vdpa: add vhost_vdpa_suspend

The function vhost.c:vhost_dev_stop fetches the vring base so the vq
state can be migrated to other devices.  However, this is unreliable in
vdpa, since we didn't signal the device to suspend the queues, making
the value fetched useless.

Suspend the device if possible before fetching first and subsequent
vring bases.

Moreover, vdpa totally reset and wipes the device at the last device
before fetch its vrings base, making that operation useless in the last
device. This will be fixed in later patches of this series.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20230303172445.1089785-7-eperezma@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index a87c5f39a2f6b1602664a7883fb49ff009d9e8d6..8f8d05cf9b01cd676f528689b96fe85f10edac13 100644 (file)
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -50,6 +50,7 @@ vhost_vdpa_set_vring_ready(void *dev) "dev: %p"
 vhost_vdpa_dump_config(void *dev, const char *line) "dev: %p %s"
 vhost_vdpa_set_config(void *dev, uint32_t offset, uint32_t size, uint32_t flags) "dev: %p offset: %"PRIu32" size: %"PRIu32" flags: 0x%"PRIx32
 vhost_vdpa_get_config(void *dev, void *config, uint32_t config_len) "dev: %p config: %p config_len: %"PRIu32
+vhost_vdpa_suspend(void *dev) "dev: %p"
 vhost_vdpa_dev_start(void *dev, bool started) "dev: %p started: %d"
 vhost_vdpa_set_log_base(void *dev, uint64_t base, unsigned long long size, int refcnt, int fd, void *log) "dev: %p base: 0x%"PRIx64" size: %llu refcnt: %d fd: %d log: %p"
 vhost_vdpa_set_vring_addr(void *dev, unsigned int index, unsigned int flags, uint64_t desc_user_addr, uint64_t used_user_addr, uint64_t avail_user_addr, uint64_t log_guest_addr) "dev: %p index: %u flags: 0x%x desc_user_addr: 0x%"PRIx64" used_user_addr: 0x%"PRIx64" avail_user_addr: 0x%"PRIx64" log_guest_addr: 0x%"PRIx64

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 517e3cdc8dd2dfa33bbd720123a8acf24213a1da..aecc01c6a724ca5141a76991755e8beae78c2c59 100644 (file)
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -692,11 +692,13 @@ static int vhost_vdpa_get_device_id(struct vhost_dev *dev,
 
 static int vhost_vdpa_reset_device(struct vhost_dev *dev)
 {
+    struct vhost_vdpa *v = dev->opaque;
     int ret;
     uint8_t status = 0;
 
     ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
     trace_vhost_vdpa_reset_device(dev, status);
+    v->suspended = false;
     return ret;
 }
 
@@ -1095,6 +1097,29 @@ static void vhost_vdpa_svqs_stop(struct vhost_dev *dev)
     }
 }
 
+static void vhost_vdpa_suspend(struct vhost_dev *dev)
+{
+    struct vhost_vdpa *v = dev->opaque;
+    int r;
+
+    if (!vhost_vdpa_first_dev(dev)) {
+        return;
+    }
+
+    if (dev->backend_cap & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) {
+        trace_vhost_vdpa_suspend(dev);
+        r = ioctl(v->device_fd, VHOST_VDPA_SUSPEND);
+        if (unlikely(r)) {
+            error_report("Cannot suspend: %s(%d)", g_strerror(errno), errno);
+        } else {
+            v->suspended = true;
+            return;
+        }
+    }
+
+    vhost_vdpa_reset_device(dev);
+}
+
 static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 {
     struct vhost_vdpa *v = dev->opaque;
@@ -1109,6 +1134,7 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
         }
         vhost_vdpa_set_vring_ready(dev);
     } else {
+        vhost_vdpa_suspend(dev);
         vhost_vdpa_svqs_stop(dev);
         vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
     }