Re: [PATCH 13/20] KVM: x86 emulator: fix memory access during x86 emulation

Stefan Bader
2010-03-08T14:17:21Z

Avi Kivity wrote:
> On 03/08/2010 04:10 PM, Stefan Bader wrote:
>> Avi Kivity wrote:
>>
>>> On 03/06/2010 03:53 PM, Stefan Bader wrote:
>>>
>>>> i Avi,
>>>>
>>>> we currently try to integrate this patch for an update into a 2.6.32
>>>> based
>>>> system (amongst other kvm updates). But as soon as this patch gets
>>>> added kvm
>>>> will die on startup in kvm_leave_lazy_mmu. This has been documented
>>>> here:
>>>>
>>>> https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/531823
>>>>
>>>> I have placed the backports of your patches, which are currently in
>>>> linux-next
>>>> and marked for stable here:
>>>>
>>>> git://kernel.ubuntu.com/smb/linux-2.6.32.y kvm
>>>>
>>>> I have tested the failure with a version that got only the following
>>>> patches in:
>>>> KVM: x86 emulator: Add Virtual-8086 mode of emulation
>>>> KVM: x86 emulator: fix memory access during x86 emulation
>>>> KVM: x86 emulator: Check IOPL level during io instruction emulation
>>>> KVM: x86 emulator: Fix popf emulation
>>>> KVM: x86 emulator: Check CPL level during privilege instruction
>>>> emulation
>>>>
>>>> and also with a version that takes all stable patches up to the bad
>>>> one:
>>>> KVM: VMX: Trap and invalid MWAIT/MONITOR instruction
>>>> KVM: x86 emulator: Add group8 instruction decoding
>>>> KVM: x86 emulator: Add group9 instruction decoding
>>>> KVM: x86 emulator: Add Virtual-8086 mode of emulation
>>>> KVM: x86 emulator: fix memory access during x86 emulation
>>>>
>>>> But as soon as the fix for memory access gets added, the bug will
>>>> occur. Would
>>>> you have an idea what might be causing this?
>>>>
>>>>
>>> Does the same guest, using the same qemu-kvm, work on kvm.git or
>>> upstream?
>>>
>>>
>> The test was done with a kvm user-space package based on 0.12.3 (which
>> seems to
>> be the current upstream version). I try to do a test on the git version.
>>
>
> I meant keep the same userspace without change, and try it on a Linus
> kernel or kvm.git master
> (http://git.kernel.org/?p=virt/kvm/kvm.git;a=summary).
>

Ok, sorry I misunderstood that. As I see Linus just pulled your patches in, I
will get that compiled and tested.