Bug#707257: linux-image-3.8-1-686-pae: KVM crashes with "entry failed, hardware error 0x80000021"

[Stefan Pietsch <stefan.pietsch@lsexperts.de>]

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

emulate_invalid_guest_state=1
[  196.481653] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481700] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481706] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481711] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481716] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481720] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481725] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481730] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481735] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481739] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.481777] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482068] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482073] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482079] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482084] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482131] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482136] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482142] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482146] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482193] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482198] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482203] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482208] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482255] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482259] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482265] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482269] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482316] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482321] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482326] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482331] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482378] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482382] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482388] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482392] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482439] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482444] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482449] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482454] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482501] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482505] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482511] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482516] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482562] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482567] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482573] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.482577] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483137] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483142] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483147] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483152] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483712] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483716] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483722] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.483727] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484321] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484326] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484333] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484337] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484897] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484901] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484907] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.484911] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.487824] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.487830] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.487836] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.487841] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.488842] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.488847] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.488853] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.488858] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.489416] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.489420] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.489426] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.489431] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490052] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490057] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490062] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490067] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490148] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490152] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490158] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490162] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490262] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490266] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490272] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.490277] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529018] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529025] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529032] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529036] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529099] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529103] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529109] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529114] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529219] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529223] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529229] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529234] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529353] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529357] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529363] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529367] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529407] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529412] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529417] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529422] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529621] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529625] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529631] base=ffff0000 limit=  (null) selector=f0000fff ar=0
[  196.529636] base=ffff0000 limit=  (null) selector=f0000fff ar=0