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* [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting
@ 2019-02-28  8:53 elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 1/7] vhost-user: Support transferring inflight buffer between qemu and backend elohimes
                   ` (6 more replies)
  0 siblings, 7 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

This patchset is aimed at supporting qemu to reconnect
vhost-user-blk backend after vhost-user-blk backend crash or
restart.

The patch 1 introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring shared
buffer between qemu and backend.

The patch 2 deletes some redundant check in contrib/libvhost-user.c.

The patch 3,4 are the corresponding libvhost-user patches of
patch 1. Make libvhost-user support VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD.

The patch 5 allows vhost-user-blk to use the two new messages
to get/set inflight buffer from/to backend.

The patch 6 supports vhost-user-blk to reconnect backend when
connection closed.

The patch 7 introduces VHOST_USER_PROTOCOL_F_SLAVE_SHMFD
to vhost-user-blk backend which is used to tell qemu that
we support reconnecting now.

To use it, we could start qemu with:

qemu-system-x86_64 \
        -chardev socket,id=char0,path=/path/vhost.socket,reconnect=1, \
        -device vhost-user-blk-pci,chardev=char0 \

and start vhost-user-blk backend with:

vhost-user-blk -b /path/file -s /path/vhost.socket

Then we can restart vhost-user-blk at any time during VM running.

V6 to V7:
- Introduce a 64-bit counter to struct DescStateSplit/DescStatePacked
  to preserve the order of fetching available descriptors
- Add support to resubmit inflight I/O in order in libvhost-user.c
- Rename process_head to last_batch_head in struct DescStateSplit

V5 to V6:
- Document the layout in inflight buffer for packed virtqueue
- Rework the layout in inflight buffer for split virtqueue
- Remove version field in VhostUserInflight
- Add a patch to remove some redundant check in
  contrib/libvhost-user.c
- Document more details in vhost-user.txt

V4 to V5:
- Drop patch that enables "nowait" option on client sockets
- Support resubmitting inflight I/O in order
- Make inflight I/O tracking more robust
- Remove align field and add queue size field in VhostUserInflight
- Document more details in vhost-user.txt

V3 to V4:
- Drop messages VHOST_USER_GET_SHM_SIZE and VHOST_USER_SET_SHM_FD
- Introduce two new messages VHOST_USER_GET_INFLIGHT_FD
  and VHOST_USER_SET_INFLIGHT_FD
- Allocate inflight buffer in backend rather than in qemu
- Document a recommended format for inflight buffer

V2 to V3:
- Using exisiting wait/nowait options to control connection on
  client sockets instead of introducing "disconnected" option.
- Support the case that vhost-user backend restart during initialzation
  of vhost-user-blk device.

V1 to V2:
- Introduce "disconnected" option for chardev instead of reuse "wait"
  option
- Support the case that QEMU starts before vhost-user backend
- Drop message VHOST_USER_SET_VRING_INFLIGHT
- Introduce two new messages VHOST_USER_GET_SHM_SIZE
  and VHOST_USER_SET_SHM_FD

Xie Yongji (7):
  vhost-user: Support transferring inflight buffer between qemu and
    backend
  libvhost-user: Remove unnecessary FD flag check for event file
    descriptors
  libvhost-user: Introduce vu_queue_map_desc()
  libvhost-user: Support tracking inflight I/O in shared memory
  vhost-user-blk: Add support to get/set inflight buffer
  vhost-user-blk: Add support to reconnect backend
  contrib/vhost-user-blk: enable inflight I/O tracking

 Makefile                                |   2 +-
 contrib/libvhost-user/libvhost-user.c   | 449 ++++++++++++++++++++----
 contrib/libvhost-user/libvhost-user.h   |  70 ++++
 contrib/vhost-user-blk/vhost-user-blk.c |   3 +-
 docs/interop/vhost-user.txt             | 285 +++++++++++++++
 hw/block/vhost-user-blk.c               | 229 +++++++++---
 hw/virtio/vhost-user.c                  | 107 ++++++
 hw/virtio/vhost.c                       |  96 +++++
 include/hw/virtio/vhost-backend.h       |  10 +
 include/hw/virtio/vhost-user-blk.h      |   5 +
 include/hw/virtio/vhost.h               |  18 +
 11 files changed, 1166 insertions(+), 108 deletions(-)

-- 
2.17.1

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 1/7] vhost-user: Support transferring inflight buffer between qemu and backend
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 2/7] libvhost-user: Remove unnecessary FD flag check for event file descriptors elohimes
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

This patch introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
buffer between qemu and backend.

Firstly, qemu uses VHOST_USER_GET_INFLIGHT_FD to get the
shared buffer from backend. Then qemu should send it back
through VHOST_USER_SET_INFLIGHT_FD each time we start vhost-user.

This shared buffer is used to track inflight I/O by backend.
Qemu should retrieve a new one when vm reset.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 docs/interop/vhost-user.txt       | 285 ++++++++++++++++++++++++++++++
 hw/virtio/vhost-user.c            | 107 +++++++++++
 hw/virtio/vhost.c                 |  96 ++++++++++
 include/hw/virtio/vhost-backend.h |  10 ++
 include/hw/virtio/vhost.h         |  18 ++
 5 files changed, 516 insertions(+)

diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index c2194711d9..de7e38c7db 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -142,6 +142,17 @@ Depending on the request type, payload can be:
    Offset: a 64-bit offset of this area from the start of the
        supplied file descriptor
 
+ * Inflight description
+   -----------------------------------------------------
+   | mmap size | mmap offset | num queues | queue size |
+   -----------------------------------------------------
+
+   mmap size: a 64-bit size of area to track inflight I/O
+   mmap offset: a 64-bit offset of this area from the start
+                of the supplied file descriptor
+   num queues: a 16-bit number of virtqueues
+   queue size: a 16-bit size of virtqueues
+
 In QEMU the vhost-user message is implemented with the following struct:
 
 typedef struct VhostUserMsg {
@@ -157,6 +168,7 @@ typedef struct VhostUserMsg {
         struct vhost_iotlb_msg iotlb;
         VhostUserConfig config;
         VhostUserVringArea area;
+        VhostUserInflight inflight;
     };
 } QEMU_PACKED VhostUserMsg;
 
@@ -175,6 +187,7 @@ the ones that do:
  * VHOST_USER_GET_PROTOCOL_FEATURES
  * VHOST_USER_GET_VRING_BASE
  * VHOST_USER_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD)
+ * VHOST_USER_GET_INFLIGHT_FD (if VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)
 
 [ Also see the section on REPLY_ACK protocol extension. ]
 
@@ -188,6 +201,7 @@ in the ancillary data:
  * VHOST_USER_SET_VRING_CALL
  * VHOST_USER_SET_VRING_ERR
  * VHOST_USER_SET_SLAVE_REQ_FD
+ * VHOST_USER_SET_INFLIGHT_FD (if VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)
 
 If Master is unable to send the full message or receives a wrong reply it will
 close the connection. An optional reconnection mechanism can be implemented.
@@ -382,6 +396,256 @@ If VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD protocol feature is negotiated,
 slave can send file descriptors (at most 8 descriptors in each message)
 to master via ancillary data using this fd communication channel.
 
+Inflight I/O tracking
+---------------------
+
+To support reconnecting after restart or crash, slave may need to resubmit
+inflight I/Os. If virtqueue is processed in order, we can easily achieve
+that by getting the inflight descriptors from descriptor table (split virtqueue)
+or descriptor ring (packed virtqueue). However, it can't work when we process
+descriptors out-of-order because some entries which store the information of
+inflight descriptors in available ring (split virtqueue) or descriptor
+ring (packed virtqueue) might be overrided by new entries. To solve this
+problem, slave need to allocate an extra buffer to store this information of inflight
+descriptors and share it with master for persistent. VHOST_USER_GET_INFLIGHT_FD and
+VHOST_USER_SET_INFLIGHT_FD are used to transfer this buffer between master
+and slave. And the format of this buffer is described below:
+
+-------------------------------------------------------
+| queue0 region | queue1 region | ... | queueN region |
+-------------------------------------------------------
+
+N is the number of available virtqueues. Slave could get it from num queues
+field of VhostUserInflight.
+
+For split virtqueue, queue region can be implemented as:
+
+typedef struct DescStateSplit {
+    /* Indicate whether this descriptor is inflight or not.
+     * Only available for head-descriptor. */
+    uint8_t inflight;
+
+    /* Padding */
+    uint8_t padding[5];
+
+    /* Maintain a list for the last batch of used descriptors.
+     * Only available when batching is used for submitting */
+    uint16_t next;
+
+    /* Used to preserve the order of fetching available descriptors.
+     * Only available for head-descriptor. */
+    uint64_t counter;
+} DescStateSplit;
+
+typedef struct QueueRegionSplit {
+    /* The feature flags of this region. Now it's initialized to 0. */
+    uint64_t features;
+
+    /* The version of this region. It's 1 currently.
+     * Zero value indicates an uninitialized buffer */
+    uint16_t version;
+
+    /* The size of DescStateSplit array. It's equal to the virtqueue
+     * size. Slave could get it from queue size field of VhostUserInflight. */
+    uint16_t desc_num;
+
+    /* The head of list that track the last batch of used descriptors. */
+    uint16_t last_batch_head;
+
+    /* Store the idx value of used ring */
+    uint16_t used_idx;
+
+    /* Used to track the state of each descriptor in descriptor table */
+    DescStateSplit desc[0];
+} QueueRegionSplit;
+
+To track inflight I/O, the queue region should be processed as follows:
+
+When receiving available buffers from the driver:
+
+    1. Get the next available head-descriptor index from available ring, i
+
+    2. Set desc[i].counter to the value of global counter
+
+    3. Increase global counter by 1
+
+    4. Set desc[i].inflight to 1
+
+When supplying used buffers to the driver:
+
+    1. Get corresponding used head-descriptor index, i
+
+    2. Set desc[i].next to last_batch_head
+
+    3. Set last_batch_head to i
+
+    4. Steps 1,2,3 may be performed repeatedly if batching is possible
+
+    5. Increase the idx value of used ring by the size of the batch
+
+    6. Set the inflight field of each DescStateSplit entry in the batch to 0
+
+    7. Set used_idx to the idx value of used ring
+
+When reconnecting:
+
+    1. If the value of used_idx does not match the idx value of used ring (means
+    the inflight field of DescStateSplit entries in last batch may be incorrect),
+
+        (a) Subtract the value of used_idx from the idx value of used ring to get
+        last batch size of DescStateSplit entries
+
+        (b) Set the inflight field of each DescStateSplit entry to 0 in last batch
+        list which starts from last_batch_head
+
+        (c) Set used_idx to the idx value of used ring
+
+    2. Resubmit inflight DescStateSplit entries in order of their counter value
+
+For packed virtqueue, queue region can be implemented as:
+
+typedef struct DescStatePacked {
+    /* Indicate whether this descriptor is inflight or not.
+     * Only available for head-descriptor. */
+    uint8_t inflight;
+
+    /* Padding */
+    uint8_t padding;
+
+    /* Link to the next free entry */
+    uint16_t next;
+
+    /* Link to the last entry of descriptor list.
+     * Only available for head-descriptor. */
+    uint16_t last;
+
+    /* The length of descriptor list.
+     * Only available for head-descriptor. */
+    uint16_t num;
+
+    /* Used to preserve the order of fetching available descriptors.
+     * Only available for head-descriptor. */
+    uint64_t counter;
+
+    /* The buffer id */
+    uint16_t id;
+
+    /* The descriptor flags */
+    uint16_t flags;
+
+    /* The buffer length */
+    uint32_t len;
+
+    /* The buffer address */
+    uint64_t addr;
+} DescStatePacked;
+
+typedef struct QueueRegionPacked {
+    /* The feature flags of this region. Now it's initialized to 0. */
+    uint64_t features;
+
+    /* The version of this region. It's 1 currently.
+     * Zero value indicates an uninitialized buffer */
+    uint16_t version;
+
+    /* The size of DescStatePacked array. It's equal to the virtqueue
+     * size. Slave could get it from queue size field of VhostUserInflight. */
+    uint16_t desc_num;
+
+    /* The head of free DescStatePacked entry list */
+    uint16_t free_head;
+
+    /* The old head of free DescStatePacked entry list */
+    uint16_t old_free_head;
+
+    /* The used index of descriptor ring */
+    uint16_t used_idx;
+
+    /* The old used index of descriptor ring */
+    uint16_t old_used_idx;
+
+    /* Device ring wrap counter */
+    uint8_t used_wrap_counter;
+
+    /* The old device ring wrap counter */
+    uint8_t old_used_wrap_counter;
+
+    /* Padding */
+    uint8_t padding[7];
+
+    /* Used to track the state of each descriptor fetched from descriptor ring */
+    DescStatePacked desc[0];
+} QueueRegionPacked;
+
+To track inflight I/O, the queue region should be processed as follows:
+
+When receiving available buffers from the driver:
+
+    1. Get the next available descriptor entry from descriptor ring, d
+
+    2. If d is head descriptor,
+
+        (a) Set desc[old_free_head].num to 0
+
+        (b) Set desc[old_free_head].counter to the value of global counter
+
+        (c) Increase global counter by 1
+
+        (d) Set desc[old_free_head].inflight to 1
+
+    3. If d is last descriptor, set desc[old_free_head].last to free_head
+
+    4. Increase desc[old_free_head].num by 1
+
+    5. Set desc[free_head].addr, desc[free_head].len, desc[free_head].flags,
+    desc[free_head].id to d.addr, d.len, d.flags, d.id
+
+    6. Set free_head to desc[free_head].next
+
+    7. If d is last descriptor, set old_free_head to free_head
+
+When supplying used buffers to the driver:
+
+    1. Get corresponding used head-descriptor entry from descriptor ring, d
+
+    2. Get corresponding DescStatePacked entry, e
+
+    3. Set desc[e.last].next to free_head
+
+    4. Set free_head to the index of e
+
+    5. Steps 1,2,3,4 may be performed repeatedly if batching is possible
+
+    6. Increase used_idx by the size of the batch and update used_wrap_counter if needed
+
+    7. Update d.flags
+
+    8. Set the inflight field of each head DescStatePacked entry in the batch to 0
+
+    9. Set old_free_head, old_used_idx, old_used_wrap_counter to free_head, used_idx,
+    used_wrap_counter
+
+When reconnecting:
+
+    1. If used_idx does not match old_used_idx (means the inflight field of DescStatePacked
+    entries in last batch may be incorrect),
+
+        (a) Get the next descriptor ring entry through old_used_idx, d
+
+        (b) Use old_used_wrap_counter to calculate the available flags
+
+        (c) If d.flags is not equal to the calculated flags value (means slave has
+        submitted the buffer to guest driver before crash, so it has to commit the
+        in-progres update), set old_free_head, old_used_idx, old_used_wrap_counter
+        to free_head, used_idx, used_wrap_counter
+
+    2. Set free_head, used_idx, used_wrap_counter to old_free_head, old_used_idx,
+    old_used_wrap_counter (roll back any in-progress update)
+
+    3. Set the inflight field of each DescStatePacked entry in free list to 0
+
+    4. Resubmit inflight DescStatePacked entries in order of their counter value
+
 Protocol features
 -----------------
 
@@ -397,6 +661,7 @@ Protocol features
 #define VHOST_USER_PROTOCOL_F_CONFIG         9
 #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD  10
 #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER  11
+#define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD 12
 
 Master message types
 --------------------
@@ -761,6 +1026,26 @@ Master message types
       was previously sent.
       The value returned is an error indication; 0 is success.
 
+ * VHOST_USER_GET_INFLIGHT_FD
+      Id: 31
+      Equivalent ioctl: N/A
+      Master payload: inflight description
+
+      When VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD protocol feature has been
+      successfully negotiated, this message is submitted by master to get
+      a shared buffer from slave. The shared buffer will be used to track
+      inflight I/O by slave. QEMU should retrieve a new one when vm reset.
+
+ * VHOST_USER_SET_INFLIGHT_FD
+      Id: 32
+      Equivalent ioctl: N/A
+      Master payload: inflight description
+
+      When VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD protocol feature has been
+      successfully negotiated, this message is submitted by master to send
+      the shared inflight buffer back to slave so that slave could get
+      inflight I/O after a crash or restart.
+
 Slave message types
 -------------------
 
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 564a31d12c..21a81998ba 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -52,6 +52,7 @@ 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 +90,8 @@ 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;
 
@@ -147,6 +150,13 @@ typedef struct VhostUserVringArea {
     uint64_t offset;
 } VhostUserVringArea;
 
+typedef struct VhostUserInflight {
+    uint64_t mmap_size;
+    uint64_t mmap_offset;
+    uint16_t num_queues;
+    uint16_t queue_size;
+} VhostUserInflight;
+
 typedef struct {
     VhostUserRequest request;
 
@@ -169,6 +179,7 @@ typedef union {
         VhostUserConfig config;
         VhostUserCryptoSession session;
         VhostUserVringArea area;
+        VhostUserInflight inflight;
 } VhostUserPayload;
 
 typedef struct VhostUserMsg {
@@ -1739,6 +1750,100 @@ static bool vhost_user_mem_section_filter(struct vhost_dev *dev,
     return result;
 }
 
+static int vhost_user_get_inflight_fd(struct vhost_dev *dev,
+                                      uint16_t queue_size,
+                                      struct vhost_inflight *inflight)
+{
+    void *addr;
+    int fd;
+    struct vhost_user *u = dev->opaque;
+    CharBackend *chr = u->user->chr;
+    VhostUserMsg msg = {
+        .hdr.request = VHOST_USER_GET_INFLIGHT_FD,
+        .hdr.flags = VHOST_USER_VERSION,
+        .payload.inflight.num_queues = dev->nvqs,
+        .payload.inflight.queue_size = queue_size,
+        .hdr.size = sizeof(msg.payload.inflight),
+    };
+
+    if (!virtio_has_feature(dev->protocol_features,
+                            VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+        return 0;
+    }
+
+    if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+        return -1;
+    }
+
+    if (vhost_user_read(dev, &msg) < 0) {
+        return -1;
+    }
+
+    if (msg.hdr.request != VHOST_USER_GET_INFLIGHT_FD) {
+        error_report("Received unexpected msg type. "
+                     "Expected %d received %d",
+                     VHOST_USER_GET_INFLIGHT_FD, msg.hdr.request);
+        return -1;
+    }
+
+    if (msg.hdr.size != sizeof(msg.payload.inflight)) {
+        error_report("Received bad msg size.");
+        return -1;
+    }
+
+    if (!msg.payload.inflight.mmap_size) {
+        return 0;
+    }
+
+    fd = qemu_chr_fe_get_msgfd(chr);
+    if (fd < 0) {
+        error_report("Failed to get mem fd");
+        return -1;
+    }
+
+    addr = mmap(0, msg.payload.inflight.mmap_size, PROT_READ | PROT_WRITE,
+                MAP_SHARED, fd, msg.payload.inflight.mmap_offset);
+
+    if (addr == MAP_FAILED) {
+        error_report("Failed to mmap mem fd");
+        close(fd);
+        return -1;
+    }
+
+    inflight->addr = addr;
+    inflight->fd = fd;
+    inflight->size = msg.payload.inflight.mmap_size;
+    inflight->offset = msg.payload.inflight.mmap_offset;
+    inflight->queue_size = queue_size;
+
+    return 0;
+}
+
+static int vhost_user_set_inflight_fd(struct vhost_dev *dev,
+                                      struct vhost_inflight *inflight)
+{
+    VhostUserMsg msg = {
+        .hdr.request = VHOST_USER_SET_INFLIGHT_FD,
+        .hdr.flags = VHOST_USER_VERSION,
+        .payload.inflight.mmap_size = inflight->size,
+        .payload.inflight.mmap_offset = inflight->offset,
+        .payload.inflight.num_queues = dev->nvqs,
+        .payload.inflight.queue_size = inflight->queue_size,
+        .hdr.size = sizeof(msg.payload.inflight),
+    };
+
+    if (!virtio_has_feature(dev->protocol_features,
+                            VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD)) {
+        return 0;
+    }
+
+    if (vhost_user_write(dev, &msg, &inflight->fd, 1) < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
 VhostUserState *vhost_user_init(void)
 {
     VhostUserState *user = g_new0(struct VhostUserState, 1);
@@ -1790,4 +1895,6 @@ 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_get_inflight_fd = vhost_user_get_inflight_fd,
+        .vhost_set_inflight_fd = vhost_user_set_inflight_fd,
 };
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 569c4053ea..8db1a855eb 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1481,6 +1481,102 @@ void vhost_dev_set_config_notifier(struct vhost_dev *hdev,
     hdev->config_ops = ops;
 }
 
+void vhost_dev_free_inflight(struct vhost_inflight *inflight)
+{
+    if (inflight->addr) {
+        qemu_memfd_free(inflight->addr, inflight->size, inflight->fd);
+        inflight->addr = NULL;
+        inflight->fd = -1;
+    }
+}
+
+static int vhost_dev_resize_inflight(struct vhost_inflight *inflight,
+                                     uint64_t new_size)
+{
+    Error *err = NULL;
+    int fd = -1;
+    void *addr = qemu_memfd_alloc("vhost-inflight", new_size,
+                                  F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL,
+                                  &fd, &err);
+
+    if (err) {
+        error_report_err(err);
+        return -1;
+    }
+
+    vhost_dev_free_inflight(inflight);
+    inflight->offset = 0;
+    inflight->addr = addr;
+    inflight->fd = fd;
+    inflight->size = new_size;
+
+    return 0;
+}
+
+void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f)
+{
+    if (inflight->addr) {
+        qemu_put_be64(f, inflight->size);
+        qemu_put_be16(f, inflight->queue_size);
+        qemu_put_buffer(f, inflight->addr, inflight->size);
+    } else {
+        qemu_put_be64(f, 0);
+    }
+}
+
+int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f)
+{
+    uint64_t size;
+
+    size = qemu_get_be64(f);
+    if (!size) {
+        return 0;
+    }
+
+    if (inflight->size != size) {
+        if (vhost_dev_resize_inflight(inflight, size)) {
+            return -1;
+        }
+    }
+    inflight->queue_size = qemu_get_be16(f);
+
+    qemu_get_buffer(f, inflight->addr, size);
+
+    return 0;
+}
+
+int vhost_dev_set_inflight(struct vhost_dev *dev,
+                           struct vhost_inflight *inflight)
+{
+    int r;
+
+    if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) {
+        r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight);
+        if (r) {
+            VHOST_OPS_DEBUG("vhost_set_inflight_fd failed");
+            return -errno;
+        }
+    }
+
+    return 0;
+}
+
+int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
+                           struct vhost_inflight *inflight)
+{
+    int r;
+
+    if (dev->vhost_ops->vhost_get_inflight_fd) {
+        r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight);
+        if (r) {
+            VHOST_OPS_DEBUG("vhost_get_inflight_fd failed");
+            return -errno;
+        }
+    }
+
+    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 81283ec50f..d6632a18e6 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -25,6 +25,7 @@ typedef enum VhostSetConfigType {
     VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
 } VhostSetConfigType;
 
+struct vhost_inflight;
 struct vhost_dev;
 struct vhost_log;
 struct vhost_memory;
@@ -104,6 +105,13 @@ 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_get_inflight_fd_op)(struct vhost_dev *dev,
+                                        uint16_t queue_size,
+                                        struct vhost_inflight *inflight);
+
+typedef int (*vhost_set_inflight_fd_op)(struct vhost_dev *dev,
+                                        struct vhost_inflight *inflight);
+
 typedef struct VhostOps {
     VhostBackendType backend_type;
     vhost_backend_init vhost_backend_init;
@@ -142,6 +150,8 @@ 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_get_inflight_fd_op vhost_get_inflight_fd;
+    vhost_set_inflight_fd_op vhost_set_inflight_fd;
 } VhostOps;
 
 extern const VhostOps user_ops;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index a7f449fa87..619498c8f4 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -7,6 +7,15 @@
 #include "exec/memory.h"
 
 /* Generic structures common for any vhost based device. */
+
+struct vhost_inflight {
+    int fd;
+    void *addr;
+    uint64_t size;
+    uint64_t offset;
+    uint16_t queue_size;
+};
+
 struct vhost_virtqueue {
     int kick;
     int call;
@@ -120,4 +129,13 @@ int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
  */
 void vhost_dev_set_config_notifier(struct vhost_dev *dev,
                                    const VhostDevConfigOps *ops);
+
+void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
+void vhost_dev_free_inflight(struct vhost_inflight *inflight);
+void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f);
+int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f);
+int vhost_dev_set_inflight(struct vhost_dev *dev,
+                           struct vhost_inflight *inflight);
+int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
+                           struct vhost_inflight *inflight);
 #endif
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 2/7] libvhost-user: Remove unnecessary FD flag check for event file descriptors
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 1/7] vhost-user: Support transferring inflight buffer between qemu and backend elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 3/7] libvhost-user: Introduce vu_queue_map_desc() elohimes
                   ` (4 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

The vu_check_queue_msg_file() has checked the FD flag. So let's
delete the redundant check after it.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 contrib/libvhost-user/libvhost-user.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 3f14b4138b..16fec3a3fd 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -907,10 +907,8 @@ vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
         dev->vq[index].kick_fd = -1;
     }
 
-    if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) {
-        dev->vq[index].kick_fd = vmsg->fds[0];
-        DPRINT("Got kick_fd: %d for vq: %d\n", vmsg->fds[0], index);
-    }
+    dev->vq[index].kick_fd = vmsg->fds[0];
+    DPRINT("Got kick_fd: %d for vq: %d\n", vmsg->fds[0], index);
 
     dev->vq[index].started = true;
     if (dev->iface->queue_set_started) {
@@ -995,9 +993,7 @@ vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
         dev->vq[index].call_fd = -1;
     }
 
-    if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) {
-        dev->vq[index].call_fd = vmsg->fds[0];
-    }
+    dev->vq[index].call_fd = vmsg->fds[0];
 
     DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
 
@@ -1020,9 +1016,7 @@ vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg)
         dev->vq[index].err_fd = -1;
     }
 
-    if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) {
-        dev->vq[index].err_fd = vmsg->fds[0];
-    }
+    dev->vq[index].err_fd = vmsg->fds[0];
 
     return false;
 }
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 3/7] libvhost-user: Introduce vu_queue_map_desc()
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 1/7] vhost-user: Support transferring inflight buffer between qemu and backend elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 2/7] libvhost-user: Remove unnecessary FD flag check for event file descriptors elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 4/7] libvhost-user: Support tracking inflight I/O in shared memory elohimes
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

Introduce vu_queue_map_desc() which should be
independent with vu_queue_pop();

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 contrib/libvhost-user/libvhost-user.c | 88 ++++++++++++++++-----------
 1 file changed, 51 insertions(+), 37 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 16fec3a3fd..ea0f414b6d 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -1847,49 +1847,20 @@ virtqueue_alloc_element(size_t sz,
     return elem;
 }
 
-void *
-vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
+static void *
+vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz)
 {
-    unsigned int i, head, max, desc_len;
+    struct vring_desc *desc = vq->vring.desc;
     uint64_t desc_addr, read_len;
+    unsigned int desc_len;
+    unsigned int max = vq->vring.num;
+    unsigned int i = idx;
     VuVirtqElement *elem;
-    unsigned out_num, in_num;
+    unsigned int out_num = 0, in_num = 0;
     struct iovec iov[VIRTQUEUE_MAX_SIZE];
     struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
-    struct vring_desc *desc;
     int rc;
 
-    if (unlikely(dev->broken) ||
-        unlikely(!vq->vring.avail)) {
-        return NULL;
-    }
-
-    if (vu_queue_empty(dev, vq)) {
-        return NULL;
-    }
-    /* Needed after virtio_queue_empty(), see comment in
-     * virtqueue_num_heads(). */
-    smp_rmb();
-
-    /* When we start there are none of either input nor output. */
-    out_num = in_num = 0;
-
-    max = vq->vring.num;
-    if (vq->inuse >= vq->vring.num) {
-        vu_panic(dev, "Virtqueue size exceeded");
-        return NULL;
-    }
-
-    if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
-        return NULL;
-    }
-
-    if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
-        vring_set_avail_event(vq, vq->last_avail_idx);
-    }
-
-    i = head;
-    desc = vq->vring.desc;
     if (desc[i].flags & VRING_DESC_F_INDIRECT) {
         if (desc[i].len % sizeof(struct vring_desc)) {
             vu_panic(dev, "Invalid size for indirect buffer table");
@@ -1941,12 +1912,13 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
     } while (rc == VIRTQUEUE_READ_DESC_MORE);
 
     if (rc == VIRTQUEUE_READ_DESC_ERROR) {
+        vu_panic(dev, "read descriptor error");
         return NULL;
     }
 
     /* Now copy what we have collected and mapped */
     elem = virtqueue_alloc_element(sz, out_num, in_num);
-    elem->index = head;
+    elem->index = idx;
     for (i = 0; i < out_num; i++) {
         elem->out_sg[i] = iov[i];
     }
@@ -1954,6 +1926,48 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
         elem->in_sg[i] = iov[out_num + i];
     }
 
+    return elem;
+}
+
+void *
+vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
+{
+    unsigned int head;
+    VuVirtqElement *elem;
+
+    if (unlikely(dev->broken) ||
+        unlikely(!vq->vring.avail)) {
+        return NULL;
+    }
+
+    if (vu_queue_empty(dev, vq)) {
+        return NULL;
+    }
+    /*
+     * Needed after virtio_queue_empty(), see comment in
+     * virtqueue_num_heads().
+     */
+    smp_rmb();
+
+    if (vq->inuse >= vq->vring.num) {
+        vu_panic(dev, "Virtqueue size exceeded");
+        return NULL;
+    }
+
+    if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
+        return NULL;
+    }
+
+    if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
+        vring_set_avail_event(vq, vq->last_avail_idx);
+    }
+
+    elem = vu_queue_map_desc(dev, vq, head, sz);
+
+    if (!elem) {
+        return NULL;
+    }
+
     vq->inuse++;
 
     return elem;
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 4/7] libvhost-user: Support tracking inflight I/O in shared memory
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
                   ` (2 preceding siblings ...)
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 3/7] libvhost-user: Introduce vu_queue_map_desc() elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-11-16 17:42   ` [Qemu-devel] [PULL 22/26] " Marc-André Lureau
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 5/7] vhost-user-blk: Add support to get/set inflight buffer elohimes
                   ` (2 subsequent siblings)
  6 siblings, 1 reply; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@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 <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 Makefile                              |   2 +-
 contrib/libvhost-user/libvhost-user.c | 349 ++++++++++++++++++++++++--
 contrib/libvhost-user/libvhost-user.h |  70 ++++++
 3 files changed, 400 insertions(+), 21 deletions(-)

diff --git a/Makefile b/Makefile
index 7fa04e0821..3cf34bf8b3 100644
--- a/Makefile
+++ b/Makefile
@@ -479,7 +479,7 @@ 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 ea0f414b6d..065ab60924 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 +920,91 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
     return true;
 }
 
+static int
+inflight_desc_compare(const void *a, const void *b)
+{
+    VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
+                        *desc1 = (VuVirtqInflightDesc *)b;
+
+    if (desc1->counter > desc0->counter &&
+        (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
+        return 1;
+    }
+
+    return -1;
+}
+
+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;
+    }
+
+    if (unlikely(!vq->inflight->version)) {
+        /* initialize the buffer */
+        vq->inflight->version = INFLIGHT_VERSION;
+        return 0;
+    }
+
+    vq->used_idx = vq->vring.used->idx;
+    vq->resubmit_num = 0;
+    vq->resubmit_list = NULL;
+    vq->counter = 0;
+
+    if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
+        vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
+
+        barrier();
+
+        vq->inflight->used_idx = vq->used_idx;
+    }
+
+    for (i = 0; i < vq->inflight->desc_num; i++) {
+        if (vq->inflight->desc[i].inflight == 1) {
+            vq->inuse++;
+        }
+    }
+
+    vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
+
+    if (vq->inuse) {
+        vq->resubmit_list = malloc(sizeof(VuVirtqInflightDesc) * vq->inuse);
+        if (!vq->resubmit_list) {
+            return -1;
+        }
+
+        for (i = 0; i < vq->inflight->desc_num; i++) {
+            if (vq->inflight->desc[i].inflight) {
+                vq->resubmit_list[vq->resubmit_num].index = i;
+                vq->resubmit_list[vq->resubmit_num].counter =
+                                        vq->inflight->desc[i].counter;
+                vq->resubmit_num++;
+            }
+        }
+
+        if (vq->resubmit_num > 1) {
+            qsort(vq->resubmit_list, vq->resubmit_num,
+                  sizeof(VuVirtqInflightDesc), inflight_desc_compare);
+        }
+        vq->counter = vq->resubmit_list[0].counter + 1;
+    }
+
+    /* in case of I/O hang after reconnecting */
+    if (eventfd_write(vq->kick_fd, 1)) {
+        return -1;
+    }
+
+    return 0;
+}
+
 static bool
 vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
 {
@@ -923,6 +1038,10 @@ 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;
 }
 
@@ -995,6 +1114,11 @@ vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
 
     dev->vq[index].call_fd = vmsg->fds[0];
 
+    /* in case of I/O hang after reconnecting */
+    if (eventfd_write(vmsg->fds[0], 1)) {
+        return -1;
+    }
+
     DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
 
     return false;
@@ -1209,6 +1333,116 @@ 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(VuDescStateSplit) * 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;
+
+    DPRINT("send inflight mmap_size: %"PRId64"\n",
+           vmsg->payload.inflight.mmap_size);
+    DPRINT("send inflight mmap offset: %"PRId64"\n",
+           vmsg->payload.inflight.mmap_offset);
+
+    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;
+    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;
+    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 num_queues: %"PRId16"\n", num_queues);
+    DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
+
+    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;
+
+    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)
 {
@@ -1286,6 +1520,10 @@ 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);
@@ -1353,8 +1591,24 @@ vu_deinit(VuDev *dev)
             close(vq->err_fd);
             vq->err_fd = -1;
         }
+
+        if (vq->resubmit_list) {
+            free(vq->resubmit_list);
+            vq->resubmit_list = NULL;
+        }
+
+        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) {
@@ -1681,20 +1935,6 @@ 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)
 {
@@ -1823,12 +2063,6 @@ 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)
@@ -1929,9 +2163,68 @@ 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].counter = vq->counter++;
+    vq->inflight->desc[desc_idx].inflight = 1;
+
+    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->last_batch_head = desc_idx;
+
+    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;
+    }
+
+    barrier();
+
+    vq->inflight->desc[desc_idx].inflight = 0;
+
+    barrier();
+
+    vq->inflight->used_idx = vq->used_idx;
+
+    return 0;
+}
+
 void *
 vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
 {
+    int i;
     unsigned int head;
     VuVirtqElement *elem;
 
@@ -1940,6 +2233,18 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
         return NULL;
     }
 
+    if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
+        i = (--vq->resubmit_num);
+        elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
+
+        if (!vq->resubmit_num) {
+            free(vq->resubmit_list);
+            vq->resubmit_list = NULL;
+        }
+
+        return elem;
+    }
+
     if (vu_queue_empty(dev, vq)) {
         return NULL;
     }
@@ -1970,6 +2275,8 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
 
     vq->inuse++;
 
+    vu_queue_inflight_get(dev, vq, head);
+
     return elem;
 }
 
@@ -2114,5 +2421,7 @@ 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..8a32456943 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 +141,13 @@ typedef struct VhostUserVringArea {
     uint64_t offset;
 } VhostUserVringArea;
 
+typedef struct VhostUserInflight {
+    uint64_t mmap_size;
+    uint64_t mmap_offset;
+    uint16_t num_queues;
+    uint16_t queue_size;
+} VhostUserInflight;
+
 #if defined(_WIN32)
 # define VU_PACKED __attribute__((gcc_struct, packed))
 #else
@@ -163,6 +173,7 @@ typedef struct VhostUserMsg {
         VhostUserLog log;
         VhostUserConfig config;
         VhostUserVringArea area;
+        VhostUserInflight inflight;
     } payload;
 
     int fds[VHOST_MEMORY_MAX_NREGIONS];
@@ -234,9 +245,61 @@ typedef struct VuRing {
     uint32_t flags;
 } VuRing;
 
+typedef struct VuDescStateSplit {
+    /* Indicate whether this descriptor is inflight or not.
+     * Only available for head-descriptor. */
+    uint8_t inflight;
+
+    /* Padding */
+    uint8_t padding[5];
+
+    /* Maintain a list for the last batch of used descriptors.
+     * Only available when batching is used for submitting */
+    uint16_t next;
+
+    /* Used to preserve the order of fetching available descriptors.
+     * Only available for head-descriptor. */
+    uint64_t counter;
+} VuDescStateSplit;
+
+typedef struct VuVirtqInflight {
+    /* The feature flags of this region. Now it's initialized to 0. */
+    uint64_t features;
+
+    /* The version of this region. It's 1 currently.
+     * Zero value indicates a vm reset happened. */
+    uint16_t version;
+
+    /* The size of VuDescStateSplit array. It's equal to the virtqueue
+     * size. Slave could get it from queue size field of VhostUserInflight. */
+    uint16_t desc_num;
+
+    /* The head of list that track the last batch of used descriptors. */
+    uint16_t last_batch_head;
+
+    /* Storing the idx value of used ring */
+    uint16_t used_idx;
+
+    /* Used to track the state of each descriptor in descriptor table */
+    VuDescStateSplit desc[0];
+} VuVirtqInflight;
+
+typedef struct VuVirtqInflightDesc {
+    uint16_t index;
+    uint64_t counter;
+} VuVirtqInflightDesc;
+
 typedef struct VuVirtq {
     VuRing vring;
 
+    VuVirtqInflight *inflight;
+
+    VuVirtqInflightDesc *resubmit_list;
+
+    uint16_t resubmit_num;
+
+    uint64_t counter;
+
     /* Next head to pop */
     uint16_t last_avail_idx;
 
@@ -279,11 +342,18 @@ 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;
+} 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

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 5/7] vhost-user-blk: Add support to get/set inflight buffer
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
                   ` (3 preceding siblings ...)
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 4/7] libvhost-user: Support tracking inflight I/O in shared memory elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 6/7] vhost-user-blk: Add support to reconnect backend elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 7/7] contrib/vhost-user-blk: enable inflight I/O tracking elohimes
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

This patch adds support for vhost-user-blk device to get/set
inflight buffer from/to backend.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 hw/block/vhost-user-blk.c          | 28 ++++++++++++++++++++++++++++
 include/hw/virtio/vhost-user-blk.h |  1 +
 2 files changed, 29 insertions(+)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 44ac814016..9682df1a7b 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -128,6 +128,21 @@ static void vhost_user_blk_start(VirtIODevice *vdev)
     }
 
     s->dev.acked_features = vdev->guest_features;
+
+    if (!s->inflight->addr) {
+        ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
+        if (ret < 0) {
+            error_report("Error get inflight: %d", -ret);
+            goto err_guest_notifiers;
+        }
+    }
+
+    ret = vhost_dev_set_inflight(&s->dev, s->inflight);
+    if (ret < 0) {
+        error_report("Error set inflight: %d", -ret);
+        goto err_guest_notifiers;
+    }
+
     ret = vhost_dev_start(&s->dev, vdev);
     if (ret < 0) {
         error_report("Error starting vhost: %d", -ret);
@@ -249,6 +264,13 @@ static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
     }
 }
 
+static void vhost_user_blk_reset(VirtIODevice *vdev)
+{
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+    vhost_dev_free_inflight(s->inflight);
+}
+
 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -289,6 +311,8 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
                          vhost_user_blk_handle_output);
     }
 
+    s->inflight = g_new0(struct vhost_inflight, 1);
+
     s->dev.nvqs = s->num_queues;
     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
     s->dev.vq_index = 0;
@@ -321,6 +345,7 @@ vhost_err:
     vhost_dev_cleanup(&s->dev);
 virtio_err:
     g_free(vqs);
+    g_free(s->inflight);
     virtio_cleanup(vdev);
 
     vhost_user_cleanup(user);
@@ -336,7 +361,9 @@ static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
 
     vhost_user_blk_set_status(vdev, 0);
     vhost_dev_cleanup(&s->dev);
+    vhost_dev_free_inflight(s->inflight);
     g_free(vqs);
+    g_free(s->inflight);
     virtio_cleanup(vdev);
 
     if (s->vhost_user) {
@@ -386,6 +413,7 @@ static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
     vdc->set_config = vhost_user_blk_set_config;
     vdc->get_features = vhost_user_blk_get_features;
     vdc->set_status = vhost_user_blk_set_status;
+    vdc->reset = vhost_user_blk_reset;
 }
 
 static const TypeInfo vhost_user_blk_info = {
diff --git a/include/hw/virtio/vhost-user-blk.h b/include/hw/virtio/vhost-user-blk.h
index d52944aeeb..445516604a 100644
--- a/include/hw/virtio/vhost-user-blk.h
+++ b/include/hw/virtio/vhost-user-blk.h
@@ -36,6 +36,7 @@ typedef struct VHostUserBlk {
     uint32_t queue_size;
     uint32_t config_wce;
     struct vhost_dev dev;
+    struct vhost_inflight *inflight;
     VhostUserState *vhost_user;
 } VHostUserBlk;
 
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 6/7] vhost-user-blk: Add support to reconnect backend
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
                   ` (4 preceding siblings ...)
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 5/7] vhost-user-blk: Add support to get/set inflight buffer elohimes
@ 2019-02-28  8:53 ` elohimes
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 7/7] contrib/vhost-user-blk: enable inflight I/O tracking elohimes
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

Since we now support the message VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD. The backend is able to restart
safely because it can track inflight I/O in shared memory.
This patch allows qemu to reconnect the backend after
connection closed.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Ni Xun <nixun@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 hw/block/vhost-user-blk.c          | 205 +++++++++++++++++++++++------
 include/hw/virtio/vhost-user-blk.h |   4 +
 2 files changed, 167 insertions(+), 42 deletions(-)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 9682df1a7b..539ea2e571 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -103,7 +103,7 @@ const VhostDevConfigOps blk_ops = {
     .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
 };
 
-static void vhost_user_blk_start(VirtIODevice *vdev)
+static int vhost_user_blk_start(VirtIODevice *vdev)
 {
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
@@ -112,13 +112,13 @@ static void vhost_user_blk_start(VirtIODevice *vdev)
 
     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
-        return;
+        return -ENOSYS;
     }
 
     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
     if (ret < 0) {
         error_report("Error enabling host notifiers: %d", -ret);
-        return;
+        return ret;
     }
 
     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
@@ -157,12 +157,13 @@ static void vhost_user_blk_start(VirtIODevice *vdev)
         vhost_virtqueue_mask(&s->dev, vdev, i, false);
     }
 
-    return;
+    return ret;
 
 err_guest_notifiers:
     k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 err_host_notifiers:
     vhost_dev_disable_notifiers(&s->dev, vdev);
+    return ret;
 }
 
 static void vhost_user_blk_stop(VirtIODevice *vdev)
@@ -181,7 +182,6 @@ static void vhost_user_blk_stop(VirtIODevice *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);
@@ -191,21 +191,43 @@ 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;
+    int ret;
 
     if (!vdev->vm_running) {
         should_start = false;
     }
 
-    if (s->dev.started == should_start) {
+    if (s->should_start == should_start) {
+        return;
+    }
+
+    if (!s->connected || s->dev.started == should_start) {
+        s->should_start = should_start;
         return;
     }
 
     if (should_start) {
-        vhost_user_blk_start(vdev);
+        s->should_start = true;
+        /*
+         * make sure vhost_user_blk_handle_output() ignores fake
+         * guest kick by vhost_dev_enable_notifiers()
+         */
+        barrier();
+        ret = vhost_user_blk_start(vdev);
+        if (ret < 0) {
+            error_report("vhost-user-blk: vhost start failed: %s",
+                         strerror(-ret));
+            qemu_chr_fe_disconnect(&s->chardev);
+        }
     } else {
         vhost_user_blk_stop(vdev);
+        /*
+         * make sure vhost_user_blk_handle_output() ignore fake
+         * guest kick by vhost_dev_disable_notifiers()
+         */
+        barrier();
+        s->should_start = false;
     }
-
 }
 
 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
@@ -237,13 +259,22 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 {
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
-    int i;
+    int i, ret;
 
     if (!(virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1))) {
         return;
     }
 
+    if (s->should_start) {
+        return;
+    }
+    s->should_start = true;
+
+    if (!s->connected) {
+        return;
+    }
+
     if (s->dev.started) {
         return;
     }
@@ -251,7 +282,13 @@ static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
     /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
      * vhost here instead of waiting for .set_status().
      */
-    vhost_user_blk_start(vdev);
+    ret = vhost_user_blk_start(vdev);
+    if (ret < 0) {
+        error_report("vhost-user-blk: vhost start failed: %s",
+                     strerror(-ret));
+        qemu_chr_fe_disconnect(&s->chardev);
+        return;
+    }
 
     /* Kick right away to begin processing requests already in vring */
     for (i = 0; i < s->dev.nvqs; i++) {
@@ -271,13 +308,106 @@ static void vhost_user_blk_reset(VirtIODevice *vdev)
     vhost_dev_free_inflight(s->inflight);
 }
 
+static int vhost_user_blk_connect(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+    int ret = 0;
+
+    if (s->connected) {
+        return 0;
+    }
+    s->connected = true;
+
+    s->dev.nvqs = s->num_queues;
+    s->dev.vqs = s->vqs;
+    s->dev.vq_index = 0;
+    s->dev.backend_features = 0;
+
+    vhost_dev_set_config_notifier(&s->dev, &blk_ops);
+
+    ret = vhost_dev_init(&s->dev, s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
+    if (ret < 0) {
+        error_report("vhost-user-blk: vhost initialization failed: %s",
+                     strerror(-ret));
+        return ret;
+    }
+
+    /* restore vhost state */
+    if (s->should_start) {
+        ret = vhost_user_blk_start(vdev);
+        if (ret < 0) {
+            error_report("vhost-user-blk: vhost start failed: %s",
+                         strerror(-ret));
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static void vhost_user_blk_disconnect(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+    if (!s->connected) {
+        return;
+    }
+    s->connected = false;
+
+    if (s->dev.started) {
+        vhost_user_blk_stop(vdev);
+    }
+
+    vhost_dev_cleanup(&s->dev);
+}
+
+static gboolean vhost_user_blk_watch(GIOChannel *chan, GIOCondition cond,
+                                     void *opaque)
+{
+    DeviceState *dev = opaque;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+    qemu_chr_fe_disconnect(&s->chardev);
+
+    return true;
+}
+
+static void vhost_user_blk_event(void *opaque, int event)
+{
+    DeviceState *dev = opaque;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+    switch (event) {
+    case CHR_EVENT_OPENED:
+        if (vhost_user_blk_connect(dev) < 0) {
+            qemu_chr_fe_disconnect(&s->chardev);
+            return;
+        }
+        s->watch = qemu_chr_fe_add_watch(&s->chardev, G_IO_HUP,
+                                         vhost_user_blk_watch, dev);
+        break;
+    case CHR_EVENT_CLOSED:
+        vhost_user_blk_disconnect(dev);
+        if (s->watch) {
+            g_source_remove(s->watch);
+            s->watch = 0;
+        }
+        break;
+    }
+}
+
+
 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
     VhostUserState *user;
-    struct vhost_virtqueue *vqs = NULL;
     int i, ret;
+    Error *err = NULL;
 
     if (!s->chardev.chr) {
         error_setg(errp, "vhost-user-blk: chardev is mandatory");
@@ -312,27 +442,28 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
     }
 
     s->inflight = g_new0(struct vhost_inflight, 1);
-
-    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;
-    vqs = s->dev.vqs;
-
-    vhost_dev_set_config_notifier(&s->dev, &blk_ops);
-
-    ret = vhost_dev_init(&s->dev, s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
-    if (ret < 0) {
-        error_setg(errp, "vhost-user-blk: vhost initialization failed: %s",
-                   strerror(-ret));
-        goto virtio_err;
-    }
+    s->vqs = g_new(struct vhost_virtqueue, s->num_queues);
+    s->watch = 0;
+    s->should_start = false;
+    s->connected = false;
+
+    qemu_chr_fe_set_handlers(&s->chardev,  NULL, NULL, vhost_user_blk_event,
+                             NULL, (void *)dev, NULL, true);
+
+reconnect:
+    do {
+        if (qemu_chr_fe_wait_connected(&s->chardev, &err) < 0) {
+            error_report_err(err);
+            err = NULL;
+            sleep(1);
+        }
+    } while (!s->connected);
 
     ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
-                              sizeof(struct virtio_blk_config));
+                               sizeof(struct virtio_blk_config));
     if (ret < 0) {
-        error_setg(errp, "vhost-user-blk: get block config failed");
-        goto vhost_err;
+        error_report("vhost-user-blk: get block config failed");
+        goto reconnect;
     }
 
     if (s->blkcfg.num_queues != s->num_queues) {
@@ -340,29 +471,19 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
     }
 
     return;
-
-vhost_err:
-    vhost_dev_cleanup(&s->dev);
-virtio_err:
-    g_free(vqs);
-    g_free(s->inflight);
-    virtio_cleanup(vdev);
-
-    vhost_user_cleanup(user);
-    g_free(user);
-    s->vhost_user = NULL;
 }
 
 static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VHostUserBlk *s = VHOST_USER_BLK(dev);
-    struct vhost_virtqueue *vqs = s->dev.vqs;
 
     vhost_user_blk_set_status(vdev, 0);
+    qemu_chr_fe_set_handlers(&s->chardev,  NULL, NULL, NULL,
+                             NULL, NULL, NULL, false);
     vhost_dev_cleanup(&s->dev);
     vhost_dev_free_inflight(s->inflight);
-    g_free(vqs);
+    g_free(s->vqs);
     g_free(s->inflight);
     virtio_cleanup(vdev);
 
diff --git a/include/hw/virtio/vhost-user-blk.h b/include/hw/virtio/vhost-user-blk.h
index 445516604a..4849aa5eb5 100644
--- a/include/hw/virtio/vhost-user-blk.h
+++ b/include/hw/virtio/vhost-user-blk.h
@@ -38,6 +38,10 @@ typedef struct VHostUserBlk {
     struct vhost_dev dev;
     struct vhost_inflight *inflight;
     VhostUserState *vhost_user;
+    struct vhost_virtqueue *vqs;
+    guint watch;
+    bool should_start;
+    bool connected;
 } VHostUserBlk;
 
 #endif
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [Qemu-devel] [PATCH v7 7/7] contrib/vhost-user-blk: enable inflight I/O tracking
  2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
                   ` (5 preceding siblings ...)
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 6/7] vhost-user-blk: Add support to reconnect backend elohimes
@ 2019-02-28  8:53 ` elohimes
  6 siblings, 0 replies; 10+ messages in thread
From: elohimes @ 2019-02-28  8:53 UTC (permalink / raw)
  To: mst, stefanha, marcandre.lureau, berrange, jasowang,
	maxime.coquelin, yury-kotov, wrfsh
  Cc: qemu-devel, zhangyu31, chaiwen, nixun, lilin24, Xie Yongji

From: Xie Yongji <xieyongji@baidu.com>

This patch enables inflight I/O tracking for
vhost-user-blk backend so that we could restart it safely.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
---
 contrib/vhost-user-blk/vhost-user-blk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
index 43583f2659..86a3987744 100644
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -398,7 +398,8 @@ vub_get_features(VuDev *dev)
 static uint64_t
 vub_get_protocol_features(VuDev *dev)
 {
-    return 1ull << VHOST_USER_PROTOCOL_F_CONFIG;
+    return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
+           1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
 }
 
 static int
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* Re: [Qemu-devel] [PULL 22/26] libvhost-user: Support tracking inflight I/O in shared memory
  2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 4/7] libvhost-user: Support tracking inflight I/O in shared memory elohimes
@ 2019-11-16 17:42   ` Marc-André Lureau
  2019-11-18  9:15     ` Yongji Xie
  0 siblings, 1 reply; 10+ messages in thread
From: Marc-André Lureau @ 2019-11-16 17:42 UTC (permalink / raw)
  To: Michael S. Tsirkin, Xie Yongji
  Cc: Peter Maydell, Zhang Yu, Markus Armbruster,
	Dr. David Alan Gilbert, Peter Xu, QEMU, Gerd Hoffmann,
	Philippe Mathieu-Daudé

On Wed, Mar 13, 2019 at 6:59 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> From: Xie Yongji <xieyongji@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 <xieyongji@baidu.com>
> Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
> Message-Id: <20190228085355.9614-5-xieyongji@baidu.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  Makefile                              |   2 +-
>  contrib/libvhost-user/libvhost-user.h |  70 ++++++
>  contrib/libvhost-user/libvhost-user.c | 349 ++++++++++++++++++++++++--
>  3 files changed, 400 insertions(+), 21 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 6ccb8639b0..abd78a9826 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -497,7 +497,7 @@ 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.h b/contrib/libvhost-user/libvhost-user.h
> index 3de8414898..414ceb0a2f 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 +141,13 @@ typedef struct VhostUserVringArea {
>      uint64_t offset;
>  } VhostUserVringArea;
>
> +typedef struct VhostUserInflight {
> +    uint64_t mmap_size;
> +    uint64_t mmap_offset;
> +    uint16_t num_queues;
> +    uint16_t queue_size;
> +} VhostUserInflight;
> +
>  #if defined(_WIN32)
>  # define VU_PACKED __attribute__((gcc_struct, packed))
>  #else
> @@ -163,6 +173,7 @@ typedef struct VhostUserMsg {
>          VhostUserLog log;
>          VhostUserConfig config;
>          VhostUserVringArea area;
> +        VhostUserInflight inflight;
>      } payload;
>
>      int fds[VHOST_MEMORY_MAX_NREGIONS];
> @@ -234,9 +245,61 @@ typedef struct VuRing {
>      uint32_t flags;
>  } VuRing;
>
> +typedef struct VuDescStateSplit {
> +    /* Indicate whether this descriptor is inflight or not.
> +     * Only available for head-descriptor. */
> +    uint8_t inflight;
> +
> +    /* Padding */
> +    uint8_t padding[5];
> +
> +    /* Maintain a list for the last batch of used descriptors.
> +     * Only available when batching is used for submitting */
> +    uint16_t next;
> +
> +    /* Used to preserve the order of fetching available descriptors.
> +     * Only available for head-descriptor. */
> +    uint64_t counter;
> +} VuDescStateSplit;
> +
> +typedef struct VuVirtqInflight {
> +    /* The feature flags of this region. Now it's initialized to 0. */
> +    uint64_t features;
> +
> +    /* The version of this region. It's 1 currently.
> +     * Zero value indicates a vm reset happened. */
> +    uint16_t version;
> +
> +    /* The size of VuDescStateSplit array. It's equal to the virtqueue
> +     * size. Slave could get it from queue size field of VhostUserInflight. */
> +    uint16_t desc_num;
> +
> +    /* The head of list that track the last batch of used descriptors. */
> +    uint16_t last_batch_head;
> +
> +    /* Storing the idx value of used ring */
> +    uint16_t used_idx;
> +
> +    /* Used to track the state of each descriptor in descriptor table */
> +    VuDescStateSplit desc[0];
> +} VuVirtqInflight;
> +
> +typedef struct VuVirtqInflightDesc {
> +    uint16_t index;
> +    uint64_t counter;
> +} VuVirtqInflightDesc;
> +
>  typedef struct VuVirtq {
>      VuRing vring;
>
> +    VuVirtqInflight *inflight;
> +
> +    VuVirtqInflightDesc *resubmit_list;
> +
> +    uint16_t resubmit_num;
> +
> +    uint64_t counter;
> +
>      /* Next head to pop */
>      uint16_t last_avail_idx;
>
> @@ -279,11 +342,18 @@ 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;
> +} 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;
> diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> index ddd15d79cf..e08d6c7b97 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 +920,91 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
>      return true;
>  }
>
> +static int
> +inflight_desc_compare(const void *a, const void *b)
> +{
> +    VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
> +                        *desc1 = (VuVirtqInflightDesc *)b;
> +
> +    if (desc1->counter > desc0->counter &&
> +        (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
> +        return 1;
> +    }
> +
> +    return -1;
> +}
> +
> +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;
> +    }
> +
> +    if (unlikely(!vq->inflight->version)) {
> +        /* initialize the buffer */
> +        vq->inflight->version = INFLIGHT_VERSION;
> +        return 0;
> +    }
> +
> +    vq->used_idx = vq->vring.used->idx;
> +    vq->resubmit_num = 0;
> +    vq->resubmit_list = NULL;
> +    vq->counter = 0;
> +
> +    if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
> +        vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
> +
> +        barrier();
> +
> +        vq->inflight->used_idx = vq->used_idx;
> +    }
> +
> +    for (i = 0; i < vq->inflight->desc_num; i++) {
> +        if (vq->inflight->desc[i].inflight == 1) {
> +            vq->inuse++;
> +        }
> +    }
> +
> +    vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
> +
> +    if (vq->inuse) {
> +        vq->resubmit_list = malloc(sizeof(VuVirtqInflightDesc) * vq->inuse);
> +        if (!vq->resubmit_list) {
> +            return -1;
> +        }
> +
> +        for (i = 0; i < vq->inflight->desc_num; i++) {
> +            if (vq->inflight->desc[i].inflight) {
> +                vq->resubmit_list[vq->resubmit_num].index = i;
> +                vq->resubmit_list[vq->resubmit_num].counter =
> +                                        vq->inflight->desc[i].counter;
> +                vq->resubmit_num++;
> +            }
> +        }
> +
> +        if (vq->resubmit_num > 1) {
> +            qsort(vq->resubmit_list, vq->resubmit_num,
> +                  sizeof(VuVirtqInflightDesc), inflight_desc_compare);
> +        }
> +        vq->counter = vq->resubmit_list[0].counter + 1;

scan-build reports that vq->resubmit_list[0].counter may be garbage
value, if it's not initialized in the loop above.
Xie, could you provide a fix?

> +    }
> +
> +    /* in case of I/O hang after reconnecting */
> +    if (eventfd_write(vq->kick_fd, 1)) {
> +        return -1;
> +    }
> +
> +    return 0;
> +}
> +
>  static bool
>  vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
>  {
> @@ -923,6 +1038,10 @@ 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;
>  }
>
> @@ -995,6 +1114,11 @@ vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
>
>      dev->vq[index].call_fd = vmsg->fds[0];
>
> +    /* in case of I/O hang after reconnecting */
> +    if (eventfd_write(vmsg->fds[0], 1)) {
> +        return -1;
> +    }
> +
>      DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
>
>      return false;
> @@ -1209,6 +1333,116 @@ 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(VuDescStateSplit) * 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;
> +
> +    DPRINT("send inflight mmap_size: %"PRId64"\n",
> +           vmsg->payload.inflight.mmap_size);
> +    DPRINT("send inflight mmap offset: %"PRId64"\n",
> +           vmsg->payload.inflight.mmap_offset);
> +
> +    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;
> +    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;
> +    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 num_queues: %"PRId16"\n", num_queues);
> +    DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
> +
> +    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;
> +
> +    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)
>  {
> @@ -1287,6 +1521,10 @@ 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);
> @@ -1354,8 +1592,24 @@ vu_deinit(VuDev *dev)
>              close(vq->err_fd);
>              vq->err_fd = -1;
>          }
> +
> +        if (vq->resubmit_list) {
> +            free(vq->resubmit_list);
> +            vq->resubmit_list = NULL;
> +        }
> +
> +        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) {
> @@ -1682,20 +1936,6 @@ 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)
>  {
> @@ -1824,12 +2064,6 @@ 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)
> @@ -1930,9 +2164,68 @@ 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].counter = vq->counter++;
> +    vq->inflight->desc[desc_idx].inflight = 1;
> +
> +    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->last_batch_head = desc_idx;
> +
> +    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;
> +    }
> +
> +    barrier();
> +
> +    vq->inflight->desc[desc_idx].inflight = 0;
> +
> +    barrier();
> +
> +    vq->inflight->used_idx = vq->used_idx;
> +
> +    return 0;
> +}
> +
>  void *
>  vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
>  {
> +    int i;
>      unsigned int head;
>      VuVirtqElement *elem;
>
> @@ -1941,6 +2234,18 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
>          return NULL;
>      }
>
> +    if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
> +        i = (--vq->resubmit_num);
> +        elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
> +
> +        if (!vq->resubmit_num) {
> +            free(vq->resubmit_list);
> +            vq->resubmit_list = NULL;
> +        }
> +
> +        return elem;
> +    }
> +
>      if (vu_queue_empty(dev, vq)) {
>          return NULL;
>      }
> @@ -1971,6 +2276,8 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
>
>      vq->inuse++;
>
> +    vu_queue_inflight_get(dev, vq, head);
> +
>      return elem;
>  }
>
> @@ -2131,5 +2438,7 @@ 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);
>  }
> --
> MST
>
>


-- 
Marc-André Lureau


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [Qemu-devel] [PULL 22/26] libvhost-user: Support tracking inflight I/O in shared memory
  2019-11-16 17:42   ` [Qemu-devel] [PULL 22/26] " Marc-André Lureau
@ 2019-11-18  9:15     ` Yongji Xie
  0 siblings, 0 replies; 10+ messages in thread
From: Yongji Xie @ 2019-11-18  9:15 UTC (permalink / raw)
  To: Marc-André Lureau
  Cc: Peter Maydell, Zhang Yu, Michael S. Tsirkin, QEMU,
	Markus Armbruster, Peter Xu, Dr. David Alan Gilbert,
	Gerd Hoffmann, Xie Yongji, Philippe Mathieu-Daudé

On Sun, 17 Nov 2019 at 01:43, Marc-André Lureau
<marcandre.lureau@gmail.com> wrote:
>
> On Wed, Mar 13, 2019 at 6:59 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > From: Xie Yongji <xieyongji@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 <xieyongji@baidu.com>
> > Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
> > Message-Id: <20190228085355.9614-5-xieyongji@baidu.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >  Makefile                              |   2 +-
> >  contrib/libvhost-user/libvhost-user.h |  70 ++++++
> >  contrib/libvhost-user/libvhost-user.c | 349 ++++++++++++++++++++++++--
> >  3 files changed, 400 insertions(+), 21 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 6ccb8639b0..abd78a9826 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -497,7 +497,7 @@ 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.h b/contrib/libvhost-user/libvhost-user.h
> > index 3de8414898..414ceb0a2f 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 +141,13 @@ typedef struct VhostUserVringArea {
> >      uint64_t offset;
> >  } VhostUserVringArea;
> >
> > +typedef struct VhostUserInflight {
> > +    uint64_t mmap_size;
> > +    uint64_t mmap_offset;
> > +    uint16_t num_queues;
> > +    uint16_t queue_size;
> > +} VhostUserInflight;
> > +
> >  #if defined(_WIN32)
> >  # define VU_PACKED __attribute__((gcc_struct, packed))
> >  #else
> > @@ -163,6 +173,7 @@ typedef struct VhostUserMsg {
> >          VhostUserLog log;
> >          VhostUserConfig config;
> >          VhostUserVringArea area;
> > +        VhostUserInflight inflight;
> >      } payload;
> >
> >      int fds[VHOST_MEMORY_MAX_NREGIONS];
> > @@ -234,9 +245,61 @@ typedef struct VuRing {
> >      uint32_t flags;
> >  } VuRing;
> >
> > +typedef struct VuDescStateSplit {
> > +    /* Indicate whether this descriptor is inflight or not.
> > +     * Only available for head-descriptor. */
> > +    uint8_t inflight;
> > +
> > +    /* Padding */
> > +    uint8_t padding[5];
> > +
> > +    /* Maintain a list for the last batch of used descriptors.
> > +     * Only available when batching is used for submitting */
> > +    uint16_t next;
> > +
> > +    /* Used to preserve the order of fetching available descriptors.
> > +     * Only available for head-descriptor. */
> > +    uint64_t counter;
> > +} VuDescStateSplit;
> > +
> > +typedef struct VuVirtqInflight {
> > +    /* The feature flags of this region. Now it's initialized to 0. */
> > +    uint64_t features;
> > +
> > +    /* The version of this region. It's 1 currently.
> > +     * Zero value indicates a vm reset happened. */
> > +    uint16_t version;
> > +
> > +    /* The size of VuDescStateSplit array. It's equal to the virtqueue
> > +     * size. Slave could get it from queue size field of VhostUserInflight. */
> > +    uint16_t desc_num;
> > +
> > +    /* The head of list that track the last batch of used descriptors. */
> > +    uint16_t last_batch_head;
> > +
> > +    /* Storing the idx value of used ring */
> > +    uint16_t used_idx;
> > +
> > +    /* Used to track the state of each descriptor in descriptor table */
> > +    VuDescStateSplit desc[0];
> > +} VuVirtqInflight;
> > +
> > +typedef struct VuVirtqInflightDesc {
> > +    uint16_t index;
> > +    uint64_t counter;
> > +} VuVirtqInflightDesc;
> > +
> >  typedef struct VuVirtq {
> >      VuRing vring;
> >
> > +    VuVirtqInflight *inflight;
> > +
> > +    VuVirtqInflightDesc *resubmit_list;
> > +
> > +    uint16_t resubmit_num;
> > +
> > +    uint64_t counter;
> > +
> >      /* Next head to pop */
> >      uint16_t last_avail_idx;
> >
> > @@ -279,11 +342,18 @@ 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;
> > +} 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;
> > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> > index ddd15d79cf..e08d6c7b97 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 +920,91 @@ vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg)
> >      return true;
> >  }
> >
> > +static int
> > +inflight_desc_compare(const void *a, const void *b)
> > +{
> > +    VuVirtqInflightDesc *desc0 = (VuVirtqInflightDesc *)a,
> > +                        *desc1 = (VuVirtqInflightDesc *)b;
> > +
> > +    if (desc1->counter > desc0->counter &&
> > +        (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
> > +        return 1;
> > +    }
> > +
> > +    return -1;
> > +}
> > +
> > +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;
> > +    }
> > +
> > +    if (unlikely(!vq->inflight->version)) {
> > +        /* initialize the buffer */
> > +        vq->inflight->version = INFLIGHT_VERSION;
> > +        return 0;
> > +    }
> > +
> > +    vq->used_idx = vq->vring.used->idx;
> > +    vq->resubmit_num = 0;
> > +    vq->resubmit_list = NULL;
> > +    vq->counter = 0;
> > +
> > +    if (unlikely(vq->inflight->used_idx != vq->used_idx)) {
> > +        vq->inflight->desc[vq->inflight->last_batch_head].inflight = 0;
> > +
> > +        barrier();
> > +
> > +        vq->inflight->used_idx = vq->used_idx;
> > +    }
> > +
> > +    for (i = 0; i < vq->inflight->desc_num; i++) {
> > +        if (vq->inflight->desc[i].inflight == 1) {
> > +            vq->inuse++;
> > +        }
> > +    }
> > +
> > +    vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
> > +
> > +    if (vq->inuse) {
> > +        vq->resubmit_list = malloc(sizeof(VuVirtqInflightDesc) * vq->inuse);
> > +        if (!vq->resubmit_list) {
> > +            return -1;
> > +        }
> > +
> > +        for (i = 0; i < vq->inflight->desc_num; i++) {
> > +            if (vq->inflight->desc[i].inflight) {
> > +                vq->resubmit_list[vq->resubmit_num].index = i;
> > +                vq->resubmit_list[vq->resubmit_num].counter =
> > +                                        vq->inflight->desc[i].counter;
> > +                vq->resubmit_num++;
> > +            }
> > +        }
> > +
> > +        if (vq->resubmit_num > 1) {
> > +            qsort(vq->resubmit_list, vq->resubmit_num,
> > +                  sizeof(VuVirtqInflightDesc), inflight_desc_compare);
> > +        }
> > +        vq->counter = vq->resubmit_list[0].counter + 1;
>
> scan-build reports that vq->resubmit_list[0].counter may be garbage
> value, if it's not initialized in the loop above.
> Xie, could you provide a fix?
>

OK, will fix it soon. Thank you!

Thanks,
Yongji
> > +    }
> > +
> > +    /* in case of I/O hang after reconnecting */
> > +    if (eventfd_write(vq->kick_fd, 1)) {
> > +        return -1;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >  static bool
> >  vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg)
> >  {
> > @@ -923,6 +1038,10 @@ 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;
> >  }
> >
> > @@ -995,6 +1114,11 @@ vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
> >
> >      dev->vq[index].call_fd = vmsg->fds[0];
> >
> > +    /* in case of I/O hang after reconnecting */
> > +    if (eventfd_write(vmsg->fds[0], 1)) {
> > +        return -1;
> > +    }
> > +
> >      DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index);
> >
> >      return false;
> > @@ -1209,6 +1333,116 @@ 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(VuDescStateSplit) * 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;
> > +
> > +    DPRINT("send inflight mmap_size: %"PRId64"\n",
> > +           vmsg->payload.inflight.mmap_size);
> > +    DPRINT("send inflight mmap offset: %"PRId64"\n",
> > +           vmsg->payload.inflight.mmap_offset);
> > +
> > +    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;
> > +    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;
> > +    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 num_queues: %"PRId16"\n", num_queues);
> > +    DPRINT("set_inflight_fd queue_size: %"PRId16"\n", queue_size);
> > +
> > +    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;
> > +
> > +    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)
> >  {
> > @@ -1287,6 +1521,10 @@ 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);
> > @@ -1354,8 +1592,24 @@ vu_deinit(VuDev *dev)
> >              close(vq->err_fd);
> >              vq->err_fd = -1;
> >          }
> > +
> > +        if (vq->resubmit_list) {
> > +            free(vq->resubmit_list);
> > +            vq->resubmit_list = NULL;
> > +        }
> > +
> > +        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) {
> > @@ -1682,20 +1936,6 @@ 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)
> >  {
> > @@ -1824,12 +2064,6 @@ 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)
> > @@ -1930,9 +2164,68 @@ 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].counter = vq->counter++;
> > +    vq->inflight->desc[desc_idx].inflight = 1;
> > +
> > +    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->last_batch_head = desc_idx;
> > +
> > +    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;
> > +    }
> > +
> > +    barrier();
> > +
> > +    vq->inflight->desc[desc_idx].inflight = 0;
> > +
> > +    barrier();
> > +
> > +    vq->inflight->used_idx = vq->used_idx;
> > +
> > +    return 0;
> > +}
> > +
> >  void *
> >  vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
> >  {
> > +    int i;
> >      unsigned int head;
> >      VuVirtqElement *elem;
> >
> > @@ -1941,6 +2234,18 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
> >          return NULL;
> >      }
> >
> > +    if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
> > +        i = (--vq->resubmit_num);
> > +        elem = vu_queue_map_desc(dev, vq, vq->resubmit_list[i].index, sz);
> > +
> > +        if (!vq->resubmit_num) {
> > +            free(vq->resubmit_list);
> > +            vq->resubmit_list = NULL;
> > +        }
> > +
> > +        return elem;
> > +    }
> > +
> >      if (vu_queue_empty(dev, vq)) {
> >          return NULL;
> >      }
> > @@ -1971,6 +2276,8 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
> >
> >      vq->inuse++;
> >
> > +    vu_queue_inflight_get(dev, vq, head);
> > +
> >      return elem;
> >  }
> >
> > @@ -2131,5 +2438,7 @@ 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);
> >  }
> > --
> > MST
> >
> >
>
>
> --
> Marc-André Lureau
>


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2019-11-18  9:18 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-28  8:53 [Qemu-devel] [PATCH v7 0/7] vhost-user-blk: Add support for backend reconnecting elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 1/7] vhost-user: Support transferring inflight buffer between qemu and backend elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 2/7] libvhost-user: Remove unnecessary FD flag check for event file descriptors elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 3/7] libvhost-user: Introduce vu_queue_map_desc() elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 4/7] libvhost-user: Support tracking inflight I/O in shared memory elohimes
2019-11-16 17:42   ` [Qemu-devel] [PULL 22/26] " Marc-André Lureau
2019-11-18  9:15     ` Yongji Xie
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 5/7] vhost-user-blk: Add support to get/set inflight buffer elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 6/7] vhost-user-blk: Add support to reconnect backend elohimes
2019-02-28  8:53 ` [Qemu-devel] [PATCH v7 7/7] contrib/vhost-user-blk: enable inflight I/O tracking elohimes

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