atapi: abort transfers with 0 byte limits

We're supposed to abort on transfers like this, unless we fill
Word 125 of our IDENTIFY data with a default transfer size, which
we don't currently do.

This is an ATA error, not a SCSI/ATAPI one.
See ATA8-ACS3 sections 7.17.6.49 or 7.21.5.

If we don't do this, QEMU will loop forever trying to transfer
zero bytes, which isn't particularly useful.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1442253685-23349-2-git-send-email-jsnow@redhat.com
This commit is contained in:
John Snow 2015-09-17 14:17:05 -04:00
parent d9033e1d3a
commit 9ef2e93f9b
3 changed files with 29 additions and 6 deletions

View File

@ -1169,20 +1169,28 @@ enum {
* 4.1.8)
*/
CHECK_READY = 0x02,
/*
* Commands flagged with NONDATA do not in any circumstances return
* any data via ide_atapi_cmd_reply. These commands are exempt from
* the normal byte_count_limit constraints.
* See ATA8-ACS3 "7.21.5 Byte Count Limit"
*/
NONDATA = 0x04,
};
static const struct {
void (*handler)(IDEState *s, uint8_t *buf);
int flags;
} atapi_cmd_table[0x100] = {
[ 0x00 ] = { cmd_test_unit_ready, CHECK_READY },
[ 0x00 ] = { cmd_test_unit_ready, CHECK_READY | NONDATA },
[ 0x03 ] = { cmd_request_sense, ALLOW_UA },
[ 0x12 ] = { cmd_inquiry, ALLOW_UA },
[ 0x1b ] = { cmd_start_stop_unit, 0 }, /* [1] */
[ 0x1e ] = { cmd_prevent_allow_medium_removal, 0 },
[ 0x1b ] = { cmd_start_stop_unit, NONDATA }, /* [1] */
[ 0x1e ] = { cmd_prevent_allow_medium_removal, NONDATA },
[ 0x25 ] = { cmd_read_cdvd_capacity, CHECK_READY },
[ 0x28 ] = { cmd_read, /* (10) */ CHECK_READY },
[ 0x2b ] = { cmd_seek, CHECK_READY },
[ 0x2b ] = { cmd_seek, CHECK_READY | NONDATA },
[ 0x43 ] = { cmd_read_toc_pma_atip, CHECK_READY },
[ 0x46 ] = { cmd_get_configuration, ALLOW_UA },
[ 0x4a ] = { cmd_get_event_status_notification, ALLOW_UA },
@ -1190,7 +1198,7 @@ static const struct {
[ 0x5a ] = { cmd_mode_sense, /* (10) */ 0 },
[ 0xa8 ] = { cmd_read, /* (12) */ CHECK_READY },
[ 0xad ] = { cmd_read_dvd_structure, CHECK_READY },
[ 0xbb ] = { cmd_set_speed, 0 },
[ 0xbb ] = { cmd_set_speed, NONDATA },
[ 0xbd ] = { cmd_mechanism_status, 0 },
[ 0xbe ] = { cmd_read_cd, CHECK_READY },
/* [1] handler detects and reports not ready condition itself */
@ -1251,6 +1259,20 @@ void ide_atapi_cmd(IDEState *s)
return;
}
/* Nondata commands permit the byte_count_limit to be 0.
* If this is a data-transferring PIO command and BCL is 0,
* we abort at the /ATA/ level, not the ATAPI level.
* See ATA8 ACS3 section 7.17.6.49 and 7.21.5 */
if (!(atapi_cmd_table[s->io_buffer[0]].flags & NONDATA)) {
/* TODO: Check IDENTIFY data word 125 for default BCL (currently 0) */
uint16_t byte_count_limit = s->lcyl | (s->hcyl << 8);
if (!(byte_count_limit || s->atapi_dma)) {
/* TODO: Move abort back into core.c and make static inline again */
ide_abort_command(s);
return;
}
}
/* Execute the command */
if (atapi_cmd_table[s->io_buffer[0]].handler) {
atapi_cmd_table[s->io_buffer[0]].handler(s, buf);

View File

@ -457,7 +457,7 @@ BlockAIOCB *ide_issue_trim(BlockBackend *blk,
return &iocb->common;
}
static inline void ide_abort_command(IDEState *s)
void ide_abort_command(IDEState *s)
{
ide_transfer_stop(s);
s->status = READY_STAT | ERR_STAT;

View File

@ -538,6 +538,7 @@ void ide_set_sector(IDEState *s, int64_t sector_num);
void ide_start_dma(IDEState *s, BlockCompletionFunc *cb);
void dma_buf_commit(IDEState *s, uint32_t tx_bytes);
void ide_dma_error(IDEState *s);
void ide_abort_command(IDEState *s);
void ide_atapi_cmd_ok(IDEState *s);
void ide_atapi_cmd_error(IDEState *s, int sense_key, int asc);