[Qemu-devel] [PATCH for 2.6 0/3] ide: fix loss of the dma/atapi state during migration

From: "Denis V. Lunev" <den@openvz.org>
To: qemu-devel@nongnu.org
Cc: den@openvz.org, John Snow <jsnow@redhat.com>,
	Pavel Butsykin <pbutsykin@virtuozzo.com>
Subject: [Qemu-devel] [PATCH for 2.6 0/3] ide: fix loss of the dma/atapi state during migration
Date: Wed, 23 Mar 2016 13:26:29 +0300	[thread overview]
Message-ID: <1458728792-15779-1-git-send-email-den@openvz.org> (raw)

This patch set fixes bugs in the IDE DMA and the IDE ATAPI on operations to
save/restore the state.

>From the user point of view this results in IDE timeouts in the guest
when the user reads from the DVD like the following:

[424332.169229] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
[424332.170423] sr 0:0:0:0: [sr0] CDB: 
[424332.171234] Read(10): 28 00 00 00 02 e4 00 00 01 00
[424332.172418] ata1.00: cmd a0/01:00:00:00:08/00:00:00:00:00/a0 tag 0 dma 2048 in
         res 40/00:02:00:0c:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
[424332.174877] ata1.00: status: { DRDY }
[424337.212099] ata1: link is slow to respond, please be patient (ready=0)
[424342.220084] ata1: device not ready (errno=-16), forcing hardreset
[424342.222700] ata1: soft resetting link
[424342.381059] ata1.00: configured for MWDMA2
[424342.383693] ata1: EH complete

Another similar nasty effects are possible.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: John Snow <jsnow@redhat.com>

Pavel Butsykin (3):
  ide: don't loose pending dma state
  ide: restart atapi dma by re-evaluating command packet
  ide: really restart pending and in-flight atapi dma

 hw/ide/atapi.c    | 33 +++++++++++++++++++--------------
 hw/ide/core.c     | 32 ++++++++++++++++++--------------
 hw/ide/internal.h | 25 +++++++++++++++++++++++++
 hw/ide/pci.c      |  3 +++
 4 files changed, 65 insertions(+), 28 deletions(-)