From: Xie Yongji <xieyon...@baidu.com>
This introduces a new message VHOST_USER_SET_VRING_INFLIGHT
to support offering shared memory to backend to record
its inflight I/O.
With this new message, the backend is able to restart without
missing I/O which would cause I/O hung for block device.
Signed-off-by: Xie Yongji <xieyon...@baidu.com>
Signed-off-by: Chai Wen <chai...@baidu.com>
Signed-off-by: Zhang Yu <zhangy...@baidu.com>
---
hw/virtio/vhost-user.c | 69 +++++++++++++++++++++++++++++++
hw/virtio/vhost.c | 8 ++++
include/hw/virtio/vhost-backend.h | 4 ++
include/hw/virtio/vhost-user.h | 8 ++++
4 files changed, 89 insertions(+)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index e09bed0e4a..4c0e64891d 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -19,6 +19,7 @@
#include "sysemu/kvm.h"
#include "qemu/error-report.h"
#include "qemu/sockets.h"
+#include "qemu/memfd.h"
#include "sysemu/cryptodev.h"
#include "migration/migration.h"
#include "migration/postcopy-ram.h"
@@ -52,6 +53,7 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_CONFIG = 9,
VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -89,6 +91,7 @@ typedef enum VhostUserRequest {
VHOST_USER_POSTCOPY_ADVISE = 28,
VHOST_USER_POSTCOPY_LISTEN = 29,
VHOST_USER_POSTCOPY_END = 30,
+ VHOST_USER_SET_VRING_INFLIGHT = 31,
VHOST_USER_MAX
} VhostUserRequest;
@@ -147,6 +150,11 @@ typedef struct VhostUserVringArea {
uint64_t offset;
} VhostUserVringArea;
+typedef struct VhostUserVringInflight {
+ uint32_t size;
+ uint32_t idx;
+} VhostUserVringInflight;
+
typedef struct {
VhostUserRequest request;
@@ -169,6 +177,7 @@ typedef union {
VhostUserConfig config;
VhostUserCryptoSession session;
VhostUserVringArea area;
+ VhostUserVringInflight inflight;
} VhostUserPayload;
typedef struct VhostUserMsg {
@@ -1739,6 +1748,58 @@ static bool vhost_user_mem_section_filter(struct
vhost_dev *dev,
return result;
}
+static int vhost_user_set_vring_inflight(struct vhost_dev *dev, int idx)
+{
+ struct vhost_user *u = dev->opaque;
+
+ if (!virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ return 0;
+ }
+
+ if (!u->user->inflight[idx].addr) {
+ Error *err = NULL;
+
+ u->user->inflight[idx].size = qemu_real_host_page_size;
+ u->user->inflight[idx].addr = qemu_memfd_alloc("vhost-inflight",
+ u->user->inflight[idx].size,
+ F_SEAL_GROW | F_SEAL_SHRINK |
F_SEAL_SEAL,
+ &u->user->inflight[idx].fd, &err);
+ if (err) {
+ error_report_err(err);
+ u->user->inflight[idx].addr = NULL;
+ return -1;
+ }
+ }
+
+ VhostUserMsg msg = {
+ .hdr.request = VHOST_USER_SET_VRING_INFLIGHT,
+ .hdr.flags = VHOST_USER_VERSION,
+ .payload.inflight.size = u->user->inflight[idx].size,
+ .payload.inflight.idx = idx,
+ .hdr.size = sizeof(msg.payload.inflight),
+ };
+
+ if (vhost_user_write(dev, &msg, &u->user->inflight[idx].fd, 1) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+void vhost_user_inflight_reset(VhostUserState *user)
+{
+ int i;
+
+ for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+ if (!user->inflight[i].addr) {
+ continue;
+ }
+
+ memset(user->inflight[i].addr, 0, user->inflight[i].size);
+ }
+}
+
VhostUserState *vhost_user_init(void)
{
VhostUserState *user = g_new0(struct VhostUserState, 1);
@@ -1756,6 +1817,13 @@ void vhost_user_cleanup(VhostUserState *user)
munmap(user->notifier[i].addr, qemu_real_host_page_size);
user->notifier[i].addr = NULL;
}
+
+ if (user->inflight[i].addr) {
+ munmap(user->inflight[i].addr, user->inflight[i].size);
+ user->inflight[i].addr = NULL;
+ close(user->inflight[i].fd);
+ user->inflight[i].fd = -1;
+ }
}
}
@@ -1790,4 +1858,5 @@ const VhostOps user_ops = {
.vhost_crypto_create_session = vhost_user_crypto_create_session,
.vhost_crypto_close_session = vhost_user_crypto_close_session,
.vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
+ .vhost_set_vring_inflight = vhost_user_set_vring_inflight,
};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 569c4053ea..2ca7b4e841 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -973,6 +973,14 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
return -errno;
}
+ if (dev->vhost_ops->vhost_set_vring_inflight) {
+ r = dev->vhost_ops->vhost_set_vring_inflight(dev, vhost_vq_index);
+ if (r) {
+ VHOST_OPS_DEBUG("vhost_set_vring_inflight failed");
+ return -errno;
+ }
+ }
+
state.num = virtio_queue_get_last_avail_idx(vdev, idx);
r = dev->vhost_ops->vhost_set_vring_base(dev, &state);
if (r) {
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
index 81283ec50f..8110e09089 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -104,6 +104,9 @@ typedef int (*vhost_crypto_close_session_op)(struct
vhost_dev *dev,
typedef bool (*vhost_backend_mem_section_filter_op)(struct vhost_dev *dev,
MemoryRegionSection *section);
+typedef int (*vhost_set_vring_inflight_op)(struct vhost_dev *dev,
+ int idx);
+
typedef struct VhostOps {
VhostBackendType backend_type;
vhost_backend_init vhost_backend_init;
@@ -142,6 +145,7 @@ typedef struct VhostOps {
vhost_crypto_create_session_op vhost_crypto_create_session;
vhost_crypto_close_session_op vhost_crypto_close_session;
vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter;
+ vhost_set_vring_inflight_op vhost_set_vring_inflight;
} VhostOps;
extern const VhostOps user_ops;
diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
index fd660393a0..ff13433153 100644
--- a/include/hw/virtio/vhost-user.h
+++ b/include/hw/virtio/vhost-user.h
@@ -17,11 +17,19 @@ typedef struct VhostUserHostNotifier {
bool set;
} VhostUserHostNotifier;
+typedef struct VhostUserInflight {
+ void *addr;
+ uint32_t size;
+ int fd;
+} VhostUserInflight;
+
typedef struct VhostUserState {
CharBackend *chr;
VhostUserHostNotifier notifier[VIRTIO_QUEUE_MAX];
+ VhostUserInflight inflight[VIRTIO_QUEUE_MAX];
} VhostUserState;
+void vhost_user_inflight_reset(VhostUserState *user);
VhostUserState *vhost_user_init(void);
void vhost_user_cleanup(VhostUserState *user);
--
2.17.1
