On 16/04/20 22:36, Maxim Levitsky wrote:
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1812399
>
> Suggested-by: Paolo Bonzini <pbonz...@redhat.com>
> Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
> ---
> hw/scsi/virtio-scsi.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index b0f4a35f81..e360b4e03e 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> @@ -35,13 +35,29 @@ static inline int virtio_scsi_get_lun(uint8_t *lun)
>
> static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t
> *lun)
> {
> + SCSIDevice *device = NULL;
> +
> if (lun[0] != 1) {
> return NULL;
> }
> if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
> return NULL;
> }
> - return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
> +
> + device = scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
> +
> + /* This function might run on the IO thread and we might race against
> + * main thread hot-plugging the device.
> + *
> + * We assume that as soon as .realized is set to true we can let
> + * the user access the device.
> + */
Likewise this needs to be load-acquire.
Paolo
> + if (!device || !atomic_read(&device->qdev.realized)) {
> + return NULL;
> + }
> +
> + return device;
> }
>
> void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
>
