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Bug 1664619 - virtio-blk: guest kernel panic when boot vm with disk over 8k sector size
Summary: virtio-blk: guest kernel panic when boot vm with disk over 8k sector size
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: kernel
Version: 8.0
Hardware: Unspecified
OS: Unspecified
low
medium
Target Milestone: rc
: ---
Assignee: Maxim Levitsky
QA Contact: qing.wang
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-01-09 10:19 UTC by Han Han
Modified: 2021-12-07 22:35 UTC (History)
13 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2021-02-01 07:31:48 UTC
Type: Bug
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
serial-rhel8.log (33.82 KB, text/plain)
2019-01-18 06:32 UTC, lchai 		no flags Details
serial-rhel7.log (34.90 KB, text/plain)
2019-01-18 06:33 UTC, lchai 		no flags Details
View All

Description Han Han 2019-01-09 10:19:07 UTC 
Description of problem:
As subject

Version-Release number of selected component (if applicable):
Guest kernel:
4.18.0-58.el8.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Start a vm. The second disk is over 4k sector size:
/usr/libexec/qemu-kvm
 -name guest=PC,debug-threads=on
 -S
 -machine pc,accel=kvm,usb=off,dump-guest-core=off
 -cpu SandyBridge-IBRS
 -m 1024
 -realtime mlock=off
 -smp 2,sockets=2,cores=1,threads=1
 -uuid 6f10e6c4-b3ce-4f55-a810-f5d4ca061468
 -no-user-config
 -nodefaults
 -rtc base=utc,driftfix=slew
 -global kvm-pit.lost_tick_policy=delay
 -no-hpet
 -no-shutdown
 -global PIIX4_PM.disable_s3=1
 -global PIIX4_PM.disable_s4=1
 -boot strict=on
 -drive file=/var/lib/libvirt/images/PC.qcow2,format=qcow2,if=none,id=drive-virtio-disk0
 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
 -drive file=/var/lib/libvirt/images/pc.raw,format=raw,if=none,id=drive-virtio-disk1
 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0xd,drive=drive-virtio-disk1,id=virtio-disk1,logical_block_size=8192,physical_block_size=8192


Actual results:
[    0.000000] Detected CPU family 6 model 42 stepping 1
[    0.000000] Warning: Intel Processor - this hardware has not undergone testing by Red Hat and might not be certified. Please consult https://hardware.redhat.com for certified hardware.
[    1.046824] device-mapper: uevent: version 1.0.3
[    1.046869] device-mapper: ioctl: 4.39.0-ioctl (2018-04-03) initialised: dm-devel
[    1.051023] usb 1-1: new high-speed USB device number 2 using ehci-pci
[    1.184003] usb 1-1: New USB device found, idVendor=0627, idProduct=0001, bcdDevice= 0.00
[    1.184016] usb 1-1: New USB device strings: Mfr=1, Product=3, SerialNumber=5
[    1.184017] usb 1-1: Product: QEMU USB Tablet
[    1.184018] usb 1-1: Manufacturer: QEMU
[    1.184019] usb 1-1: SerialNumber: 42
[    1.187471] input: QEMU QEMU USB Tablet as /devices/pci0000:00/0000:00:04.7/usb1/1-1/1-1:1.0/0003:0627:0001.0001/input/input5
[    1.187567] hid-generic 0003:0627:0001.0001: input,hidraw0: USB HID v0.01 Mouse [QEMU QEMU USB Tablet] on usb-0000:00:04.7-1/input0
[    1.196196] virtio_blk virtio1: [vda] 20971520 512-byte logical blocks (10.7 GB/10.0 GiB)
[    1.209068]  vda: vda1 vda2
[    1.210228] virtio_blk virtio6: [vdb] 1310720 8192-byte logical blocks (10.7 GB/10.0 GiB)
[    1.210398] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[    1.210398] PGD 0 P4D 0
[    1.210400] Oops: 0000 [#1] SMP PTI
[    1.210402] CPU: 1 PID: 348 Comm: systemd-udevd Tainted: G               X --------- ---  4.18.0-58.el8.x86_64 #1
[    1.210403] Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
[    1.210407] RIP: 0010:create_empty_buffers+0x24/0x100
[    1.210408] Code: 5c c3 0f 1f 40 00 66 66 66 66 90 41 54 49 89 d4 ba 01 00 00 00 55 53 48 89 fb e8 e7 f5 ff ff 48 89 c5 48 89 c2 eb 03 48 89 ca <48> 8b 4a 08 4c 09 22 48 85 c9 75 f1 48 89 6a 08 48 8b 43 18 48 8d
[    1.210409] RSP: 0000:ffffb1a080423678 EFLAGS: 00010292
[    1.210410] RAX: 0000000000000000 RBX: ffffec6900d63a00 RCX: 000000000000000d
[    1.210410] RDX: 0000000000000000 RSI: 0000000000002000 RDI: ffffec6900d63a00
[    1.210411] RBP: 0000000000000000 R08: dead0000000000ff R09: 0000000000000004
[    1.210411] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    1.210412] R13: 0000000000000000 R14: 0000000000000000 R15: ffffec6900d63a00
[    1.210413] FS:  00007f37b7200940(0000) GS:ffff8f067eb00000(0000) knlGS:0000000000000000
[    1.210414] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.210415] CR2: 0000000000000008 CR3: 000000003660e000 CR4: 00000000000406e0
[    1.210418] Call Trace:
[    1.210422]  create_page_buffers+0x4c/0x60
[    1.210423]  block_read_full_page+0x47/0x300
[    1.210426]  ? check_disk_change+0x60/0x60
[    1.210429]  ? __add_to_page_cache_locked+0x1df/0x240
[    1.210430]  do_read_cache_page+0x2be/0x5d0
[    1.210432]  ? blkdev_writepages+0x10/0x10
[    1.210434]  ? find_valid_gpt+0xd1/0x560
[    1.210435]  read_dev_sector+0x28/0xc0
[    1.210436]  read_lba+0xc6/0x210
[    1.210439]  ? kmem_cache_alloc_trace+0x159/0x1d0
[    1.210440]  find_valid_gpt+0xf1/0x560
[    1.210442]  ? vmap_page_range_noflush+0x2ed/0x450
[    1.210444]  ? format_decode+0x22e/0x390
[    1.210445]  efi_partition+0x89/0x3a3
[    1.210447]  ? snprintf+0x49/0x60
[    1.210448]  ? find_valid_gpt+0x560/0x560
[    1.210449]  check_partition+0x136/0x22d
[    1.210450]  rescan_partitions+0xae/0x290
[    1.210452]  ? down_write+0xe/0x40
[    1.210453]  __blkdev_get+0x35e/0x4f0
[    1.210455]  blkdev_get+0x107/0x310
[    1.210457]  ? unlock_new_inode+0x50/0x60
[    1.210459]  ? bdget+0x12c/0x150
[    1.210461]  __device_add_disk+0x3a3/0x440
[    1.210464]  virtblk_probe+0x4bc/0x6ca [virtio_blk]
[    1.210466]  virtio_dev_probe+0x170/0x230
[    1.210469]  driver_probe_device+0x2da/0x450
[    1.210470]  __driver_attach+0xdd/0x110
[    1.210472]  ? driver_probe_device+0x450/0x450
[    1.210473]  bus_for_each_dev+0x76/0xc0
[    1.210475]  ? klist_add_tail+0x57/0x70
[    1.210476]  bus_add_driver+0x152/0x230
[    1.210477]  ? 0xffffffffc01f2000
[    1.210479]  driver_register+0x6b/0xb0
[    1.210479]  ? 0xffffffffc01f2000
[    1.210481]  init+0x52/0x1000 [virtio_blk]
[    1.210483]  do_one_initcall+0x46/0x1c3
[    1.210485]  ? free_unref_page_commit+0x91/0x100
[    1.210486]  ? _cond_resched+0x15/0x30
[    1.210487]  ? kmem_cache_alloc_trace+0x159/0x1d0
[    1.210490]  do_init_module+0x5a/0x210
[    1.210491]  load_module+0x13e6/0x1770
[    1.210494]  ? __do_sys_init_module+0x13d/0x180
[    1.210495]  ? _cond_resched+0x15/0x30
[    1.210496]  __do_sys_init_module+0x13d/0x180
[    1.210498]  do_syscall_64+0x5b/0x1b0
[    1.210500]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[    1.210502] RIP: 0033:0x7f37b5df32be
[    1.210503] Code: 48 8b 0d cd fb 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 9a fb 2b 00 f7 d8 64 89 01 48
[    1.210503] RSP: 002b:00007ffc95fa9a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[    1.210504] RAX: ffffffffffffffda RBX: 0000558239f8f830 RCX: 00007f37b5df32be
[    1.210505] RDX: 00007f37b695db2d RSI: 00000000000094e0 RDI: 0000558239fc4f80
[    1.210506] RBP: 00007f37b695db2d R08: 0000000000000007 R09: 0000000000000006
[    1.210506] R10: 0000558239f88010 R11: 0000000000000246 R12: 0000558239fc4f80
[    1.210507] R13: 0000558239f8f060 R14: 0000000000020000 R15: 0000000000000000
[    1.210508] Modules linked in: serio_raw net_failover failover virtio_console(+) virtio_scsi(+) virtio_blk(+) dm_mirror dm_region_hash dm_log dm_mod
[    1.210513] CR2: 0000000000000008
[    1.210515] ---[ end trace ef2784eddff2a870 ]---
[    1.210516] RIP: 0010:create_empty_buffers+0x24/0x100
[    1.210517] Code: 5c c3 0f 1f 40 00 66 66 66 66 90 41 54 49 89 d4 ba 01 00 00 00 55 53 48 89 fb e8 e7 f5 ff ff 48 89 c5 48 89 c2 eb 03 48 89 ca <48> 8b 4a 08 4c 09 22 48 85 c9 75 f1 48 89 6a 08 48 8b 43 18 48 8d
[    1.210518] RSP: 0000:ffffb1a080423678 EFLAGS: 00010292
[    1.210518] RAX: 0000000000000000 RBX: ffffec6900d63a00 RCX: 000000000000000d
[    1.210519] RDX: 0000000000000000 RSI: 0000000000002000 RDI: ffffec6900d63a00
[    1.210520] RBP: 0000000000000000 R08: dead0000000000ff R09: 0000000000000004
[    1.210520] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    1.210521] R13: 0000000000000000 R14: 0000000000000000 R15: ffffec6900d63a00
[    1.210522] FS:  00007f37b7200940(0000) GS:ffff8f067eb00000(0000) knlGS:0000000000000000
[    1.210522] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.210523] CR2: 0000000000000008 CR3: 000000003660e000 CR4: 00000000000406e0
[    1.210524] Kernel panic - not syncing: Fatal exception
[    1.210740] Kernel Offset: 0x36600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    1.379010] ---[ end Kernel panic - not syncing: Fatal exception ]---

Expected results:
No panic

Additional info:
Only reproduced on virtio-blk disk, no reproduced on virtio-scsi and usb disk
Comment 2 Kevin Wolf 2019-01-16 12:20:14 UTC 
This looks like a guest driver bug.

Note that this is not about 4k sector size, but about 8k, which makes it rather low priority in my opinion.
Comment 3 lchai 2019-01-18 06:32:10 UTC 
This issue could be reproduced on both RHEL7 and RHEL8 guests.

Host:
kernel-4.18.0-56.el8.x86_64
qemu-kvm-core-3.1.0-3.module+el8+2638+e43dad09.x86_64

Guest:
RHEL7: kernel-3.10.0-957.el7.x86_64
RHEL8: kernel-4.18.0-58.el8.x86_64

Steps:
Boot the guest with below command line:
/usr/libexec/qemu-kvm \
       	-S \
       	-name 'test' \
       	-sandbox off \
       	-machine pc \
       	-nodefaults \
       	-device qxl-vga \
	-object iothread,id=iothread0 \
	-object iothread,id=iothread1 \
	-object iothread,id=iothread2 \
	-blockdev driver=file,cache.direct=off,cache.no-flush=on,node-name=file_win1,filename=/root/rhel80-64-virtio-scsi.qcow2 \
	-blockdev driver=qcow2,node-name=drive_win1,file=file_win1 \
	-device virtio-blk-pci,id=image2,drive=drive_win1,iothread=iothread0 \
	-blockdev driver=file,cache.direct=off,cache.no-flush=on,node-name=file_stg1,filename=/home/chai/disk1.qcow2 \
	-blockdev driver=qcow2,node-name=drive_stg1,file=file_stg1 \
	-device virtio-blk-pci,id=image3,drive=drive_stg1,iothread=iothread1,logical_block_size=8192,physical_block_size=8192 \
	-chardev file,path=/home/chai/serial.log,id=serial_id_serial0 \
	-device isa-serial,chardev=serial_id_serial0  \
	-device virtio-net-pci,mac=6c:ae:8b:20:80:70,id=iddd,vectors=4,netdev=idttt \
	-netdev tap,id=idttt,vhost=on \
	-m 4G \
	-smp 12,maxcpus=12,cores=6,threads=1,sockets=2 \
	-cpu 'SandyBridge' \
	-rtc base=utc,clock=host,driftfix=slew \
	-enable-kvm \
	-monitor stdio \
	-device qemu-xhci,id=usb1 \
	-device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1  \
	-qmp tcp:0:4441,server,nowait \
	-vnc :1


P.S.
The detailed logs (serial-rhel7.log and serial-rhel8.log) are attached.
Comment 4 lchai 2019-01-18 06:32:48 UTC 
Created attachment 1521419 [details]
serial-rhel8.log
Comment 5 lchai 2019-01-18 06:33:15 UTC 
Created attachment 1521420 [details]
serial-rhel7.log
Comment 8 Maxim Levitsky 2019-07-22 11:03:20 UTC 
To be honest, Linux kernel doesn't support block devices with sector size > PAGE_SIZE.

This is very hard limitation, based on assumption that most of the IO is going through page cache, so you should be allowed
to read/write a single page.
In theory a block driver can emulate a 4K block size by RMW, and there is even a 'depricated' pktcdvd driver which emulates an 4K block device on top
of CD/DVD-RW drive which has 64K/32K block size.


I researched this very, like very long ago.
What _is_ strange here is that we get an oops instead of a clear error message, and I can look at fixing this.



PS:
Actually this brings memories from my childhood, when I just switched to Linux,
and was trying to evaluate the options of supporting packet writing on CD/DVD media,
a feature that I missed so much from windows.
(we haven't had flash drives yet, so readin/writing files 'normally' instead of using burner program on a CD-RW was a big deal back then)
This was kind of my first encounter with the Linux kernel, I actually had to understand both filesystem and memory subsystems very well,
to reach this conclusion.
Comment 9 Maxim Levitsky 2020-07-15 07:35:36 UTC 
Reproduced upstream with roughly the same backtrace.

[    1.859335] BUG: kernel NULL pointer dereference, address: 0000000000000000
[    1.859629] [drm] number of cap sets: 2
[    1.860424] #PF: supervisor write access in kernel mode
[    1.860424] #PF: error_code(0x0002) - not-present page
[    1.860425] PGD 0 P4D 0 
[    1.860427] Oops: 0002 [#1] SMP
[    1.860428] CPU: 21 PID: 639 Comm: systemd-udevd Not tainted 5.8.0-rc4.stable #27
[    1.860429] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[    1.860432] RIP: 0010:create_empty_buffers+0x21/0x110
[    1.860434] Code: 0b 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 49 89 d5 ba 01 00 00 00 41 54 53 48 89 fb e8 e2 f5 ff ff 49 89 c4 <4c> 09 28 48 89 c2 48 8b 40 08 48 85 c0 75 f1 4c 89 62 08 48 8b 43
[    1.861070] [drm] cap set 0: id 1, max-version 1, max-size 308
[    1.861581] RSP: 0018:ffffc90000abb5f8 EFLAGS: 00010286
[    1.861582] RAX: 0000000000000000 RBX: ffffea00213f9740 RCX: 000000000000000d
[    1.861583] RDX: 00006077a0004558 RSI: ffff888854715000 RDI: ffffea00213f9740
[    1.861583] RBP: ffffc90000abb610 R08: ffff888854715000 R09: 000000000074e1ad
[    1.861584] R10: 0000000000000001 R11: ffff888850388758 R12: 0000000000000000
[    1.861584] R13: 0000000000000000 R14: ffffea00213f9740 R15: 0000000000000000
[    1.861586] FS:  00007f34edb4bb80(0000) GS:ffff88885f340000(0000) knlGS:0000000000000000
[    1.861587] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.861587] CR2: 0000000000000000 CR3: 000000084fdea000 CR4: 0000000000340ee0
[    1.861588] Call Trace:
[    1.861592]  create_page_buffers+0x55/0x60
[    1.862255] [drm] cap set 1: id 2, max-version 2, max-size 688
[    1.862544]  block_read_full_page+0x4f/0x3e0
[    1.863064] [drm] Initialized virtio_gpu 0.1.0 0 for virtio3 on minor 0
[    1.863824]  ? bdev_evict_inode+0xe0/0xe0
[    1.863826]  ? __add_to_page_cache_locked+0x11c/0x330
[    1.863828]  ? scan_shadow_nodes+0x30/0x30
[    1.863829]  blkdev_readpage+0x18/0x20
[    1.863830]  do_read_cache_page+0x2a6/0x390
[    1.863831]  read_cache_page+0x12/0x20
[    1.863833]  read_part_sector+0x37/0xc8
[    1.863833]  read_lba+0x11a/0x1e0
[    1.863835]  ? kmem_cache_alloc_trace+0x153/0x220
[    1.863836]  efi_partition+0x1d9/0x81d
[    1.863837]  ? vsnprintf+0x2d4/0x470
[    1.863838]  ? snprintf+0x49/0x60
[    1.863839]  blk_add_partitions+0x145/0x390
[    1.863841]  ? blk_drop_partitions+0x9c/0xd0
[    1.884870]  bdev_disk_changed+0x73/0xe0
[    1.884872]  __blkdev_get+0x3cb/0x540
[    1.884873]  blkdev_get+0x3d/0x160
[    1.884874]  __device_add_disk+0x336/0x4a0
[    1.884875]  device_add_disk+0x13/0x20
[    1.884878]  virtblk_probe+0x4d3/0x7d4 [virtio_blk]
[    1.884880]  virtio_dev_probe+0x14d/0x1e0 [virtio]
[    1.884884]  really_probe+0x171/0x420
[    1.888786]  driver_probe_device+0xe9/0x160
[    1.888788]  device_driver_attach+0xab/0xb0
[    1.888789]  __driver_attach+0x8c/0x150
[    1.888790]  ? device_driver_attach+0xb0/0xb0
[    1.888790]  bus_for_each_dev+0x7c/0xc0
[    1.888791]  driver_attach+0x1e/0x20
[    1.888792]  bus_add_driver+0x135/0x1f0
[    1.888793] fbcon: Deferring console take-over
[    1.888795]  driver_register+0x91/0xf0
[    1.888797]  register_virtio_driver+0x20/0x30 [virtio]
[    1.889317] virtio_gpu virtio3: fb0: virtio_gpudrmfb frame buffer device
[    1.889788]  init+0x54/0x1000 [virtio_blk]
[    1.894847]  ? 0xffffffffa0188000
[    1.894849]  do_one_initcall+0x48/0x1f0
[    1.894850]  ? _cond_resched+0x1a/0x50
[    1.894851]  ? kmem_cache_alloc_trace+0x153/0x220
[    1.894853]  ? do_init_module+0x28/0x270
[    1.894855]  do_init_module+0x62/0x270
[    1.897652]  load_module+0x2a3e/0x2c80
[    1.897654]  __do_sys_finit_module+0xbe/0x120
[    1.897656]  __x64_sys_finit_module+0x1a/0x20
[    1.897657]  do_syscall_64+0x46/0xc0
[    1.897658]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[    1.897659] RIP: 0033:0x7f34eec9743d
[    1.897660] Code: Bad RIP value.
[    1.900892] RSP: 002b:00007ffd3bb159b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[    1.900893] RAX: ffffffffffffffda RBX: 00005645ca6b1710 RCX: 00007f34eec9743d
[    1.900894] RDX: 0000000000000000 RSI: 00007f34ee8f795d RDI: 0000000000000006
[    1.900894] RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
[    1.900894] R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000
[    1.900895] R13: 00007f34ee8f795d R14: 00005645ca68a360 R15: 00005645ca689520
[    1.900896] Modules linked in: virtio_gpu(+) drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm virtio_net net_failover i2c_core failover virtio_scsi virtio_blk(+) crc32c_intel xhci_pci virtio_pci virtio_ring xhci_hcd virtio dm_mirror dm_region_hash dm_log fuse ipv6 autofs4
[    1.908874] CR2: 0000000000000000
[    1.909270] ---[ end trace 33dbeb0325d38ff9 ]---
[    1.909800] RIP: 0010:create_empty_buffers+0x21/0x110
[    1.910382] Code: 0b 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 49 89 d5 ba 01 00 00 00 41 54 53 48 89 fb e8 e2 f5 ff ff 49 89 c4 <4c> 09 28 48 89 c2 48 8b 40 08 48 85 c0 75 f1 4c 89 62 08 48 8b 43
[    1.912502] RSP: 0018:ffffc90000abb5f8 EFLAGS: 00010286
[    1.913099] RAX: 0000000000000000 RBX: ffffea00213f9740 RCX: 000000000000000d
[    1.913913] RDX: 00006077a0004558 RSI: ffff888854715000 RDI: ffffea00213f9740
[    1.914729] RBP: ffffc90000abb610 R08: ffff888854715000 R09: 000000000074e1ad
[    1.915551] R10: 0000000000000001 R11: ffff888850388758 R12: 0000000000000000
[    1.916414] R13: 0000000000000000 R14: ffffea00213f9740 R15: 0000000000000000
[    1.917324] FS:  00007f34edb4bb80(0000) GS:ffff88885f340000(0000) knlGS:0000000000000000
[    1.917324] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.917325] CR2: 0000000000000000 CR3: 000000084fdea000 CR4: 0000000000340ee0
[    1.917326] Kernel panic - not syncing: Fatal exception
[    1.918370] Kernel Offset: disabled
[    1.920849] Rebooting in 10 seconds..
[   11.921756] ACPI MEMORY or I/O RESET_REG.
Comment 10 Maxim Levitsky 2020-07-15 07:39:30 UTC 
virtio-scsi kernel driver on the other hand is immune to this issue:

[    1.963928] sd 1:0:0:0: Power-on or device reset occurred
[    1.963934] sd 0:0:0:0: Power-on or device reset occurred
[    1.964753] sd 1:0:0:0: [sdb] 314572800 512-byte logical blocks: (161 GB/150 GiB)
[    1.965337] sd 0:0:0:0: [sda] Unsupported sector size 8192.
[    1.966210] sd 1:0:0:0: [sdb] Write Protect is off
[    1.966972] sd 0:0:0:0: [sda] 0 512-byte logical blocks: (0 B/0 B)
[    1.967499] sd 1:0:0:0: [sdb] Mode Sense: 63 00 00 08
[    1.968214] sd 0:0:0:0: [sda] 8192-byte physical blocks
[    1.968240] sd 0:0:0:0: [sda] Write Protect is off
[    1.968241] sd 0:0:0:0: [sda] Mode Sense: 63 00 00 08
[    1.968282] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    1.968974] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    1.970112] sd 0:0:0:0: [sda] Unsupported sector size 8192.
[    1.972661] sd 0:0:0:0: [sda] Attached SCSI disk
Comment 11 Maxim Levitsky 2020-07-15 10:22:35 UTC 
Patch posted upstream: https://lkml.org/lkml/2020/7/15/421

Can we make this bug public since it doesn't contain IMHO anything really private.
I didn't notice that it is private and added link to it on the patch.
Comment 12 qing.wang 2020-07-16 03:01:24 UTC 
Reproduced this issue on guest kernel-4.18.0-214.el8.x86_64

/usr/libexec/qemu-kvm \
    -name 'test-vm1' \
    -machine q35  \
    -nodefaults \
    -device VGA,bus=pcie.0,addr=0x1  \
    -device pvpanic,ioport=0x505,id=idZcGD6F  \
    -device pcie-root-port,id=pcie.0-root-port-2,slot=2,chassis=2,addr=0x2,bus=pcie.0 \
    -device qemu-xhci,id=usb1,bus=pcie.0-root-port-2,addr=0x0 \
    -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1  \
    -object iothread,id=iothread0 \
    -device pcie-root-port,id=pcie.0-root-port-3,slot=3,chassis=3,addr=0x3,bus=pcie.0 \
    -device pcie-root-port,id=pcie.0-root-port-4,slot=4,chassis=4,addr=0x4,bus=pcie.0 \
    -device pcie-root-port,id=pcie.0-root-port-6,slot=6,chassis=6,addr=0x6,bus=pcie.0 \
    -device pcie-root-port,id=pcie.0-root-port-7,slot=7,chassis=7,addr=0x7,bus=pcie.0 \
    -device pcie-root-port,id=pcie.0-root-port-8,slot=8,chassis=8,addr=0x8,bus=pcie.0 \
    -device virtio-scsi-pci,id=scsi0,bus=pcie.0-root-port-3,addr=0x0,iothread=iothread0 \
    -device virtio-scsi-pci,id=scsi2,bus=pcie.0-root-port-4,addr=0x0 \
    \
    -blockdev driver=file,cache.direct=off,cache.no-flush=on,filename=/home/kvm_autotest_root/images/rhel830-64-virtio.qcow2,node-name=os_img \
    -blockdev driver=qcow2,node-name=os_drive,file=os_img \
    -device virtio-blk-pci,drive=os_drive,id=os_disk,bus=pcie.0-root-port-6 \
    \
    -blockdev driver=file,cache.direct=on,cache.no-flush=off,node-name=file_stg1,filename=/home/kvm_autotest_root/images/stg1.qcow2 \
    -blockdev driver=qcow2,node-name=drive_stg1,file=file_stg1 \
    -device virtio-blk-pci,drive=drive_stg1,id=data,bus=pcie.0-root-port-7,addr=0x0,iothread=iothread0,logical_block_size=8192,physical_block_size=8192 \
    \
    -device pcie-root-port,id=pcie.0-root-port-5,slot=5,chassis=5,addr=0x5,bus=pcie.0 \
    -device virtio-net-pci,mac=9a:55:56:57:58:59,id=id18Xcuo,netdev=idGRsMas,bus=pcie.0-root-port-5,addr=0x0  \
    -netdev tap,id=idGRsMas,vhost=on \
    -m 8G  \
    -vnc :5  \
    -rtc base=localtime,clock=host,driftfix=slew  \
    -boot order=cdn,once=c,menu=off,strict=off \
    -enable-kvm \
    -monitor stdio \
    -qmp tcp:0:5955,server,nowait \
Comment 13 John Ferlan 2020-07-23 14:17:56 UTC 
updated version posted: https://lkml.org/lkml/2020/7/21/381
Comment 16 RHEL Program Management 2021-02-01 07:31:48 UTC 
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.
Comment 17 qing.wang 2021-02-01 08:23:24 UTC 
QE agree to close.
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