On Tue, Jan 17, 2017 at 11:41:44AM +0100, Paolo Bonzini wrote: > > > On 17/01/2017 09:03, Fabian Grünbichler wrote: > > Commit 8fdc7839e40f43a426bc7e858cf1dbfe315a3804 (first included in > > 2.7.0)[1] changed the behaviour of scsi-block passthrough. Previously > > this worked with SATA disks, now it doesn't anymore. A bisect run > > confirmed this, scsi-block with a SATA disk passed through via > > virtio-scsi-single corrupts on writes since that commit, scsi-hd and > > scsi-disk work fine (scsi-generic corrupts as well). > > > > PVE's detection logic for passthrough just differentiated between disks > > and tape drives, and unfortunately the SG_IO ioctl says SATA disks are > > disks as well.. we probably need to default to scsi-hd or scsi-disk > > instead of scsi-block, and only when we explicitly detect a "real" SCSI > > disk we are allowed to use scsi-block? > > > > @Paolo: was the old behaviour just an accident and the new bevaviour > > intentional? documentation is quite sparse, or maybe I am looking in the > > wrong places.. > > No, it would be a bug (QEMU or kernel). > > Do you have an easy reproducer with dd, as suggested at > https://forum.proxmox.com/threads/proxmox-4-4-virtio_scsi-regression.31471/page-2? > > Paolo >
setup 1) dd 1G of (u)random data to a file on a file system on a SATA disk on the host (I tested with ext2/3/4, ZFS and btrfs, btrfs produces corruption the fastest here, but raw writes to the device should already trigger the kernel error messages) 2) calculate the md5sum of this file, and store it on the same FS test (with current qemu master, using PVE's 4.4.35 kernel as host kernel 1) start Ubuntu 16.04 VM (see full commandline at the end, I tested with three disks, one for each of the file systems above) - the same behaviour can also be observed when booting from an Alpine Linux iso 2) mount FS 3) dd random file from above to new file on same FS 4) sync 5) check md5sum of resulting file 6) repeat 3-5 until md5sum does not match, kernel spews error messages, or you are convinced that everything is OK sample kernel message (for ext3): Jan 17 11:39:32 ubuntu kernel: sd 2:0:0:0: [sda] tag#32 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE Jan 17 11:39:32 ubuntu kernel: sd 2:0:0:0: [sda] tag#32 Sense Key : Illegal Request [current] Jan 17 11:39:32 ubuntu kernel: sd 2:0:0:0: [sda] tag#32 Add. Sense: Invalid field in cdb Jan 17 11:39:32 ubuntu kernel: sd 2:0:0:0: [sda] tag#32 CDB: Write(10) 2a 00 0f 3a 90 00 00 07 d8 00 Jan 17 11:39:32 ubuntu kernel: blk_update_request: critical target error, dev sda, sector 255496192 Jan 17 11:39:32 ubuntu kernel: EXT4-fs warning (device sda1): ext4_end_bio:329: I/O error -121 writing to inode 125 (offset 0 size 0 starting block 31937280) Jan 17 11:39:32 ubuntu kernel: buffer_io_error: 246 callbacks suppressed Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936768 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936769 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936770 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936771 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936772 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936773 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936774 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936775 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936776 Jan 17 11:39:32 ubuntu kernel: Buffer I/O error on device sda1, logical block 31936777 Jan 17 11:39:39 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:39:41 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:39:55 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:39:56 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:40:07 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:40:08 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:40:15 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 Jan 17 11:40:22 ubuntu kernel: JBD2: Detected IO errors while flushing file data on sda1-8 qemu commandline, originally generated by PVE, feel free to adapt or minimize.. sdb, sdc and sde are the three SATA disks from above, vm-101-disk-1 is the Ubuntu rootfs on LVM-thin. /root/qemu/build/x86_64-softmmu/qemu-system-x86_64 \ -enable-kvm \ -chardev 'socket,id=qmp,path=/var/run/qemu-server/101.qmp,server,nowait' \ -mon 'chardev=qmp,mode=control' \ -pidfile /var/run/qemu-server/101.pid \ -smbios 'type=1,uuid=3e550136-9d7f-4a12-9d98-e25a5d2d5806' \ -name diskpassthroughtest \ -smp '8,sockets=1,cores=8,maxcpus=8' \ -nodefaults \ -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' \ -vga cirrus \ -vnc unix:/var/run/qemu-server/101.vnc,x509,password \ -cpu kvm64,+lahf_lm,+sep,+kvm_pv_unhalt,+kvm_pv_eoi,enforce \ -m 4096 \ -k de \ -device 'pci-bridge,id=pci.1,chassis_nr=1,bus=pci.0,addr=0x1e' \ -device 'pci-bridge,id=pci.2,chassis_nr=2,bus=pci.0,addr=0x1f' \ -device 'pci-bridge,id=pci.3,chassis_nr=3,bus=pci.0,addr=0x5' \ -device 'piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2' \ -device 'usb-tablet,id=tablet,bus=uhci.0,port=1' \ -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3' \ -iscsi 'initiator-name=iqn.1993-08.org.debian:01:c6676e1b1f72' \ -drive 'file=/mnt/pve/iso/template/iso/ubuntu-16.04.1-server-amd64.iso,if=none,id=drive-ide2,media=cdrom,aio=threads' \ -device 'ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200' \ -device 'virtio-scsi-pci,id=virtioscsi0,bus=pci.3,addr=0x1' \ -drive 'file=/dev/sdb,if=none,id=drive-scsi0,format=raw,cache=none,aio=native,detect-zeroes=on' \ -device 'scsi-block,bus=virtioscsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0' \ -device 'virtio-scsi-pci,id=virtioscsi1,bus=pci.3,addr=0x2' \ -drive 'file=/dev/sdc,if=none,id=drive-scsi1,format=raw,cache=none,aio=native,detect-zeroes=on' \ -device 'scsi-block,bus=virtioscsi1.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi1,id=scsi1' \ -device 'virtio-scsi-pci,id=virtioscsi3,bus=pci.3,addr=0x4' \ -drive 'file=/dev/sde,if=none,id=drive-scsi3,format=raw,cache=none,aio=native,detect-zeroes=on' \ -device 'scsi-block,bus=virtioscsi3.0,channel=0,scsi-id=0,lun=3,drive=drive-scsi3,id=scsi3' \ -drive 'file=/dev/pve/vm-101-disk-1,if=none,id=drive-virtio0,format=raw,cache=none,aio=native,detect-zeroes=on' \ -device 'virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=103' \ -netdev 'type=tap,id=net0,ifname=tap101i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on' \ -device 'virtio-net-pci,mac=46:83:4B:92:EC:88,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300'
