Commit 383ee445 authored by David Hildenbrand's avatar David Hildenbrand Committed by Michael S. Tsirkin
Browse files

virtio-mem: Migration sanity checks 



We want to make sure that certain properties don't change during
migration, especially to catch user errors in a nice way. Let's migrate
a temporary structure and validate that the properties didn't change.

Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-19-david@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 722a3c78

hw/virtio/virtio-mem.c

+70 −0
Original line number Diff line number Diff line
@@ -519,12 +519,82 @@ static int virtio_mem_post_load(void *opaque, int version_id) 
    return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));

}



typedef struct VirtIOMEMMigSanityChecks {

    VirtIOMEM *parent;

    uint64_t addr;

    uint64_t region_size;

    uint64_t block_size;

    uint32_t node;

} VirtIOMEMMigSanityChecks;



static int virtio_mem_mig_sanity_checks_pre_save(void *opaque)

{

    VirtIOMEMMigSanityChecks *tmp = opaque;

    VirtIOMEM *vmem = tmp->parent;



    tmp->addr = vmem->addr;

    tmp->region_size = memory_region_size(&vmem->memdev->mr);

    tmp->block_size = vmem->block_size;

    tmp->node = vmem->node;

    return 0;

}



static int virtio_mem_mig_sanity_checks_post_load(void *opaque, int version_id)

{

    VirtIOMEMMigSanityChecks *tmp = opaque;

    VirtIOMEM *vmem = tmp->parent;

    const uint64_t new_region_size = memory_region_size(&vmem->memdev->mr);



    if (tmp->addr != vmem->addr) {

        error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,

                     VIRTIO_MEM_ADDR_PROP, tmp->addr, vmem->addr);

        return -EINVAL;

    }

    /*

     * Note: Preparation for resizeable memory regions. The maximum size

     * of the memory region must not change during migration.

     */

    if (tmp->region_size != new_region_size) {

        error_report("Property '%s' size changed from 0x%" PRIx64 " to 0x%"

                     PRIx64, VIRTIO_MEM_MEMDEV_PROP, tmp->region_size,

                     new_region_size);

        return -EINVAL;

    }

    if (tmp->block_size != vmem->block_size) {

        error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,

                     VIRTIO_MEM_BLOCK_SIZE_PROP, tmp->block_size,

                     vmem->block_size);

        return -EINVAL;

    }

    if (tmp->node != vmem->node) {

        error_report("Property '%s' changed from %" PRIu32 " to %" PRIu32,

                     VIRTIO_MEM_NODE_PROP, tmp->node, vmem->node);

        return -EINVAL;

    }

    return 0;

}



static const VMStateDescription vmstate_virtio_mem_sanity_checks = {

    .name = "virtio-mem-device/sanity-checks",

    .pre_save = virtio_mem_mig_sanity_checks_pre_save,

    .post_load = virtio_mem_mig_sanity_checks_post_load,

    .fields = (VMStateField[]) {

        VMSTATE_UINT64(addr, VirtIOMEMMigSanityChecks),

        VMSTATE_UINT64(region_size, VirtIOMEMMigSanityChecks),

        VMSTATE_UINT64(block_size, VirtIOMEMMigSanityChecks),

        VMSTATE_UINT32(node, VirtIOMEMMigSanityChecks),

        VMSTATE_END_OF_LIST(),

    },

};



static const VMStateDescription vmstate_virtio_mem_device = {

    .name = "virtio-mem-device",

    .minimum_version_id = 1,

    .version_id = 1,

    .post_load = virtio_mem_post_load,

    .fields = (VMStateField[]) {

        VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks,

                         vmstate_virtio_mem_sanity_checks),

        VMSTATE_UINT64(usable_region_size, VirtIOMEM),

        VMSTATE_UINT64(size, VirtIOMEM),

        VMSTATE_UINT64(requested_size, VirtIOMEM),