[PATCH v2 0/4] scsi-block: Fix error handling with r/werror=stop

[Kevin Wolf]

Running validation tests in Windows 2019's Failover Cluster Manager
fails in two different ways when run with rerror/werror=stop:

1. It runs into an assertion failure because the sgio-based I/O path
   takes shortcuts in its error handling that skip necessary cleanup

2. RESERVATION_CONFLICT is treated as a host error and stops the VM,
   which in some cases can't be resumed at all because nothing will make
   the error go away on retry. The error should always go to the guest
   instead, it's an invalid request from the guest.

This series fixes these problems.

v2:
- Patch 4: [Paolo]
  * Set error = 0 explicitly, remove useless variable initialisation
  * Add comment to explain why we consider it a guest error
  * Mention scsi-block specifically in the commit message

Kevin Wolf (4):
  scsi-disk: Use positive return value for status in dma_readv/writev
  scsi-block: Don't skip callback for sgio error status/driver_status
  scsi-disk: Add warning comments that host_status errors take a
    shortcut
  scsi-disk: Always report RESERVATION_CONFLICT to guest

 hw/scsi/scsi-disk.c | 73 +++++++++++++++++++++++++++++++--------------
 1 file changed, 51 insertions(+), 22 deletions(-)

-- 
2.45.2