From: Xie Yongji <xieyon...@baidu.com>
This patch adds support for VHOST_USER_GET_INFLIGHT_FD and
VHOST_USER_SET_INFLIGHT_FD message to set/get shared buffer
to/from qemu. Then backend can track inflight I/O in this buffer.
Signed-off-by: Xie Yongji <xieyon...@baidu.com>
Signed-off-by: Zhang Yu <zhangy...@baidu.com>
---
Makefile | 2 +-
contrib/libvhost-user/libvhost-user.c | 314 ++++++++++++++++++++++++--
contrib/libvhost-user/libvhost-user.h | 40 ++++
3 files changed, 335 insertions(+), 21 deletions(-)
diff --git a/Makefile b/Makefile
index dccba1dca2..3f3a5ace66 100644
--- a/Makefile
+++ b/Makefile
@@ -474,7 +474,7 @@ Makefile: $(version-obj-y)
# Build libraries
libqemuutil.a: $(util-obj-y) $(trace-obj-y) $(stub-obj-y)
-libvhost-user.a: $(libvhost-user-obj-y)
+libvhost-user.a: $(libvhost-user-obj-y) $(util-obj-y) $(stub-obj-y)
######################################################################
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index 23bd52264c..066fea668b 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -41,6 +41,8 @@
#endif
#include "qemu/atomic.h"
+#include "qemu/osdep.h"
+#include "qemu/memfd.h"
#include "libvhost-user.h"
@@ -53,6 +55,18 @@
_min1 < _min2 ? _min1 : _min2; })
#endif
+/* Round number down to multiple */
+#define ALIGN_DOWN(n, m) ((n) / (m) * (m))
+
+/* Round number up to multiple */
+#define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
+
+/* Align each region to cache line size in inflight buffer */
+#define INFLIGHT_ALIGNMENT 64
+
+/* The version of inflight buffer */
+#define INFLIGHT_VERSION 1
+
#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
/* The version of the protocol we support */
@@ -66,6 +80,20 @@
} \
} while (0)
+static inline
+bool has_feature(uint64_t features, unsigned int fbit)
+{
+ assert(fbit < 64);
+ return !!(features & (1ULL << fbit));
+}
+
+static inline
+bool vu_has_feature(VuDev *dev,
+ unsigned int fbit)
+{
+ return has_feature(dev->features, fbit);
+}
+
static const char *
vu_request_to_string(unsigned int req)
{
@@ -100,6 +128,8 @@ vu_request_to_string(unsigned int req)
REQ(VHOST_USER_POSTCOPY_ADVISE),
REQ(VHOST_USER_POSTCOPY_LISTEN),
REQ(VHOST_USER_POSTCOPY_END),
+ REQ(VHOST_USER_GET_INFLIGHT_FD),
+ REQ(VHOST_USER_SET_INFLIGHT_FD),
REQ(VHOST_USER_MAX),
};
#undef REQ
@@ -890,6 +920,59 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
return true;
}
+static int
+vu_check_queue_inflights(VuDev *dev, VuVirtq *vq)
+{
+ int i = 0;
+
+ if (!has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ return 0;
+ }
+
+ if (unlikely(!vq->inflight)) {
+ return -1;
+ }
+
+ /* check whether vm is reset */
+ if (unlikely(!vq->inflight->valid)) {
+ vq->inflight->valid = 1;
+ return 0;
+ }
+
+ vq->used_idx = vq->vring.used->idx;
+ vq->inflight_num = 0;
+ for (i = 0; i < vq->inflight->desc_num; i++) {
+ if (unlikely(vq->inflight->desc[i].version % 2 == 1)) {
+ if (vq->inflight->desc[i].used_idx != vq->used_idx) {
+ vq->inflight->desc[i].inuse = 0;
+ } else {
+ vq->inflight->desc[i].inuse = 1;
+ }
+
+ barrier();
+
+ vq->inflight->desc[i].version++;
+ }
+
+ if (vq->inflight->desc[i].inuse == 0) {
+ continue;
+ }
+
+ vq->inflight_desc[vq->inflight_num++] = i;
+ vq->inuse++;
+ }
+ vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
+
+ /* in case of I/O hang after reconnecting */
+ if (eventfd_write(vq->kick_fd, 1) ||
+ eventfd_write(vq->call_fd, 1)) {
+ return -1;
+ }
+
+ return 0;
+}
+
static bool
vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
{
@@ -925,6 +1008,10 @@ vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
dev->vq[index].kick_fd, index);
}
+ if (vu_check_queue_inflights(dev, &dev->vq[index])) {
+ vu_panic(dev, "Failed to check inflights for vq: %d\n", index);
+ }
+
return false;
}
@@ -1215,6 +1302,127 @@ vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
return true;
}
+static inline uint64_t
+vu_inflight_queue_size(uint16_t queue_size)
+{
+ return ALIGN_UP(sizeof(VuDescState) * queue_size +
+ sizeof(uint16_t), INFLIGHT_ALIGNMENT);
+}
+
+static bool
+vu_get_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
+{
+ int fd;
+ void *addr;
+ uint64_t mmap_size;
+ uint16_t num_queues, queue_size;
+
+ if (vmsg->size != sizeof(vmsg->payload.inflight)) {
+ vu_panic(dev, "Invalid get_inflight_fd message:%d", vmsg->size);
+ vmsg->payload.inflight.mmap_size = 0;
+ return true;
+ }
+
+ num_queues = vmsg->payload.inflight.num_queues;
+ queue_size = vmsg->payload.inflight.queue_size;
+
+ DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
+ DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
+
+ mmap_size = vu_inflight_queue_size(queue_size) * num_queues;
+
+ addr = qemu_memfd_alloc("vhost-inflight", mmap_size,
+ F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,
+ &fd, NULL);
+
+ if (!addr) {
+ vu_panic(dev, "Failed to alloc vhost inflight area");
+ vmsg->payload.inflight.mmap_size = 0;
+ return true;
+ }
+
+ memset(addr, 0, mmap_size);
+
+ dev->inflight_info.addr = addr;
+ dev->inflight_info.size = vmsg->payload.inflight.mmap_size = mmap_size;
+ dev->inflight_info.fd = vmsg->fds[0] = fd;
+ vmsg->fd_num = 1;
+ vmsg->payload.inflight.mmap_offset = 0;
+ vmsg->payload.inflight.version = INFLIGHT_VERSION;
+
+ DPRINT("send inflight mmap_size: %"PRId64"\n",
+ vmsg->payload.inflight.mmap_size);
+ DPRINT("send inflight mmap offset: %"PRId64"\n",
+ vmsg->payload.inflight.mmap_offset);
+ DPRINT("send inflight version: %"PRId16"\n",
+ vmsg->payload.inflight.version);
+
+ return true;
+}
+
+static bool
+vu_set_inflight_fd(VuDev *dev, VhostUserMsg *vmsg)
+{
+ int fd, i;
+ uint64_t mmap_size, mmap_offset;
+ uint16_t num_queues, queue_size, version;
+ void *rc;
+
+ if (vmsg->fd_num != 1 ||
+ vmsg->size != sizeof(vmsg->payload.inflight)) {
+ vu_panic(dev, "Invalid set_inflight_fd message size:%d fds:%d",
+ vmsg->size, vmsg->fd_num);
+ return false;
+ }
+
+ fd = vmsg->fds[0];
+ mmap_size = vmsg->payload.inflight.mmap_size;
+ mmap_offset = vmsg->payload.inflight.mmap_offset;
+ version = vmsg->payload.inflight.version;
+ num_queues = vmsg->payload.inflight.num_queues;
+ queue_size = vmsg->payload.inflight.queue_size;
+
+ DPRINT("set_inflight_fd mmap_size: %"PRId64"\n", mmap_size);
+ DPRINT("set_inflight_fd mmap_offset: %"PRId64"\n", mmap_offset);
+ DPRINT("set_inflight_fd version: %"PRId16"\n", version);
+ DPRINT("set_inflight_fd num_queues: %"PRId16"\n", num_queues);
+ DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
+
+ if (version > INFLIGHT_VERSION) {
+ vu_panic(dev, "Invalid set_inflight_fd version: %d", version);
+ return false;
+ }
+
+ rc = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+ fd, mmap_offset);
+
+ if (rc == MAP_FAILED) {
+ vu_panic(dev, "set_inflight_fd mmap error: %s", strerror(errno));
+ return false;
+ }
+
+ if (dev->inflight_info.fd) {
+ close(dev->inflight_info.fd);
+ }
+
+ if (dev->inflight_info.addr) {
+ munmap(dev->inflight_info.addr, dev->inflight_info.size);
+ }
+
+ dev->inflight_info.fd = fd;
+ dev->inflight_info.addr = rc;
+ dev->inflight_info.size = mmap_size;
+ dev->inflight_info.version = version;
+
+ for (i = 0; i < num_queues; i++) {
+ dev->vq[i].inflight = (VuVirtqInflight *)rc;
+ dev->vq[i].inflight->desc_num = queue_size;
+ rc = (void *)((char *)rc + vu_inflight_queue_size(queue_size));
+ }
+
+ return false;
+}
+
static bool
vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
{
@@ -1292,6 +1500,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
return vu_set_postcopy_listen(dev, vmsg);
case VHOST_USER_POSTCOPY_END:
return vu_set_postcopy_end(dev, vmsg);
+ case VHOST_USER_GET_INFLIGHT_FD:
+ return vu_get_inflight_fd(dev, vmsg);
+ case VHOST_USER_SET_INFLIGHT_FD:
+ return vu_set_inflight_fd(dev, vmsg);
default:
vmsg_close_fds(vmsg);
vu_panic(dev, "Unhandled request: %d", vmsg->request);
@@ -1359,8 +1571,18 @@ vu_deinit(VuDev *dev)
close(vq->err_fd);
vq->err_fd = -1;
}
+ vq->inflight = NULL;
}
+ if (dev->inflight_info.addr) {
+ munmap(dev->inflight_info.addr, dev->inflight_info.size);
+ dev->inflight_info.addr = NULL;
+ }
+
+ if (dev->inflight_info.fd > 0) {
+ close(dev->inflight_info.fd);
+ dev->inflight_info.fd = -1;
+ }
vu_close_log(dev);
if (dev->slave_fd != -1) {
@@ -1687,20 +1909,6 @@ vu_queue_empty(VuDev *dev, VuVirtq *vq)
return vring_avail_idx(vq) == vq->last_avail_idx;
}
-static inline
-bool has_feature(uint64_t features, unsigned int fbit)
-{
- assert(fbit < 64);
- return !!(features & (1ULL << fbit));
-}
-
-static inline
-bool vu_has_feature(VuDev *dev,
- unsigned int fbit)
-{
- return has_feature(dev->features, fbit);
-}
-
static bool
vring_notify(VuDev *dev, VuVirtq *vq)
{
@@ -1829,12 +2037,6 @@ virtqueue_map_desc(VuDev *dev,
*p_num_sg = num_sg;
}
-/* Round number down to multiple */
-#define ALIGN_DOWN(n, m) ((n) / (m) * (m))
-
-/* Round number up to multiple */
-#define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
-
static void *
virtqueue_alloc_element(size_t sz,
unsigned out_num, unsigned in_num)
@@ -1935,9 +2137,71 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int
idx, size_t sz)
return elem;
}
+static int
+vu_queue_inflight_get(VuDev *dev, VuVirtq *vq, int desc_idx)
+{
+ if (!has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ return 0;
+ }
+
+ if (unlikely(!vq->inflight)) {
+ return -1;
+ }
+
+ vq->inflight->desc[desc_idx].inuse = 1;
+
+ vq->inflight->desc[desc_idx].avail_idx = vq->last_avail_idx;
+
+ return 0;
+}
+
+static int
+vu_queue_inflight_pre_put(VuDev *dev, VuVirtq *vq, int desc_idx)
+{
+ if (!has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ return 0;
+ }
+
+ if (unlikely(!vq->inflight)) {
+ return -1;
+ }
+
+ vq->inflight->desc[desc_idx].used_idx = vq->used_idx;
+
+ barrier();
+
+ vq->inflight->desc[desc_idx].version++;
+
+ return 0;
+}
+
+static int
+vu_queue_inflight_post_put(VuDev *dev, VuVirtq *vq, int desc_idx)
+{
+ if (!has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+ return 0;
+ }
+
+ if (unlikely(!vq->inflight)) {
+ return -1;
+ }
+
+ vq->inflight->desc[desc_idx].inuse = 0;
+
+ barrier();
+
+ vq->inflight->desc[desc_idx].version++;
+
+ return 0;
+}
+
void *
vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
{
+ int i;
unsigned int head;
VuVirtqElement *elem;
@@ -1946,6 +2210,12 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
return NULL;
}
+ if (unlikely(vq->inflight_num > 0)) {
+ i = (--vq->inflight_num);
+ elem = vu_queue_map_desc(dev, vq, vq->inflight_desc[i], sz);
+ return elem;
+ }
+
if (vu_queue_empty(dev, vq)) {
return NULL;
}
@@ -1976,6 +2246,8 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
vq->inuse++;
+ vu_queue_inflight_get(dev, vq, head);
+
return elem;
}
@@ -2120,5 +2392,7 @@ vu_queue_push(VuDev *dev, VuVirtq *vq,
const VuVirtqElement *elem, unsigned int len)
{
vu_queue_fill(dev, vq, elem, len, 0);
+ vu_queue_inflight_pre_put(dev, vq, elem->index);
vu_queue_flush(dev, vq, 1);
+ vu_queue_inflight_post_put(dev, vq, elem->index);
}
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 4aa55b4d2d..a244342129 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -53,6 +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
};
@@ -91,6 +92,8 @@ typedef enum VhostUserRequest {
VHOST_USER_POSTCOPY_ADVISE = 28,
VHOST_USER_POSTCOPY_LISTEN = 29,
VHOST_USER_POSTCOPY_END = 30,
+ VHOST_USER_GET_INFLIGHT_FD = 31,
+ VHOST_USER_SET_INFLIGHT_FD = 32,
VHOST_USER_MAX
} VhostUserRequest;
@@ -138,6 +141,14 @@ typedef struct VhostUserVringArea {
uint64_t offset;
} VhostUserVringArea;
+typedef struct VhostUserInflight {
+ uint64_t mmap_size;
+ uint64_t mmap_offset;
+ uint16_t version;
+ uint16_t num_queues;
+ uint16_t queue_size;
+} VhostUserInflight;
+
#if defined(_WIN32)
# define VU_PACKED __attribute__((gcc_struct, packed))
#else
@@ -163,6 +174,7 @@ typedef struct VhostUserMsg {
VhostUserLog log;
VhostUserConfig config;
VhostUserVringArea area;
+ VhostUserInflight inflight;
} payload;
int fds[VHOST_MEMORY_MAX_NREGIONS];
@@ -234,9 +246,29 @@ typedef struct VuRing {
uint32_t flags;
} VuRing;
+typedef struct VuDescState {
+ uint8_t inuse;
+ uint8_t version;
+ uint16_t used_idx;
+ uint16_t avail_idx;
+ uint16_t reserved;
+} VuDescState;
+
+typedef struct VuVirtqInflight {
+ uint8_t valid;
+ uint16_t desc_num;
+ VuDescState desc[0];
+} VuVirtqInflight;
+
typedef struct VuVirtq {
VuRing vring;
+ VuVirtqInflight *inflight;
+
+ uint16_t inflight_desc[VIRTQUEUE_MAX_SIZE];
+
+ uint16_t inflight_num;
+
/* Next head to pop */
uint16_t last_avail_idx;
@@ -279,11 +311,19 @@ typedef void (*vu_set_watch_cb) (VuDev *dev, int fd, int
condition,
vu_watch_cb cb, void *data);
typedef void (*vu_remove_watch_cb) (VuDev *dev, int fd);
+typedef struct VuDevInflightInfo {
+ int fd;
+ void *addr;
+ uint64_t size;
+ uint16_t version;
+} VuDevInflightInfo;
+
struct VuDev {
int sock;
uint32_t nregions;
VuDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
+ VuDevInflightInfo inflight_info;
int log_call_fd;
int slave_fd;
uint64_t log_size;
--
2.17.1
