> > ide_cancel_dma_sync() is also invoked from bmdma_cmd_writeb() and this > > is in fact the code path taken when the assertion fails. > > > > Yep, I wonder why your guest is trying to cancel DMA, though? Something > else is probably going wrong first.
Beats me. > Can you compile QEMU from a branch and let me know what kind of info it > barfs out when it dies? > > https://github.com/jnsnow/qemu/commit/2baa57a58bba00a45151d8544cfd457197ecfa39 > > Please make backups of your data as appropriate as this is a development > branch not suitable for production use (etc etc etc!) > > It's just some dumb printfs so I can see what the device was up to when > it decided to reset itself. I'm hoping that if I can see what command it > is trying to cancel I can work out why it isn't getting canceled correctly. It looks like the command being canceled when the assertion fails is DSM, which explains why it does not happen with TRIM disabled (I retried the test twice to make sure the canceled command is consistent; it is): $ tail -20 qemu.log == ide_cancel_dma_sync == ATA Registers: cmd 0x06 feature 0x01 error 0x00 nsector 0x00000001 sector 0x00 lcyl 0x00 hcyl 0x00 hob_feature 0x00 hob_nsector 0x00 hob_sector 0x00 hob_lcyl 0x00 hob_hcyl 0x00 select 0x60 status 0x58 lba48 0x00000000 qemu-system-x86_64: hw/ide/core.c:704: ide_cancel_dma_sync: Assertion `s->bus->dma->aiocb == NULL' failed. $ grep ^cmd qemu.log | sort | uniq -c 128 cmd 0x06 151854 cmd 0xc8 217496 cmd 0xca I am happy to help if any further debugging is required. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1681439 Title: qemu-system-x86_64: hw/ide/core.c:685: ide_cancel_dma_sync: Assertion `s->bus->dma->aiocb == NULL' failed. Status in QEMU: New Bug description: Since upgrading to QEMU 2.8.0, my Windows 7 64-bit virtual machines started crashing due to the assertion quoted in the summary failing. The assertion in question was added by commit 9972354856 ("block: add BDS field to count in-flight requests"). My tests show that setting discard=unmap is needed to reproduce the issue. Speaking of reproduction, it is a bit flaky, because I have been unable to come up with specific instructions that would allow the issue to be triggered outside of my environment, but I do have a semi-sane way of testing that appears to depend on a specific initial state of data on the underlying storage volume, actions taken within the VM and waiting for about 20 minutes. Here is the shortest QEMU command line that I managed to reproduce the bug with: qemu-system-x86_64 \ -machine pc-i440fx-2.7,accel=kvm \ -m 3072 \ -drive file=/dev/lvm/qemu,format=raw,if=ide,discard=unmap \ -netdev tap,id=hostnet0,ifname=tap0,script=no,downscript=no,vhost=on \ -device virtio-net-pci,netdev=hostnet0 \ -vnc :0 The underlying storage (/dev/lvm/qemu) is a thin LVM snapshot. QEMU was compiled using: ./configure --python=/usr/bin/python2.7 --target-list=x86_64-softmmu make -j3 My virtualization environment is not really a critical one and reproduction is not that much of a hassle, so if you need me to gather further diagnostic information or test patches, I will be happy to help. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1681439/+subscriptions
