* [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu ***
@ 2017-11-16 20:44 Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
` (3 more replies)
0 siblings, 4 replies; 14+ messages in thread
From: Changpeng Liu @ 2017-11-16 20:44 UTC (permalink / raw)
To: changpeng.liu, qemu-devel
Cc: stefanha, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
Although virtio scsi specification was designed as a replacement for virtio_blk,
there are still many users using virtio_blk. Qemu 2.9 introduced a new device
vhost user scsi which can process I/O in user space for virtio_scsi, this commit
introduces a new vhost user block host device, which can support virtio_blk in
Guest OS, and I/O processing in another I/O target.
Due to the limitation for virtio_blk specification, virtio_blk device cannot get
block information such as capacity, block size etc via the specification, several
new vhost user messages were added to deliver virtio config space
information between Qemu and I/O target, VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG
messages used for get/set config space from/to I/O target, VHOST_USER_SET_CONFIG_FD
was added for event notifier in case the change of virtio config space. Also, those
messages can be used for vhost device live migration as well.
V4-v5: add header offset and size for virtio config space.
v3-v4: refactoring the vhost user block example patch based on new libvhost-user library.
v2-v3: add new vhost user message to get/set virtio config space.
Changpeng Liu (4):
vhost-user: add new vhost user messages to support virtio config space
vhost-user-blk: introduce a new vhost-user-blk host device
contrib/libvhost-user: enable virtio config space messages
contrib/vhost-user-blk: introduce a vhost-user-blk sample application
.gitignore | 1 +
Makefile | 3 +
Makefile.objs | 1 +
contrib/libvhost-user/libvhost-user.c | 79 +++++
contrib/libvhost-user/libvhost-user.h | 24 +-
contrib/vhost-user-blk/Makefile.objs | 1 +
contrib/vhost-user-blk/vhost-user-blk.c | 536 ++++++++++++++++++++++++++++++++
default-configs/pci.mak | 1 +
docs/interop/vhost-user.txt | 39 +++
hw/block/Makefile.objs | 3 +
hw/block/vhost-user-blk.c | 356 +++++++++++++++++++++
hw/virtio/vhost-user.c | 98 ++++++
hw/virtio/vhost.c | 63 ++++
hw/virtio/virtio-pci.c | 55 ++++
hw/virtio/virtio-pci.h | 18 ++
include/hw/virtio/vhost-backend.h | 8 +
include/hw/virtio/vhost-user-blk.h | 42 +++
include/hw/virtio/vhost.h | 16 +
18 files changed, 1343 insertions(+), 1 deletion(-)
create mode 100644 contrib/vhost-user-blk/Makefile.objs
create mode 100644 contrib/vhost-user-blk/vhost-user-blk.c
create mode 100644 hw/block/vhost-user-blk.c
create mode 100644 include/hw/virtio/vhost-user-blk.h
--
1.9.3
^ permalink raw reply [flat|nested] 14+ messages in thread
* [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
@ 2017-11-16 20:44 ` Changpeng Liu
2017-11-20 16:26 ` Stefan Hajnoczi
2017-11-22 14:49 ` Michael S. Tsirkin
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 2/4] vhost-user-blk: introduce a new vhost-user-blk host device Changpeng Liu
` (2 subsequent siblings)
3 siblings, 2 replies; 14+ messages in thread
From: Changpeng Liu @ 2017-11-16 20:44 UTC (permalink / raw)
To: changpeng.liu, qemu-devel
Cc: stefanha, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
used for live migration of vhost user devices, also vhost user devices
can benefit from the messages to get/set virtio config space from/to the
I/O target. For the purpose to support virtio config space change,
VHOST_USER_SET_CONFIG_FD message is added as the event notifier
in case virtio config space change in the I/O target.
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
docs/interop/vhost-user.txt | 39 ++++++++++++++++
hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++
hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
include/hw/virtio/vhost-backend.h | 8 ++++
include/hw/virtio/vhost.h | 16 +++++++
5 files changed, 224 insertions(+)
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index 954771d..1b98388 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -116,6 +116,16 @@ Depending on the request type, payload can be:
- 3: IOTLB invalidate
- 4: IOTLB access fail
+ * Virtio device config space
+ ---------------------------
+ | offset | size | payload |
+ ---------------------------
+
+ Offset: a 32-bit offset of virtio device's configuration space
+ Size: a 32-bit size of configuration space that master wanted to change
+ Payload: a 256-bytes array holding the contents of the virtio
+ device's configuration space
+
In QEMU the vhost-user message is implemented with the following struct:
typedef struct VhostUserMsg {
@@ -129,6 +139,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
+ VhostUserConfig config;
};
} QEMU_PACKED VhostUserMsg;
@@ -596,6 +607,34 @@ Master message types
and expect this message once (per VQ) during device configuration
(ie. before the master starts the VQ).
+ * VHOST_USER_GET_CONFIG
+ Id: 24
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+
+ Submitted by the vhost-user master to fetch the contents of the virtio
+ device configuration space. The vhost-user master may cache the contents
+ to avoid repeated VHOST_USER_GET_CONFIG calls.
+
+* VHOST_USER_SET_CONFIG
+ Id: 25
+ Equivalent ioctl: N/A
+ Master payload: virtio device config space
+
+ Submitted by the vhost-user master when the Guest changes the virtio
+ device configuration space and also can be used for live migration
+ on the destination host.
+
+* VHOST_USER_SET_CONFIG_FD
+ Id: 26
+ Equivalent ioctl: N/A
+ Master payload: N/A
+
+ Sets the notifier file descriptor, which is passed as ancillary data.
+ The vhost-user slave uses the file descriptor to notify the vhost-user
+ master of changes to the virtio configuration space. The vhost-user
+ master can read the virtio configuration space to get the latest update.
+
Slave message types
-------------------
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 093675e..ef1687b 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -26,6 +26,11 @@
#define VHOST_MEMORY_MAX_NREGIONS 8
#define VHOST_USER_F_PROTOCOL_FEATURES 30
+/*
+ * Maximum size of virtio device config space
+ */
+#define VHOST_USER_MAX_CONFIG_SIZE 256
+
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -65,6 +70,9 @@ typedef enum VhostUserRequest {
VHOST_USER_SET_SLAVE_REQ_FD = 21,
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
+ VHOST_USER_GET_CONFIG = 24,
+ VHOST_USER_SET_CONFIG = 25,
+ VHOST_USER_SET_CONFIG_FD = 26,
VHOST_USER_MAX
} VhostUserRequest;
@@ -92,6 +100,12 @@ typedef struct VhostUserLog {
uint64_t mmap_offset;
} VhostUserLog;
+typedef struct VhostUserConfig {
+ uint32_t offset;
+ uint32_t size;
+ uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+} VhostUserConfig;
+
typedef struct VhostUserMsg {
VhostUserRequest request;
@@ -109,6 +123,7 @@ typedef struct VhostUserMsg {
VhostUserMemory memory;
VhostUserLog log;
struct vhost_iotlb_msg iotlb;
+ VhostUserConfig config;
} payload;
} QEMU_PACKED VhostUserMsg;
@@ -922,6 +937,86 @@ static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabled)
/* No-op as the receive channel is not dedicated to IOTLB messages. */
}
+static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
+ size_t config_len)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_GET_CONFIG,
+ .flags = VHOST_USER_VERSION,
+ .size = sizeof(msg.payload.config),
+ };
+
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ return -1;
+ }
+
+ if (vhost_user_read(dev, &msg) < 0) {
+ return -1;
+ }
+
+ if (msg.request != VHOST_USER_GET_CONFIG) {
+ error_report("Received unexpected msg type. Expected %d received %d",
+ VHOST_USER_GET_CONFIG, msg.request);
+ return -1;
+ }
+
+ if (msg.size != sizeof(msg.payload.config)) {
+ error_report("Received bad msg size.");
+ return -1;
+ }
+
+ memcpy(config, msg.payload.config.region, config_len);
+
+ return 0;
+}
+
+static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size)
+{
+ uint8_t *p;
+ bool reply_supported = virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_REPLY_ACK);
+
+ VhostUserMsg msg = {
+ .request = VHOST_USER_SET_CONFIG,
+ .flags = VHOST_USER_VERSION,
+ .size = sizeof(msg.payload.config),
+ };
+
+ if (reply_supported) {
+ msg.flags |= VHOST_USER_NEED_REPLY_MASK;
+ }
+
+ msg.payload.config.offset = offset;
+ msg.payload.config.size = size;
+ p = msg.payload.config.region;
+ memcpy(p + offset, config + offset, size);
+
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ return -1;
+ }
+
+ if (reply_supported) {
+ return process_message_reply(dev, &msg);
+ }
+
+ return 0;
+}
+
+static int vhost_user_set_config_fd(struct vhost_dev *dev, int fd)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_SET_CONFIG_FD,
+ .flags = VHOST_USER_VERSION,
+ };
+
+ if (vhost_user_write(dev, &msg, &fd, 1) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
@@ -948,4 +1043,7 @@ const VhostOps user_ops = {
.vhost_net_set_mtu = vhost_user_net_set_mtu,
.vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
.vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
+ .vhost_get_config = vhost_user_get_config,
+ .vhost_set_config = vhost_user_set_config,
+ .vhost_set_config_fd = vhost_user_set_config_fd,
};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ddc42f0..744ca85 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1354,6 +1354,9 @@ void vhost_dev_cleanup(struct vhost_dev *hdev)
for (i = 0; i < hdev->nvqs; ++i) {
vhost_virtqueue_cleanup(hdev->vqs + i);
}
+ if (hdev->config_ops) {
+ event_notifier_cleanup(&hdev->config_notifier);
+ }
if (hdev->mem) {
/* those are only safe after successful init */
memory_listener_unregister(&hdev->memory_listener);
@@ -1501,6 +1504,66 @@ void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
}
}
+int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
+ size_t config_len)
+{
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_get_config) {
+ return hdev->vhost_ops->vhost_get_config(hdev, config, config_len);
+ }
+
+ return 0;
+}
+
+int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *config,
+ uint32_t offset, uint32_t size)
+{
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_set_config) {
+ return hdev->vhost_ops->vhost_set_config(hdev, config, offset, size);
+ }
+
+ return 0;
+}
+
+static void vhost_dev_config_notifier_read(EventNotifier *n)
+{
+ struct vhost_dev *hdev = container_of(n, struct vhost_dev,
+ config_notifier);
+
+ if (event_notifier_test_and_clear(n)) {
+ if (hdev->config_ops) {
+ hdev->config_ops->vhost_dev_config_notifier(hdev);
+ }
+ }
+}
+
+int vhost_dev_set_config_notifier(struct vhost_dev *hdev,
+ const VhostDevConfigOps *ops)
+{
+ int r, fd;
+
+ assert(hdev->vhost_ops);
+
+ r = event_notifier_init(&hdev->config_notifier, 0);
+ if (r < 0) {
+ return r;
+ }
+
+ hdev->config_ops = ops;
+ event_notifier_set_handler(&hdev->config_notifier,
+ vhost_dev_config_notifier_read);
+
+ if (hdev->vhost_ops->vhost_set_config_fd) {
+ fd = event_notifier_get_fd(&hdev->config_notifier);
+ return hdev->vhost_ops->vhost_set_config_fd(hdev, fd);
+ }
+
+ return 0;
+}
+
/* Host notifiers must be enabled at this point. */
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
{
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index a7a5f22..3ab0b79 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -84,6 +84,11 @@ typedef void (*vhost_set_iotlb_callback_op)(struct vhost_dev *dev,
int enabled);
typedef int (*vhost_send_device_iotlb_msg_op)(struct vhost_dev *dev,
struct vhost_iotlb_msg *imsg);
+typedef int (*vhost_set_config_op)(struct vhost_dev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size);
+typedef int (*vhost_get_config_op)(struct vhost_dev *dev, uint8_t *config,
+ size_t config_len);
+typedef int (*vhost_set_config_fd_op)(struct vhost_dev *dev, int fd);
typedef struct VhostOps {
VhostBackendType backend_type;
@@ -118,6 +123,9 @@ typedef struct VhostOps {
vhost_vsock_set_running_op vhost_vsock_set_running;
vhost_set_iotlb_callback_op vhost_set_iotlb_callback;
vhost_send_device_iotlb_msg_op vhost_send_device_iotlb_msg;
+ vhost_get_config_op vhost_get_config;
+ vhost_set_config_op vhost_set_config;
+ vhost_set_config_fd_op vhost_set_config_fd;
} VhostOps;
extern const VhostOps user_ops;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 467dc77..593056d 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -46,6 +46,12 @@ struct vhost_iommu {
QLIST_ENTRY(vhost_iommu) iommu_next;
};
+typedef struct VhostDevConfigOps {
+ /* Vhost device config space changed callback
+ */
+ void (*vhost_dev_config_notifier)(struct vhost_dev *dev);
+} VhostDevConfigOps;
+
struct vhost_memory;
struct vhost_dev {
VirtIODevice *vdev;
@@ -76,6 +82,8 @@ struct vhost_dev {
QLIST_ENTRY(vhost_dev) entry;
QLIST_HEAD(, vhost_iommu) iommu_list;
IOMMUNotifier n;
+ EventNotifier config_notifier;
+ const VhostDevConfigOps *config_ops;
};
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
@@ -106,4 +114,12 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
struct vhost_vring_file *file);
int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
+int vhost_dev_get_config(struct vhost_dev *dev, uint8_t *config,
+ size_t config_len);
+int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size);
+/* notifier callback in case vhost device config space changed
+ */
+int vhost_dev_set_config_notifier(struct vhost_dev *dev,
+ const VhostDevConfigOps *ops);
#endif
--
1.9.3
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [Qemu-devel] [PATCH v5 2/4] vhost-user-blk: introduce a new vhost-user-blk host device
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
@ 2017-11-16 20:44 ` Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 3/4] contrib/libvhost-user: enable virtio config space messages Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 4/4] contrib/vhost-user-blk: introduce a vhost-user-blk sample application Changpeng Liu
3 siblings, 0 replies; 14+ messages in thread
From: Changpeng Liu @ 2017-11-16 20:44 UTC (permalink / raw)
To: changpeng.liu, qemu-devel
Cc: stefanha, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
This commit introduces a new vhost-user device for block, it uses a
chardev to connect with the backend, same with Qemu virito-blk device,
Guest OS still uses the virtio-blk frontend driver.
To use it, start Qemu with command line like this:
qemu-system-x86_64 \
-chardev socket,id=char0,path=/path/vhost.socket \
-device vhost-user-blk-pci,chardev=char0,num-queues=2, \
bootindex=2... \
Users can use different parameters for `num-queues` and `bootindex`.
Different with exist Qemu virtio-blk host device, it makes more easy
for users to implement their own I/O processing logic, such as all
user space I/O stack against hardware block device. It uses the new
vhost messages(VHOST_USER_GET_CONFIG) to get block virtio config
information from backend process.
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
default-configs/pci.mak | 1 +
hw/block/Makefile.objs | 3 +
hw/block/vhost-user-blk.c | 356 +++++++++++++++++++++++++++++++++++++
hw/virtio/virtio-pci.c | 55 ++++++
hw/virtio/virtio-pci.h | 18 ++
include/hw/virtio/vhost-user-blk.h | 42 +++++
6 files changed, 475 insertions(+)
create mode 100644 hw/block/vhost-user-blk.c
create mode 100644 include/hw/virtio/vhost-user-blk.h
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index e514bde..49a0f28 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -43,3 +43,4 @@ CONFIG_VGA_PCI=y
CONFIG_IVSHMEM_DEVICE=$(CONFIG_IVSHMEM)
CONFIG_ROCKER=y
CONFIG_VHOST_USER_SCSI=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
+CONFIG_VHOST_USER_BLK=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
index e0ed980..4c19a58 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -13,3 +13,6 @@ obj-$(CONFIG_SH4) += tc58128.o
obj-$(CONFIG_VIRTIO) += virtio-blk.o
obj-$(CONFIG_VIRTIO) += dataplane/
+ifeq ($(CONFIG_VIRTIO),y)
+obj-$(CONFIG_VHOST_USER_BLK) += vhost-user-blk.o
+endif
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
new file mode 100644
index 0000000..71bd6e7
--- /dev/null
+++ b/hw/block/vhost-user-blk.c
@@ -0,0 +1,356 @@
+/*
+ * vhost-user-blk host device
+ *
+ * Copyright(C) 2017 Intel Corporation.
+ *
+ * Authors:
+ * Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * Largely based on the "vhost-user-scsi.c" and "vhost-scsi.c" implemented by:
+ * Felipe Franciosi <felipe@nutanix.com>
+ * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
+ * Nicholas Bellinger <nab@risingtidesystems.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/typedefs.h"
+#include "qemu/cutils.h"
+#include "qom/object.h"
+#include "hw/qdev-core.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user-blk.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+
+static const int user_feature_bits[] = {
+ VIRTIO_BLK_F_SIZE_MAX,
+ VIRTIO_BLK_F_SEG_MAX,
+ VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_BLK_SIZE,
+ VIRTIO_BLK_F_TOPOLOGY,
+ VIRTIO_BLK_F_MQ,
+ VIRTIO_BLK_F_RO,
+ VIRTIO_BLK_F_FLUSH,
+ VIRTIO_BLK_F_CONFIG_WCE,
+ VIRTIO_F_VERSION_1,
+ VIRTIO_RING_F_INDIRECT_DESC,
+ VIRTIO_RING_F_EVENT_IDX,
+ VIRTIO_F_NOTIFY_ON_EMPTY,
+ VHOST_INVALID_FEATURE_BIT
+};
+
+static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+ memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
+}
+
+static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
+ int ret;
+
+ if (blkcfg->wce == s->blkcfg.wce) {
+ return;
+ }
+
+ ret = vhost_dev_set_config(&s->dev, config,
+ offsetof(struct virtio_blk_config, wce),
+ sizeof(blkcfg->wce));
+ if (ret) {
+ error_report("set device config space failed");
+ return;
+ }
+
+ s->blkcfg.wce = blkcfg->wce;
+}
+
+static void vhost_user_blk_handle_config_change(struct vhost_dev *dev)
+{
+ int ret;
+ struct virtio_blk_config blkcfg;
+ VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
+
+ ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
+ sizeof(struct virtio_blk_config));
+ if (ret < 0) {
+ error_report("get config space failed");
+ return;
+ }
+
+ /* valid for resize only */
+ if (blkcfg.capacity != s->blkcfg.capacity) {
+ s->blkcfg.capacity = blkcfg.capacity;
+ memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config));
+ virtio_notify_config(dev->vdev);
+ }
+}
+
+const VhostDevConfigOps blk_ops = {
+ .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
+};
+
+static void vhost_user_blk_start(VirtIODevice *vdev)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+ int i, ret;
+
+ if (!k->set_guest_notifiers) {
+ error_report("binding does not support guest notifiers");
+ return;
+ }
+
+ ret = vhost_dev_enable_notifiers(&s->dev, vdev);
+ if (ret < 0) {
+ error_report("Error enabling host notifiers: %d", -ret);
+ return;
+ }
+
+ ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
+ if (ret < 0) {
+ error_report("Error binding guest notifier: %d", -ret);
+ goto err_host_notifiers;
+ }
+
+ s->dev.acked_features = vdev->guest_features;
+ ret = vhost_dev_start(&s->dev, vdev);
+ if (ret < 0) {
+ error_report("Error starting vhost: %d", -ret);
+ goto err_guest_notifiers;
+ }
+
+ /* guest_notifier_mask/pending not used yet, so just unmask
+ * everything here. virtio-pci will do the right thing by
+ * enabling/disabling irqfd.
+ */
+ for (i = 0; i < s->dev.nvqs; i++) {
+ vhost_virtqueue_mask(&s->dev, vdev, i, false);
+ }
+
+ return;
+
+err_guest_notifiers:
+ k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+err_host_notifiers:
+ vhost_dev_disable_notifiers(&s->dev, vdev);
+}
+
+static void vhost_user_blk_stop(VirtIODevice *vdev)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+ int ret;
+
+ if (!k->set_guest_notifiers) {
+ return;
+ }
+
+ vhost_dev_stop(&s->dev, vdev);
+
+ ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+ if (ret < 0) {
+ error_report("vhost guest notifier cleanup failed: %d", ret);
+ return;
+ }
+
+ vhost_dev_disable_notifiers(&s->dev, vdev);
+}
+
+static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
+
+ if (!vdev->vm_running) {
+ should_start = false;
+ }
+
+ if (s->dev.started == should_start) {
+ return;
+ }
+
+ if (should_start) {
+ vhost_user_blk_start(vdev);
+ } else {
+ vhost_user_blk_stop(vdev);
+ }
+
+}
+
+static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
+ uint64_t features,
+ Error **errp)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ uint64_t get_features;
+
+ /* Turn on pre-defined features */
+ virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
+ virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
+ virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
+ virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
+ virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
+
+ if (s->config_wce) {
+ virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
+ }
+ if (s->config_ro) {
+ virtio_add_feature(&features, VIRTIO_BLK_F_RO);
+ }
+ if (s->num_queues > 1) {
+ virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
+ }
+
+ get_features = vhost_get_features(&s->dev, user_feature_bits, features);
+
+ return get_features;
+}
+
+static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+
+}
+
+static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ int i, ret;
+
+ if (!s->chardev.chr) {
+ error_setg(errp, "vhost-user-blk: chardev is mandatory");
+ return;
+ }
+
+ if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
+ error_setg(errp, "vhost-user-blk: invalid number of IO queues");
+ return;
+ }
+
+ if (!s->queue_size) {
+ error_setg(errp, "vhost-user-blk: queue size must be non-zero");
+ return;
+ }
+
+ virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
+ sizeof(struct virtio_blk_config));
+
+ for (i = 0; i < s->num_queues; i++) {
+ virtio_add_queue(vdev, s->queue_size,
+ vhost_user_blk_handle_output);
+ }
+
+ s->dev.nvqs = s->num_queues;
+ s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
+ s->dev.vq_index = 0;
+ s->dev.backend_features = 0;
+
+ ret = vhost_dev_init(&s->dev, &s->chardev, VHOST_BACKEND_TYPE_USER, 0);
+ if (ret < 0) {
+ error_setg(errp, "vhost-user-blk: vhost initialization failed: %s",
+ strerror(-ret));
+ goto virtio_err;
+ }
+
+ ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
+ sizeof(struct virtio_blk_config));
+ if (ret < 0) {
+ error_setg(errp, "vhost-user-blk: get block config failed");
+ goto vhost_err;
+ }
+
+ if (s->blkcfg.num_queues != s->num_queues) {
+ s->blkcfg.num_queues = s->num_queues;
+ }
+
+ vhost_dev_set_config_notifier(&s->dev, &blk_ops);
+
+ return;
+
+vhost_err:
+ vhost_dev_cleanup(&s->dev);
+virtio_err:
+ g_free(s->dev.vqs);
+ virtio_cleanup(vdev);
+}
+
+static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserBlk *s = VHOST_USER_BLK(dev);
+
+ vhost_user_blk_set_status(vdev, 0);
+ vhost_dev_cleanup(&s->dev);
+ g_free(s->dev.vqs);
+ virtio_cleanup(vdev);
+}
+
+static void vhost_user_blk_instance_init(Object *obj)
+{
+ VHostUserBlk *s = VHOST_USER_BLK(obj);
+
+ device_add_bootindex_property(obj, &s->bootindex, "bootindex",
+ "/disk@0,0", DEVICE(obj), NULL);
+}
+
+static const VMStateDescription vmstate_vhost_user_blk = {
+ .name = "vhost-user-blk",
+ .minimum_version_id = 1,
+ .version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_VIRTIO_DEVICE,
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static Property vhost_user_blk_properties[] = {
+ DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
+ DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1),
+ DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
+ DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
+ DEFINE_PROP_BIT("config-ro", VHostUserBlk, config_ro, 0, false),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+ dc->props = vhost_user_blk_properties;
+ dc->vmsd = &vmstate_vhost_user_blk;
+ set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+ vdc->realize = vhost_user_blk_device_realize;
+ vdc->unrealize = vhost_user_blk_device_unrealize;
+ vdc->get_config = vhost_user_blk_update_config;
+ vdc->set_config = vhost_user_blk_set_config;
+ vdc->get_features = vhost_user_blk_get_features;
+ vdc->set_status = vhost_user_blk_set_status;
+}
+
+static const TypeInfo vhost_user_blk_info = {
+ .name = TYPE_VHOST_USER_BLK,
+ .parent = TYPE_VIRTIO_DEVICE,
+ .instance_size = sizeof(VHostUserBlk),
+ .instance_init = vhost_user_blk_instance_init,
+ .class_init = vhost_user_blk_class_init,
+};
+
+static void virtio_register_types(void)
+{
+ type_register_static(&vhost_user_blk_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index e92837c..b5e05d9 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1976,6 +1976,58 @@ static const TypeInfo virtio_blk_pci_info = {
.class_init = virtio_blk_pci_class_init,
};
+#if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX)
+/* vhost-user-blk */
+
+static Property vhost_user_blk_pci_properties[] = {
+ DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
+ DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+ VHostUserBlkPCI *dev = VHOST_USER_BLK_PCI(vpci_dev);
+ DeviceState *vdev = DEVICE(&dev->vdev);
+
+ qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+ object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void vhost_user_blk_pci_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+ PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+
+ set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+ dc->props = vhost_user_blk_pci_properties;
+ k->realize = vhost_user_blk_pci_realize;
+ pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+ pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_BLOCK;
+ pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
+ pcidev_k->class_id = PCI_CLASS_STORAGE_SCSI;
+}
+
+static void vhost_user_blk_pci_instance_init(Object *obj)
+{
+ VHostUserBlkPCI *dev = VHOST_USER_BLK_PCI(obj);
+
+ virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+ TYPE_VHOST_USER_BLK);
+ object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
+ "bootindex", &error_abort);
+}
+
+static const TypeInfo vhost_user_blk_pci_info = {
+ .name = TYPE_VHOST_USER_BLK_PCI,
+ .parent = TYPE_VIRTIO_PCI,
+ .instance_size = sizeof(VHostUserBlkPCI),
+ .instance_init = vhost_user_blk_pci_instance_init,
+ .class_init = vhost_user_blk_pci_class_init,
+};
+#endif
+
/* virtio-scsi-pci */
static Property virtio_scsi_pci_properties[] = {
@@ -2622,6 +2674,9 @@ static void virtio_pci_register_types(void)
type_register_static(&virtio_9p_pci_info);
#endif
type_register_static(&virtio_blk_pci_info);
+#if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX)
+ type_register_static(&vhost_user_blk_pci_info);
+#endif
type_register_static(&virtio_scsi_pci_info);
type_register_static(&virtio_balloon_pci_info);
type_register_static(&virtio_serial_pci_info);
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 12d3a90..813082b 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -27,6 +27,9 @@
#include "hw/virtio/virtio-gpu.h"
#include "hw/virtio/virtio-crypto.h"
#include "hw/virtio/vhost-user-scsi.h"
+#if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX)
+#include "hw/virtio/vhost-user-blk.h"
+#endif
#ifdef CONFIG_VIRTFS
#include "hw/9pfs/virtio-9p.h"
@@ -46,6 +49,7 @@ typedef struct VirtIOSerialPCI VirtIOSerialPCI;
typedef struct VirtIONetPCI VirtIONetPCI;
typedef struct VHostSCSIPCI VHostSCSIPCI;
typedef struct VHostUserSCSIPCI VHostUserSCSIPCI;
+typedef struct VHostUserBlkPCI VHostUserBlkPCI;
typedef struct VirtIORngPCI VirtIORngPCI;
typedef struct VirtIOInputPCI VirtIOInputPCI;
typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
@@ -244,6 +248,20 @@ struct VHostUserSCSIPCI {
VHostUserSCSI vdev;
};
+#if defined(CONFIG_VHOST_USER) && defined(CONFIG_LINUX)
+/*
+ * vhost-user-blk-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VHOST_USER_BLK_PCI "vhost-user-blk-pci"
+#define VHOST_USER_BLK_PCI(obj) \
+ OBJECT_CHECK(VHostUserBlkPCI, (obj), TYPE_VHOST_USER_BLK_PCI)
+
+struct VHostUserBlkPCI {
+ VirtIOPCIProxy parent_obj;
+ VHostUserBlk vdev;
+};
+#endif
+
/*
* virtio-blk-pci: This extends VirtioPCIProxy.
*/
diff --git a/include/hw/virtio/vhost-user-blk.h b/include/hw/virtio/vhost-user-blk.h
new file mode 100644
index 0000000..a120b06
--- /dev/null
+++ b/include/hw/virtio/vhost-user-blk.h
@@ -0,0 +1,42 @@
+/*
+ * vhost-user-blk host device
+ * Copyright(C) 2017 Intel Corporation.
+ *
+ * Authors:
+ * Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * Based on "vhost-scsi.h" implemention by:
+ * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef VHOST_USER_BLK_H
+#define VHOST_USER_BLK_H
+
+#include "standard-headers/linux/virtio_blk.h"
+#include "qemu-common.h"
+#include "hw/qdev.h"
+#include "hw/block/block.h"
+#include "chardev/char-fe.h"
+#include "hw/virtio/vhost.h"
+
+#define TYPE_VHOST_USER_BLK "vhost-user-blk"
+#define VHOST_USER_BLK(obj) \
+ OBJECT_CHECK(VHostUserBlk, (obj), TYPE_VHOST_USER_BLK)
+
+typedef struct VHostUserBlk {
+ VirtIODevice parent_obj;
+ CharBackend chardev;
+ int32_t bootindex;
+ struct virtio_blk_config blkcfg;
+ uint16_t num_queues;
+ uint32_t queue_size;
+ uint32_t config_wce;
+ uint32_t config_ro;
+ struct vhost_dev dev;
+} VHostUserBlk;
+
+#endif
--
1.9.3
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [Qemu-devel] [PATCH v5 3/4] contrib/libvhost-user: enable virtio config space messages
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 2/4] vhost-user-blk: introduce a new vhost-user-blk host device Changpeng Liu
@ 2017-11-16 20:44 ` Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 4/4] contrib/vhost-user-blk: introduce a vhost-user-blk sample application Changpeng Liu
3 siblings, 0 replies; 14+ messages in thread
From: Changpeng Liu @ 2017-11-16 20:44 UTC (permalink / raw)
To: changpeng.liu, qemu-devel
Cc: stefanha, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG/VHOST_USER_SET_CONFIG_FD
messages in libvhost-user library, users can implement their own I/O target
based on the library. This enable the virtio config space delivered between
Qemu host device and the I/O target, also event notifier is added in case
of virtio config space changed.
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
contrib/libvhost-user/libvhost-user.c | 79 +++++++++++++++++++++++++++++++++++
contrib/libvhost-user/libvhost-user.h | 24 ++++++++++-
2 files changed, 102 insertions(+), 1 deletion(-)
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index f409bd3..16fc4f2 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -84,6 +84,9 @@ vu_request_to_string(unsigned int req)
REQ(VHOST_USER_SET_SLAVE_REQ_FD),
REQ(VHOST_USER_IOTLB_MSG),
REQ(VHOST_USER_SET_VRING_ENDIAN),
+ REQ(VHOST_USER_GET_CONFIG),
+ REQ(VHOST_USER_SET_CONFIG),
+ REQ(VHOST_USER_SET_CONFIG_FD),
REQ(VHOST_USER_MAX),
};
#undef REQ
@@ -798,6 +801,69 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
}
static bool
+vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+ int ret = -1;
+
+ if (dev->iface->get_config) {
+ ret = dev->iface->get_config(dev, vmsg->payload.config.region,
+ sizeof(vmsg->payload.config.region));
+ }
+
+ if (ret) {
+ /* resize to zero to indicate an error to master */
+ vmsg->size = 0;
+ }
+
+ return true;
+}
+
+static bool
+vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+ int ret = -1;
+ bool reply_supported = !!(dev->protocol_features &
+ (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK));
+
+ if (dev->iface->set_config) {
+ ret = dev->iface->set_config(dev, vmsg->payload.config.region,
+ vmsg->payload.config.offset,
+ vmsg->payload.config.size);
+ }
+
+ vmsg->size = sizeof(vmsg->payload.u64);
+ if (!ret) {
+ vmsg->payload.u64 = 0;
+ } else {
+ /* indicate an error in case reply supported */
+ vmsg->payload.u64 = 1;
+ }
+
+ if (reply_supported) {
+ return true;
+ }
+
+ return false;
+}
+
+static bool
+vu_set_config_fd(VuDev *dev, VhostUserMsg *vmsg)
+{
+ if (vmsg->fd_num != 1) {
+ vu_panic(dev, "Invalid config_fd message");
+ return false;
+ }
+
+ if (dev->config_fd != -1) {
+ close(dev->config_fd);
+ }
+ dev->config_fd = vmsg->fds[0];
+ DPRINT("Got config_fd: %d\n", vmsg->fds[0]);
+
+ return false;
+}
+
+static bool
vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
{
int do_reply = 0;
@@ -862,6 +928,12 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
return vu_set_vring_enable_exec(dev, vmsg);
case VHOST_USER_SET_SLAVE_REQ_FD:
return vu_set_slave_req_fd(dev, vmsg);
+ case VHOST_USER_GET_CONFIG:
+ return vu_get_config(dev, vmsg);
+ case VHOST_USER_SET_CONFIG:
+ return vu_set_config(dev, vmsg);
+ case VHOST_USER_SET_CONFIG_FD:
+ return vu_set_config_fd(dev, vmsg);
case VHOST_USER_NONE:
break;
default:
@@ -940,6 +1012,11 @@ vu_deinit(VuDev *dev)
dev->slave_fd = -1;
}
+ if (dev->config_fd != -1) {
+ close(dev->config_fd);
+ dev->config_fd = -1;
+ }
+
if (dev->sock != -1) {
close(dev->sock);
}
@@ -970,6 +1047,8 @@ vu_init(VuDev *dev,
dev->iface = iface;
dev->log_call_fd = -1;
dev->slave_fd = -1;
+ dev->config_fd = -1;
+
for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) {
dev->vq[i] = (VuVirtq) {
.call_fd = -1, .kick_fd = -1, .err_fd = -1,
diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
index 2f5864b..0d1f674 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -30,6 +30,11 @@
#define VHOST_MEMORY_MAX_NREGIONS 8
+/*
+ * Maximum size of virtio device config space
+ */
+#define VHOST_USER_MAX_CONFIG_SIZE 256
+
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -38,7 +43,6 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_NET_MTU = 4,
VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
-
VHOST_USER_PROTOCOL_F_MAX
};
@@ -69,6 +73,9 @@ typedef enum VhostUserRequest {
VHOST_USER_SET_SLAVE_REQ_FD = 21,
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
+ VHOST_USER_GET_CONFIG = 24,
+ VHOST_USER_SET_CONFIG = 25,
+ VHOST_USER_SET_CONFIG_FD = 26,
VHOST_USER_MAX
} VhostUserRequest;
@@ -90,6 +97,12 @@ typedef struct VhostUserLog {
uint64_t mmap_offset;
} VhostUserLog;
+typedef struct VhostUserConfig {
+ uint32_t offset;
+ uint32_t size;
+ uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+} VhostUserConfig;
+
#if defined(_WIN32)
# define VU_PACKED __attribute__((gcc_struct, packed))
#else
@@ -112,6 +125,7 @@ typedef struct VhostUserMsg {
struct vhost_vring_addr addr;
VhostUserMemory memory;
VhostUserLog log;
+ VhostUserConfig config;
} payload;
int fds[VHOST_MEMORY_MAX_NREGIONS];
@@ -140,6 +154,9 @@ typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
int *do_reply);
typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
+typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, size_t len);
+typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *config,
+ uint32_t offset, uint32_t size);
typedef struct VuDevIface {
/* called by VHOST_USER_GET_FEATURES to get the features bitmask */
@@ -162,6 +179,10 @@ typedef struct VuDevIface {
* on unmanaged exit/crash.
*/
vu_queue_is_processed_in_order_cb queue_is_processed_in_order;
+ /* get the config space of the device */
+ vu_get_config_cb get_config;
+ /* set the config space of the device */
+ vu_set_config_cb set_config;
} VuDevIface;
typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
@@ -227,6 +248,7 @@ struct VuDev {
VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
int log_call_fd;
int slave_fd;
+ int config_fd;
uint64_t log_size;
uint8_t *log_table;
uint64_t features;
--
1.9.3
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [Qemu-devel] [PATCH v5 4/4] contrib/vhost-user-blk: introduce a vhost-user-blk sample application
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
` (2 preceding siblings ...)
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 3/4] contrib/libvhost-user: enable virtio config space messages Changpeng Liu
@ 2017-11-16 20:44 ` Changpeng Liu
3 siblings, 0 replies; 14+ messages in thread
From: Changpeng Liu @ 2017-11-16 20:44 UTC (permalink / raw)
To: changpeng.liu, qemu-devel
Cc: stefanha, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
This commit introcudes a vhost-user-blk backend device, it uses UNIX
domain socket to communicate with Qemu. The vhost-user-blk sample
application should be used with Qemu vhost-user-blk-pci device.
To use it, complie with:
make vhost-user-blk
and start like this:
vhost-user-blk -b /dev/sdb -s /path/vhost.socket
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
.gitignore | 1 +
Makefile | 3 +
Makefile.objs | 1 +
contrib/vhost-user-blk/Makefile.objs | 1 +
contrib/vhost-user-blk/vhost-user-blk.c | 536 ++++++++++++++++++++++++++++++++
5 files changed, 542 insertions(+)
create mode 100644 contrib/vhost-user-blk/Makefile.objs
create mode 100644 contrib/vhost-user-blk/vhost-user-blk.c
diff --git a/.gitignore b/.gitignore
index 588769b..495f854 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,6 +55,7 @@
/scsi/qemu-pr-helper
/vscclient
/vhost-user-scsi
+/vhost-user-blk
/fsdev/virtfs-proxy-helper
*.tmp
*.[1-9]
diff --git a/Makefile b/Makefile
index d2e31d9..0cfb0f1 100644
--- a/Makefile
+++ b/Makefile
@@ -327,6 +327,7 @@ dummy := $(call unnest-vars,, \
ivshmem-server-obj-y \
libvhost-user-obj-y \
vhost-user-scsi-obj-y \
+ vhost-user-blk-obj-y \
qga-vss-dll-obj-y \
block-obj-y \
block-obj-m \
@@ -558,6 +559,8 @@ ivshmem-server$(EXESUF): $(ivshmem-server-obj-y) $(COMMON_LDADDS)
endif
vhost-user-scsi$(EXESUF): $(vhost-user-scsi-obj-y) libvhost-user.a
$(call LINK, $^)
+vhost-user-blk$(EXESUF): $(vhost-user-blk-obj-y) libvhost-user.a
+ $(call LINK, $^)
module_block.h: $(SRC_PATH)/scripts/modules/module_block.py config-host.mak
$(call quiet-command,$(PYTHON) $< $@ \
diff --git a/Makefile.objs b/Makefile.objs
index 285c6f3..ae9aef7 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -115,6 +115,7 @@ libvhost-user-obj-y = contrib/libvhost-user/
vhost-user-scsi.o-cflags := $(LIBISCSI_CFLAGS)
vhost-user-scsi.o-libs := $(LIBISCSI_LIBS)
vhost-user-scsi-obj-y = contrib/vhost-user-scsi/
+vhost-user-blk-obj-y = contrib/vhost-user-blk/
######################################################################
trace-events-subdirs =
diff --git a/contrib/vhost-user-blk/Makefile.objs b/contrib/vhost-user-blk/Makefile.objs
new file mode 100644
index 0000000..72e2cdc
--- /dev/null
+++ b/contrib/vhost-user-blk/Makefile.objs
@@ -0,0 +1 @@
+vhost-user-blk-obj-y = vhost-user-blk.o
diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
new file mode 100644
index 0000000..076ec62
--- /dev/null
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -0,0 +1,536 @@
+/*
+ * vhost-user-blk sample application
+ *
+ * Copyright (c) 2017 Intel Corporation. All rights reserved.
+ *
+ * Author:
+ * Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * This work is based on the "vhost-user-scsi" sample and "virtio-blk" driver
+ * implemention by:
+ * Felipe Franciosi <felipe@nutanix.com>
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 only.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "standard-headers/linux/virtio_blk.h"
+#include "contrib/libvhost-user/libvhost-user-glib.h"
+#include "contrib/libvhost-user/libvhost-user.h"
+
+#include <glib.h>
+
+struct virtio_blk_inhdr {
+ unsigned char status;
+};
+
+/* vhost user block device */
+typedef struct VubDev {
+ VugDev parent;
+ int blk_fd;
+ struct virtio_blk_config blkcfg;
+ char *blk_name;
+ GMainLoop *loop;
+} VubDev;
+
+typedef struct VubReq {
+ VuVirtqElement *elem;
+ int64_t sector_num;
+ size_t size;
+ struct virtio_blk_inhdr *in;
+ struct virtio_blk_outhdr *out;
+ VubDev *vdev_blk;
+ struct VuVirtq *vq;
+} VubReq;
+
+/** refer util/iov.c **/
+static size_t vub_iov_size(const struct iovec *iov,
+ const unsigned int iov_cnt)
+{
+ size_t len;
+ unsigned int i;
+
+ len = 0;
+ for (i = 0; i < iov_cnt; i++) {
+ len += iov[i].iov_len;
+ }
+ return len;
+}
+
+static void vub_panic_cb(VuDev *vu_dev, const char *buf)
+{
+ VugDev *gdev;
+ VubDev *vdev_blk;
+
+ assert(vu_dev);
+
+ gdev = container_of(vu_dev, VugDev, parent);
+ vdev_blk = container_of(gdev, VubDev, parent);
+ if (buf) {
+ g_warning("vu_panic: %s", buf);
+ }
+
+ g_main_loop_quit(vdev_blk->loop);
+}
+
+static void vub_req_complete(VubReq *req)
+{
+ VugDev *gdev = &req->vdev_blk->parent;
+ VuDev *vu_dev = &gdev->parent;
+
+ /* IO size with 1 extra status byte */
+ vu_queue_push(vu_dev, req->vq, req->elem,
+ req->size + 1);
+ vu_queue_notify(vu_dev, req->vq);
+
+ if (req->elem) {
+ free(req->elem);
+ }
+ g_free(req);
+}
+
+static int vub_open(const char *file_name, bool wce)
+{
+ int fd;
+ int flags = O_RDWR;
+
+ if (!wce) {
+ flags |= O_DIRECT;
+ }
+
+ fd = open(file_name, flags);
+ if (fd < 0) {
+ fprintf(stderr, "Cannot open file %s, %s\n", file_name,
+ strerror(errno));
+ return -1;
+ }
+
+ return fd;
+}
+
+static void vub_close(int fd)
+{
+ if (fd >= 0) {
+ close(fd);
+ }
+}
+
+static ssize_t
+vub_readv(VubReq *req, struct iovec *iov, uint32_t iovcnt)
+{
+ VubDev *vdev_blk = req->vdev_blk;
+ ssize_t rc;
+
+ if (!iovcnt) {
+ fprintf(stderr, "Invalid Read IOV count\n");
+ return -1;
+ }
+
+ req->size = vub_iov_size(iov, iovcnt);
+ rc = preadv(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
+ if (rc < 0) {
+ fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
+ vdev_blk->blk_name, req->sector_num, req->size,
+ strerror(errno));
+ return -1;
+ }
+
+ return rc;
+}
+
+static ssize_t
+vub_writev(VubReq *req, struct iovec *iov, uint32_t iovcnt)
+{
+ VubDev *vdev_blk = req->vdev_blk;
+ ssize_t rc;
+
+ if (!iovcnt) {
+ fprintf(stderr, "Invalid Write IOV count\n");
+ return -1;
+ }
+
+ req->size = vub_iov_size(iov, iovcnt);
+ rc = pwritev(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
+ if (rc < 0) {
+ fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
+ vdev_blk->blk_name, req->sector_num, req->size,
+ strerror(errno));
+ return -1;
+ }
+
+ return rc;
+}
+
+static void
+vub_flush(VubReq *req)
+{
+ VubDev *vdev_blk = req->vdev_blk;
+
+ fdatasync(vdev_blk->blk_fd);
+}
+
+
+static int vub_virtio_process_req(VubDev *vdev_blk,
+ VuVirtq *vq)
+{
+ VugDev *gdev = &vdev_blk->parent;
+ VuDev *vu_dev = &gdev->parent;
+ VuVirtqElement *elem;
+ uint32_t type;
+ unsigned in_num;
+ unsigned out_num;
+ VubReq *req;
+
+ elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement));
+ if (!elem) {
+ return -1;
+ }
+
+ /* refer to hw/block/virtio_blk.c */
+ if (elem->out_num < 1 || elem->in_num < 1) {
+ fprintf(stderr, "virtio-blk request missing headers\n");
+ free(elem);
+ return -1;
+ }
+
+ req = g_new0(VubReq, 1);
+ req->vdev_blk = vdev_blk;
+ req->vq = vq;
+ req->elem = elem;
+
+ in_num = elem->in_num;
+ out_num = elem->out_num;
+
+ /* don't support VIRTIO_F_ANY_LAYOUT and virtio 1.0 only */
+ if (elem->out_sg[0].iov_len < sizeof(struct virtio_blk_outhdr)) {
+ fprintf(stderr, "Invalid outhdr size\n");
+ goto err;
+ }
+ req->out = (struct virtio_blk_outhdr *)elem->out_sg[0].iov_base;
+ out_num--;
+
+ if (elem->in_sg[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
+ fprintf(stderr, "Invalid inhdr size\n");
+ goto err;
+ }
+ req->in = (struct virtio_blk_inhdr *)elem->in_sg[in_num - 1].iov_base;
+ in_num--;
+
+ type = le32toh(req->out->type);
+ switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
+ case VIRTIO_BLK_T_IN: {
+ ssize_t ret = 0;
+ bool is_write = type & VIRTIO_BLK_T_OUT;
+ req->sector_num = le64toh(req->out->sector);
+ if (is_write) {
+ ret = vub_writev(req, &elem->out_sg[1], out_num);
+ } else {
+ ret = vub_readv(req, &elem->in_sg[0], in_num);
+ }
+ if (ret >= 0) {
+ req->in->status = VIRTIO_BLK_S_OK;
+ } else {
+ req->in->status = VIRTIO_BLK_S_IOERR;
+ }
+ vub_req_complete(req);
+ break;
+ }
+ case VIRTIO_BLK_T_FLUSH: {
+ vub_flush(req);
+ req->in->status = VIRTIO_BLK_S_OK;
+ vub_req_complete(req);
+ break;
+ }
+ case VIRTIO_BLK_T_GET_ID: {
+ size_t size = MIN(vub_iov_size(&elem->in_sg[0], in_num),
+ VIRTIO_BLK_ID_BYTES);
+ snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk");
+ req->in->status = VIRTIO_BLK_S_OK;
+ req->size = elem->in_sg[0].iov_len;
+ vub_req_complete(req);
+ break;
+ }
+ default: {
+ req->in->status = VIRTIO_BLK_S_UNSUPP;
+ vub_req_complete(req);
+ break;
+ }
+ }
+
+ return 0;
+
+err:
+ free(elem);
+ g_free(req);
+ return -1;
+}
+
+static void vub_process_vq(VuDev *vu_dev, int idx)
+{
+ VugDev *gdev;
+ VubDev *vdev_blk;
+ VuVirtq *vq;
+ int ret;
+
+ if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) {
+ fprintf(stderr, "VQ Index out of range: %d\n", idx);
+ vub_panic_cb(vu_dev, NULL);
+ return;
+ }
+
+ gdev = container_of(vu_dev, VugDev, parent);
+ vdev_blk = container_of(gdev, VubDev, parent);
+ assert(vdev_blk);
+
+ vq = vu_get_queue(vu_dev, idx);
+ assert(vq);
+
+ while (1) {
+ ret = vub_virtio_process_req(vdev_blk, vq);
+ if (ret) {
+ break;
+ }
+ }
+}
+
+static void vub_queue_set_started(VuDev *vu_dev, int idx, bool started)
+{
+ VuVirtq *vq;
+
+ assert(vu_dev);
+
+ if ((idx < 0) || (idx >= VHOST_MAX_NR_VIRTQUEUE)) {
+ fprintf(stderr, "VQ Index out of range: %d\n", idx);
+ vub_panic_cb(vu_dev, NULL);
+ return;
+ }
+
+ vq = vu_get_queue(vu_dev, idx);
+ vu_set_queue_handler(vu_dev, vq, started ? vub_process_vq : NULL);
+}
+
+static uint64_t
+vub_get_features(VuDev *dev)
+{
+ return 1ull << VIRTIO_BLK_F_SIZE_MAX |
+ 1ull << VIRTIO_BLK_F_SEG_MAX |
+ 1ull << VIRTIO_BLK_F_TOPOLOGY |
+ 1ull << VIRTIO_BLK_F_BLK_SIZE |
+ 1ull << VIRTIO_BLK_F_FLUSH |
+ 1ull << VIRTIO_BLK_F_CONFIG_WCE |
+ 1ull << VIRTIO_F_VERSION_1 |
+ 1ull << VHOST_USER_F_PROTOCOL_FEATURES;
+}
+
+static int
+vub_get_config(VuDev *vu_dev, uint8_t *config, size_t len)
+{
+ VugDev *gdev;
+ VubDev *vdev_blk;
+
+ gdev = container_of(vu_dev, VugDev, parent);
+ vdev_blk = container_of(gdev, VubDev, parent);
+ memcpy(config, &vdev_blk->blkcfg, sizeof(vdev_blk->blkcfg));
+
+ return 0;
+}
+
+static int
+vub_set_config(VuDev *vu_dev, const uint8_t *config,
+ uint32_t offset, uint32_t size)
+{
+ VugDev *gdev;
+ VubDev *vdev_blk;
+ uint8_t wce;
+ int fd;
+
+ gdev = container_of(vu_dev, VugDev, parent);
+ vdev_blk = container_of(gdev, VubDev, parent);
+
+ if (offset != offsetof(struct virtio_blk_config, wce) ||
+ size != 1) {
+ return -1;
+ }
+
+ wce = *(config + offset);
+ if (wce == vdev_blk->blkcfg.wce) {
+ /* Do nothing as same with old configuration */
+ return 0;
+ }
+
+ fprintf(stdout, "Write Cache Policy Changed\n");
+ vub_close(vdev_blk->blk_fd);
+
+ fd = vub_open(vdev_blk->blk_name, wce);
+ if (fd < 0) {
+ fprintf(stderr, "Error to open block device %s\n", vdev_blk->blk_name);
+ vdev_blk->blk_fd = -1;
+ return -1;
+ }
+ vdev_blk->blk_fd = fd;
+
+ return 0;
+}
+
+static const VuDevIface vub_iface = {
+ .get_features = vub_get_features,
+ .queue_set_started = vub_queue_set_started,
+ .get_config = vub_get_config,
+ .set_config = vub_set_config,
+};
+
+static int unix_sock_new(char *unix_fn)
+{
+ int sock;
+ struct sockaddr_un un;
+ size_t len;
+
+ assert(unix_fn);
+
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock <= 0) {
+ perror("socket");
+ return -1;
+ }
+
+ un.sun_family = AF_UNIX;
+ (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
+ len = sizeof(un.sun_family) + strlen(un.sun_path);
+
+ (void)unlink(unix_fn);
+ if (bind(sock, (struct sockaddr *)&un, len) < 0) {
+ perror("bind");
+ goto fail;
+ }
+
+ if (listen(sock, 1) < 0) {
+ perror("listen");
+ goto fail;
+ }
+
+ return sock;
+
+fail:
+ (void)close(sock);
+
+ return -1;
+}
+
+static void vub_deinit(struct VubDev *vdev_blk)
+{
+ if (!vdev_blk) {
+ return;
+ }
+
+ if (vdev_blk->blk_fd) {
+ vub_close(vdev_blk->blk_fd);
+ }
+}
+
+static void
+vub_initialize_config(int fd, struct virtio_blk_config *config)
+{
+ off64_t capacity;
+
+ capacity = lseek64(fd, 0, SEEK_END);
+ config->capacity = capacity >> 9;
+ config->blk_size = 512;
+ config->size_max = 65536;
+ config->seg_max = 128 - 2;
+ config->min_io_size = 1;
+ config->opt_io_size = 1;
+ config->num_queues = 1;
+}
+
+static int
+vub_new_block(VubDev *vdev_blk, char *blk_file)
+{
+ vdev_blk->blk_fd = vub_open(blk_file, 0);
+ if (vdev_blk->blk_fd < 0) {
+ fprintf(stderr, "Error to open block device %s\n", blk_file);
+ return -1;
+ }
+ vdev_blk->blkcfg.wce = 0;
+ vdev_blk->blk_name = blk_file;
+
+ /* fill virtio_blk_config with block parameters */
+ vub_initialize_config(vdev_blk->blk_fd, &vdev_blk->blkcfg);
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int opt;
+ char *unix_socket = NULL;
+ char *blk_file = NULL;
+ int lsock = -1, csock = -1, rc;
+ VubDev *vdev_blk = NULL;
+
+ while ((opt = getopt(argc, argv, "b:h:s:")) != -1) {
+ switch (opt) {
+ case 'b':
+ blk_file = g_strdup(optarg);
+ break;
+ case 's':
+ unix_socket = g_strdup(optarg);
+ break;
+ case 'h':
+ default:
+ printf("Usage: %s [-b block device or file, -s UNIX domain socket]"
+ " | [ -h ]\n", argv[0]);
+ return -1;
+ }
+ }
+
+ if (!unix_socket || !blk_file) {
+ printf("Usage: %s [-b block device or file, -s UNIX domain socket] |"
+ " [ -h ]\n", argv[0]);
+ return -1;
+ }
+
+ lsock = unix_sock_new(unix_socket);
+ if (lsock < 0) {
+ goto err;
+ }
+
+ csock = accept(lsock, (void *)0, (void *)0);
+ if (csock < 0) {
+ fprintf(stderr, "Accept error %s\n", strerror(errno));
+ goto err;
+ }
+
+ vdev_blk = g_new0(VubDev, 1);
+ vdev_blk->loop = g_main_loop_new(NULL, FALSE);
+
+ rc = vub_new_block(vdev_blk, blk_file);
+ if (rc) {
+ goto err;
+ }
+
+ vug_init(&vdev_blk->parent, csock, vub_panic_cb, &vub_iface);
+
+ g_main_loop_run(vdev_blk->loop);
+
+ vug_deinit(&vdev_blk->parent);
+
+err:
+ if (vdev_blk) {
+ g_main_loop_unref(vdev_blk->loop);
+ vub_deinit(vdev_blk);
+ g_free(vdev_blk);
+ }
+ if (csock >= 0) {
+ close(csock);
+ }
+ if (lsock >= 0) {
+ close(lsock);
+ }
+ g_free(unix_socket);
+ g_free(blk_file);
+
+ return 0;
+}
+
--
1.9.3
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
@ 2017-11-20 16:26 ` Stefan Hajnoczi
2017-11-20 20:44 ` Michael S. Tsirkin
2017-11-22 2:25 ` Liu, Changpeng
2017-11-22 14:49 ` Michael S. Tsirkin
1 sibling, 2 replies; 14+ messages in thread
From: Stefan Hajnoczi @ 2017-11-20 16:26 UTC (permalink / raw)
To: Changpeng Liu
Cc: qemu-devel, pbonzini, mst, marcandre.lureau, felipe, james.r.harris
[-- Attachment #1: Type: text/plain, Size: 4059 bytes --]
On Fri, Nov 17, 2017 at 04:44:37AM +0800, Changpeng Liu wrote:
> Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
> used for live migration of vhost user devices, also vhost user devices
> can benefit from the messages to get/set virtio config space from/to the
> I/O target. For the purpose to support virtio config space change,
> VHOST_USER_SET_CONFIG_FD message is added as the event notifier
> in case virtio config space change in the I/O target.
>
> Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> ---
> docs/interop/vhost-user.txt | 39 ++++++++++++++++
> hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++
> hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
> include/hw/virtio/vhost-backend.h | 8 ++++
> include/hw/virtio/vhost.h | 16 +++++++
> 5 files changed, 224 insertions(+)
>
> diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> index 954771d..1b98388 100644
> --- a/docs/interop/vhost-user.txt
> +++ b/docs/interop/vhost-user.txt
> @@ -116,6 +116,16 @@ Depending on the request type, payload can be:
> - 3: IOTLB invalidate
> - 4: IOTLB access fail
>
> + * Virtio device config space
> + ---------------------------
> + | offset | size | payload |
> + ---------------------------
> +
> + Offset: a 32-bit offset of virtio device's configuration space
s/of/in the/
> + Size: a 32-bit size of configuration space that master wanted to change
Is this also used for GET_CONFIG? If yes, I suggest "a 32-bit
configuration space access size in bytes".
Please mention that Size must be <= 256 bytes.
> + Payload: a 256-bytes array holding the contents of the virtio
> + device's configuration space
What about bytes outside the [offset, offset+size) range? I guess they
must be 0 and are ignored by the master/slave.
Would it be cleaner to make Payload a variable-sized field with Size
bytes? That way it's not necessary to transfer 0s and memcpy() a subset
of the payload array.
> +
> In QEMU the vhost-user message is implemented with the following struct:
>
> typedef struct VhostUserMsg {
> @@ -129,6 +139,7 @@ typedef struct VhostUserMsg {
> VhostUserMemory memory;
> VhostUserLog log;
> struct vhost_iotlb_msg iotlb;
> + VhostUserConfig config;
> };
> } QEMU_PACKED VhostUserMsg;
>
> @@ -596,6 +607,34 @@ Master message types
> and expect this message once (per VQ) during device configuration
> (ie. before the master starts the VQ).
>
> + * VHOST_USER_GET_CONFIG
> + Id: 24
> + Equivalent ioctl: N/A
> + Master payload: virtio device config space
> +
> + Submitted by the vhost-user master to fetch the contents of the virtio
> + device configuration space. The vhost-user master may cache the contents
> + to avoid repeated VHOST_USER_GET_CONFIG calls.
> +
> +* VHOST_USER_SET_CONFIG
> + Id: 25
> + Equivalent ioctl: N/A
> + Master payload: virtio device config space
> +
> + Submitted by the vhost-user master when the Guest changes the virtio
> + device configuration space and also can be used for live migration
> + on the destination host.
There might be security issues if the vhost slave cannot tell whether
SET_CONFIG is coming from the guest driver or from the master process
(live migration). Typically certain fields are read-only for the guest
driver. Maybe those fields need to be set by the master after live
migration.
One way to solve this is adding a flags field to the message. A special
flag can be used for live migration so the slave knows that this
SET_CONFIG message is allowed to write to read-only fields.
It's also worth documenting that slaves MUST NOT accept SET_CONFIG for
read-only configuration space fields unless the live migration bit is
set. Hopefully this will remind implementors to think through the
security issues.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 455 bytes --]
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-20 16:26 ` Stefan Hajnoczi
@ 2017-11-20 20:44 ` Michael S. Tsirkin
2017-11-21 0:16 ` Paolo Bonzini
2017-11-22 2:28 ` Liu, Changpeng
2017-11-22 2:25 ` Liu, Changpeng
1 sibling, 2 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2017-11-20 20:44 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: Changpeng Liu, qemu-devel, pbonzini, marcandre.lureau, felipe,
james.r.harris
On Mon, Nov 20, 2017 at 04:26:31PM +0000, Stefan Hajnoczi wrote:
> On Fri, Nov 17, 2017 at 04:44:37AM +0800, Changpeng Liu wrote:
> > Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
> > used for live migration of vhost user devices, also vhost user devices
> > can benefit from the messages to get/set virtio config space from/to the
> > I/O target. For the purpose to support virtio config space change,
> > VHOST_USER_SET_CONFIG_FD message is added as the event notifier
> > in case virtio config space change in the I/O target.
> >
> > Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> > ---
> > docs/interop/vhost-user.txt | 39 ++++++++++++++++
> > hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++
> > hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
> > include/hw/virtio/vhost-backend.h | 8 ++++
> > include/hw/virtio/vhost.h | 16 +++++++
> > 5 files changed, 224 insertions(+)
> >
> > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> > index 954771d..1b98388 100644
> > --- a/docs/interop/vhost-user.txt
> > +++ b/docs/interop/vhost-user.txt
> > @@ -116,6 +116,16 @@ Depending on the request type, payload can be:
> > - 3: IOTLB invalidate
> > - 4: IOTLB access fail
> >
> > + * Virtio device config space
> > + ---------------------------
> > + | offset | size | payload |
> > + ---------------------------
> > +
> > + Offset: a 32-bit offset of virtio device's configuration space
>
> s/of/in the/
>
> > + Size: a 32-bit size of configuration space that master wanted to change
>
> Is this also used for GET_CONFIG? If yes, I suggest "a 32-bit
> configuration space access size in bytes".
>
> Please mention that Size must be <= 256 bytes.
>
> > + Payload: a 256-bytes array holding the contents of the virtio
> > + device's configuration space
>
> What about bytes outside the [offset, offset+size) range? I guess they
> must be 0 and are ignored by the master/slave.
>
> Would it be cleaner to make Payload a variable-sized field with Size
> bytes? That way it's not necessary to transfer 0s and memcpy() a subset
> of the payload array.
>
> > +
> > In QEMU the vhost-user message is implemented with the following struct:
> >
> > typedef struct VhostUserMsg {
> > @@ -129,6 +139,7 @@ typedef struct VhostUserMsg {
> > VhostUserMemory memory;
> > VhostUserLog log;
> > struct vhost_iotlb_msg iotlb;
> > + VhostUserConfig config;
> > };
> > } QEMU_PACKED VhostUserMsg;
> >
> > @@ -596,6 +607,34 @@ Master message types
> > and expect this message once (per VQ) during device configuration
> > (ie. before the master starts the VQ).
> >
> > + * VHOST_USER_GET_CONFIG
> > + Id: 24
> > + Equivalent ioctl: N/A
> > + Master payload: virtio device config space
> > +
> > + Submitted by the vhost-user master to fetch the contents of the virtio
> > + device configuration space. The vhost-user master may cache the contents
> > + to avoid repeated VHOST_USER_GET_CONFIG calls.
> > +
> > +* VHOST_USER_SET_CONFIG
> > + Id: 25
> > + Equivalent ioctl: N/A
> > + Master payload: virtio device config space
> > +
> > + Submitted by the vhost-user master when the Guest changes the virtio
> > + device configuration space and also can be used for live migration
> > + on the destination host.
>
> There might be security issues if the vhost slave cannot tell whether
> SET_CONFIG is coming from the guest driver or from the master process
> (live migration). Typically certain fields are read-only for the guest
> driver. Maybe those fields need to be set by the master after live
> migration.
>
> One way to solve this is adding a flags field to the message. A special
> flag can be used for live migration so the slave knows that this
> SET_CONFIG message is allowed to write to read-only fields.
>
> It's also worth documenting that slaves MUST NOT accept SET_CONFIG for
> read-only configuration space fields unless the live migration bit is
> set. Hopefully this will remind implementors to think through the
> security issues.
Live migrations is supposed to be migrating guest writeable state too.
If you mean migrating RO fields like size, then
I don't think it's a good idea to reuse SET_CONFIG for that.
SET_CONFIG should obey exactly the virtio semantics.
And I agree, it should say that slave must treat it as a write,
and get config as a read according to virtio semantics.
If someone needs to pass configuration from qemu to
slave, let's add specific messages with precisely defined semantics.
Which reminds me.
virtio 1 changed endian-ness for config.
I think we should specify it's all virtio 1 format, and
just disallow vhost blk for virtio 0 guests.
--
MST
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-20 20:44 ` Michael S. Tsirkin
@ 2017-11-21 0:16 ` Paolo Bonzini
2017-11-21 3:12 ` Michael S. Tsirkin
2017-11-22 2:27 ` Liu, Changpeng
2017-11-22 2:28 ` Liu, Changpeng
1 sibling, 2 replies; 14+ messages in thread
From: Paolo Bonzini @ 2017-11-21 0:16 UTC (permalink / raw)
To: Michael S. Tsirkin, Stefan Hajnoczi
Cc: Changpeng Liu, qemu-devel, marcandre.lureau, felipe, james.r.harris
On 20/11/2017 21:44, Michael S. Tsirkin wrote:
> Live migrations is supposed to be migrating guest writeable state too.
> If you mean migrating RO fields like size, then
> I don't think it's a good idea to reuse SET_CONFIG for that.
> SET_CONFIG should obey exactly the virtio semantics.
>
> And I agree, it should say that slave must treat it as a write,
> and get config as a read according to virtio semantics.
>
> If someone needs to pass configuration from qemu to
> slave, let's add specific messages with precisely defined semantics.
Fair enough, but I'd add nevertheless a 32-bit flags field to both
GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
it is zero and otherwise fail.
Paolo
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-21 0:16 ` Paolo Bonzini
@ 2017-11-21 3:12 ` Michael S. Tsirkin
2017-11-22 14:36 ` Paolo Bonzini
2017-11-22 2:27 ` Liu, Changpeng
1 sibling, 1 reply; 14+ messages in thread
From: Michael S. Tsirkin @ 2017-11-21 3:12 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Stefan Hajnoczi, Changpeng Liu, qemu-devel, marcandre.lureau,
felipe, james.r.harris
On Tue, Nov 21, 2017 at 01:16:12AM +0100, Paolo Bonzini wrote:
> On 20/11/2017 21:44, Michael S. Tsirkin wrote:
> > Live migrations is supposed to be migrating guest writeable state too.
> > If you mean migrating RO fields like size, then
> > I don't think it's a good idea to reuse SET_CONFIG for that.
> > SET_CONFIG should obey exactly the virtio semantics.
> >
> > And I agree, it should say that slave must treat it as a write,
> > and get config as a read according to virtio semantics.
> >
> > If someone needs to pass configuration from qemu to
> > slave, let's add specific messages with precisely defined semantics.
>
> Fair enough, but I'd add nevertheless a 32-bit flags field to both
> GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
> it is zero and otherwise fail.
>
> Paolo
We generally just use protocol feature bits for extensions.
But I have no problem with reserved padding if desired
which seems to be what's described here.
--
MST
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-20 16:26 ` Stefan Hajnoczi
2017-11-20 20:44 ` Michael S. Tsirkin
@ 2017-11-22 2:25 ` Liu, Changpeng
1 sibling, 0 replies; 14+ messages in thread
From: Liu, Changpeng @ 2017-11-22 2:25 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: qemu-devel, pbonzini, mst, marcandre.lureau, felipe, Harris, James R
> -----Original Message-----
> From: Stefan Hajnoczi [mailto:stefanha@gmail.com]
> Sent: Tuesday, November 21, 2017 12:27 AM
> To: Liu, Changpeng <changpeng.liu@intel.com>
> Cc: qemu-devel@nongnu.org; pbonzini@redhat.com; mst@redhat.com;
> marcandre.lureau@redhat.com; felipe@nutanix.com; Harris, James R
> <james.r.harris@intel.com>
> Subject: Re: [PATCH v5 1/4] vhost-user: add new vhost user messages to support
> virtio config space
>
> On Fri, Nov 17, 2017 at 04:44:37AM +0800, Changpeng Liu wrote:
> > Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can
> be
> > used for live migration of vhost user devices, also vhost user devices
> > can benefit from the messages to get/set virtio config space from/to the
> > I/O target. For the purpose to support virtio config space change,
> > VHOST_USER_SET_CONFIG_FD message is added as the event notifier
> > in case virtio config space change in the I/O target.
> >
> > Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> > ---
> > docs/interop/vhost-user.txt | 39 ++++++++++++++++
> > hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++
> > hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
> > include/hw/virtio/vhost-backend.h | 8 ++++
> > include/hw/virtio/vhost.h | 16 +++++++
> > 5 files changed, 224 insertions(+)
> >
> > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> > index 954771d..1b98388 100644
> > --- a/docs/interop/vhost-user.txt
> > +++ b/docs/interop/vhost-user.txt
> > @@ -116,6 +116,16 @@ Depending on the request type, payload can be:
> > - 3: IOTLB invalidate
> > - 4: IOTLB access fail
> >
> > + * Virtio device config space
> > + ---------------------------
> > + | offset | size | payload |
> > + ---------------------------
> > +
> > + Offset: a 32-bit offset of virtio device's configuration space
>
> s/of/in the/
>
> > + Size: a 32-bit size of configuration space that master wanted to change
>
> Is this also used for GET_CONFIG? If yes, I suggest "a 32-bit
> configuration space access size in bytes".
ok.
>
> Please mention that Size must be <= 256 bytes.
>
> > + Payload: a 256-bytes array holding the contents of the virtio
> > + device's configuration space
>
> What about bytes outside the [offset, offset+size) range? I guess they
> must be 0 and are ignored by the master/slave.
>
> Would it be cleaner to make Payload a variable-sized field with Size
> bytes? That way it's not necessary to transfer 0s and memcpy() a subset
> of the payload array.
sounds good, but for vhost-blk driver it can call get_config for the whole virtio_blk_config space.
>
> > +
> > In QEMU the vhost-user message is implemented with the following struct:
> >
> > typedef struct VhostUserMsg {
> > @@ -129,6 +139,7 @@ typedef struct VhostUserMsg {
> > VhostUserMemory memory;
> > VhostUserLog log;
> > struct vhost_iotlb_msg iotlb;
> > + VhostUserConfig config;
> > };
> > } QEMU_PACKED VhostUserMsg;
> >
> > @@ -596,6 +607,34 @@ Master message types
> > and expect this message once (per VQ) during device configuration
> > (ie. before the master starts the VQ).
> >
> > + * VHOST_USER_GET_CONFIG
> > + Id: 24
> > + Equivalent ioctl: N/A
> > + Master payload: virtio device config space
> > +
> > + Submitted by the vhost-user master to fetch the contents of the virtio
> > + device configuration space. The vhost-user master may cache the contents
> > + to avoid repeated VHOST_USER_GET_CONFIG calls.
> > +
> > +* VHOST_USER_SET_CONFIG
> > + Id: 25
> > + Equivalent ioctl: N/A
> > + Master payload: virtio device config space
> > +
> > + Submitted by the vhost-user master when the Guest changes the virtio
> > + device configuration space and also can be used for live migration
> > + on the destination host.
>
> There might be security issues if the vhost slave cannot tell whether
> SET_CONFIG is coming from the guest driver or from the master process
> (live migration). Typically certain fields are read-only for the guest
> driver. Maybe those fields need to be set by the master after live
> migration.
>
> One way to solve this is adding a flags field to the message. A special
> flag can be used for live migration so the slave knows that this
> SET_CONFIG message is allowed to write to read-only fields.
>
Ok.
> It's also worth documenting that slaves MUST NOT accept SET_CONFIG for
> read-only configuration space fields unless the live migration bit is
> set. Hopefully this will remind implementors to think through the
> security issues.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-21 0:16 ` Paolo Bonzini
2017-11-21 3:12 ` Michael S. Tsirkin
@ 2017-11-22 2:27 ` Liu, Changpeng
1 sibling, 0 replies; 14+ messages in thread
From: Liu, Changpeng @ 2017-11-22 2:27 UTC (permalink / raw)
To: Paolo Bonzini, Michael S. Tsirkin, Stefan Hajnoczi
Cc: qemu-devel, marcandre.lureau, felipe, Harris, James R
> -----Original Message-----
> From: Paolo Bonzini [mailto:pbonzini@redhat.com]
> Sent: Tuesday, November 21, 2017 8:16 AM
> To: Michael S. Tsirkin <mst@redhat.com>; Stefan Hajnoczi <stefanha@gmail.com>
> Cc: Liu, Changpeng <changpeng.liu@intel.com>; qemu-devel@nongnu.org;
> marcandre.lureau@redhat.com; felipe@nutanix.com; Harris, James R
> <james.r.harris@intel.com>
> Subject: Re: [PATCH v5 1/4] vhost-user: add new vhost user messages to support
> virtio config space
>
> On 20/11/2017 21:44, Michael S. Tsirkin wrote:
> > Live migrations is supposed to be migrating guest writeable state too.
> > If you mean migrating RO fields like size, then
> > I don't think it's a good idea to reuse SET_CONFIG for that.
> > SET_CONFIG should obey exactly the virtio semantics.
> >
> > And I agree, it should say that slave must treat it as a write,
> > and get config as a read according to virtio semantics.
> >
> > If someone needs to pass configuration from qemu to
> > slave, let's add specific messages with precisely defined semantics.
>
> Fair enough, but I'd add nevertheless a 32-bit flags field to both
> GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
> it is zero and otherwise fail.
Ok.
>
> Paolo
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-20 20:44 ` Michael S. Tsirkin
2017-11-21 0:16 ` Paolo Bonzini
@ 2017-11-22 2:28 ` Liu, Changpeng
1 sibling, 0 replies; 14+ messages in thread
From: Liu, Changpeng @ 2017-11-22 2:28 UTC (permalink / raw)
To: Michael S. Tsirkin, Stefan Hajnoczi
Cc: qemu-devel, pbonzini, marcandre.lureau, felipe, Harris, James R
> -----Original Message-----
> From: Michael S. Tsirkin [mailto:mst@redhat.com]
> Sent: Tuesday, November 21, 2017 4:45 AM
> To: Stefan Hajnoczi <stefanha@gmail.com>
> Cc: Liu, Changpeng <changpeng.liu@intel.com>; qemu-devel@nongnu.org;
> pbonzini@redhat.com; marcandre.lureau@redhat.com; felipe@nutanix.com;
> Harris, James R <james.r.harris@intel.com>
> Subject: Re: [PATCH v5 1/4] vhost-user: add new vhost user messages to support
> virtio config space
>
> On Mon, Nov 20, 2017 at 04:26:31PM +0000, Stefan Hajnoczi wrote:
> > On Fri, Nov 17, 2017 at 04:44:37AM +0800, Changpeng Liu wrote:
> > > Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which
> can be
> > > used for live migration of vhost user devices, also vhost user devices
> > > can benefit from the messages to get/set virtio config space from/to the
> > > I/O target. For the purpose to support virtio config space change,
> > > VHOST_USER_SET_CONFIG_FD message is added as the event notifier
> > > in case virtio config space change in the I/O target.
> > >
> > > Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> > > ---
> > > docs/interop/vhost-user.txt | 39 ++++++++++++++++
> > > hw/virtio/vhost-user.c | 98
> +++++++++++++++++++++++++++++++++++++++
> > > hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
> > > include/hw/virtio/vhost-backend.h | 8 ++++
> > > include/hw/virtio/vhost.h | 16 +++++++
> > > 5 files changed, 224 insertions(+)
> > >
> > > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> > > index 954771d..1b98388 100644
> > > --- a/docs/interop/vhost-user.txt
> > > +++ b/docs/interop/vhost-user.txt
> > > @@ -116,6 +116,16 @@ Depending on the request type, payload can be:
> > > - 3: IOTLB invalidate
> > > - 4: IOTLB access fail
> > >
> > > + * Virtio device config space
> > > + ---------------------------
> > > + | offset | size | payload |
> > > + ---------------------------
> > > +
> > > + Offset: a 32-bit offset of virtio device's configuration space
> >
> > s/of/in the/
> >
> > > + Size: a 32-bit size of configuration space that master wanted to change
> >
> > Is this also used for GET_CONFIG? If yes, I suggest "a 32-bit
> > configuration space access size in bytes".
> >
> > Please mention that Size must be <= 256 bytes.
> >
> > > + Payload: a 256-bytes array holding the contents of the virtio
> > > + device's configuration space
> >
> > What about bytes outside the [offset, offset+size) range? I guess they
> > must be 0 and are ignored by the master/slave.
> >
> > Would it be cleaner to make Payload a variable-sized field with Size
> > bytes? That way it's not necessary to transfer 0s and memcpy() a subset
> > of the payload array.
> >
> > > +
> > > In QEMU the vhost-user message is implemented with the following struct:
> > >
> > > typedef struct VhostUserMsg {
> > > @@ -129,6 +139,7 @@ typedef struct VhostUserMsg {
> > > VhostUserMemory memory;
> > > VhostUserLog log;
> > > struct vhost_iotlb_msg iotlb;
> > > + VhostUserConfig config;
> > > };
> > > } QEMU_PACKED VhostUserMsg;
> > >
> > > @@ -596,6 +607,34 @@ Master message types
> > > and expect this message once (per VQ) during device configuration
> > > (ie. before the master starts the VQ).
> > >
> > > + * VHOST_USER_GET_CONFIG
> > > + Id: 24
> > > + Equivalent ioctl: N/A
> > > + Master payload: virtio device config space
> > > +
> > > + Submitted by the vhost-user master to fetch the contents of the virtio
> > > + device configuration space. The vhost-user master may cache the contents
> > > + to avoid repeated VHOST_USER_GET_CONFIG calls.
> > > +
> > > +* VHOST_USER_SET_CONFIG
> > > + Id: 25
> > > + Equivalent ioctl: N/A
> > > + Master payload: virtio device config space
> > > +
> > > + Submitted by the vhost-user master when the Guest changes the virtio
> > > + device configuration space and also can be used for live migration
> > > + on the destination host.
> >
> > There might be security issues if the vhost slave cannot tell whether
> > SET_CONFIG is coming from the guest driver or from the master process
> > (live migration). Typically certain fields are read-only for the guest
> > driver. Maybe those fields need to be set by the master after live
> > migration.
> >
> > One way to solve this is adding a flags field to the message. A special
> > flag can be used for live migration so the slave knows that this
> > SET_CONFIG message is allowed to write to read-only fields.
> >
> > It's also worth documenting that slaves MUST NOT accept SET_CONFIG for
> > read-only configuration space fields unless the live migration bit is
> > set. Hopefully this will remind implementors to think through the
> > security issues.
>
> Live migrations is supposed to be migrating guest writeable state too.
> If you mean migrating RO fields like size, then
> I don't think it's a good idea to reuse SET_CONFIG for that.
> SET_CONFIG should obey exactly the virtio semantics.
>
> And I agree, it should say that slave must treat it as a write,
> and get config as a read according to virtio semantics.
>
> If someone needs to pass configuration from qemu to
> slave, let's add specific messages with precisely defined semantics.
>
> Which reminds me.
>
> virtio 1 changed endian-ness for config.
>
> I think we should specify it's all virtio 1 format, and
> just disallow vhost blk for virtio 0 guests.
Will add the limitation to this txt file.
>
> --
> MST
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-21 3:12 ` Michael S. Tsirkin
@ 2017-11-22 14:36 ` Paolo Bonzini
0 siblings, 0 replies; 14+ messages in thread
From: Paolo Bonzini @ 2017-11-22 14:36 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Stefan Hajnoczi, Changpeng Liu, qemu-devel, marcandre.lureau,
felipe, james.r.harris
On 21/11/2017 04:12, Michael S. Tsirkin wrote:
>> Fair enough, but I'd add nevertheless a 32-bit flags field to both
>> GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
>> it is zero and otherwise fail.
>
> We generally just use protocol feature bits for extensions.
> But I have no problem with reserved padding if desired
> which seems to be what's described here.
Correct, you would still have a protocol feature bit, but the format
would be less susceptible to struct size changes which can simplify the
implementation a bit.
Paolo
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
2017-11-20 16:26 ` Stefan Hajnoczi
@ 2017-11-22 14:49 ` Michael S. Tsirkin
1 sibling, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2017-11-22 14:49 UTC (permalink / raw)
To: Changpeng Liu
Cc: qemu-devel, stefanha, pbonzini, marcandre.lureau, felipe, james.r.harris
On Fri, Nov 17, 2017 at 04:44:37AM +0800, Changpeng Liu wrote:
> Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
> used for live migration of vhost user devices, also vhost user devices
> can benefit from the messages to get/set virtio config space from/to the
> I/O target. For the purpose to support virtio config space change,
> VHOST_USER_SET_CONFIG_FD message is added as the event notifier
> in case virtio config space change in the I/O target.
>
> Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> ---
> docs/interop/vhost-user.txt | 39 ++++++++++++++++
> hw/virtio/vhost-user.c | 98 +++++++++++++++++++++++++++++++++++++++
> hw/virtio/vhost.c | 63 +++++++++++++++++++++++++
> include/hw/virtio/vhost-backend.h | 8 ++++
> include/hw/virtio/vhost.h | 16 +++++++
> 5 files changed, 224 insertions(+)
>
> diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> index 954771d..1b98388 100644
> --- a/docs/interop/vhost-user.txt
> +++ b/docs/interop/vhost-user.txt
> @@ -116,6 +116,16 @@ Depending on the request type, payload can be:
> - 3: IOTLB invalidate
> - 4: IOTLB access fail
>
> + * Virtio device config space
> + ---------------------------
> + | offset | size | payload |
> + ---------------------------
> +
> + Offset: a 32-bit offset of virtio device's configuration space
> + Size: a 32-bit size of configuration space that master wanted to change
I guess only legal values here are 1-256? But also see below. Also, we
already know the structure size.
> + Payload: a 256-bytes array holding the contents of the virtio
> + device's configuration space
> +
Why not *size* bytes? These are not performance critical but still,
why waste cycles.
> In QEMU the vhost-user message is implemented with the following struct:
>
> typedef struct VhostUserMsg {
Virtio spec says:
For device configuration access, the driver MUST use 8-bit wide accesses for 8-bit wide fields, 16-bit wide
and aligned accesses for 16-bit wide fields and 32-bit wide and aligned accesses for 32-bit and 64-bit wide
fields. For 64-bit fields, the driver MAY access each of the high and low 32-bit parts of the field independently.
So if these commands mirror guest accesses, they are always 1,2,4 or 8 bytes,
and aligned.
--
MST
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2017-11-22 14:49 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
2017-11-20 16:26 ` Stefan Hajnoczi
2017-11-20 20:44 ` Michael S. Tsirkin
2017-11-21 0:16 ` Paolo Bonzini
2017-11-21 3:12 ` Michael S. Tsirkin
2017-11-22 14:36 ` Paolo Bonzini
2017-11-22 2:27 ` Liu, Changpeng
2017-11-22 2:28 ` Liu, Changpeng
2017-11-22 2:25 ` Liu, Changpeng
2017-11-22 14:49 ` Michael S. Tsirkin
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 2/4] vhost-user-blk: introduce a new vhost-user-blk host device Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 3/4] contrib/libvhost-user: enable virtio config space messages Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 4/4] contrib/vhost-user-blk: introduce a vhost-user-blk sample application Changpeng Liu
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.