[Qemu-devel] [PULL 1/5] xen-platform: re-structure unplug_disks

Stefano Stabellini posted 5 patches 8 years, 9 months ago
Only 1 patches received!
[Qemu-devel] [PULL 1/5] xen-platform: re-structure unplug_disks
Posted by Stefano Stabellini 8 years, 9 months ago
From: Paul Durrant <paul.durrant@citrix.com>

The current code is poorly structured and potentially leads to multiple
config space reads when one is sufficient. Also the UNPLUG_ALL_IDE_DISKS
flag is mis-named since it also results in SCSI disks being unplugged.

This patch renames the flag and re-structures the code to be more
efficient, and readable.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/i386/xen/xen_platform.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 2e1e543..f50915f 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -88,7 +88,7 @@ static void log_writeb(PCIXenPlatformState *s, char val)
 }
 
 /* Xen Platform, Fixed IOPort */
-#define UNPLUG_ALL_IDE_DISKS 1
+#define UNPLUG_ALL_DISKS 1
 #define UNPLUG_ALL_NICS 2
 #define UNPLUG_AUX_IDE_DISKS 4
 
@@ -110,14 +110,21 @@ static void pci_unplug_nics(PCIBus *bus)
 static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
 {
     /* We have to ignore passthrough devices */
-    if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
-            PCI_CLASS_STORAGE_IDE
-            && strcmp(d->name, "xen-pci-passthrough") != 0) {
+    if (!strcmp(d->name, "xen-pci-passthrough")) {
+        return;
+    }
+
+    switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
+    case PCI_CLASS_STORAGE_IDE:
         pci_piix3_xen_ide_unplug(DEVICE(d));
-    } else if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
-            PCI_CLASS_STORAGE_SCSI
-            && strcmp(d->name, "xen-pci-passthrough") != 0) {
+        break;
+
+    case PCI_CLASS_STORAGE_SCSI:
         object_unparent(OBJECT(d));
+        break;
+
+    default:
+        break;
     }
 }
 
@@ -134,9 +141,9 @@ static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t v
     case 0: {
         PCIDevice *pci_dev = PCI_DEVICE(s);
         /* Unplug devices.  Value is a bitmask of which devices to
-           unplug, with bit 0 the IDE devices, bit 1 the network
+           unplug, with bit 0 the disk devices, bit 1 the network
            devices, and bit 2 the non-primary-master IDE devices. */
-        if (val & UNPLUG_ALL_IDE_DISKS) {
+        if (val & UNPLUG_ALL_DISKS) {
             DPRINTF("unplug disks\n");
             pci_unplug_disks(pci_dev->bus);
         }
-- 
1.9.1


[Qemu-devel] [PULL 2/5] xen-platform: add support for unplugging NVMe disks...
Posted by Stefano Stabellini 8 years, 9 months ago
From: Paul Durrant <paul.durrant@citrix.com>

...not just IDE and SCSI.

This patch allows the Xen tool-stack to fully support of NVMe as an
emulated disk type. See [1] for the relevant tool-stack patch discussion.

[1] https://lists.xen.org/archives/html/xen-devel/2017-01/msg01225.html

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/i386/xen/xen_platform.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index f50915f..7d41ebb 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -120,6 +120,7 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
         break;
 
     case PCI_CLASS_STORAGE_SCSI:
+    case PCI_CLASS_STORAGE_EXPRESS:
         object_unparent(OBJECT(d));
         break;
 
-- 
1.9.1


[Qemu-devel] [PULL 3/5] xen-platform: add missing disk unplug option
Posted by Stefano Stabellini 8 years, 9 months ago
From: Paul Durrant <paul.durrant@citrix.com>

The Xen HVM unplug protocol [1] specifies a mechanism to allow guests to
request unplug of 'aux' disks (which is stated to mean all IDE disks,
except the primary master). This patch adds support for that unplug request.

NOTE: The semantics of what happens if unplug of all disks and 'aux' disks
      is simultaneously requests is not clear. The patch makes that
      assumption that an 'all' request overrides an 'aux' request.

[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/hvm-emulated-unplug.markdown

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
----
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: John Snow <jsnow@redhat.com>
---
 hw/i386/xen/xen_platform.c | 27 +++++++++++++++------------
 hw/ide/piix.c              |  4 ++--
 include/hw/ide.h           |  2 +-
 3 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
index 7d41ebb..6010f35 100644
--- a/hw/i386/xen/xen_platform.c
+++ b/hw/i386/xen/xen_platform.c
@@ -107,8 +107,12 @@ static void pci_unplug_nics(PCIBus *bus)
     pci_for_each_device(bus, 0, unplug_nic, NULL);
 }
 
-static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
+static void unplug_disks(PCIBus *b, PCIDevice *d, void *opaque)
 {
+    uint32_t flags = *(uint32_t *)opaque;
+    bool aux = (flags & UNPLUG_AUX_IDE_DISKS) &&
+        !(flags & UNPLUG_ALL_DISKS);
+
     /* We have to ignore passthrough devices */
     if (!strcmp(d->name, "xen-pci-passthrough")) {
         return;
@@ -116,12 +120,14 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
 
     switch (pci_get_word(d->config + PCI_CLASS_DEVICE)) {
     case PCI_CLASS_STORAGE_IDE:
-        pci_piix3_xen_ide_unplug(DEVICE(d));
+        pci_piix3_xen_ide_unplug(DEVICE(d), aux);
         break;
 
     case PCI_CLASS_STORAGE_SCSI:
     case PCI_CLASS_STORAGE_EXPRESS:
-        object_unparent(OBJECT(d));
+        if (!aux) {
+            object_unparent(OBJECT(d));
+        }
         break;
 
     default:
@@ -129,9 +135,9 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
     }
 }
 
-static void pci_unplug_disks(PCIBus *bus)
+static void pci_unplug_disks(PCIBus *bus, uint32_t flags)
 {
-    pci_for_each_device(bus, 0, unplug_disks, NULL);
+    pci_for_each_device(bus, 0, unplug_disks, &flags);
 }
 
 static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
@@ -144,17 +150,14 @@ static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t v
         /* Unplug devices.  Value is a bitmask of which devices to
            unplug, with bit 0 the disk devices, bit 1 the network
            devices, and bit 2 the non-primary-master IDE devices. */
-        if (val & UNPLUG_ALL_DISKS) {
+        if (val & (UNPLUG_ALL_DISKS | UNPLUG_AUX_IDE_DISKS)) {
             DPRINTF("unplug disks\n");
-            pci_unplug_disks(pci_dev->bus);
+            pci_unplug_disks(pci_dev->bus, val);
         }
         if (val & UNPLUG_ALL_NICS) {
             DPRINTF("unplug nics\n");
             pci_unplug_nics(pci_dev->bus);
         }
-        if (val & UNPLUG_AUX_IDE_DISKS) {
-            DPRINTF("unplug auxiliary disks not supported\n");
-        }
         break;
     }
     case 2:
@@ -335,14 +338,14 @@ static void xen_platform_ioport_writeb(void *opaque, hwaddr addr,
              * If VMDP was to control both disk and LAN it would use 4.
              * If it controlled just disk or just LAN, it would use 8 below.
              */
-            pci_unplug_disks(pci_dev->bus);
+            pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS);
             pci_unplug_nics(pci_dev->bus);
         }
         break;
     case 8:
         switch (val) {
         case 1:
-            pci_unplug_disks(pci_dev->bus);
+            pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS);
             break;
         case 2:
             pci_unplug_nics(pci_dev->bus);
diff --git a/hw/ide/piix.c b/hw/ide/piix.c
index d5777fd..7e2d767 100644
--- a/hw/ide/piix.c
+++ b/hw/ide/piix.c
@@ -165,7 +165,7 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp)
     pci_piix_init_ports(d);
 }
 
-int pci_piix3_xen_ide_unplug(DeviceState *dev)
+int pci_piix3_xen_ide_unplug(DeviceState *dev, bool aux)
 {
     PCIIDEState *pci_ide;
     DriveInfo *di;
@@ -174,7 +174,7 @@ int pci_piix3_xen_ide_unplug(DeviceState *dev)
 
     pci_ide = PCI_IDE(dev);
 
-    for (i = 0; i < 4; i++) {
+    for (i = aux ? 1 : 0; i < 4; i++) {
         di = drive_get_by_index(IF_IDE, i);
         if (di != NULL && !di->media_cd) {
             BlockBackend *blk = blk_by_legacy_dinfo(di);
diff --git a/include/hw/ide.h b/include/hw/ide.h
index bc8bd32..3ae087c 100644
--- a/include/hw/ide.h
+++ b/include/hw/ide.h
@@ -17,7 +17,7 @@ void pci_cmd646_ide_init(PCIBus *bus, DriveInfo **hd_table,
 PCIDevice *pci_piix3_xen_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 PCIDevice *pci_piix3_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 PCIDevice *pci_piix4_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
-int pci_piix3_xen_ide_unplug(DeviceState *dev);
+int pci_piix3_xen_ide_unplug(DeviceState *dev, bool aux);
 void vt82c686b_ide_init(PCIBus *bus, DriveInfo **hd_table, int devfn);
 
 /* ide-mmio.c */
-- 
1.9.1


[Qemu-devel] [PULL 4/5] MAINTAINERS: Update xen-devel mailing list address
Posted by Stefano Stabellini 8 years, 9 months ago
From: Anthony PERARD <anthony.perard@citrix.com>

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
---
 MAINTAINERS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index a428cb2..baea7c7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -323,7 +323,7 @@ Guest CPU Cores (Xen):
 X86
 M: Stefano Stabellini <sstabellini@kernel.org>
 M: Anthony Perard <anthony.perard@citrix.com>
-L: xen-devel@lists.xensource.com
+L: xen-devel@lists.xenproject.org
 S: Supported
 F: xen-*
 F: */xen*
-- 
1.9.1


[Qemu-devel] [PULL 5/5] xen: use qdev_unplug() instead of g_free() in xen_pv_find_xendev()
Posted by Stefano Stabellini 8 years, 9 months ago
From: Juergen Gross <jgross@suse.com>

The error exits of xen_pv_find_xendev() free the new xen-device via
g_free() which is wrong.

As the xen-device has been initialized as qdev it must be removed
via qdev_unplug().

This bug has been introduced with commit 3a6c9172ac5951e6dac2b3f6
("xen: create qdev for each backend device").

Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/xen/xen_backend.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c
index d119004..6c21c37 100644
--- a/hw/xen/xen_backend.c
+++ b/hw/xen/xen_backend.c
@@ -124,10 +124,11 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
     /* init new xendev */
     xendev = g_malloc0(ops->size);
     object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
-    qdev_set_parent_bus(&xendev->qdev, xen_sysbus);
-    qdev_set_id(&xendev->qdev, g_strdup_printf("xen-%s-%d", type, dev));
-    qdev_init_nofail(&xendev->qdev);
-    object_unref(OBJECT(&xendev->qdev));
+    OBJECT(xendev)->free = g_free;
+    qdev_set_parent_bus(DEVICE(xendev), xen_sysbus);
+    qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev));
+    qdev_init_nofail(DEVICE(xendev));
+    object_unref(OBJECT(xendev));
 
     xendev->type  = type;
     xendev->dom   = dom;
@@ -145,7 +146,7 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
     xendev->evtchndev = xenevtchn_open(NULL, 0);
     if (xendev->evtchndev == NULL) {
         xen_pv_printf(NULL, 0, "can't open evtchn device\n");
-        g_free(xendev);
+        qdev_unplug(DEVICE(xendev), NULL);
         return NULL;
     }
     fcntl(xenevtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
@@ -155,7 +156,7 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
         if (xendev->gnttabdev == NULL) {
             xen_pv_printf(NULL, 0, "can't open gnttab device\n");
             xenevtchn_close(xendev->evtchndev);
-            g_free(xendev);
+            qdev_unplug(DEVICE(xendev), NULL);
             return NULL;
         }
     } else {
-- 
1.9.1


  • [Qemu-devel] [PULL 1/5] xen-platform: re-structure unplug_disks