| Message ID | 20231019143455.2377694-3-eperezma@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Map memory at destination .load_setup in vDPA-net migration | expand |
On 10/19/2023 7:34 AM, Eugenio Pérez wrote: > 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 iova tree to VhostVDPAShared so all vhost_vdpa can use it, > rather than always in the first or last vhost_vdpa. > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com> > --- > include/hw/virtio/vhost-vdpa.h | 4 +-- > hw/virtio/vhost-vdpa.c | 19 ++++++------ > net/vhost-vdpa.c | 54 +++++++++++++++------------------- > 3 files changed, 35 insertions(+), 42 deletions(-) > > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h > index eb1a56d75a..ac036055d3 100644 > --- a/include/hw/virtio/vhost-vdpa.h > +++ b/include/hw/virtio/vhost-vdpa.h > @@ -32,6 +32,8 @@ typedef struct VhostVDPAHostNotifier { > > /* Info shared by all vhost_vdpa device models */ > typedef struct vhost_vdpa_shared { > + /* IOVA mapping used by the Shadow Virtqueue */ > + VhostIOVATree *iova_tree; > } VhostVDPAShared; > > typedef struct vhost_vdpa { > @@ -48,8 +50,6 @@ typedef struct vhost_vdpa { > bool shadow_data; > /* Device suspended successfully */ > bool suspended; > - /* IOVA mapping used by the Shadow Virtqueue */ > - VhostIOVATree *iova_tree; > VhostVDPAShared *shared; > GPtrArray *shadow_vqs; > const VhostShadowVirtqueueOps *shadow_vq_ops; > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > index 819b2d811a..9cee38cb6d 100644 > --- a/hw/virtio/vhost-vdpa.c > +++ b/hw/virtio/vhost-vdpa.c > @@ -358,7 +358,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, > mem_region.size = int128_get64(llsize) - 1, > mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly), > > - r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region); > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &mem_region); > if (unlikely(r != IOVA_OK)) { > error_report("Can't allocate a mapping (%d)", r); > goto fail; > @@ -379,7 +379,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, > > fail_map: > if (v->shadow_data) { > - vhost_iova_tree_remove(v->iova_tree, mem_region); > + vhost_iova_tree_remove(v->shared->iova_tree, mem_region); > } > > fail: > @@ -441,13 +441,13 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener, > .size = int128_get64(llsize) - 1, > }; > > - result = vhost_iova_tree_find_iova(v->iova_tree, &mem_region); > + result = vhost_iova_tree_find_iova(v->shared->iova_tree, &mem_region); > if (!result) { > /* The memory listener map wasn't mapped */ > return; > } > iova = result->iova; > - vhost_iova_tree_remove(v->iova_tree, *result); > + vhost_iova_tree_remove(v->shared->iova_tree, *result); > } > vhost_vdpa_iotlb_batch_begin_once(v); > /* > @@ -1059,7 +1059,8 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) > const DMAMap needle = { > .translated_addr = addr, > }; > - const DMAMap *result = vhost_iova_tree_find_iova(v->iova_tree, &needle); > + const DMAMap *result = vhost_iova_tree_find_iova(v->shared->iova_tree, > + &needle); > hwaddr size; > int r; > > @@ -1075,7 +1076,7 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) > return; > } > > - vhost_iova_tree_remove(v->iova_tree, *result); > + vhost_iova_tree_remove(v->shared->iova_tree, *result); > } > > static void vhost_vdpa_svq_unmap_rings(struct vhost_dev *dev, > @@ -1103,7 +1104,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, > { > int r; > > - r = vhost_iova_tree_map_alloc(v->iova_tree, needle); > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, needle); > if (unlikely(r != IOVA_OK)) { > error_setg(errp, "Cannot allocate iova (%d)", r); > return false; > @@ -1115,7 +1116,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, > needle->perm == IOMMU_RO); > if (unlikely(r != 0)) { > error_setg_errno(errp, -r, "Cannot map region to device"); > - vhost_iova_tree_remove(v->iova_tree, *needle); > + vhost_iova_tree_remove(v->shared->iova_tree, *needle); > } > > return r == 0; > @@ -1216,7 +1217,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev) > goto err; > } > > - vhost_svq_start(svq, dev->vdev, vq, v->iova_tree); > + vhost_svq_start(svq, dev->vdev, vq, v->shared->iova_tree); > ok = vhost_vdpa_svq_map_rings(dev, svq, &addr, &err); > if (unlikely(!ok)) { > goto err_map; > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index a2f9855288..15e7579b13 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -345,8 +345,8 @@ static void vhost_vdpa_net_data_start_first(VhostVDPAState *s) > > add_migration_state_change_notifier(&s->migration_state); > if (v->shadow_vqs_enabled) { > - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > - v->iova_range.last); > + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, > + v->iova_range.last); This code change is okay so far without .load_setup involved, but if interacting with .load_setup the iova_tree can be NULL when x-svq=on. Below is a stacktrace showing the problem. #0 0x00005582bf00944c in vhost_iova_tree_map_alloc (tree=0x0, map=map@entry=0x7fb16bfffde0) at ../hw/virtio/vhost-iova-tree.c:89 #1 0x00005582bee8cdb3 in vhost_vdpa_listener_region_add (listener=0x5582c138ee58, section=0x7fb16bfffe50) at ../include/qemu/int128.h:33 #2 0x00005582bf029d4b in memory_listener_register (as=0x5582bfb53d20 <address_space_memory>, listener=0x5582c138ee58) at ../system/memory.c:3026 #3 0x00005582bf029d4b in memory_listener_register (listener=0x5582c138ee58, as=0x5582bfb53d20 <address_space_memory>) at ../system/memory.c:3096 #4 0x00005582bee8e712 in vhost_vdpa_load_setup (shared=0x5582c138ee50, dma_as=0x5582bfb53d20 <address_space_memory>) at ../hw/virtio/vhost-vdpa.c:1550 #5 0x00005582bef0b7df in vhost_vdpa_net_load_setup (nc=0x7fb172a27010, nic=<optimized out>) at ../net/vhost-vdpa.c:415 #6 0x00005582beeeb4f5 in qemu_loadvm_state (f=0x5582c1c1a800) at ../migration/savevm.c:2682 #7 0x00005582beeeb4f5 in qemu_loadvm_state (f=0x5582c1c1a800) at ../migration/savevm.c:2866 #8 0x00005582beed5e17 in process_incoming_migration_co (opaque=<optimized out>) at ../migration/migration.c:548 #9 0x00005582bf21b29b in coroutine_trampoline (i0=<optimized out>, i1=<optimized out>) at ../util/coroutine-ucontext.c:177 #10 0x00007fb16e448190 in __start_context () at /lib64/libc.so.6 -Siwei > } > } > > @@ -371,11 +371,6 @@ static int vhost_vdpa_net_data_start(NetClientState *nc) > return 0; > } > > - if (v->shadow_vqs_enabled) { > - VhostVDPAState *s0 = vhost_vdpa_net_first_nc_vdpa(s); > - v->iova_tree = s0->vhost_vdpa.iova_tree; > - } > - > return 0; > } > > @@ -408,9 +403,8 @@ static void vhost_vdpa_net_client_stop(NetClientState *nc) > > dev = s->vhost_vdpa.dev; > if (dev->vq_index + dev->nvqs == dev->vq_index_end) { > - g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete); > - } else { > - s->vhost_vdpa.iova_tree = NULL; > + g_clear_pointer(&s->vhost_vdpa.shared->iova_tree, > + vhost_iova_tree_delete); > } > } > > @@ -464,7 +458,7 @@ static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v, > > static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr) > { > - VhostIOVATree *tree = v->iova_tree; > + VhostIOVATree *tree = v->shared->iova_tree; > DMAMap needle = { > /* > * No need to specify size or to look for more translations since > @@ -498,7 +492,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, > map.translated_addr = (hwaddr)(uintptr_t)buf; > map.size = size - 1; > map.perm = write ? IOMMU_RW : IOMMU_RO, > - r = vhost_iova_tree_map_alloc(v->iova_tree, &map); > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &map); > if (unlikely(r != IOVA_OK)) { > error_report("Cannot map injected element"); > return r; > @@ -513,7 +507,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, > return 0; > > dma_map_err: > - vhost_iova_tree_remove(v->iova_tree, map); > + vhost_iova_tree_remove(v->shared->iova_tree, map); > return r; > } > > @@ -573,24 +567,22 @@ out: > return 0; > } > > - if (s0->vhost_vdpa.iova_tree) { > - /* > - * SVQ is already configured for all virtqueues. Reuse IOVA tree for > - * simplicity, whether CVQ shares ASID with guest or not, because: > - * - Memory listener need access to guest's memory addresses allocated > - * in the IOVA tree. > - * - There should be plenty of IOVA address space for both ASID not to > - * worry about collisions between them. Guest's translations are > - * still validated with virtio virtqueue_pop so there is no risk for > - * the guest to access memory that it shouldn't. > - * > - * To allocate a iova tree per ASID is doable but it complicates the > - * code and it is not worth it for the moment. > - */ > - v->iova_tree = s0->vhost_vdpa.iova_tree; > - } else { > - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > - v->iova_range.last); > + /* > + * If other vhost_vdpa already have an iova_tree, reuse it for simplicity, > + * whether CVQ shares ASID with guest or not, because: > + * - Memory listener need access to guest's memory addresses allocated in > + * the IOVA tree. > + * - There should be plenty of IOVA address space for both ASID not to > + * worry about collisions between them. Guest's translations are still > + * validated with virtio virtqueue_pop so there is no risk for the guest > + * to access memory that it shouldn't. > + * > + * To allocate a iova tree per ASID is doable but it complicates the code > + * and it is not worth it for the moment. > + */ > + if (!v->shared->iova_tree) { > + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, > + v->iova_range.last); > } > > r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
On Thu, Nov 2, 2023 at 10:37 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote: > > > > On 10/19/2023 7:34 AM, Eugenio Pérez wrote: > > 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 iova tree to VhostVDPAShared so all vhost_vdpa can use it, > > rather than always in the first or last vhost_vdpa. > > > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com> > > --- > > include/hw/virtio/vhost-vdpa.h | 4 +-- > > hw/virtio/vhost-vdpa.c | 19 ++++++------ > > net/vhost-vdpa.c | 54 +++++++++++++++------------------- > > 3 files changed, 35 insertions(+), 42 deletions(-) > > > > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h > > index eb1a56d75a..ac036055d3 100644 > > --- a/include/hw/virtio/vhost-vdpa.h > > +++ b/include/hw/virtio/vhost-vdpa.h > > @@ -32,6 +32,8 @@ typedef struct VhostVDPAHostNotifier { > > > > /* Info shared by all vhost_vdpa device models */ > > typedef struct vhost_vdpa_shared { > > + /* IOVA mapping used by the Shadow Virtqueue */ > > + VhostIOVATree *iova_tree; > > } VhostVDPAShared; > > > > typedef struct vhost_vdpa { > > @@ -48,8 +50,6 @@ typedef struct vhost_vdpa { > > bool shadow_data; > > /* Device suspended successfully */ > > bool suspended; > > - /* IOVA mapping used by the Shadow Virtqueue */ > > - VhostIOVATree *iova_tree; > > VhostVDPAShared *shared; > > GPtrArray *shadow_vqs; > > const VhostShadowVirtqueueOps *shadow_vq_ops; > > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > > index 819b2d811a..9cee38cb6d 100644 > > --- a/hw/virtio/vhost-vdpa.c > > +++ b/hw/virtio/vhost-vdpa.c > > @@ -358,7 +358,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, > > mem_region.size = int128_get64(llsize) - 1, > > mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly), > > > > - r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region); > > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &mem_region); > > if (unlikely(r != IOVA_OK)) { > > error_report("Can't allocate a mapping (%d)", r); > > goto fail; > > @@ -379,7 +379,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, > > > > fail_map: > > if (v->shadow_data) { > > - vhost_iova_tree_remove(v->iova_tree, mem_region); > > + vhost_iova_tree_remove(v->shared->iova_tree, mem_region); > > } > > > > fail: > > @@ -441,13 +441,13 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener, > > .size = int128_get64(llsize) - 1, > > }; > > > > - result = vhost_iova_tree_find_iova(v->iova_tree, &mem_region); > > + result = vhost_iova_tree_find_iova(v->shared->iova_tree, &mem_region); > > if (!result) { > > /* The memory listener map wasn't mapped */ > > return; > > } > > iova = result->iova; > > - vhost_iova_tree_remove(v->iova_tree, *result); > > + vhost_iova_tree_remove(v->shared->iova_tree, *result); > > } > > vhost_vdpa_iotlb_batch_begin_once(v); > > /* > > @@ -1059,7 +1059,8 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) > > const DMAMap needle = { > > .translated_addr = addr, > > }; > > - const DMAMap *result = vhost_iova_tree_find_iova(v->iova_tree, &needle); > > + const DMAMap *result = vhost_iova_tree_find_iova(v->shared->iova_tree, > > + &needle); > > hwaddr size; > > int r; > > > > @@ -1075,7 +1076,7 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) > > return; > > } > > > > - vhost_iova_tree_remove(v->iova_tree, *result); > > + vhost_iova_tree_remove(v->shared->iova_tree, *result); > > } > > > > static void vhost_vdpa_svq_unmap_rings(struct vhost_dev *dev, > > @@ -1103,7 +1104,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, > > { > > int r; > > > > - r = vhost_iova_tree_map_alloc(v->iova_tree, needle); > > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, needle); > > if (unlikely(r != IOVA_OK)) { > > error_setg(errp, "Cannot allocate iova (%d)", r); > > return false; > > @@ -1115,7 +1116,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, > > needle->perm == IOMMU_RO); > > if (unlikely(r != 0)) { > > error_setg_errno(errp, -r, "Cannot map region to device"); > > - vhost_iova_tree_remove(v->iova_tree, *needle); > > + vhost_iova_tree_remove(v->shared->iova_tree, *needle); > > } > > > > return r == 0; > > @@ -1216,7 +1217,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev) > > goto err; > > } > > > > - vhost_svq_start(svq, dev->vdev, vq, v->iova_tree); > > + vhost_svq_start(svq, dev->vdev, vq, v->shared->iova_tree); > > ok = vhost_vdpa_svq_map_rings(dev, svq, &addr, &err); > > if (unlikely(!ok)) { > > goto err_map; > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > > index a2f9855288..15e7579b13 100644 > > --- a/net/vhost-vdpa.c > > +++ b/net/vhost-vdpa.c > > @@ -345,8 +345,8 @@ static void vhost_vdpa_net_data_start_first(VhostVDPAState *s) > > > > add_migration_state_change_notifier(&s->migration_state); > > if (v->shadow_vqs_enabled) { > > - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > > - v->iova_range.last); > > + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, > > + v->iova_range.last); > This code change is okay so far without .load_setup involved, but if > interacting with .load_setup the iova_tree can be NULL when x-svq=on. > Below is a stacktrace showing the problem. > Right, the next version of the series including .load_setup will take this into account. Thanks! > #0 0x00005582bf00944c in vhost_iova_tree_map_alloc (tree=0x0, > map=map@entry=0x7fb16bfffde0) at ../hw/virtio/vhost-iova-tree.c:89 > #1 0x00005582bee8cdb3 in vhost_vdpa_listener_region_add > (listener=0x5582c138ee58, section=0x7fb16bfffe50) > at ../include/qemu/int128.h:33 > #2 0x00005582bf029d4b in memory_listener_register (as=0x5582bfb53d20 > <address_space_memory>, listener=0x5582c138ee58) > at ../system/memory.c:3026 > #3 0x00005582bf029d4b in memory_listener_register > (listener=0x5582c138ee58, as=0x5582bfb53d20 <address_space_memory>) > at ../system/memory.c:3096 > #4 0x00005582bee8e712 in vhost_vdpa_load_setup (shared=0x5582c138ee50, > dma_as=0x5582bfb53d20 <address_space_memory>) > at ../hw/virtio/vhost-vdpa.c:1550 > #5 0x00005582bef0b7df in vhost_vdpa_net_load_setup (nc=0x7fb172a27010, > nic=<optimized out>) at ../net/vhost-vdpa.c:415 > #6 0x00005582beeeb4f5 in qemu_loadvm_state (f=0x5582c1c1a800) at > ../migration/savevm.c:2682 > #7 0x00005582beeeb4f5 in qemu_loadvm_state (f=0x5582c1c1a800) at > ../migration/savevm.c:2866 > #8 0x00005582beed5e17 in process_incoming_migration_co > (opaque=<optimized out>) at ../migration/migration.c:548 > #9 0x00005582bf21b29b in coroutine_trampoline (i0=<optimized out>, > i1=<optimized out>) at ../util/coroutine-ucontext.c:177 > #10 0x00007fb16e448190 in __start_context () at /lib64/libc.so.6 > > -Siwei > > } > > } > > > > @@ -371,11 +371,6 @@ static int vhost_vdpa_net_data_start(NetClientState *nc) > > return 0; > > } > > > > - if (v->shadow_vqs_enabled) { > > - VhostVDPAState *s0 = vhost_vdpa_net_first_nc_vdpa(s); > > - v->iova_tree = s0->vhost_vdpa.iova_tree; > > - } > > - > > return 0; > > } > > > > @@ -408,9 +403,8 @@ static void vhost_vdpa_net_client_stop(NetClientState *nc) > > > > dev = s->vhost_vdpa.dev; > > if (dev->vq_index + dev->nvqs == dev->vq_index_end) { > > - g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete); > > - } else { > > - s->vhost_vdpa.iova_tree = NULL; > > + g_clear_pointer(&s->vhost_vdpa.shared->iova_tree, > > + vhost_iova_tree_delete); > > } > > } > > > > @@ -464,7 +458,7 @@ static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v, > > > > static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr) > > { > > - VhostIOVATree *tree = v->iova_tree; > > + VhostIOVATree *tree = v->shared->iova_tree; > > DMAMap needle = { > > /* > > * No need to specify size or to look for more translations since > > @@ -498,7 +492,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, > > map.translated_addr = (hwaddr)(uintptr_t)buf; > > map.size = size - 1; > > map.perm = write ? IOMMU_RW : IOMMU_RO, > > - r = vhost_iova_tree_map_alloc(v->iova_tree, &map); > > + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &map); > > if (unlikely(r != IOVA_OK)) { > > error_report("Cannot map injected element"); > > return r; > > @@ -513,7 +507,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, > > return 0; > > > > dma_map_err: > > - vhost_iova_tree_remove(v->iova_tree, map); > > + vhost_iova_tree_remove(v->shared->iova_tree, map); > > return r; > > } > > > > @@ -573,24 +567,22 @@ out: > > return 0; > > } > > > > - if (s0->vhost_vdpa.iova_tree) { > > - /* > > - * SVQ is already configured for all virtqueues. Reuse IOVA tree for > > - * simplicity, whether CVQ shares ASID with guest or not, because: > > - * - Memory listener need access to guest's memory addresses allocated > > - * in the IOVA tree. > > - * - There should be plenty of IOVA address space for both ASID not to > > - * worry about collisions between them. Guest's translations are > > - * still validated with virtio virtqueue_pop so there is no risk for > > - * the guest to access memory that it shouldn't. > > - * > > - * To allocate a iova tree per ASID is doable but it complicates the > > - * code and it is not worth it for the moment. > > - */ > > - v->iova_tree = s0->vhost_vdpa.iova_tree; > > - } else { > > - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, > > - v->iova_range.last); > > + /* > > + * If other vhost_vdpa already have an iova_tree, reuse it for simplicity, > > + * whether CVQ shares ASID with guest or not, because: > > + * - Memory listener need access to guest's memory addresses allocated in > > + * the IOVA tree. > > + * - There should be plenty of IOVA address space for both ASID not to > > + * worry about collisions between them. Guest's translations are still > > + * validated with virtio virtqueue_pop so there is no risk for the guest > > + * to access memory that it shouldn't. > > + * > > + * To allocate a iova tree per ASID is doable but it complicates the code > > + * and it is not worth it for the moment. > > + */ > > + if (!v->shared->iova_tree) { > > + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, > > + v->iova_range.last); > > } > > > > r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer, >
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h index eb1a56d75a..ac036055d3 100644 --- a/include/hw/virtio/vhost-vdpa.h +++ b/include/hw/virtio/vhost-vdpa.h @@ -32,6 +32,8 @@ typedef struct VhostVDPAHostNotifier { /* Info shared by all vhost_vdpa device models */ typedef struct vhost_vdpa_shared { + /* IOVA mapping used by the Shadow Virtqueue */ + VhostIOVATree *iova_tree; } VhostVDPAShared; typedef struct vhost_vdpa { @@ -48,8 +50,6 @@ typedef struct vhost_vdpa { bool shadow_data; /* Device suspended successfully */ bool suspended; - /* IOVA mapping used by the Shadow Virtqueue */ - VhostIOVATree *iova_tree; VhostVDPAShared *shared; GPtrArray *shadow_vqs; const VhostShadowVirtqueueOps *shadow_vq_ops; diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 819b2d811a..9cee38cb6d 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -358,7 +358,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, mem_region.size = int128_get64(llsize) - 1, mem_region.perm = IOMMU_ACCESS_FLAG(true, section->readonly), - r = vhost_iova_tree_map_alloc(v->iova_tree, &mem_region); + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &mem_region); if (unlikely(r != IOVA_OK)) { error_report("Can't allocate a mapping (%d)", r); goto fail; @@ -379,7 +379,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener, fail_map: if (v->shadow_data) { - vhost_iova_tree_remove(v->iova_tree, mem_region); + vhost_iova_tree_remove(v->shared->iova_tree, mem_region); } fail: @@ -441,13 +441,13 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener, .size = int128_get64(llsize) - 1, }; - result = vhost_iova_tree_find_iova(v->iova_tree, &mem_region); + result = vhost_iova_tree_find_iova(v->shared->iova_tree, &mem_region); if (!result) { /* The memory listener map wasn't mapped */ return; } iova = result->iova; - vhost_iova_tree_remove(v->iova_tree, *result); + vhost_iova_tree_remove(v->shared->iova_tree, *result); } vhost_vdpa_iotlb_batch_begin_once(v); /* @@ -1059,7 +1059,8 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) const DMAMap needle = { .translated_addr = addr, }; - const DMAMap *result = vhost_iova_tree_find_iova(v->iova_tree, &needle); + const DMAMap *result = vhost_iova_tree_find_iova(v->shared->iova_tree, + &needle); hwaddr size; int r; @@ -1075,7 +1076,7 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr) return; } - vhost_iova_tree_remove(v->iova_tree, *result); + vhost_iova_tree_remove(v->shared->iova_tree, *result); } static void vhost_vdpa_svq_unmap_rings(struct vhost_dev *dev, @@ -1103,7 +1104,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, { int r; - r = vhost_iova_tree_map_alloc(v->iova_tree, needle); + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, needle); if (unlikely(r != IOVA_OK)) { error_setg(errp, "Cannot allocate iova (%d)", r); return false; @@ -1115,7 +1116,7 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle, needle->perm == IOMMU_RO); if (unlikely(r != 0)) { error_setg_errno(errp, -r, "Cannot map region to device"); - vhost_iova_tree_remove(v->iova_tree, *needle); + vhost_iova_tree_remove(v->shared->iova_tree, *needle); } return r == 0; @@ -1216,7 +1217,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev) goto err; } - vhost_svq_start(svq, dev->vdev, vq, v->iova_tree); + vhost_svq_start(svq, dev->vdev, vq, v->shared->iova_tree); ok = vhost_vdpa_svq_map_rings(dev, svq, &addr, &err); if (unlikely(!ok)) { goto err_map; diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index a2f9855288..15e7579b13 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -345,8 +345,8 @@ static void vhost_vdpa_net_data_start_first(VhostVDPAState *s) add_migration_state_change_notifier(&s->migration_state); if (v->shadow_vqs_enabled) { - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, - v->iova_range.last); + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, + v->iova_range.last); } } @@ -371,11 +371,6 @@ static int vhost_vdpa_net_data_start(NetClientState *nc) return 0; } - if (v->shadow_vqs_enabled) { - VhostVDPAState *s0 = vhost_vdpa_net_first_nc_vdpa(s); - v->iova_tree = s0->vhost_vdpa.iova_tree; - } - return 0; } @@ -408,9 +403,8 @@ static void vhost_vdpa_net_client_stop(NetClientState *nc) dev = s->vhost_vdpa.dev; if (dev->vq_index + dev->nvqs == dev->vq_index_end) { - g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete); - } else { - s->vhost_vdpa.iova_tree = NULL; + g_clear_pointer(&s->vhost_vdpa.shared->iova_tree, + vhost_iova_tree_delete); } } @@ -464,7 +458,7 @@ static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v, static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr) { - VhostIOVATree *tree = v->iova_tree; + VhostIOVATree *tree = v->shared->iova_tree; DMAMap needle = { /* * No need to specify size or to look for more translations since @@ -498,7 +492,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, map.translated_addr = (hwaddr)(uintptr_t)buf; map.size = size - 1; map.perm = write ? IOMMU_RW : IOMMU_RO, - r = vhost_iova_tree_map_alloc(v->iova_tree, &map); + r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &map); if (unlikely(r != IOVA_OK)) { error_report("Cannot map injected element"); return r; @@ -513,7 +507,7 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size, return 0; dma_map_err: - vhost_iova_tree_remove(v->iova_tree, map); + vhost_iova_tree_remove(v->shared->iova_tree, map); return r; } @@ -573,24 +567,22 @@ out: return 0; } - if (s0->vhost_vdpa.iova_tree) { - /* - * SVQ is already configured for all virtqueues. Reuse IOVA tree for - * simplicity, whether CVQ shares ASID with guest or not, because: - * - Memory listener need access to guest's memory addresses allocated - * in the IOVA tree. - * - There should be plenty of IOVA address space for both ASID not to - * worry about collisions between them. Guest's translations are - * still validated with virtio virtqueue_pop so there is no risk for - * the guest to access memory that it shouldn't. - * - * To allocate a iova tree per ASID is doable but it complicates the - * code and it is not worth it for the moment. - */ - v->iova_tree = s0->vhost_vdpa.iova_tree; - } else { - v->iova_tree = vhost_iova_tree_new(v->iova_range.first, - v->iova_range.last); + /* + * If other vhost_vdpa already have an iova_tree, reuse it for simplicity, + * whether CVQ shares ASID with guest or not, because: + * - Memory listener need access to guest's memory addresses allocated in + * the IOVA tree. + * - There should be plenty of IOVA address space for both ASID not to + * worry about collisions between them. Guest's translations are still + * validated with virtio virtqueue_pop so there is no risk for the guest + * to access memory that it shouldn't. + * + * To allocate a iova tree per ASID is doable but it complicates the code + * and it is not worth it for the moment. + */ + if (!v->shared->iova_tree) { + v->shared->iova_tree = vhost_iova_tree_new(v->iova_range.first, + v->iova_range.last); } r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
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 iova tree to VhostVDPAShared so all vhost_vdpa can use it, rather than always in the first or last vhost_vdpa. Signed-off-by: Eugenio Pérez <eperezma@redhat.com> --- include/hw/virtio/vhost-vdpa.h | 4 +-- hw/virtio/vhost-vdpa.c | 19 ++++++------ net/vhost-vdpa.c | 54 +++++++++++++++------------------- 3 files changed, 35 insertions(+), 42 deletions(-)