If asked for DMA request and no data is available, simply wait
for data to be queued, do not abort. This fixes:
$ cat << EOF | \
qemu-system-i386 -nographic -M q35,accel=qtest -serial none \
-monitor none -qtest stdio -trace lsi* \
-drive if=none,id=drive0,file=null-co://,file.read-zeroes=on,format=raw \
-device lsi53c895a,id=scsi0 -device
scsi-hd,drive=drive0,bus=scsi0.0,channel=0,scsi-id=0,lun=0
lsi_reset Reset
lsi_reg_write Write reg DSP2 0x2e = 0xff
lsi_reg_write Write reg DSP3 0x2f = 0xff
lsi_execute_script SCRIPTS dsp=0xffff0000 opcode 0x184a3900 arg 0x4a8b2d75
qemu-system-i386: hw/scsi/lsi53c895a.c:624: lsi_do_dma: Assertion
`s->current' failed.
(gdb) bt
#5 0x00007ffff4e8a3a6 in __GI___assert_fail
(assertion=0x5555560accbc "s->current", file=0x5555560acc28
"hw/scsi/lsi53c895a.c", line=624, function=0x5555560adb18 "lsi_do_dma") at assert.c:101
#6 0x0000555555aa33b9 in lsi_do_dma (s=0x555557805ac0, out=1) at
hw/scsi/lsi53c895a.c:624
#7 0x0000555555aa5042 in lsi_execute_script (s=0x555557805ac0) at
hw/scsi/lsi53c895a.c:1250
#8 0x0000555555aa757a in lsi_reg_writeb (s=0x555557805ac0, offset=47,
val=255 '\377') at hw/scsi/lsi53c895a.c:1984
#9 0x0000555555aa875b in lsi_mmio_write (opaque=0x555557805ac0, addr=47,
val=255, size=1) at hw/scsi/lsi53c895a.c:2095
Cc: qemu-stable@nongnu.org
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Reported-by: Ruhr-University <bugs-syssec@rub.de>
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
Fixes: b96a0da06bd ("lsi: move dma_len+dma_buf into lsi_request")
BugLink: https://bugs.launchpad.net/qemu/+bug/697510
BugLink: https://bugs.launchpad.net/qemu/+bug/1905521
BugLink: https://bugs.launchpad.net/qemu/+bug/1908515
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/84
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/305
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/552
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
hw/scsi/lsi53c895a.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
index 85e907a7854..4c431adb774 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -621,8 +621,7 @@ static void lsi_do_dma(LSIState *s, int out)
dma_addr_t addr;
SCSIDevice *dev;
- assert(s->current);
- if (!s->current->dma_len) {
+ if (!s->current || !s->current->dma_len) {
/* Wait until data is available. */
trace_lsi_do_dma_unavailable();
return;