The VMApple machine exposes AUX and ROOT block devices (as well as USB OTG
emulation) via virtio-pci as well as a special, simple backdoor platform
device.
This patch implements this backdoor platform device to the best of my
understanding. I left out any USB OTG parts; they're only needed for
guest recovery and I don't understand the protocol yet.
Signed-off-by: Alexander Graf <graf@amazon.com>
---
v1 -> v2:
- Adapt to system_ss meson.build target
---
include/hw/vmapple/bdif.h | 31 +++++
hw/vmapple/bdif.c | 245 ++++++++++++++++++++++++++++++++++++++
hw/vmapple/Kconfig | 2 +
hw/vmapple/meson.build | 1 +
hw/vmapple/trace-events | 5 +
5 files changed, 284 insertions(+)
create mode 100644 include/hw/vmapple/bdif.h
create mode 100644 hw/vmapple/bdif.c
diff --git a/include/hw/vmapple/bdif.h b/include/hw/vmapple/bdif.h
new file mode 100644
index 0000000000..65ee43457b
--- /dev/null
+++ b/include/hw/vmapple/bdif.h
@@ -0,0 +1,31 @@
+/*
+ * VMApple Backdoor Interface
+ *
+ * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * 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_VMAPPLE_BDIF_H
+#define HW_VMAPPLE_BDIF_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_VMAPPLE_BDIF "vmapple-bdif"
+OBJECT_DECLARE_SIMPLE_TYPE(VMAppleBdifState, VMAPPLE_BDIF)
+
+struct VMAppleBdifState {
+ /* <private> */
+ SysBusDevice parent_obj;
+
+ /* <public> */
+ BlockBackend *aux;
+ BlockBackend *root;
+ MemoryRegion mmio;
+};
+
+#define VMAPPLE_BDIF_SIZE 0x00200000
+
+#endif /* HW_VMAPPLE_BDIF_H */
diff --git a/hw/vmapple/bdif.c b/hw/vmapple/bdif.c
new file mode 100644
index 0000000000..36b5915ff3
--- /dev/null
+++ b/hw/vmapple/bdif.c
@@ -0,0 +1,245 @@
+/*
+ * VMApple Backdoor Interface
+ *
+ * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * 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 "hw/vmapple/bdif.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "trace.h"
+#include "hw/block/block.h"
+#include "sysemu/block-backend.h"
+
+#define REG_DEVID_MASK 0xffff0000
+#define DEVID_ROOT 0x00000000
+#define DEVID_AUX 0x00010000
+#define DEVID_USB 0x00100000
+
+#define REG_STATUS 0x0
+#define REG_STATUS_ACTIVE BIT(0)
+#define REG_CFG 0x4
+#define REG_CFG_ACTIVE BIT(1)
+#define REG_UNK1 0x8
+#define REG_BUSY 0x10
+#define REG_BUSY_READY BIT(0)
+#define REG_UNK2 0x400
+#define REG_CMD 0x408
+#define REG_NEXT_DEVICE 0x420
+#define REG_UNK3 0x434
+
+typedef struct vblk_sector {
+ uint32_t pad;
+ uint32_t pad2;
+ uint32_t sector;
+ uint32_t pad3;
+} VblkSector;
+
+typedef struct vblk_req_cmd {
+ uint64_t addr;
+ uint32_t len;
+ uint32_t flags;
+} VblkReqCmd;
+
+typedef struct vblk_req {
+ VblkReqCmd sector;
+ VblkReqCmd data;
+ VblkReqCmd retval;
+} VblkReq;
+
+#define VBLK_DATA_FLAGS_READ 0x00030001
+#define VBLK_DATA_FLAGS_WRITE 0x00010001
+
+#define VBLK_RET_SUCCESS 0
+#define VBLK_RET_FAILED 1
+
+static uint64_t bdif_read(void *opaque, hwaddr offset, unsigned size)
+{
+ uint64_t ret = -1;
+ uint64_t devid = (offset & REG_DEVID_MASK);
+
+ switch (offset & ~REG_DEVID_MASK) {
+ case REG_STATUS:
+ ret = REG_STATUS_ACTIVE;
+ break;
+ case REG_CFG:
+ ret = REG_CFG_ACTIVE;
+ break;
+ case REG_UNK1:
+ ret = 0x420;
+ break;
+ case REG_BUSY:
+ ret = REG_BUSY_READY;
+ break;
+ case REG_UNK2:
+ ret = 0x1;
+ break;
+ case REG_UNK3:
+ ret = 0x0;
+ break;
+ case REG_NEXT_DEVICE:
+ switch (devid) {
+ case DEVID_ROOT:
+ ret = 0x8000000;
+ break;
+ case DEVID_AUX:
+ ret = 0x10000;
+ break;
+ }
+ break;
+ }
+
+ trace_bdif_read(offset, size, ret);
+ return ret;
+}
+
+static void le2cpu_sector(VblkSector *sector)
+{
+ sector->sector = le32_to_cpu(sector->sector);
+}
+
+static void le2cpu_reqcmd(VblkReqCmd *cmd)
+{
+ cmd->addr = le64_to_cpu(cmd->addr);
+ cmd->len = le32_to_cpu(cmd->len);
+ cmd->flags = le32_to_cpu(cmd->flags);
+}
+
+static void le2cpu_req(VblkReq *req)
+{
+ le2cpu_reqcmd(&req->sector);
+ le2cpu_reqcmd(&req->data);
+ le2cpu_reqcmd(&req->retval);
+}
+
+static void vblk_cmd(uint64_t devid, BlockBackend *blk, uint64_t value,
+ uint64_t static_off)
+{
+ VblkReq req;
+ VblkSector sector;
+ uint64_t off = 0;
+ char *buf = NULL;
+ uint8_t ret = VBLK_RET_FAILED;
+ int r;
+
+ cpu_physical_memory_read(value, &req, sizeof(req));
+ le2cpu_req(&req);
+
+ if (req.sector.len != sizeof(sector)) {
+ ret = VBLK_RET_FAILED;
+ goto out;
+ }
+
+ /* Read the vblk command */
+ cpu_physical_memory_read(req.sector.addr, §or, sizeof(sector));
+ le2cpu_sector(§or);
+
+ off = sector.sector * 512ULL + static_off;
+
+ /* Sanity check that we're not allocating bogus sizes */
+ if (req.data.len > (128 * 1024 * 1024)) {
+ goto out;
+ }
+
+ buf = g_malloc0(req.data.len);
+ switch (req.data.flags) {
+ case VBLK_DATA_FLAGS_READ:
+ r = blk_pread(blk, off, req.data.len, buf, 0);
+ trace_bdif_vblk_read(devid == DEVID_AUX ? "aux" : "root",
+ req.data.addr, off, req.data.len, r);
+ if (r < 0) {
+ goto out;
+ }
+ cpu_physical_memory_write(req.data.addr, buf, req.data.len);
+ ret = VBLK_RET_SUCCESS;
+ break;
+ case VBLK_DATA_FLAGS_WRITE:
+ /* Not needed, iBoot only reads */
+ break;
+ default:
+ break;
+ }
+
+out:
+ g_free(buf);
+ cpu_physical_memory_write(req.retval.addr, &ret, 1);
+}
+
+static void bdif_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ VMAppleBdifState *s = opaque;
+ uint64_t devid = (offset & REG_DEVID_MASK);
+
+ trace_bdif_write(offset, size, value);
+
+ switch (offset & ~REG_DEVID_MASK) {
+ case REG_CMD:
+ switch (devid) {
+ case DEVID_ROOT:
+ vblk_cmd(devid, s->root, value, 0x0);
+ break;
+ case DEVID_AUX:
+ vblk_cmd(devid, s->aux, value, 0x0);
+ break;
+ }
+ break;
+ }
+}
+
+static const MemoryRegionOps bdif_ops = {
+ .read = bdif_read,
+ .write = bdif_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+ .valid = {
+ .min_access_size = 1,
+ .max_access_size = 8,
+ },
+ .impl = {
+ .min_access_size = 1,
+ .max_access_size = 8,
+ },
+};
+
+static void bdif_init(Object *obj)
+{
+ VMAppleBdifState *s = VMAPPLE_BDIF(obj);
+
+ memory_region_init_io(&s->mmio, obj, &bdif_ops, obj,
+ "VMApple Backdoor Interface", VMAPPLE_BDIF_SIZE);
+ sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static Property bdif_properties[] = {
+ DEFINE_PROP_DRIVE("aux", VMAppleBdifState, aux),
+ DEFINE_PROP_DRIVE("root", VMAppleBdifState, root),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void bdif_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->desc = "VMApple Backdoor Interface";
+ device_class_set_props(dc, bdif_properties);
+}
+
+static const TypeInfo bdif_info = {
+ .name = TYPE_VMAPPLE_BDIF,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(VMAppleBdifState),
+ .instance_init = bdif_init,
+ .class_init = bdif_class_init,
+};
+
+static void bdif_register_types(void)
+{
+ type_register_static(&bdif_info);
+}
+
+type_init(bdif_register_types)
diff --git a/hw/vmapple/Kconfig b/hw/vmapple/Kconfig
index a73504d599..388a2bc60c 100644
--- a/hw/vmapple/Kconfig
+++ b/hw/vmapple/Kconfig
@@ -1,3 +1,5 @@
config VMAPPLE_AES
bool
+config VMAPPLE_BDIF
+ bool
diff --git a/hw/vmapple/meson.build b/hw/vmapple/meson.build
index bcd4dcb28d..d4624713de 100644
--- a/hw/vmapple/meson.build
+++ b/hw/vmapple/meson.build
@@ -1 +1,2 @@
system_ss.add(when: 'CONFIG_VMAPPLE_AES', if_true: files('aes.c'))
+system_ss.add(when: 'CONFIG_VMAPPLE_BDIF', if_true: files('bdif.c'))
diff --git a/hw/vmapple/trace-events b/hw/vmapple/trace-events
index 03585cdf0f..45c69de2e0 100644
--- a/hw/vmapple/trace-events
+++ b/hw/vmapple/trace-events
@@ -18,3 +18,8 @@ aes_2_read(uint64_t offset, uint64_t res) "offset=0x%"PRIx64" res=0x%"PRIx64
aes_2_write_unknown(uint64_t offset) "offset=0x%"PRIx64
aes_2_write(uint64_t offset, uint64_t val) "offset=0x%"PRIx64" val=0x%"PRIx64
aes_dump_data(const char *desc, const char *hex) "%s%s"
+
+# bdif.c
+bdif_read(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
+bdif_write(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
+bdif_vblk_read(const char *dev, uint64_t addr, uint64_t offset, uint32_t len, int r) "dev=%s addr=0x%"PRIx64" off=0x%"PRIx64" size=0x%x r=%d"
--
2.39.2 (Apple Git-143)
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
On 30/08/2023 17:14, Alexander Graf wrote:
Hi Alex,
> The VMApple machine exposes AUX and ROOT block devices (as well as USB OTG
> emulation) via virtio-pci as well as a special, simple backdoor platform
> device.
>
> This patch implements this backdoor platform device to the best of my
> understanding. I left out any USB OTG parts; they're only needed for
> guest recovery and I don't understand the protocol yet.
>
> Signed-off-by: Alexander Graf <graf@amazon.com>
>
> ---
>
> v1 -> v2:
>
> - Adapt to system_ss meson.build target
> ---
> include/hw/vmapple/bdif.h | 31 +++++
> hw/vmapple/bdif.c | 245 ++++++++++++++++++++++++++++++++++++++
> hw/vmapple/Kconfig | 2 +
> hw/vmapple/meson.build | 1 +
> hw/vmapple/trace-events | 5 +
> 5 files changed, 284 insertions(+)
> create mode 100644 include/hw/vmapple/bdif.h
> create mode 100644 hw/vmapple/bdif.c
>
> diff --git a/include/hw/vmapple/bdif.h b/include/hw/vmapple/bdif.h
> new file mode 100644
> index 0000000000..65ee43457b
> --- /dev/null
> +++ b/include/hw/vmapple/bdif.h
> @@ -0,0 +1,31 @@
> +/*
> + * VMApple Backdoor Interface
> + *
> + * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
> + *
> + * 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_VMAPPLE_BDIF_H
> +#define HW_VMAPPLE_BDIF_H
> +
> +#include "hw/sysbus.h"
> +#include "qom/object.h"
> +
> +#define TYPE_VMAPPLE_BDIF "vmapple-bdif"
> +OBJECT_DECLARE_SIMPLE_TYPE(VMAppleBdifState, VMAPPLE_BDIF)
> +
> +struct VMAppleBdifState {
> + /* <private> */
> + SysBusDevice parent_obj;
> +
> + /* <public> */
> + BlockBackend *aux;
> + BlockBackend *root;
> + MemoryRegion mmio;
> +};
This looks better :). You can drop the private/public comments though.
> +
> +#define VMAPPLE_BDIF_SIZE 0x00200000
> +
> +#endif /* HW_VMAPPLE_BDIF_H */
> diff --git a/hw/vmapple/bdif.c b/hw/vmapple/bdif.c
> new file mode 100644
> index 0000000000..36b5915ff3
> --- /dev/null
> +++ b/hw/vmapple/bdif.c
> @@ -0,0 +1,245 @@
> +/*
> + * VMApple Backdoor Interface
> + *
> + * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
> + *
> + * 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 "hw/vmapple/bdif.h"
> +#include "qemu/log.h"
> +#include "qemu/module.h"
> +#include "qapi/error.h"
> +#include "trace.h"
> +#include "hw/block/block.h"
> +#include "sysemu/block-backend.h"
> +
> +#define REG_DEVID_MASK 0xffff0000
> +#define DEVID_ROOT 0x00000000
> +#define DEVID_AUX 0x00010000
> +#define DEVID_USB 0x00100000
> +
> +#define REG_STATUS 0x0
> +#define REG_STATUS_ACTIVE BIT(0)
> +#define REG_CFG 0x4
> +#define REG_CFG_ACTIVE BIT(1)
> +#define REG_UNK1 0x8
> +#define REG_BUSY 0x10
> +#define REG_BUSY_READY BIT(0)
> +#define REG_UNK2 0x400
> +#define REG_CMD 0x408
> +#define REG_NEXT_DEVICE 0x420
> +#define REG_UNK3 0x434
> +
> +typedef struct vblk_sector {
> + uint32_t pad;
> + uint32_t pad2;
> + uint32_t sector;
> + uint32_t pad3;
> +} VblkSector;
> +
> +typedef struct vblk_req_cmd {
> + uint64_t addr;
> + uint32_t len;
> + uint32_t flags;
> +} VblkReqCmd;
> +
> +typedef struct vblk_req {
> + VblkReqCmd sector;
> + VblkReqCmd data;
> + VblkReqCmd retval;
> +} VblkReq;
> +
> +#define VBLK_DATA_FLAGS_READ 0x00030001
> +#define VBLK_DATA_FLAGS_WRITE 0x00010001
> +
> +#define VBLK_RET_SUCCESS 0
> +#define VBLK_RET_FAILED 1
> +
> +static uint64_t bdif_read(void *opaque, hwaddr offset, unsigned size)
> +{
> + uint64_t ret = -1;
> + uint64_t devid = (offset & REG_DEVID_MASK);
> +
> + switch (offset & ~REG_DEVID_MASK) {
> + case REG_STATUS:
> + ret = REG_STATUS_ACTIVE;
> + break;
> + case REG_CFG:
> + ret = REG_CFG_ACTIVE;
> + break;
> + case REG_UNK1:
> + ret = 0x420;
> + break;
> + case REG_BUSY:
> + ret = REG_BUSY_READY;
> + break;
> + case REG_UNK2:
> + ret = 0x1;
> + break;
> + case REG_UNK3:
> + ret = 0x0;
> + break;
> + case REG_NEXT_DEVICE:
> + switch (devid) {
> + case DEVID_ROOT:
> + ret = 0x8000000;
> + break;
> + case DEVID_AUX:
> + ret = 0x10000;
> + break;
> + }
> + break;
> + }
> +
> + trace_bdif_read(offset, size, ret);
> + return ret;
> +}
> +
> +static void le2cpu_sector(VblkSector *sector)
> +{
> + sector->sector = le32_to_cpu(sector->sector);
> +}
> +
> +static void le2cpu_reqcmd(VblkReqCmd *cmd)
> +{
> + cmd->addr = le64_to_cpu(cmd->addr);
> + cmd->len = le32_to_cpu(cmd->len);
> + cmd->flags = le32_to_cpu(cmd->flags);
> +}
> +
> +static void le2cpu_req(VblkReq *req)
> +{
> + le2cpu_reqcmd(&req->sector);
> + le2cpu_reqcmd(&req->data);
> + le2cpu_reqcmd(&req->retval);
> +}
> +
> +static void vblk_cmd(uint64_t devid, BlockBackend *blk, uint64_t value,
> + uint64_t static_off)
> +{
> + VblkReq req;
> + VblkSector sector;
> + uint64_t off = 0;
> + char *buf = NULL;
> + uint8_t ret = VBLK_RET_FAILED;
> + int r;
> +
> + cpu_physical_memory_read(value, &req, sizeof(req));
> + le2cpu_req(&req);
> +
> + if (req.sector.len != sizeof(sector)) {
> + ret = VBLK_RET_FAILED;
> + goto out;
> + }
> +
> + /* Read the vblk command */
> + cpu_physical_memory_read(req.sector.addr, §or, sizeof(sector));
> + le2cpu_sector(§or);
> +
> + off = sector.sector * 512ULL + static_off;
> +
> + /* Sanity check that we're not allocating bogus sizes */
> + if (req.data.len > (128 * 1024 * 1024)) {
> + goto out;
> + }
> +
> + buf = g_malloc0(req.data.len);
> + switch (req.data.flags) {
> + case VBLK_DATA_FLAGS_READ:
> + r = blk_pread(blk, off, req.data.len, buf, 0);
> + trace_bdif_vblk_read(devid == DEVID_AUX ? "aux" : "root",
> + req.data.addr, off, req.data.len, r);
> + if (r < 0) {
> + goto out;
> + }
> + cpu_physical_memory_write(req.data.addr, buf, req.data.len);
> + ret = VBLK_RET_SUCCESS;
> + break;
> + case VBLK_DATA_FLAGS_WRITE:
> + /* Not needed, iBoot only reads */
> + break;
> + default:
> + break;
> + }
> +
> +out:
> + g_free(buf);
> + cpu_physical_memory_write(req.retval.addr, &ret, 1);
> +}
> +
> +static void bdif_write(void *opaque, hwaddr offset,
> + uint64_t value, unsigned size)
> +{
> + VMAppleBdifState *s = opaque;
> + uint64_t devid = (offset & REG_DEVID_MASK);
> +
> + trace_bdif_write(offset, size, value);
> +
> + switch (offset & ~REG_DEVID_MASK) {
> + case REG_CMD:
> + switch (devid) {
> + case DEVID_ROOT:
> + vblk_cmd(devid, s->root, value, 0x0);
> + break;
> + case DEVID_AUX:
> + vblk_cmd(devid, s->aux, value, 0x0);
> + break;
> + }
> + break;
> + }
> +}
> +
> +static const MemoryRegionOps bdif_ops = {
> + .read = bdif_read,
> + .write = bdif_write,
> + .endianness = DEVICE_NATIVE_ENDIAN,
Similar comment here re: DEVICE_NATIVE_ENDIAN.
> + .valid = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + },
> + .impl = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + },
> +};
> +
> +static void bdif_init(Object *obj)
> +{
> + VMAppleBdifState *s = VMAPPLE_BDIF(obj);
> +
> + memory_region_init_io(&s->mmio, obj, &bdif_ops, obj,
> + "VMApple Backdoor Interface", VMAPPLE_BDIF_SIZE);
> + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
> +}
> +
> +static Property bdif_properties[] = {
> + DEFINE_PROP_DRIVE("aux", VMAppleBdifState, aux),
> + DEFINE_PROP_DRIVE("root", VMAppleBdifState, root),
> + DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void bdif_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> +
> + dc->desc = "VMApple Backdoor Interface";
> + device_class_set_props(dc, bdif_properties);
> +}
> +
> +static const TypeInfo bdif_info = {
> + .name = TYPE_VMAPPLE_BDIF,
> + .parent = TYPE_SYS_BUS_DEVICE,
> + .instance_size = sizeof(VMAppleBdifState),
> + .instance_init = bdif_init,
> + .class_init = bdif_class_init,
> +};
> +
> +static void bdif_register_types(void)
> +{
> + type_register_static(&bdif_info);
> +}
> +
> +type_init(bdif_register_types)
And same again re: DEFINE_TYPES().
> diff --git a/hw/vmapple/Kconfig b/hw/vmapple/Kconfig
> index a73504d599..388a2bc60c 100644
> --- a/hw/vmapple/Kconfig
> +++ b/hw/vmapple/Kconfig
> @@ -1,3 +1,5 @@
> config VMAPPLE_AES
> bool
>
> +config VMAPPLE_BDIF
> + bool
> diff --git a/hw/vmapple/meson.build b/hw/vmapple/meson.build
> index bcd4dcb28d..d4624713de 100644
> --- a/hw/vmapple/meson.build
> +++ b/hw/vmapple/meson.build
> @@ -1 +1,2 @@
> system_ss.add(when: 'CONFIG_VMAPPLE_AES', if_true: files('aes.c'))
> +system_ss.add(when: 'CONFIG_VMAPPLE_BDIF', if_true: files('bdif.c'))
> diff --git a/hw/vmapple/trace-events b/hw/vmapple/trace-events
> index 03585cdf0f..45c69de2e0 100644
> --- a/hw/vmapple/trace-events
> +++ b/hw/vmapple/trace-events
> @@ -18,3 +18,8 @@ aes_2_read(uint64_t offset, uint64_t res) "offset=0x%"PRIx64" res=0x%"PRIx64
> aes_2_write_unknown(uint64_t offset) "offset=0x%"PRIx64
> aes_2_write(uint64_t offset, uint64_t val) "offset=0x%"PRIx64" val=0x%"PRIx64
> aes_dump_data(const char *desc, const char *hex) "%s%s"
> +
> +# bdif.c
> +bdif_read(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
> +bdif_write(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
> +bdif_vblk_read(const char *dev, uint64_t addr, uint64_t offset, uint32_t len, int r) "dev=%s addr=0x%"PRIx64" off=0x%"PRIx64" size=0x%x r=%d"
Out of curiosity I see that this and the AES device both make use of
cpu_physical_memory_read() and cpu_physical_memory_write(): would it make sense to
pass in a target MemoryRegion or use an AddressSpace here?
ATB,
Mark.
On Wed, Aug 30, 2023 at 04:14:21PM +0000, Alexander Graf wrote:
> The VMApple machine exposes AUX and ROOT block devices (as well as USB OTG
> emulation) via virtio-pci as well as a special, simple backdoor platform
> device.
>
> This patch implements this backdoor platform device to the best of my
> understanding. I left out any USB OTG parts; they're only needed for
> guest recovery and I don't understand the protocol yet.
Out of curiosity: This interface has no way to check the size of the
block device? I guess that's not necessary in a boot loader that just
parses a boot record and then loads the next stage...
I posted comments below. Otherwise:
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
>
> Signed-off-by: Alexander Graf <graf@amazon.com>
>
> ---
>
> v1 -> v2:
>
> - Adapt to system_ss meson.build target
> ---
> include/hw/vmapple/bdif.h | 31 +++++
> hw/vmapple/bdif.c | 245 ++++++++++++++++++++++++++++++++++++++
> hw/vmapple/Kconfig | 2 +
> hw/vmapple/meson.build | 1 +
> hw/vmapple/trace-events | 5 +
> 5 files changed, 284 insertions(+)
> create mode 100644 include/hw/vmapple/bdif.h
> create mode 100644 hw/vmapple/bdif.c
>
> diff --git a/include/hw/vmapple/bdif.h b/include/hw/vmapple/bdif.h
> new file mode 100644
> index 0000000000..65ee43457b
> --- /dev/null
> +++ b/include/hw/vmapple/bdif.h
> @@ -0,0 +1,31 @@
> +/*
> + * VMApple Backdoor Interface
> + *
> + * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
> + *
> + * 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_VMAPPLE_BDIF_H
> +#define HW_VMAPPLE_BDIF_H
> +
> +#include "hw/sysbus.h"
> +#include "qom/object.h"
> +
> +#define TYPE_VMAPPLE_BDIF "vmapple-bdif"
> +OBJECT_DECLARE_SIMPLE_TYPE(VMAppleBdifState, VMAPPLE_BDIF)
> +
> +struct VMAppleBdifState {
> + /* <private> */
> + SysBusDevice parent_obj;
> +
> + /* <public> */
> + BlockBackend *aux;
> + BlockBackend *root;
> + MemoryRegion mmio;
> +};
> +
> +#define VMAPPLE_BDIF_SIZE 0x00200000
> +
> +#endif /* HW_VMAPPLE_BDIF_H */
> diff --git a/hw/vmapple/bdif.c b/hw/vmapple/bdif.c
> new file mode 100644
> index 0000000000..36b5915ff3
> --- /dev/null
> +++ b/hw/vmapple/bdif.c
> @@ -0,0 +1,245 @@
> +/*
> + * VMApple Backdoor Interface
> + *
> + * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
> + *
> + * 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 "hw/vmapple/bdif.h"
> +#include "qemu/log.h"
> +#include "qemu/module.h"
> +#include "qapi/error.h"
> +#include "trace.h"
> +#include "hw/block/block.h"
> +#include "sysemu/block-backend.h"
> +
> +#define REG_DEVID_MASK 0xffff0000
> +#define DEVID_ROOT 0x00000000
> +#define DEVID_AUX 0x00010000
> +#define DEVID_USB 0x00100000
> +
> +#define REG_STATUS 0x0
> +#define REG_STATUS_ACTIVE BIT(0)
> +#define REG_CFG 0x4
> +#define REG_CFG_ACTIVE BIT(1)
> +#define REG_UNK1 0x8
> +#define REG_BUSY 0x10
> +#define REG_BUSY_READY BIT(0)
> +#define REG_UNK2 0x400
> +#define REG_CMD 0x408
> +#define REG_NEXT_DEVICE 0x420
> +#define REG_UNK3 0x434
> +
> +typedef struct vblk_sector {
> + uint32_t pad;
> + uint32_t pad2;
> + uint32_t sector;
> + uint32_t pad3;
> +} VblkSector;
> +
> +typedef struct vblk_req_cmd {
> + uint64_t addr;
> + uint32_t len;
> + uint32_t flags;
> +} VblkReqCmd;
> +
> +typedef struct vblk_req {
> + VblkReqCmd sector;
> + VblkReqCmd data;
> + VblkReqCmd retval;
> +} VblkReq;
> +
> +#define VBLK_DATA_FLAGS_READ 0x00030001
> +#define VBLK_DATA_FLAGS_WRITE 0x00010001
> +
> +#define VBLK_RET_SUCCESS 0
> +#define VBLK_RET_FAILED 1
> +
> +static uint64_t bdif_read(void *opaque, hwaddr offset, unsigned size)
> +{
> + uint64_t ret = -1;
> + uint64_t devid = (offset & REG_DEVID_MASK);
> +
> + switch (offset & ~REG_DEVID_MASK) {
> + case REG_STATUS:
> + ret = REG_STATUS_ACTIVE;
> + break;
> + case REG_CFG:
> + ret = REG_CFG_ACTIVE;
> + break;
> + case REG_UNK1:
> + ret = 0x420;
> + break;
> + case REG_BUSY:
> + ret = REG_BUSY_READY;
> + break;
> + case REG_UNK2:
> + ret = 0x1;
> + break;
> + case REG_UNK3:
> + ret = 0x0;
> + break;
> + case REG_NEXT_DEVICE:
> + switch (devid) {
> + case DEVID_ROOT:
> + ret = 0x8000000;
> + break;
> + case DEVID_AUX:
> + ret = 0x10000;
> + break;
> + }
> + break;
> + }
> +
> + trace_bdif_read(offset, size, ret);
> + return ret;
> +}
> +
> +static void le2cpu_sector(VblkSector *sector)
> +{
> + sector->sector = le32_to_cpu(sector->sector);
> +}
> +
> +static void le2cpu_reqcmd(VblkReqCmd *cmd)
> +{
> + cmd->addr = le64_to_cpu(cmd->addr);
> + cmd->len = le32_to_cpu(cmd->len);
> + cmd->flags = le32_to_cpu(cmd->flags);
> +}
> +
> +static void le2cpu_req(VblkReq *req)
> +{
> + le2cpu_reqcmd(&req->sector);
> + le2cpu_reqcmd(&req->data);
> + le2cpu_reqcmd(&req->retval);
> +}
> +
> +static void vblk_cmd(uint64_t devid, BlockBackend *blk, uint64_t value,
> + uint64_t static_off)
> +{
> + VblkReq req;
> + VblkSector sector;
> + uint64_t off = 0;
> + char *buf = NULL;
> + uint8_t ret = VBLK_RET_FAILED;
> + int r;
> +
> + cpu_physical_memory_read(value, &req, sizeof(req));
Please zero req first so that when value is bogus and
cpu_physical_memory_read() does not store to &req, we don't process
req's uninitialized stack memory:
VblkReq req = {};
> + le2cpu_req(&req);
> +
> + if (req.sector.len != sizeof(sector)) {
> + ret = VBLK_RET_FAILED;
> + goto out;
> + }
> +
> + /* Read the vblk command */
> + cpu_physical_memory_read(req.sector.addr, §or, sizeof(sector));
Same here:
VblkSectors sector = {};
> + le2cpu_sector(§or);
> +
> + off = sector.sector * 512ULL + static_off;
> +
> + /* Sanity check that we're not allocating bogus sizes */
> + if (req.data.len > (128 * 1024 * 1024)) {
> + goto out;
> + }
> +
> + buf = g_malloc0(req.data.len);
> + switch (req.data.flags) {
> + case VBLK_DATA_FLAGS_READ:
> + r = blk_pread(blk, off, req.data.len, buf, 0);
> + trace_bdif_vblk_read(devid == DEVID_AUX ? "aux" : "root",
> + req.data.addr, off, req.data.len, r);
> + if (r < 0) {
> + goto out;
> + }
> + cpu_physical_memory_write(req.data.addr, buf, req.data.len);
> + ret = VBLK_RET_SUCCESS;
> + break;
> + case VBLK_DATA_FLAGS_WRITE:
> + /* Not needed, iBoot only reads */
> + break;
> + default:
> + break;
> + }
> +
> +out:
> + g_free(buf);
> + cpu_physical_memory_write(req.retval.addr, &ret, 1);
> +}
> +
> +static void bdif_write(void *opaque, hwaddr offset,
> + uint64_t value, unsigned size)
> +{
> + VMAppleBdifState *s = opaque;
> + uint64_t devid = (offset & REG_DEVID_MASK);
> +
> + trace_bdif_write(offset, size, value);
> +
> + switch (offset & ~REG_DEVID_MASK) {
> + case REG_CMD:
> + switch (devid) {
> + case DEVID_ROOT:
> + vblk_cmd(devid, s->root, value, 0x0);
> + break;
> + case DEVID_AUX:
> + vblk_cmd(devid, s->aux, value, 0x0);
> + break;
> + }
> + break;
> + }
> +}
> +
> +static const MemoryRegionOps bdif_ops = {
> + .read = bdif_read,
> + .write = bdif_write,
> + .endianness = DEVICE_NATIVE_ENDIAN,
> + .valid = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + },
> + .impl = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + },
> +};
> +
> +static void bdif_init(Object *obj)
> +{
> + VMAppleBdifState *s = VMAPPLE_BDIF(obj);
> +
> + memory_region_init_io(&s->mmio, obj, &bdif_ops, obj,
> + "VMApple Backdoor Interface", VMAPPLE_BDIF_SIZE);
> + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
> +}
> +
> +static Property bdif_properties[] = {
> + DEFINE_PROP_DRIVE("aux", VMAppleBdifState, aux),
> + DEFINE_PROP_DRIVE("root", VMAppleBdifState, root),
> + DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void bdif_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> +
> + dc->desc = "VMApple Backdoor Interface";
> + device_class_set_props(dc, bdif_properties);
> +}
> +
> +static const TypeInfo bdif_info = {
> + .name = TYPE_VMAPPLE_BDIF,
> + .parent = TYPE_SYS_BUS_DEVICE,
> + .instance_size = sizeof(VMAppleBdifState),
> + .instance_init = bdif_init,
> + .class_init = bdif_class_init,
> +};
> +
> +static void bdif_register_types(void)
> +{
> + type_register_static(&bdif_info);
> +}
> +
> +type_init(bdif_register_types)
> diff --git a/hw/vmapple/Kconfig b/hw/vmapple/Kconfig
> index a73504d599..388a2bc60c 100644
> --- a/hw/vmapple/Kconfig
> +++ b/hw/vmapple/Kconfig
> @@ -1,3 +1,5 @@
> config VMAPPLE_AES
> bool
>
> +config VMAPPLE_BDIF
> + bool
> diff --git a/hw/vmapple/meson.build b/hw/vmapple/meson.build
> index bcd4dcb28d..d4624713de 100644
> --- a/hw/vmapple/meson.build
> +++ b/hw/vmapple/meson.build
> @@ -1 +1,2 @@
> system_ss.add(when: 'CONFIG_VMAPPLE_AES', if_true: files('aes.c'))
> +system_ss.add(when: 'CONFIG_VMAPPLE_BDIF', if_true: files('bdif.c'))
> diff --git a/hw/vmapple/trace-events b/hw/vmapple/trace-events
> index 03585cdf0f..45c69de2e0 100644
> --- a/hw/vmapple/trace-events
> +++ b/hw/vmapple/trace-events
> @@ -18,3 +18,8 @@ aes_2_read(uint64_t offset, uint64_t res) "offset=0x%"PRIx64" res=0x%"PRIx64
> aes_2_write_unknown(uint64_t offset) "offset=0x%"PRIx64
> aes_2_write(uint64_t offset, uint64_t val) "offset=0x%"PRIx64" val=0x%"PRIx64
> aes_dump_data(const char *desc, const char *hex) "%s%s"
> +
> +# bdif.c
> +bdif_read(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
> +bdif_write(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64" size=0x%x value=0x%"PRIx64
> +bdif_vblk_read(const char *dev, uint64_t addr, uint64_t offset, uint32_t len, int r) "dev=%s addr=0x%"PRIx64" off=0x%"PRIx64" size=0x%x r=%d"
> --
> 2.39.2 (Apple Git-143)
>
>
>
>
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>
>
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