \
+    g_assert(resp_has_props(_resp));                                   \
+    _props = resp_get_props(_resp);                                    \
+    g_assert(qdict_get(_props, feature));                              \
+    g_assert(qdict_get_bool(_props, feature) == (expected_value));     \
+    qobject_unref(_resp);                                              \
+})
+
+#define assert_has_feature_enabled(qts, cpu_type, feature)             \
+    assert_feature(qts, cpu_type, feature, true)
+
+#define assert_has_feature_disabled(qts, cpu_type, feature)            \
+    assert_feature(qts, cpu_type, feature, false)
+
 static void assert_type_full(QTestState *qts)
 {
     const char *error;
@@ -XXX,XX +XXX,XX @@ static void test_query_cpu_model_expansion(const void *data)
     assert_error(qts, "host", "The CPU type 'host' requires KVM", NULL);
 
     /* Test expected feature presence/absence for some cpu types */
-    assert_has_feature(qts, "max", "pmu");
-    assert_has_feature(qts, "cortex-a15", "pmu");
+    assert_has_feature_enabled(qts, "max", "pmu");
+    assert_has_feature_enabled(qts, "cortex-a15", "pmu");
     assert_has_not_feature(qts, "cortex-a15", "aarch64");
 
     if (g_str_equal(qtest_get_arch(), "aarch64")) {
-        assert_has_feature(qts, "max", "aarch64");
-        assert_has_feature(qts, "max", "sve");
-        assert_has_feature(qts, "max", "sve128");
-        assert_has_feature(qts, "cortex-a57", "pmu");
-        assert_has_feature(qts, "cortex-a57", "aarch64");
+        assert_has_feature_enabled(qts, "max", "aarch64");
+        assert_has_feature_enabled(qts, "max", "sve");
+        assert_has_feature_enabled(qts, "max", "sve128");
+        assert_has_feature_enabled(qts, "cortex-a57", "pmu");
+        assert_has_feature_enabled(qts, "cortex-a57", "aarch64");
 
         sve_tests_default(qts, "max");
 
@@ -XXX,XX +XXX,XX @@ static void test_query_cpu_model_expansion_kvm(const void *data)
         QDict *resp;
         char *error;
 
-        assert_has_feature(qts, "host", "aarch64");
-        assert_has_feature(qts, "host", "pmu");
+        assert_has_feature_enabled(qts, "host", "aarch64");
+        assert_has_feature_enabled(qts, "host", "pmu");
 
         assert_error(qts, "cortex-a15",
             "We cannot guarantee the CPU type 'cortex-a15' works "
-- 
2.20.1

From: Andrew Jones <drjones@redhat.com>

When a VM is stopped (such as when it's paused) guest virtual time
should stop counting. Otherwise, when the VM is resumed it will
experience time jumps and its kernel may report soft lockups. Not
counting virtual time while the VM is stopped has the side effect
of making the guest's time appear to lag when compared with real
time, and even with time derived from the physical counter. For
this reason, this change, which is enabled by default, comes with
a KVM CPU feature allowing it to be disabled, restoring legacy
behavior.

This patch only provides the implementation of the virtual time
adjustment. A subsequent patch will provide the CPU property
allowing the change to be enabled and disabled.

Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-6-drjones@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu.h     |  7 ++++
 target/arm/kvm_arm.h | 38 ++++++++++++++++++
 target/arm/kvm.c     | 92 ++++++++++++++++++++++++++++++++++++++++++++
 target/arm/kvm32.c   |  3 ++
 target/arm/kvm64.c   |  3 ++
 target/arm/machine.c |  7 ++++
 6 files changed, 150 insertions(+)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -XXX,XX +XXX,XX @@ struct ARMCPU {
     /* KVM init features for this CPU */
     uint32_t kvm_init_features[7];
 
+    /* KVM CPU state */
+
+    /* KVM virtual time adjustment */
+    bool kvm_adjvtime;
+    bool kvm_vtime_dirty;
+    uint64_t kvm_vtime;
+
     /* Uniprocessor system with MP extensions */
     bool mp_is_up;
 
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -XXX,XX +XXX,XX @@ bool write_list_to_kvmstate(ARMCPU *cpu, int level);
  */
 bool write_kvmstate_to_list(ARMCPU *cpu);
 
+/**
+ * kvm_arm_cpu_pre_save:
+ * @cpu: ARMCPU
+ *
+ * Called after write_kvmstate_to_list() from cpu_pre_save() to update
+ * the cpreg list with KVM CPU state.
+ */
+void kvm_arm_cpu_pre_save(ARMCPU *cpu);
+
+/**
+ * kvm_arm_cpu_post_load:
+ * @cpu: ARMCPU
+ *
+ * Called from cpu_post_load() to update KVM CPU state from the cpreg list.
+ */
+void kvm_arm_cpu_post_load(ARMCPU *cpu);
+
 /**
  * kvm_arm_reset_vcpu:
  * @cpu: ARMCPU
@@ -XXX,XX +XXX,XX @@ int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu);
  */
 int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu);
 
+/**
+ * kvm_arm_get_virtual_time:
+ * @cs: CPUState
+ *
+ * Gets the VCPU's virtual counter and stores it in the KVM CPU state.
+ */
+void kvm_arm_get_virtual_time(CPUState *cs);
+
+/**
+ * kvm_arm_put_virtual_time:
+ * @cs: CPUState
+ *
+ * Sets the VCPU's virtual counter to the value stored in the KVM CPU state.
+ */
+void kvm_arm_put_virtual_time(CPUState *cs);
+
+void kvm_arm_vm_state_change(void *opaque, int running, RunState state);
+
 int kvm_arm_vgic_probe(void);
 
 void kvm_arm_pmu_set_irq(CPUState *cs, int irq);
@@ -XXX,XX +XXX,XX @@ static inline void kvm_arm_pmu_set_irq(CPUState *cs, int irq) {}
 static inline void kvm_arm_pmu_init(CPUState *cs) {}
 
 static inline void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map) {}
+
+static inline void kvm_arm_get_virtual_time(CPUState *cs) {}
+static inline void kvm_arm_put_virtual_time(CPUState *cs) {}
 #endif
 
 static inline const char *gic_class_name(void)
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -XXX,XX +XXX,XX @@ static int compare_u64(const void *a, const void *b)
     return 0;
 }
 
+/*
+ * cpreg_values are sorted in ascending order by KVM register ID
+ * (see kvm_arm_init_cpreg_list). This allows us to cheaply find
+ * the storage for a KVM register by ID with a binary search.
+ */
+static uint64_t *kvm_arm_get_cpreg_ptr(ARMCPU *cpu, uint64_t regidx)
+{
+    uint64_t *res;
+
+    res = bsearch(&regidx, cpu->cpreg_indexes, cpu->cpreg_array_len,
+                  sizeof(uint64_t), compare_u64);
+    assert(res);
+
+    return &cpu->cpreg_values[res - cpu->cpreg_indexes];
+}
+
 /* Initialize the ARMCPU cpreg list according to the kernel's
  * definition of what CPU registers it knows about (and throw away
  * the previous TCG-created cpreg list).
@@ -XXX,XX +XXX,XX @@ bool write_list_to_kvmstate(ARMCPU *cpu, int level)
     return ok;
 }
 
+void kvm_arm_cpu_pre_save(ARMCPU *cpu)
+{
+    /* KVM virtual time adjustment */
+    if (cpu->kvm_vtime_dirty) {
+        *kvm_arm_get_cpreg_ptr(cpu, KVM_REG_ARM_TIMER_CNT) = cpu->kvm_vtime;
+    }
+}
+
+void kvm_arm_cpu_post_load(ARMCPU *cpu)
+{
+    /* KVM virtual time adjustment */
+    if (cpu->kvm_adjvtime) {
+        cpu->kvm_vtime = *kvm_arm_get_cpreg_ptr(cpu, KVM_REG_ARM_TIMER_CNT);
+        cpu->kvm_vtime_dirty = true;
+    }
+}
+
 void kvm_arm_reset_vcpu(ARMCPU *cpu)
 {
     int ret;
@@ -XXX,XX +XXX,XX @@ int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu)
     return 0;
 }
 
+void kvm_arm_get_virtual_time(CPUState *cs)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    struct kvm_one_reg reg = {
+        .id = KVM_REG_ARM_TIMER_CNT,
+        .addr = (uintptr_t)&cpu->kvm_vtime,
+    };
+    int ret;
+
+    if (cpu->kvm_vtime_dirty) {
+        return;
+    }
+
+    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
+    if (ret) {
+        error_report("Failed to get KVM_REG_ARM_TIMER_CNT");
+        abort();
+    }
+
+    cpu->kvm_vtime_dirty = true;
+}
+
+void kvm_arm_put_virtual_time(CPUState *cs)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    struct kvm_one_reg reg = {
+        .id = KVM_REG_ARM_TIMER_CNT,
+        .addr = (uintptr_t)&cpu->kvm_vtime,
+    };
+    int ret;
+
+    if (!cpu->kvm_vtime_dirty) {
+        return;
+    }
+
+    ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+    if (ret) {
+        error_report("Failed to set KVM_REG_ARM_TIMER_CNT");
+        abort();
+    }
+
+    cpu->kvm_vtime_dirty = false;
+}
+
 int kvm_put_vcpu_events(ARMCPU *cpu)
 {
     CPUARMState *env = &cpu->env;
@@ -XXX,XX +XXX,XX @@ MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
     return MEMTXATTRS_UNSPECIFIED;
 }
 
+void kvm_arm_vm_state_change(void *opaque, int running, RunState state)
+{
+    CPUState *cs = opaque;
+    ARMCPU *cpu = ARM_CPU(cs);
+
+    if (running) {
+        if (cpu->kvm_adjvtime) {
+            kvm_arm_put_virtual_time(cs);
+        }
+    } else {
+        if (cpu->kvm_adjvtime) {
+            kvm_arm_get_virtual_time(cs);
+        }
+    }
+}
 
 int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
 {
diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm32.c
+++ b/target/arm/kvm32.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu-common.h"
 #include "cpu.h"
 #include "qemu/timer.h"
+#include "sysemu/runstate.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
 #include "internals.h"
@@ -XXX,XX +XXX,XX @@ int kvm_arch_init_vcpu(CPUState *cs)
         return -EINVAL;
     }
 
+    qemu_add_vm_change_state_handler(kvm_arm_vm_state_change, cs);
+
     /* Determine init features for this CPU */
     memset(cpu->kvm_init_features, 0, sizeof(cpu->kvm_init_features));
     if (cpu->start_powered_off) {
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu/host-utils.h"
 #include "qemu/main-loop.h"
 #include "exec/gdbstub.h"
+#include "sysemu/runstate.h"
 #include "sysemu/kvm.h"
 #include "sysemu/kvm_int.h"
 #include "kvm_arm.h"
@@ -XXX,XX +XXX,XX @@ int kvm_arch_init_vcpu(CPUState *cs)
         return -EINVAL;
     }
 
+    qemu_add_vm_change_state_handler(kvm_arm_vm_state_change, cs);
+
     /* Determine init features for this CPU */
     memset(cpu->kvm_init_features, 0, sizeof(cpu->kvm_init_features));
     if (cpu->start_powered_off) {
diff --git a/target/arm/machine.c b/target/arm/machine.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -XXX,XX +XXX,XX @@ static int cpu_pre_save(void *opaque)
             /* This should never fail */
             abort();
         }
+
+        /*
+         * kvm_arm_cpu_pre_save() must be called after
+         * write_kvmstate_to_list()
+         */
+        kvm_arm_cpu_pre_save(cpu);
     } else {
         if (!write_cpustate_to_list(cpu, false)) {
             /* This should never fail. */
@@ -XXX,XX +XXX,XX @@ static int cpu_post_load(void *opaque, int version_id)
          * we're using it.
          */
         write_list_to_cpustate(cpu);
+        kvm_arm_cpu_post_load(cpu);
     } else {
         if (!write_list_to_cpustate(cpu)) {
             return -1;
-- 
2.20.1

From: Andrew Jones <drjones@redhat.com>

kvm-no-adjvtime is a KVM specific CPU property and a first of its
kind. To accommodate it we also add kvm_arm_add_vcpu_properties()
and a KVM specific CPU properties description to the CPU features
document.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200120101023.16030-7-drjones@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/arm/virt.h          |  1 +
 target/arm/kvm_arm.h           | 11 ++++++++++
 hw/arm/virt.c                  |  8 ++++++++
 target/arm/cpu.c               |  2 ++
 target/arm/cpu64.c             |  1 +
 target/arm/kvm.c               | 28 +++++++++++++++++++++++++
 target/arm/monitor.c           |  1 +
 tests/qtest/arm-cpu-features.c |  4 ++++
 docs/arm-cpu-features.rst      | 37 +++++++++++++++++++++++++++++++++-
 9 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -XXX,XX +XXX,XX @@ typedef struct {
     bool smbios_old_sys_ver;
     bool no_highmem_ecam;
     bool no_ged;   /* Machines < 4.2 has no support for ACPI GED device */
+    bool kvm_no_adjvtime;
 } VirtMachineClass;
 
 typedef struct {
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -XXX,XX +XXX,XX @@ void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map);
  */
 void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu);
 
+/**
+ * kvm_arm_add_vcpu_properties:
+ * @obj: The CPU object to add the properties to
+ *
+ * Add all KVM specific CPU properties to the CPU object. These
+ * are the CPU properties with "kvm-" prefixed names.
+ */
+void kvm_arm_add_vcpu_properties(Object *obj);
+
 /**
  * kvm_arm_aarch32_supported:
  * @cs: CPUState
@@ -XXX,XX +XXX,XX @@ static inline void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
     cpu->host_cpu_probe_failed = true;
 }
 
+static inline void kvm_arm_add_vcpu_properties(Object *obj) {}
+
 static inline bool kvm_arm_aarch32_supported(CPUState *cs)
 {
     return false;
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -XXX,XX +XXX,XX @@ static void machvirt_init(MachineState *machine)
             }
         }
 
+        if (vmc->kvm_no_adjvtime &&
+            object_property_find(cpuobj, "kvm-no-adjvtime", NULL)) {
+            object_property_set_bool(cpuobj, true, "kvm-no-adjvtime", NULL);
+        }
+
         if (vmc->no_pmu && object_property_find(cpuobj, "pmu", NULL)) {
             object_property_set_bool(cpuobj, false, "pmu", NULL);
         }
@@ -XXX,XX +XXX,XX @@ DEFINE_VIRT_MACHINE_AS_LATEST(5, 0)
 
 static void virt_machine_4_2_options(MachineClass *mc)
 {
+    VirtMachineClass *vmc = VIRT_MACHINE_CLASS(OBJECT_CLASS(mc));
+
     virt_machine_5_0_options(mc);
     compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len);
+    vmc->kvm_no_adjvtime = true;
 }
 DEFINE_VIRT_MACHINE(4, 2)
 
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -XXX,XX +XXX,XX @@ static void arm_max_initfn(Object *obj)
 
     if (kvm_enabled()) {
         kvm_arm_set_cpu_features_from_host(cpu);
+        kvm_arm_add_vcpu_properties(obj);
     } else {
         cortex_a15_initfn(obj);
 
@@ -XXX,XX +XXX,XX @@ static void arm_host_initfn(Object *obj)
     if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
         aarch64_add_sve_properties(obj);
     }
+    kvm_arm_add_vcpu_properties(obj);
     arm_cpu_post_init(obj);
 }
 
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -XXX,XX +XXX,XX @@ static void aarch64_max_initfn(Object *obj)
 
     if (kvm_enabled()) {
         kvm_arm_set_cpu_features_from_host(cpu);
+        kvm_arm_add_vcpu_properties(obj);
     } else {
         uint64_t t;
         uint32_t u;
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu/timer.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
+#include "qom/object.h"
+#include "qapi/error.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
 #include "sysemu/kvm_int.h"
@@ -XXX,XX +XXX,XX @@ void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
     env->features = arm_host_cpu_features.features;
 }
 
+static bool kvm_no_adjvtime_get(Object *obj, Error **errp)
+{
+    return !ARM_CPU(obj)->kvm_adjvtime;
+}
+
+static void kvm_no_adjvtime_set(Object *obj, bool value, Error **errp)
+{
+    ARM_CPU(obj)->kvm_adjvtime = !value;
+}
+
+/* KVM VCPU properties should be prefixed with "kvm-". */
+void kvm_arm_add_vcpu_properties(Object *obj)
+{
+    if (!kvm_enabled()) {
+        return;
+    }
+
+    ARM_CPU(obj)->kvm_adjvtime = true;
+    object_property_add_bool(obj, "kvm-no-adjvtime", kvm_no_adjvtime_get,
+                             kvm_no_adjvtime_set, &error_abort);
+    object_property_set_description(obj, "kvm-no-adjvtime",
+                                    "Set on to disable the adjustment of "
+                                    "the virtual counter. VM stopped time "
+                                    "will be counted.", &error_abort);
+}
+
 bool kvm_arm_pmu_supported(CPUState *cpu)
 {
     return kvm_check_extension(cpu->kvm_state, KVM_CAP_ARM_PMU_V3);
diff --git a/target/arm/monitor.c b/target/arm/monitor.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/monitor.c
+++ b/target/arm/monitor.c
@@ -XXX,XX +XXX,XX @@ static const char *cpu_model_advertised_features[] = {
     "sve128", "sve256", "sve384", "sve512",
     "sve640", "sve768", "sve896", "sve1024", "sve1152", "sve1280",
     "sve1408", "sve1536", "sve1664", "sve1792", "sve1920", "sve2048",
+    "kvm-no-adjvtime",
     NULL
 };
 
diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/qtest/arm-cpu-features.c
+++ b/tests/qtest/arm-cpu-features.c
@@ -XXX,XX +XXX,XX @@ static void test_query_cpu_model_expansion(const void *data)
     assert_has_feature_enabled(qts, "cortex-a15", "pmu");
     assert_has_not_feature(qts, "cortex-a15", "aarch64");
 
+    assert_has_not_feature(qts, "max", "kvm-no-adjvtime");
+
     if (g_str_equal(qtest_get_arch(), "aarch64")) {
         assert_has_feature_enabled(qts, "max", "aarch64");
         assert_has_feature_enabled(qts, "max", "sve");
@@ -XXX,XX +XXX,XX @@ static void test_query_cpu_model_expansion_kvm(const void *data)
         return;
     }
 
+    assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");
+
     if (g_str_equal(qtest_get_arch(), "aarch64")) {
         bool kvm_supports_sve;
         char max_name[8], name[8];
diff --git a/docs/arm-cpu-features.rst b/docs/arm-cpu-features.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/arm-cpu-features.rst
+++ b/docs/arm-cpu-features.rst
@@ -XXX,XX +XXX,XX @@ supporting the feature or only supporting the feature under certain
 configurations.  For example, the `aarch64` CPU feature, which, when
 disabled, enables the optional AArch32 CPU feature, is only supported
 when using the KVM accelerator and when running on a host CPU type that
-supports the feature.
+supports the feature.  While `aarch64` currently only works with KVM,
+it could work with TCG.  CPU features that are specific to KVM are
+prefixed with "kvm-" and are described in "KVM VCPU Features".
 
 CPU Feature Probing
 ===================
@@ -XXX,XX +XXX,XX @@ disabling many SVE vector lengths would be quite verbose, the `sve<N>` CPU
 properties have special semantics (see "SVE CPU Property Parsing
 Semantics").
 
+KVM VCPU Features
+=================
+
+KVM VCPU features are CPU features that are specific to KVM, such as
+paravirt features or features that enable CPU virtualization extensions.
+The features' CPU properties are only available when KVM is enabled and
+are named with the prefix "kvm-".  KVM VCPU features may be probed,
+enabled, and disabled in the same way as other CPU features.  Below is
+the list of KVM VCPU features and their descriptions.
+
+  kvm-no-adjvtime          By default kvm-no-adjvtime is disabled.  This
+                           means that by default the virtual time
+                           adjustment is enabled (vtime is *not not*
+                           adjusted).
+
+                           When virtual time adjustment is enabled each
+                           time the VM transitions back to running state
+                           the VCPU's virtual counter is updated to ensure
+                           stopped time is not counted.  This avoids time
+                           jumps surprising guest OSes and applications,
+                           as long as they use the virtual counter for
+                           timekeeping.  However it has the side effect of
+                           the virtual and physical counters diverging.
+                           All timekeeping based on the virtual counter
+                           will appear to lag behind any timekeeping that
+                           does not subtract VM stopped time.  The guest
+                           may resynchronize its virtual counter with
+                           other time sources as needed.
+
+                           Enable kvm-no-adjvtime to disable virtual time
+                           adjustment, also restoring the legacy (pre-5.0)
+                           behavior.
+
 SVE CPU Properties
 ==================
 
-- 
2.20.1

v3->v4: Windows headers define an INT type which clashed
with an enum value name in arm_gicv3_its.c...

The following changes since commit eae587e8e3694b1aceab23239493fb4c7e1a80f5:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-09-13' into staging (2021-09-13 11:00:30 +0100)

are available in the Git repository at:

https://git.linaro.org/people/pmaydell/qemu-arm.git tags/pull-target-arm-20210913-3

for you to fetch changes up to 28e987a7e7edaa3ca7feeac65edca26145df8814:

hw/arm/mps2.c: Mark internal-only I2C buses as 'full' (2021-09-13 21:01:08 +0100)

----------------------------------------------------------------
target-arm queue:
 * mark MPS2/MPS3 board-internal i2c buses as 'full' so that command
   line user-created devices are not plugged into them
 * Take an exception if PSTATE.IL is set
 * Support an emulated ITS in the virt board
 * Add support for kudo-bmc board
 * Probe for KVM_CAP_ARM_VM_IPA_SIZE when creating scratch VM
 * cadence_uart: Fix clock handling issues that prevented
   u-boot from running

----------------------------------------------------------------
Bin Meng (6):
      hw/misc: zynq_slcr: Correctly compute output clocks in the reset exit phase
      hw/char: cadence_uart: Disable transmit when input clock is disabled
      hw/char: cadence_uart: Move clock/reset check to uart_can_receive()
      hw/char: cadence_uart: Convert to memop_with_attrs() ops
      hw/char: cadence_uart: Ignore access when unclocked or in reset for uart_{read, write}()
      hw/char: cadence_uart: Log a guest error when device is unclocked or in reset

Chris Rauer (1):
      hw/arm: Add support for kudo-bmc board.

Marc Zyngier (1):
      hw/arm/virt: KVM: Probe for KVM_CAP_ARM_VM_IPA_SIZE when creating scratch VM

Peter Maydell (5):
      target/arm: Take an exception if PSTATE.IL is set
      qdev: Support marking individual buses as 'full'
      hw/arm/mps2-tz.c: Add extra data parameter to MakeDevFn
      hw/arm/mps2-tz.c: Mark internal-only I2C buses as 'full'
      hw/arm/mps2.c: Mark internal-only I2C buses as 'full'

Richard Henderson (1):
      target/arm: Merge disas_a64_insn into aarch64_tr_translate_insn

Shashi Mallela (9):
      hw/intc: GICv3 ITS initial framework
      hw/intc: GICv3 ITS register definitions added
      hw/intc: GICv3 ITS command queue framework
      hw/intc: GICv3 ITS Command processing
      hw/intc: GICv3 ITS Feature enablement
      hw/intc: GICv3 redistributor ITS processing
      tests/data/acpi/virt: Add IORT files for ITS
      hw/arm/virt: add ITS support in virt GIC
      tests/data/acpi/virt: Update IORT files for ITS