Re: The latest Qemu release can't bootup VM with latest guest kernel.

[Claudio Fontana]

On 6/3/21 4:08 PM, Dr. David Alan Gilbert wrote:
> * Yang Zhong (yang.zhong@intel.com) wrote:
>> On Sun, May 23, 2021 at 03:23:30PM +0300, Gal Hammer wrote:
>>> Hi Yang,
>>>
>>> On Thu, 20 May 2021 at 11:27, Yang Zhong <yang.zhong@intel.com> wrote:
>>>
>>>> Hello all,
>>>>
>>>> I found the latest Qemu release can't bootup the VM with latest guest
>>>> kernel(>5.13).
>>>>
>>>> The normal v6.0.0 release is good to bootup the latest guest kernel.
>>>>
>>>> There are two issues were found
>>>> 1. Guest kernel panic.
>>>> 2. kvm disabled by bios
>>>>
>>>> The panic log as below:
>>>> [    2.250024] BUG: unable to handle page fault for address:
>>>> ffffffffac06c55f
>>>> [    2.252226] #PF: supervisor write access in kernel mode
>>>> [    2.253892] #PF: error_code(0x0003) - permissions violation
>>>> [    2.255671] PGD 5940e067 P4D 5940f067 PUD 59410063 PMD 580001e1
>>>> [    2.257567] Oops: 0003 [#1] SMP NOPTI
>>>> [    2.258738] CPU: 2 PID: 313 Comm: systemd-udevd Not tainted 5.13.0-rc1+
>>>> #1
>>>> [    2.260899] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
>>>> 0.0.0 02/06/2015
>>>> [    2.263375] RIP: 0010:__send_ipi_mask+0x1bf/0x240
>>>> [    2.264855] Code: c0 48 c7 44 24 18 00 00 00 00 e9 48 ff ff ff 48 89 d0
>>>> 4c 09 c8 74 1b 49 63 d7 48 63 74 24 0c b8 0a 00 00 00 4c 89 cb 4c 89 d1
>>>> <0f> 01 d9 48 85 c0 78 4a 48 f7 04 24 00 02 00 00 0f 84 80 fe ff ff
>>>> [    2.270643] RSP: 0018:ff591a62c0193ab0 EFLAGS: 00010006
>>>> [    2.272277] RAX: 000000000000000a RBX: 0000000000000009 RCX:
>>>> 0000000000000000
>>>> [    2.274482] RDX: 0000000000000000 RSI: 00000000000000fc RDI:
>>>> ff13a83dc003c830
>>>> [    2.276663] RBP: ff591a62c0193b08 R08: 0000000000000004 R09:
>>>> 0000000000000009
>>>> [    2.278866] R10: 0000000000000000 R11: 0000000000000000 R12:
>>>> 0000000000000000
>>>> [    2.281065] R13: ff13a83dc003c830 R14: 0000000000011580 R15:
>>>> 0000000000000000
>>>> [    2.283272] FS:  00007f23ebd07940(0000) GS:ff13a83e3bd00000(0000)
>>>> knlGS:0000000000000000
>>>> [    2.285794] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> [    2.287574] CR2: ffffffffac06c55f CR3: 0000000106ce2003 CR4:
>>>> 0000000000771ee0
>>>> [    2.289757] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
>>>> 0000000000000000
>>>> [    2.291972] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
>>>> 0000000000000400
>>>> [    2.294177] PKRU: 55555554
>>>> [    2.295043] Call Trace:
>>>> [    2.295820]  kvm_smp_send_call_func_ipi+0xe/0x60
>>>> [    2.297220]  smp_call_function_many_cond+0x25d/0x2a0
>>>> [    2.298772]  ? flush_tlb_one_kernel+0x20/0x20
>>>> [    2.300145]  on_each_cpu_cond_mask+0x1e/0x20
>>>> [    2.301514]  flush_tlb_kernel_range+0x8d/0x90
>>>> [    2.302799]  __purge_vmap_area_lazy+0xc1/0x6a0
>>>> [    2.304097]  ? cpumask_next+0x1f/0x20
>>>> [    2.305160]  ? purge_fragmented_blocks_allcpus+0x3d/0x210
>>>> [    2.306686]  _vm_unmap_aliases+0xf1/0x120
>>>> [    2.307861]  change_page_attr_set_clr+0x95/0x280
>>>> [    2.309203]  set_memory_ro+0x26/0x30
>>>> [    2.310259]  ? 0xffffffffc00f7000
>>>> [    2.311214]  module_enable_ro.part.58+0x62/0xc0
>>>> [    2.312417]  do_init_module+0x17a/0x230
>>>> [    2.313460]  load_module+0x1a30/0x1b00
>>>> [    2.314463]  ? __do_sys_finit_module+0xad/0x110
>>>> [    2.315702]  __do_sys_finit_module+0xad/0x110
>>>> [    2.316890]  do_syscall_64+0x39/0x80
>>>> [    2.317868]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>>>> [    2.319226] RIP: 0033:0x7f23ea8f32bd
>>>>
>>>>
>>>> I also used the bisect to get the bad commit id:
>>>> f5cc5a5c168674f84bf061cdb307c2d25fba5448
>>>>
>>>> This issue is known issue? or some fixs are ready to fix those issues?
>>>> thanks!
>>>>
>>>
>>> What's your qemu command line?
>>>
>>> I'm also having a kernel crash (although I think mine is with a different
>>> call stack) when using "-cpu host". The crash doesn't occur when I use
>>> "kvm64" cpu type.
>>>
>>
>>   Hello Gal,
>>
>>   Let me list my host and guest environment
>>   Host: Icelake, Linux5.13.0-rc1+
>>   Guest: Linux5.13.0-rc1+
>>
>>   The Qemu command line:
>>   ./qemu-system-x86_64 \
>>      -machine q35 \
>>      -accel kvm \
>>      -m 4096 \
>>      -smp 4 \
>>      -cpu host \
>>      -bios /home/vmm/project/images/OVMF-upstream.fd \
>>      -drive 
>> format=raw,file=/root/project/images/SGX_rhel8_efi.img,index=0,media=disk \
>>      -netdev user,id=guest0,hostfwd=tcp::10022-:22 \
>>      -device virtio-net-pci,netdev=guest0 \
>>      -qmp tcp:127.0.0.1:12345,server,nowait \
>>      -monitor telnet:127.0.0.1:55555,server,nowait \
>>      -nographic -nodefaults -serial stdio
>>
>>   I also tried the 'cpu kvm64' in my side, and there is not any issue.
> 
> This is the same one as the one I was chatting to Claudio Fontana about
> in the thread 'Windows fails to boot after rebase to QEMU master',
> it's the commit 'i386: split cpu accelerators from cpu.c, using
> AccelCPUClass'

Hi, version 2 of my proposed changes to fix this are at:

https://lists.gnu.org/archive/html/qemu-devel/2021-06/msg00758.html

Claudio