Checking whether the memory regions are equal is sufficient: if they are equal, then most certainly the contained fd is equal.
The whole vhost-user memslot handling is suboptimal and overly complicated. We shouldn't have to lookup a RAM memory regions we got notified about in vhost_user_get_mr_data() using a host pointer. But that requires a bigger rework -- especially an alternative vhost_set_mem_table() backend call that simply consumes MemoryRegionSections. For now, let's just drop vhost_backend_can_merge(). Acked-by: Stefan Hajnoczi <stefa...@redhat.com> Reviewed-by: Igor Mammedov <imamm...@redhat.com> Acked-by: Igor Mammedov <imamm...@redhat.com> Reviewed-by: Peter Xu <pet...@redhat.com> Signed-off-by: David Hildenbrand <da...@redhat.com> --- hw/virtio/vhost-user.c | 14 -------------- hw/virtio/vhost-vdpa.c | 1 - hw/virtio/vhost.c | 6 +----- include/hw/virtio/vhost-backend.h | 4 ---- 4 files changed, 1 insertion(+), 24 deletions(-) diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 1e7553352a..e6de930872 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -2205,19 +2205,6 @@ static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr) return -ENOTSUP; } -static bool vhost_user_can_merge(struct vhost_dev *dev, - uint64_t start1, uint64_t size1, - uint64_t start2, uint64_t size2) -{ - ram_addr_t offset; - int mfd, rfd; - - (void)vhost_user_get_mr_data(start1, &offset, &mfd); - (void)vhost_user_get_mr_data(start2, &offset, &rfd); - - return mfd == rfd; -} - static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu) { VhostUserMsg msg; @@ -2764,7 +2751,6 @@ const VhostOps user_ops = { .vhost_set_vring_enable = vhost_user_set_vring_enable, .vhost_requires_shm_log = vhost_user_requires_shm_log, .vhost_migration_done = vhost_user_migration_done, - .vhost_backend_can_merge = vhost_user_can_merge, .vhost_net_set_mtu = vhost_user_net_set_mtu, .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback, .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg, diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 42f2a4bae9..8f07bee041 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -1508,7 +1508,6 @@ const VhostOps vdpa_ops = { .vhost_set_config = vhost_vdpa_set_config, .vhost_requires_shm_log = NULL, .vhost_migration_done = NULL, - .vhost_backend_can_merge = NULL, .vhost_net_set_mtu = NULL, .vhost_set_iotlb_callback = NULL, .vhost_send_device_iotlb_msg = NULL, diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index c1e6148833..c16ad14535 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -728,11 +728,7 @@ static void vhost_region_add_section(struct vhost_dev *dev, size_t offset = mrs_gpa - prev_gpa_start; if (prev_host_start + offset == mrs_host && - section->mr == prev_sec->mr && - (!dev->vhost_ops->vhost_backend_can_merge || - dev->vhost_ops->vhost_backend_can_merge(dev, - mrs_host, mrs_size, - prev_host_start, prev_size))) { + section->mr == prev_sec->mr) { uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size); need_add = false; prev_sec->offset_within_address_space = diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index df2821ddae..12d578824b 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h @@ -86,9 +86,6 @@ typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev, typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev); typedef int (*vhost_migration_done_op)(struct vhost_dev *dev, char *mac_addr); -typedef bool (*vhost_backend_can_merge_op)(struct vhost_dev *dev, - uint64_t start1, uint64_t size1, - uint64_t start2, uint64_t size2); typedef int (*vhost_vsock_set_guest_cid_op)(struct vhost_dev *dev, uint64_t guest_cid); typedef int (*vhost_vsock_set_running_op)(struct vhost_dev *dev, int start); @@ -163,7 +160,6 @@ typedef struct VhostOps { vhost_set_vring_enable_op vhost_set_vring_enable; vhost_requires_shm_log_op vhost_requires_shm_log; vhost_migration_done_op vhost_migration_done; - vhost_backend_can_merge_op vhost_backend_can_merge; vhost_vsock_set_guest_cid_op vhost_vsock_set_guest_cid; vhost_vsock_set_running_op vhost_vsock_set_running; vhost_set_iotlb_callback_op vhost_set_iotlb_callback; -- 2.41.0