From: Pavel Butsykin <pbutsy...@virtuozzo.com> ide_atapi_dma_restart() used to just complete the DMA with an error, under the assumption that there isn't enough information to restart it.
However, as the contents of the ->io_buffer is preserved, it looks safe to just re-evaluate it and dispatch the ATAPI command again. Signed-off-by: Pavel Butsykin <pbutsy...@virtuozzo.com> Reviewed-by: Roman Kagan <rka...@virtuozzo.com> Signed-off-by: Denis V. Lunev <d...@openvz.org> CC: John Snow <js...@redhat.com> --- hw/ide/atapi.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c index 268220d..8816b38 100644 --- a/hw/ide/atapi.c +++ b/hw/ide/atapi.c @@ -495,14 +495,13 @@ static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors, void ide_atapi_dma_restart(IDEState *s) { /* - * I'm not sure we have enough stored to restart the command - * safely, so give the guest an error it should recover from. - * I'm assuming most guests will try to recover from something - * listed as a medium error on a CD; it seems to work on Linux. - * This would be more of a problem if we did any other type of - * DMA operation. + * At this point we can just re-evaluate the packet command and start over. + * The presence of ->dma_cb callback in the pre_save ensures that the packet + * command has been completely sent and we can safely restart command. */ - ide_atapi_cmd_error(s, MEDIUM_ERROR, ASC_NO_SEEK_COMPLETE); + s->unit = s->bus->retry_unit; + s->bus->dma->ops->restart_dma(s->bus->dma); + ide_atapi_cmd(s); } static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index, -- 2.1.4