On 26.06.2013 12:47, Gleb Natapov wrote:
> On Mon, Jun 24, 2013 at 10:42:57PM +0200, Stefan Pietsch wrote:
>> On 24.06.2013 14:30, Gleb Natapov wrote:
>>> On Mon, Jun 24, 2013 at 01:59:34PM +0200, Stefan Pietsch wrote:
>>>> As soon as I remove "kvmvapic.bin" the virtual machine boots with
>>>> qemu-kvm 1.5.0. I just verified this with Linux kernel 3.10.0-rc5.
>>>> "emulate_invalid_guest_state=0" or "emulate_invalid_guest_state=1" make
>>>> no difference.
>>>>
>>>> Please send your patches.
>>> Here it is, run with it and kvmvapic.bin present. See what is printed in
>>> dmesg after the failure.
>>>
>>>
>>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>>> index f4a5b3f..65488a4 100644
>>> --- a/arch/x86/kvm/vmx.c
>>> +++ b/arch/x86/kvm/vmx.c
>>> @@ -3385,6 +3385,7 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
>>> {
>>> struct vcpu_vmx *vmx = to_vmx(vcpu);
>>> u32 ar;
>>> + unsigned long rip;
>>>
>>> if (vmx->rmode.vm86_active && seg != VCPU_SREG_LDTR) {
>>> *var = vmx->rmode.segs[seg];
>>> @@ -3408,6 +3409,9 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
>>> var->db = (ar >> 14) & 1;
>>> var->g = (ar >> 15) & 1;
>>> var->unusable = (ar >> 16) & 1;
>>> + rip = kvm_rip_read(vcpu);
>>> + if ((rip == 0xc101611c || rip == 0xc101611a) && seg == VCPU_SREG_FS)
>>> + printk("base=%p limit=%p selector=%x ar=%x\n", var->base, var->limit, var->selector, ar);
>>> }
>>>
>>> static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
>>
>>
>> Booting kernel Linux 3.10-rc5 with your patch applied produces these
>> messages in dmesg when starting a virtual machine:
>>
>> emulate_invalid_guest_state=0
>> [ 118.732151] base=ffff0000 limit= (null) selector=f0000fff ar=0
>> [ 118.732341] base=ffff0000 limit= (null) selector=f0000fff ar=0
>>
> I've butchered printk format, but it gives me the idea of what is going
> on anyway. Can you try the patch below with
> emulate_invalid_guest_state=0|1?
>
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index f4a5b3f..eb062ce 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -3395,19 +3395,20 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
> var->selector = vmx_read_guest_seg_selector(vmx, seg);
> return;
> }
> +
> var->base = vmx_read_guest_seg_base(vmx, seg);
> var->limit = vmx_read_guest_seg_limit(vmx, seg);
> var->selector = vmx_read_guest_seg_selector(vmx, seg);
> ar = vmx_read_guest_seg_ar(vmx, seg);
> + var->unusable = (ar >> 16) & 1;
> var->type = ar & 15;
> var->s = (ar >> 4) & 1;
> var->dpl = (ar >> 5) & 3;
> - var->present = (ar >> 7) & 1;
> + var->present = !var->unusable;
> var->avl = (ar >> 12) & 1;
> var->l = (ar >> 13) & 1;
> var->db = (ar >> 14) & 1;
> var->g = (ar >> 15) & 1;
> - var->unusable = (ar >> 16) & 1;
> }
>
> static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
Kernel 3.10-rc5 with your latest patch applied can successfully boot the
virtual machine with emulate_invalid_guest_state 0 or 1.
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