Re: RE: [Qemu-devel] [PATCH] SeaBios: Fix reset procedure reentrancy problem on qemu-kvm platform

[Kevin O'Connor]

On Tue, Dec 22, 2015 at 03:15:26AM +, Xulei (Stone) wrote:
> Hi, Kevin,
> Can you tell how to reset/reboot this VM, if it goes to the handle_hwpic1()
> on its booting procedure? I mean, usually, SeaBIOS would not go to 
> handle_hwpic routine. But in my test case, SeaBIOS calls handle_hwpic when
> KVM injects a #UD expcetion (not irq) and  SeaBIOS will loop to handle this
> if KVM persistently injects exception.
>  
> Now, i just wish to reset/reboot this VM if it is fall into handle_hwpic. I
> tried follwing patch and it seems not work. What can i do to force 
> reset/reboot? 

Call the reset() function.

-Kevin
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: RE: [Qemu-devel] [PATCH] SeaBios: Fix reset procedure reentrancy problem on qemu-kvm platform

[Xulei (Stone)]

, loop handle PIC irq0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
[2015-12-17 12:37:35] handle_hwpic1 irq=0
... always hanle_hwpic1 irq=0, never ends anymore...


>> -Original Message-
>> From: Kevin O'Connor [mailto:ke...@koconnor.net]
>> Sent: Tuesday, December 22, 2015 2:47 AM
>> To: Gonglei (Arei)
>> Cc: Xulei (Stone); Paolo Bonzini; qemu-devel; seab...@seabios.org;
>> Huangweidong (C); kvm@vger.kernel.org; Radim Krcmar
>> Subject: Re: [Qemu-devel] [PATCH] SeaBios: Fix reset procedure reentrancy
>> problem on qemu-kvm platform
>>
>> On Mon, Dec 21, 2015 at 09:41:32AM +, Gonglei (Arei) wrote:
>> > When the gurb of OS is booting, then the softirq and C function
>> > send_disk_op() may use extra stack of SeaBIOS. If we inject a NMI,
>> > romlayout.S: irqentry_extrastack is invoked, and the extra stack will
>> > be used again. And the stack of first calling will be broken, so that the
>> SeaBIOS stuck.
>> >
>> > You can easily reproduce the problem.
>> >
>> > 1. start on guest
>> > 2. reset the guest
>> > 3. inject a NMI when the guest show the grub surface 4. then the guest
>> > stuck
>>
>> Does the SeaBIOS patch below help? 
>
>Sorry, it doesn't work. What's worse is we cannot stop SeaBIOS stuck by
>Setting "CONFIG_ENTRY_EXTRASTACK=n" after applying this patch.
>
>
>> I'm not familiar with how to "inject a
>> NMI" - can you describe the process in more detail?
>>
>
>1. Qemu Command line:
>
>#: /home/qemu/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 4096 -smp 8 
>-name suse -vnc 0.0.0.0:10 \
>-device virtio-scsi-pci,id=scsi0 -drive 
>file=/home/suse11_sp3_32_2,if=none,id=drive-scsi0-0-0-0,format=raw,cache=none,aio=native
> \
>-device scsi-hd,bus=scsi0.0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0 \
>-chardev file,id=seabios,path=/home/seabios.log -device 
>isa-debugcon,iobase=0x402,chardev=seabios \
>-monitor stdio -qmp unix:/tmp/qmp,server,nowait
>
>2. Inject a NMI by QMP:
>
>#: /home/qemu/scripts/qmp # ./qmp-shell /tmp/qmp
>Welcome to the QMP low-level shell!
>Connected to QEMU 2.5.0
>
>(QEMU) system_reset
>{"return": {}}
>(QEMU) inject-nmi 
>{"return": {}}
>(QEMU) inject-nmi
>{"return": {}}
>
>
>Regards,
>-Gonglei
>
>> -Kevin
>>
>>
>> --- a/src/romlayout.S
>> +++ b/src/romlayout.S
>> @@ -548,7 +548,9 @@ entry_post:
>>  ENTRY_INTO32 _cfunc32flat_handle_post   // Normal entry point
>>
>>  ORG 0xe2c3
>> -IRQ_ENTRY 02
>> +.global entry_02
>> +entry_02:
>> +ENTRY handle_02  // NMI handler does not switch onto extra
>> +stack
>>
>>  ORG 0xe3fe
>>  .global 
>> entry_13_officialN�r��yb�X��ǧv�^�)޺{.n�+h����ܨ}���Ơz�:+v���zZ+��+zf���h���~i���z��w���?�&�)ߢf