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[PATCH v4 3/4] vhost-user: add shared_object msg
From: |
Albert Esteve |
Subject: |
[PATCH v4 3/4] vhost-user: add shared_object msg |
Date: |
Mon, 26 Jun 2023 09:34:25 +0200 |
Add three new vhost-user protocol
`VHOST_USER_BACKEND_SHARED_OBJECT_* messages`.
These new messages are sent from vhost-user
back-ends to interact with the virtio-dmabuf
table in order to add, remove, or lookup for
virtio dma-buf shared objects.
The action taken in the front-end depends
on the type stored in the payload struct.
In the libvhost-user library we need to add
helper functions to allow sending messages to
interact with the virtio shared objects
hash table.
The messages can only be sent after successfully
negotiating a new VHOST_USER_PROTOCOL_F_SHARED_OBJECT
vhost-user protocol feature bit.
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
docs/interop/vhost-user.rst | 42 +++++++++
hw/virtio/vhost-user.c | 99 +++++++++++++++++++++
subprojects/libvhost-user/libvhost-user.c | 101 ++++++++++++++++++++++
subprojects/libvhost-user/libvhost-user.h | 53 +++++++++++-
4 files changed, 294 insertions(+), 1 deletion(-)
diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
index 5a070adbc1..bca5600ff1 100644
--- a/docs/interop/vhost-user.rst
+++ b/docs/interop/vhost-user.rst
@@ -1528,6 +1528,48 @@ is sent by the front-end.
The state.num field is currently reserved and must be set to 0.
+``VHOST_USER_BACKEND_SHARED_OBJECT_ADD``
+ :id: 6
+ :equivalent ioctl: N/A
+ :request payload: ``struct VhostUserShared``
+ :reply payload: N/A
+
+ When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol
+ feature has been successfully negotiated, this message can be submitted
+ by the backends to add a new dma-buf fd to the virtio-dmabuf shared
+ table API can send this message. The fd gets associated with a UUID.
+ If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, and the back-end sets
+ the ``VHOST_USER_NEED_REPLY`` flag, the front-end must respond with zero when
+ operation is successfully completed, or non-zero otherwise.
+
+``VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE``
+ :id: 7
+ :equivalent ioctl: N/A
+ :request payload: ``struct VhostUserShared``
+ :reply payload: N/A
+
+ When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol
+ feature has been successfully negotiated, this message can be submitted
+ by the backend to remove a dma-buf from to the virtio-dmabuf shared
+ table API can send this message. The shared table will remove the dma-buf
+ fd associated with the UUID. If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is
+ negotiated, and the back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the
+ front-end must respond with zero when operation is successfully completed,
+ or non-zero otherwise.
+
+``VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP``
+ :id: 8
+ :equivalent ioctl: N/A
+ :request payload: ``struct VhostUserShared``
+ :reply payload: dmabuf fd and ``u64``
+
+ When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol
+ feature has been successfully negotiated, this message can be submitted
+ by the backends to retrieve a given dma-buf fd from the virtio-dmabuf
+ shared table given a UUID. Frontend will reply passing the fd and a zero
+ when the operation is successful, or non-zero otherwise. Note that if the
+ operation fails, no fd is sent to the backend.
+
.. _reply_ack:
VHOST_USER_PROTOCOL_F_REPLY_ACK
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 74a2a28663..e340c39a19 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -10,6 +10,7 @@
#include "qemu/osdep.h"
#include "qapi/error.h"
+#include "hw/virtio/virtio-dmabuf.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-user.h"
#include "hw/virtio/vhost-backend.h"
@@ -20,6 +21,7 @@
#include "sysemu/kvm.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
+#include "qemu/uuid.h"
#include "qemu/sockets.h"
#include "sysemu/runstate.h"
#include "sysemu/cryptodev.h"
@@ -73,6 +75,7 @@ enum VhostUserProtocolFeature {
/* Feature 14 reserved for VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS. */
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15,
VHOST_USER_PROTOCOL_F_STATUS = 16,
+ VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 17,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -128,6 +131,9 @@ typedef enum VhostUserSlaveRequest {
VHOST_USER_BACKEND_IOTLB_MSG = 1,
VHOST_USER_BACKEND_CONFIG_CHANGE_MSG = 2,
VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG = 3,
+ VHOST_USER_BACKEND_SHARED_OBJECT_ADD = 6,
+ VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE = 7,
+ VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP = 8,
VHOST_USER_BACKEND_MAX
} VhostUserSlaveRequest;
@@ -190,6 +196,10 @@ typedef struct VhostUserInflight {
uint16_t queue_size;
} VhostUserInflight;
+typedef struct VhostUserShared {
+ unsigned char uuid[16];
+} VhostUserShared;
+
typedef struct {
VhostUserRequest request;
@@ -214,6 +224,7 @@ typedef union {
VhostUserCryptoSession session;
VhostUserVringArea area;
VhostUserInflight inflight;
+ VhostUserShared object;
} VhostUserPayload;
typedef struct VhostUserMsg {
@@ -1582,6 +1593,83 @@ static int
vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev,
return 0;
}
+static int
+vhost_user_backend_handle_shared_object_add(VhostUserShared *object,
+ int dmabuf_fd)
+{
+ QemuUUID uuid;
+
+ memcpy(uuid.data, object->uuid, sizeof(object->uuid));
+ return virtio_add_dmabuf(&uuid, dmabuf_fd);
+}
+
+static int
+vhost_user_backend_handle_shared_object_remove(VhostUserShared *object)
+{
+ QemuUUID uuid;
+
+ memcpy(uuid.data, object->uuid, sizeof(object->uuid));
+ return virtio_remove_resource(&uuid);
+}
+
+static bool
+vhost_user_backend_send_dmabuf_fd(QIOChannel *ioc, VhostUserHeader *hdr,
+ VhostUserPayload *payload)
+{
+ Error *local_err = NULL;
+ struct iovec iov[2];
+
+ if (hdr->flags & VHOST_USER_NEED_REPLY_MASK) {
+ hdr->flags &= ~VHOST_USER_NEED_REPLY_MASK;
+ }
+ hdr->flags |= VHOST_USER_REPLY_MASK;
+
+ hdr->size = sizeof(payload->u64);
+
+ iov[0].iov_base = hdr;
+ iov[0].iov_len = VHOST_USER_HDR_SIZE;
+ iov[1].iov_base = payload;
+ iov[1].iov_len = hdr->size;
+
+ if (qio_channel_writev_all(ioc, iov, ARRAY_SIZE(iov), &local_err)) {
+ error_report_err(local_err);
+ return false;
+ }
+ return true;
+}
+
+static int
+vhost_user_backend_handle_shared_object_lookup(struct vhost_user *u,
+ QIOChannel *ioc,
+ VhostUserHeader *hdr,
+ VhostUserPayload *payload)
+{
+ QemuUUID uuid;
+ CharBackend *chr = u->user->chr;
+ int dmabuf_fd = -1;
+ int fd_num = 0;
+
+ memcpy(uuid.data, payload->object.uuid, sizeof(payload->object.uuid));
+
+ dmabuf_fd = virtio_lookup_dmabuf(&uuid);
+ if (dmabuf_fd != -1) {
+ fd_num++;
+ }
+
+ payload->u64 = 0;
+ if (qemu_chr_fe_set_msgfds(chr, &dmabuf_fd, fd_num) < 0) {
+ error_report("Failed to set msg fds.");
+ payload->u64 = -EINVAL;
+ }
+
+ if (!vhost_user_backend_send_dmabuf_fd(ioc, hdr, payload)) {
+ error_report("Failed to write response msg.");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static void close_slave_channel(struct vhost_user *u)
{
g_source_destroy(u->slave_src);
@@ -1639,6 +1727,17 @@ static gboolean slave_read(QIOChannel *ioc, GIOCondition
condition,
ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area,
fd ? fd[0] : -1);
break;
+ case VHOST_USER_BACKEND_SHARED_OBJECT_ADD:
+ ret = vhost_user_backend_handle_shared_object_add(&payload.object,
+ fd ? fd[0] : -1);
+ break;
+ case VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE:
+ ret = vhost_user_backend_handle_shared_object_remove(&payload.object);
+ break;
+ case VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP:
+ ret = vhost_user_backend_handle_shared_object_lookup(dev->opaque, ioc,
+ &hdr, &payload);
+ break;
default:
error_report("Received unexpected msg type: %d.", hdr.request);
ret = -EINVAL;
diff --git a/subprojects/libvhost-user/libvhost-user.c
b/subprojects/libvhost-user/libvhost-user.c
index 8fb61e2df2..672d8292a0 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -1403,6 +1403,107 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq
*vq, int fd,
return vu_process_message_reply(dev, &vmsg);
}
+bool
+vu_get_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN], int *dmabuf_fd)
+{
+ bool result = false;
+ VhostUserMsg msg_reply;
+ VhostUserMsg msg = {
+ .request = VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP,
+ .size = sizeof(msg.payload.object),
+ .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
+ };
+
+ memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN);
+
+ if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) {
+ return false;
+ }
+
+ pthread_mutex_lock(&dev->slave_mutex);
+ if (!vu_message_write(dev, dev->slave_fd, &msg)) {
+ goto out;
+ }
+
+ if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
+ goto out;
+ }
+
+ if (msg_reply.request != msg.request) {
+ DPRINT("Received unexpected msg type. Expected %d, received %d",
+ msg.request, msg_reply.request);
+ goto out;
+ }
+
+ if (msg_reply.fd_num != 1) {
+ DPRINT("Received unexpected number of fds. Expected 1, received %d",
+ msg_reply.fd_num);
+ goto out;
+ }
+
+ *dmabuf_fd = msg_reply.fds[0];
+ result = *dmabuf_fd > 0 && msg_reply.payload.u64 == 0;
+out:
+ pthread_mutex_unlock(&dev->slave_mutex);
+
+ return result;
+}
+
+static bool
+vu_send_message(VuDev *dev, VhostUserMsg *vmsg)
+{
+ bool result = false;
+ pthread_mutex_lock(&dev->slave_mutex);
+ if (!vu_message_write(dev, dev->slave_fd, vmsg)) {
+ goto out;
+ }
+
+ result = true;
+out:
+ pthread_mutex_unlock(&dev->slave_mutex);
+
+ return result;
+}
+
+bool
+vu_add_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN], int dmabuf_fd)
+{
+ int fd_num = 0;
+ VhostUserMsg msg = {
+ .request = VHOST_USER_BACKEND_SHARED_OBJECT_ADD,
+ .size = sizeof(msg.payload.object),
+ .flags = VHOST_USER_VERSION,
+ };
+
+ msg.fds[fd_num++] = dmabuf_fd;
+ msg.fd_num = fd_num;
+ memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN);
+
+ if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) {
+ return false;
+ }
+
+ return vu_send_message(dev, &msg);
+}
+
+bool
+vu_rm_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN])
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE,
+ .size = sizeof(msg.payload.object),
+ .flags = VHOST_USER_VERSION,
+ };
+
+ memcpy(msg.payload.object.uuid, uuid, sizeof(uuid[0]) * UUID_LEN);
+
+ if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SHARED_OBJECT)) {
+ return false;
+ }
+
+ return vu_send_message(dev, &msg);
+}
+
static bool
vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
{
diff --git a/subprojects/libvhost-user/libvhost-user.h
b/subprojects/libvhost-user/libvhost-user.h
index 49208cceaa..907af1bcda 100644
--- a/subprojects/libvhost-user/libvhost-user.h
+++ b/subprojects/libvhost-user/libvhost-user.h
@@ -64,7 +64,8 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS = 14,
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15,
-
+ /* Feature 16 is reserved for VHOST_USER_PROTOCOL_F_STATUS. */
+ VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 17,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -119,6 +120,9 @@ typedef enum VhostUserSlaveRequest {
VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG = 3,
VHOST_USER_BACKEND_VRING_CALL = 4,
VHOST_USER_BACKEND_VRING_ERR = 5,
+ VHOST_USER_BACKEND_SHARED_OBJECT_ADD = 6,
+ VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE = 7,
+ VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP = 8,
VHOST_USER_BACKEND_MAX
} VhostUserSlaveRequest;
@@ -172,6 +176,12 @@ typedef struct VhostUserInflight {
uint16_t queue_size;
} VhostUserInflight;
+#define UUID_LEN 16
+
+typedef struct VhostUserShared {
+ unsigned char uuid[UUID_LEN];
+} VhostUserShared;
+
#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__))
# define VU_PACKED __attribute__((gcc_struct, packed))
#else
@@ -199,6 +209,7 @@ typedef struct VhostUserMsg {
VhostUserConfig config;
VhostUserVringArea area;
VhostUserInflight inflight;
+ VhostUserShared object;
} payload;
int fds[VHOST_MEMORY_BASELINE_NREGIONS];
@@ -539,6 +550,46 @@ void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
int size, int offset);
+/**
+ * vu_get_shared_object:
+ * @dev: a VuDev context
+ * @uuid: UUID of the shared object
+ * @dmabuf_fd: output dma-buf file descriptor
+ *
+ * Lookup for a virtio shared object (i.e., dma-buf fd) associated with the
+ * received UUID. Result, if found, is stored in the dmabuf_fd argument.
+ *
+ * Returns: whether the virtio object was found.
+ */
+bool vu_get_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN],
+ int *dmabuf_fd);
+
+/**
+ * vu_add_shared_object:
+ * @dev: a VuDev context
+ * @uuid: UUID of the shared object
+ * @dmabuf_fd: output dma-buf file descriptor
+ *
+ * Stores a new shared object (i.e., dma-buf fd) in the hash table, and
+ * associates it with the received UUID.
+ *
+ * Returns: TRUE on success, FALSE on failure.
+ */
+bool vu_add_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN],
+ int dmabuf_fd);
+
+/**
+ * vu_rm_shared_object:
+ * @dev: a VuDev context
+ * @uuid: UUID of the shared object
+ *
+ * Removes a shared object (i.e., dma-buf fd) associated with the
+ * received UUID from the hash table.
+ *
+ * Returns: TRUE on success, FALSE on failure.
+ */
+bool vu_rm_shared_object(VuDev *dev, unsigned char uuid[UUID_LEN]);
+
/**
* vu_queue_set_notification:
* @dev: a VuDev context
--
2.40.0