vdpa: move memory listener to vhost_vdpa_shared

Next patches will register the vhost_vdpa memory listener while the VM
is migrating at the destination, so we can map the memory to the device
before stopping the VM at the source.  The main goal is to reduce the
downtime.

However, the destination QEMU is unaware of which vhost_vdpa device will
register its memory_listener.  If the source guest has CVQ enabled, it
will be the CVQ device.  Otherwise, it  will be the first one.

Move the memory listener to a common place rather than always in the
first / last vhost_vdpa.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20231221174322.3130442-14-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>

2 files changed, 40 insertions, 46 deletions

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index e6276fb1e4..ddae494ca8 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -170,28 +170,28 @@ static void vhost_vdpa_iotlb_batch_begin_once(VhostVDPAShared *s)
 
 static void vhost_vdpa_listener_commit(MemoryListener *listener)
 {
-    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    VhostVDPAShared *s = container_of(listener, VhostVDPAShared, listener);
     struct vhost_msg_v2 msg = {};
-    int fd = v->shared->device_fd;
+    int fd = s->device_fd;
 
-    if (!(v->shared->backend_cap & (0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH))) {
+    if (!(s->backend_cap & (0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH))) {
         return;
     }
 
-    if (!v->shared->iotlb_batch_begin_sent) {
+    if (!s->iotlb_batch_begin_sent) {
         return;
     }
 
     msg.type = VHOST_IOTLB_MSG_V2;
     msg.iotlb.type = VHOST_IOTLB_BATCH_END;
 
-    trace_vhost_vdpa_listener_commit(v->shared, fd, msg.type, msg.iotlb.type);
+    trace_vhost_vdpa_listener_commit(s, fd, msg.type, msg.iotlb.type);
     if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
         error_report("failed to write, fd=%d, errno=%d (%s)",
                      fd, errno, strerror(errno));
     }
 
-    v->shared->iotlb_batch_begin_sent = false;
+    s->iotlb_batch_begin_sent = false;
 }
 
 static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
@@ -246,7 +246,7 @@ static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
 static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
                                         MemoryRegionSection *section)
 {
-    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    VhostVDPAShared *s = container_of(listener, VhostVDPAShared, listener);
 
     struct vdpa_iommu *iommu;
     Int128 end;
@@ -270,7 +270,7 @@ static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
                         iommu_idx);
     iommu->iommu_offset = section->offset_within_address_space -
                           section->offset_within_region;
-    iommu->dev_shared = v->shared;
+    iommu->dev_shared = s;
 
     ret = memory_region_register_iommu_notifier(section->mr, &iommu->n, NULL);
     if (ret) {
@@ -278,7 +278,7 @@ static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
         return;
     }
 
-    QLIST_INSERT_HEAD(&v->shared->iommu_list, iommu, iommu_next);
+    QLIST_INSERT_HEAD(&s->iommu_list, iommu, iommu_next);
     memory_region_iommu_replay(iommu->iommu_mr, &iommu->n);
 
     return;
@@ -287,11 +287,11 @@ static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
 static void vhost_vdpa_iommu_region_del(MemoryListener *listener,
                                         MemoryRegionSection *section)
 {
-    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    VhostVDPAShared *s = container_of(listener, VhostVDPAShared, listener);
 
     struct vdpa_iommu *iommu;
 
-    QLIST_FOREACH(iommu, &v->shared->iommu_list, iommu_next)
+    QLIST_FOREACH(iommu, &s->iommu_list, iommu_next)
     {
         if (MEMORY_REGION(iommu->iommu_mr) == section->mr &&
             iommu->n.start == section->offset_within_region) {
@@ -307,7 +307,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
                                            MemoryRegionSection *section)
 {
     DMAMap mem_region = {};
-    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    VhostVDPAShared *s = container_of(listener, VhostVDPAShared, listener);
     hwaddr iova;
     Int128 llend, llsize;
     void *vaddr;
@@ -315,10 +315,8 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     int page_size = qemu_target_page_size();
     int page_mask = -page_size;
 
-    if (vhost_vdpa_listener_skipped_section(section,
-                                            v->shared->iova_range.first,
-                                            v->shared->iova_range.last,
-                                            page_mask)) {
+    if (vhost_vdpa_listener_skipped_section(section, s->iova_range.first,
+                                            s->iova_range.last, page_mask)) {
         return;
     }
     if (memory_region_is_iommu(section->mr)) {
@@ -328,8 +326,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
 
     if (unlikely((section->offset_within_address_space & ~page_mask) !=
                  (section->offset_within_region & ~page_mask))) {
-        trace_vhost_vdpa_listener_region_add_unaligned(v->shared,
-                       section->mr->name,
+        trace_vhost_vdpa_listener_region_add_unaligned(s, section->mr->name,
                        section->offset_within_address_space & ~page_mask,
                        section->offset_within_region & ~page_mask);
         return;
@@ -349,18 +346,18 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
             section->offset_within_region +
             (iova - section->offset_within_address_space);
 
-    trace_vhost_vdpa_listener_region_add(v->shared, iova, int128_get64(llend),
+    trace_vhost_vdpa_listener_region_add(s, iova, int128_get64(llend),
                                          vaddr, section->readonly);
 
     llsize = int128_sub(llend, int128_make64(iova));
-    if (v->shared->shadow_data) {
+    if (s->shadow_data) {
         int r;
 
         mem_region.translated_addr = (hwaddr)(uintptr_t)vaddr,
         mem_region.size = int128_get64(llsize) - 1,
         mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly),
 
-        r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &mem_region);
+        r = vhost_iova_tree_map_alloc(s->iova_tree, &mem_region);
         if (unlikely(r != IOVA_OK)) {
             error_report("Can't allocate a mapping (%d)", r);
             goto fail;
@@ -369,8 +366,8 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
         iova = mem_region.iova;
     }
 
-    vhost_vdpa_iotlb_batch_begin_once(v->shared);
-    ret = vhost_vdpa_dma_map(v->shared, VHOST_VDPA_GUEST_PA_ASID, iova,
+    vhost_vdpa_iotlb_batch_begin_once(s);
+    ret = vhost_vdpa_dma_map(s, VHOST_VDPA_GUEST_PA_ASID, iova,
                              int128_get64(llsize), vaddr, section->readonly);
     if (ret) {
         error_report("vhost vdpa map fail!");
@@ -380,8 +377,8 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     return;
 
 fail_map:
-    if (v->shared->shadow_data) {
-        vhost_iova_tree_remove(v->shared->iova_tree, mem_region);
+    if (s->shadow_data) {
+        vhost_iova_tree_remove(s->iova_tree, mem_region);
     }
 
 fail:
@@ -398,17 +395,15 @@ fail:
 static void vhost_vdpa_listener_region_del(MemoryListener *listener,
                                            MemoryRegionSection *section)
 {
-    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    VhostVDPAShared *s = container_of(listener, VhostVDPAShared, listener);
     hwaddr iova;
     Int128 llend, llsize;
     int ret;
     int page_size = qemu_target_page_size();
     int page_mask = -page_size;
 
-    if (vhost_vdpa_listener_skipped_section(section,
-                                            v->shared->iova_range.first,
-                                            v->shared->iova_range.last,
-                                            page_mask)) {
+    if (vhost_vdpa_listener_skipped_section(section, s->iova_range.first,
+                                            s->iova_range.last, page_mask)) {
         return;
     }
     if (memory_region_is_iommu(section->mr)) {
@@ -417,8 +412,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
 
     if (unlikely((section->offset_within_address_space & ~page_mask) !=
                  (section->offset_within_region & ~page_mask))) {
-        trace_vhost_vdpa_listener_region_del_unaligned(v->shared,
-                       section->mr->name,
+        trace_vhost_vdpa_listener_region_del_unaligned(s, section->mr->name,
                        section->offset_within_address_space & ~page_mask,
                        section->offset_within_region & ~page_mask);
         return;
@@ -427,7 +421,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
     iova = ROUND_UP(section->offset_within_address_space, page_size);
     llend = vhost_vdpa_section_end(section, page_mask);
 
-    trace_vhost_vdpa_listener_region_del(v->shared, iova,
+    trace_vhost_vdpa_listener_region_del(s, iova,
         int128_get64(int128_sub(llend, int128_one())));
 
     if (int128_ge(int128_make64(iova), llend)) {
@@ -436,7 +430,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
 
     llsize = int128_sub(llend, int128_make64(iova));
 
-    if (v->shared->shadow_data) {
+    if (s->shadow_data) {
         const DMAMap *result;
         const void *vaddr = memory_region_get_ram_ptr(section->mr) +
             section->offset_within_region +
@@ -446,37 +440,37 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
             .size = int128_get64(llsize) - 1,
         };
 
-        result = vhost_iova_tree_find_iova(v->shared->iova_tree, &mem_region);
+        result = vhost_iova_tree_find_iova(s->iova_tree, &mem_region);
         if (!result) {
             /* The memory listener map wasn't mapped */
             return;
         }
         iova = result->iova;
-        vhost_iova_tree_remove(v->shared->iova_tree, *result);
+        vhost_iova_tree_remove(s->iova_tree, *result);
     }
-    vhost_vdpa_iotlb_batch_begin_once(v->shared);
+    vhost_vdpa_iotlb_batch_begin_once(s);
     /*
      * The unmap ioctl doesn't accept a full 64-bit. need to check it
      */
     if (int128_eq(llsize, int128_2_64())) {
         llsize = int128_rshift(llsize, 1);
-        ret = vhost_vdpa_dma_unmap(v->shared, VHOST_VDPA_GUEST_PA_ASID, iova,
+        ret = vhost_vdpa_dma_unmap(s, VHOST_VDPA_GUEST_PA_ASID, iova,
                                    int128_get64(llsize));
 
         if (ret) {
             error_report("vhost_vdpa_dma_unmap(%p, 0x%" HWADDR_PRIx ", "
                          "0x%" HWADDR_PRIx ") = %d (%m)",
-                         v, iova, int128_get64(llsize), ret);
+                         s, iova, int128_get64(llsize), ret);
         }
         iova += int128_get64(llsize);
     }
-    ret = vhost_vdpa_dma_unmap(v->shared, VHOST_VDPA_GUEST_PA_ASID, iova,
+    ret = vhost_vdpa_dma_unmap(s, VHOST_VDPA_GUEST_PA_ASID, iova,
                                int128_get64(llsize));
 
     if (ret) {
         error_report("vhost_vdpa_dma_unmap(%p, 0x%" HWADDR_PRIx ", "
                      "0x%" HWADDR_PRIx ") = %d (%m)",
-                     v, iova, int128_get64(llsize), ret);
+                     s, iova, int128_get64(llsize), ret);
     }
 
     memory_region_unref(section->mr);
@@ -595,7 +589,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
 
     v->dev = dev;
     dev->opaque =  opaque ;
-    v->listener = vhost_vdpa_memory_listener;
+    v->shared->listener = vhost_vdpa_memory_listener;
     vhost_vdpa_init_svq(dev, v);
 
     error_propagate(&dev->migration_blocker, v->migration_blocker);
@@ -755,10 +749,10 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev)
     trace_vhost_vdpa_cleanup(dev, v);
     if (vhost_vdpa_first_dev(dev)) {
         ram_block_discard_disable(false);
+        memory_listener_unregister(&v->shared->listener);
     }
 
     vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
-    memory_listener_unregister(&v->listener);
     vhost_vdpa_svq_cleanup(dev);
 
     dev->opaque = NULL;
@@ -1331,7 +1325,7 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
                          "IOMMU and try again");
             return -1;
         }
-        memory_listener_register(&v->listener, dev->vdev->dma_as);
+        memory_listener_register(&v->shared->listener, dev->vdev->dma_as);
 
         return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
     }
@@ -1350,7 +1344,7 @@ static void vhost_vdpa_reset_status(struct vhost_dev *dev)
     vhost_vdpa_reset_device(dev);
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
-    memory_listener_unregister(&v->listener);
+    memory_listener_unregister(&v->shared->listener);
 }
 
 static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 2abee2164a..8f54e5edd4 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -33,6 +33,7 @@ typedef struct VhostVDPAHostNotifier {
 /* Info shared by all vhost_vdpa device models */
 typedef struct vhost_vdpa_shared {
     int device_fd;
+    MemoryListener listener;
     struct vhost_vdpa_iova_range iova_range;
     QLIST_HEAD(, vdpa_iommu) iommu_list;
 
@@ -51,7 +52,6 @@ typedef struct vhost_vdpa_shared {
 typedef struct vhost_vdpa {
     int index;
     uint32_t address_space_id;
-    MemoryListener listener;
     uint64_t acked_features;
     bool shadow_vqs_enabled;
     /* Device suspended successfully */