Re: [Qemu-devel] [WIP PATCH 00/24] IDE cleanups, initial work on AHCI rerror/werror=stop

[Michael S. Tsirkin]

On Mon, Oct 28, 2013 at 05:43:16PM +0100, Paolo Bonzini wrote:
> Hi all,
> 
> this is some cleanup to the IDE code that I started long ago
> and picked up again on my flight back from KVM Forum...
> 
> The patches clean up the callbacks to prepare for implementing request
> retry for AHCI.  After these patches, PIO retry should work for AHCI and
> non-NCQ retry should be very close (you need an implementation of the
> new restart_dma callback).  NCQ retry and save/restore is AHCI-specific
> and has to be done separately, similar to how we do it for SCSI already.
> 
> Patches 1-4 set up a new (incomplete) testcase.  Patches 5-13 are no-op
> cleanups, or so I hope.  Patches 14-23 genericize retry and make it
> "just work" for all adapters for PIO.  Patch 24 is another cleanup that
> could probably be moved earlier in the series.
> 
> Throwing it out since I know Kevin and mst are working on AHCI, to avoid
> doing duplicate work.  Patches 2 and 4 are known to be racy and
> incomplete.  Extremely light testing, if something breaks tells me and
> I'll look at it.
> 
> Paolo

Well ATM win7 boot is broken with non NCQ (crash on boot).
Do you patches help?

Also, without NCQ win 7 boot will sometime hang.
The following patch by Alex makes it behave better:
it still sometimes hangs for a very long time but with the patch it
will after a long time proceed. Sometimes it proceeds normally.

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index a8be62c..fbea9e8 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -961,7 +961,8 @@ static int handle_cmd(AHCIState *s, int port, int slot)
         /* We're ready to process the command in FIS byte 2. */
         ide_exec_cmd(&s->dev[port].port, cmd_fis[2]);
 
-        if (s->dev[port].port.ifs[0].status & READY_STAT) {
+        if ((s->dev[port].port.ifs[0].status & 
(READY_STAT|DRQ_STAT|BUSY_STAT)) ==
+            READY_STAT) {
             ahci_write_fis_d2h(&s->dev[port], cmd_fis);
         }
     }