On 17/12/2014 02:36, John Snow wrote:
> When the AHCI HBA device is migrated, all of the information that
> led to the request being created is stored in the AHCIDevice
> structures, except for pointers into guest data where return
> information needs to be stored.
>
> The "cur_cmd" field is usually responsible for this.
>
> To rebuild the cur_cmd pointer post-migration, we can utilize
> the busy_slot index to figure out where the command header
> we are still processing is.
>
> This allows a machine in a halted state from rerror=stop or
> werror=stop to be migrated and resume operations without issue.
>
> Signed-off-by: John Snow <js...@redhat.com>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> hw/ide/ahci.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index c153228..8078d3e 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -1373,6 +1373,10 @@ static int ahci_state_post_load(void *opaque, int
> version_id)
> */
> if (ad->busy_slot == -1) {
> check_cmd(s, i);
> + } else {
> + /* We are in the middle of a command, and may need to access
> + * the command header in guest memory again. */
> + ad->cur_cmd = &((AHCICmdHdr *)ad->lst)[ad->busy_slot];
> }
> }
>
>
