diff options
| -rw-r--r-- | hw/ide/atapi.c | 51 |
1 files changed, 40 insertions, 11 deletions
diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c index 6189675036..fc1d19c6d4 100644 --- a/hw/ide/atapi.c +++ b/hw/ide/atapi.c @@ -637,6 +637,23 @@ static unsigned int event_status_media(IDEState *s, return 8; /* We wrote to 4 extra bytes from the header */ } +/* + * Before transferring data or otherwise signalling acceptance of a command + * marked CONDDATA, we must check the validity of the byte_count_limit. + */ +static bool validate_bcl(IDEState *s) +{ + /* TODO: Check IDENTIFY data word 125 for defacult BCL (currently 0) */ + if (s->atapi_dma || atapi_byte_count_limit(s)) { + return true; + } + + /* TODO: Move abort back into core.c and introduce proper error flow between + * ATAPI layer and IDE core layer */ + ide_abort_command(s); + return false; +} + static void cmd_get_event_status_notification(IDEState *s, uint8_t *buf) { @@ -1028,12 +1045,19 @@ static void cmd_read_cd(IDEState *s, uint8_t* buf) return; } - transfer_request = buf[9]; - switch(transfer_request & 0xf8) { - case 0x00: + transfer_request = buf[9] & 0xf8; + if (transfer_request == 0x00) { /* nothing */ ide_atapi_cmd_ok(s); - break; + return; + } + + /* Check validity of BCL before transferring data */ + if (!validate_bcl(s)) { + return; + } + + switch (transfer_request) { case 0x10: /* normal read */ ide_atapi_cmd_read(s, lba, nb_sectors, 2048); @@ -1266,6 +1290,14 @@ enum { * See ATA8-ACS3 "7.21.5 Byte Count Limit" */ NONDATA = 0x04, + + /* + * CONDDATA implies a command that transfers data only conditionally based + * on the presence of suboptions. It should be exempt from the BCL check at + * command validation time, but it needs to be checked at the command + * handler level instead. + */ + CONDDATA = 0x08, }; static const struct AtapiCmd { @@ -1289,7 +1321,7 @@ static const struct AtapiCmd { [ 0xad ] = { cmd_read_dvd_structure, CHECK_READY }, [ 0xbb ] = { cmd_set_speed, NONDATA }, [ 0xbd ] = { cmd_mechanism_status, 0 }, - [ 0xbe ] = { cmd_read_cd, CHECK_READY }, + [ 0xbe ] = { cmd_read_cd, CHECK_READY | CONDDATA }, /* [1] handler detects and reports not ready condition itself */ }; @@ -1348,15 +1380,12 @@ void ide_atapi_cmd(IDEState *s) return; } - /* Nondata commands permit the byte_count_limit to be 0. + /* Commands that don't transfer DATA 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 (cmd->handler && !(cmd->flags & NONDATA)) { - /* TODO: Check IDENTIFY data word 125 for default BCL (currently 0) */ - if (!(atapi_byte_count_limit(s) || s->atapi_dma)) { - /* TODO: Move abort back into core.c and make static inline again */ - ide_abort_command(s); + if (cmd->handler && !(cmd->flags & (NONDATA | CONDDATA))) { + if (!validate_bcl(s)) { return; } } |