Re: [Qemu-block] [PATCH for-2.7 1/1] ide: fix halted IO segfault at reset

[John Snow]

On 08/01/2016 04:52 AM, Paolo Bonzini wrote:
> On 27/07/2016 00:07, John Snow wrote:
> > If one attempts to perform a system_reset after a failed IO request
> > that causes the VM to enter a paused state, QEMU will segfault trying
> > to free up the pending IO requests.
> >
> > These requests have already been completed and freed, though, so all
> > we need to do is free them before we enter the paused state.
> >
> > Existing AHCI tests verify that halted requests are still resumed
> > successfully after a STOP event.
> >
> > Signed-off-by: John Snow <address@hidden>
> > ---
> >  hw/ide/core.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/hw/ide/core.c b/hw/ide/core.c
> > index 081c9eb..d117b7c 100644
> > --- a/hw/ide/core.c
> > +++ b/hw/ide/core.c
> > @@ -823,6 +823,7 @@ static void ide_dma_cb(void *opaque, int ret)
> >      }
> >      if (ret < 0) {
> >          if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s->dma_cmd))) {
> > +            s->bus->dma->aiocb = NULL;
> >              return;
> >          }
> >      }
>
> The patch is (was, since it's committed :)) okay, but I think there is
> another bug in the REPORT case, where ide_rw_error and
> ide_atapi_io_error are not calling ide_set_inactive and thus are leaving
> s->bus->dma->aiocb non-NULL.
>
> Paolo

Actually, won't we hit ide_dma_error on REPORT which calls 
ide_set_inactive? I think this might be OK, but I have to audit a little 
more carefully -- I will do so tomorrow.

I think the ide_rw_error case is likely OK, but I always manage to 
forget exactly how the ATAPI DMA looks.