[PATCH] x86: emulate read/write access to cr8

[PATCH] x86: emulate read/write access to cr8

[Joerg Roedel]

From: Joerg Roedel <jroedel-Ug2OvFXVNAT2eFz/2MeuCQ@public.gmane.org>

This patch adds code to emulate the access to the cr8 register to the x86
instruction emulator in kvm.

Signed-off-by: Joerg Roedel <joerg.roedel-5C7GfCeVMHo@public.gmane.org>
Signed-off-by: Markus Rechberger <markus.rechberger-5C7GfCeVMHo@public.gmane.org>
---
 drivers/kvm/x86.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 6deb052..9db4e32 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -2236,6 +2236,8 @@ unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
 		return vcpu->cr3;
 	case 4:
 		return vcpu->cr4;
+	case 8:
+		return get_cr8(vcpu);
 	default:
 		vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
 		return 0;
@@ -2259,6 +2261,9 @@ void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
 	case 4:
 		set_cr4(vcpu, mk_cr_64(vcpu->cr4, val));
 		break;
+	case 8:
+		set_cr8(vcpu, val & 0xfUL);
+		break;
 	default:
 		vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
 	}
-- 
1.5.2.5




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Re: [PATCH] x86: emulate read/write access to cr8

[Avi Kivity]

Joerg Roedel wrote:
> This patch adds code to emulate the access to the cr8 register to the x86
> instruction emulator in kvm.
>   

Applied, thanks.


-- 
error compiling committee.c: too many arguments to function


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Re: [PATCH] x86: emulate read/write access to cr8

[Avi Kivity]

Joerg Roedel wrote:
> From: Joerg Roedel <jroedel-Ug2OvFXVNAT2eFz/2MeuCQ@public.gmane.org>
>
> This patch adds code to emulate the access to the cr8 register to the x86
> instruction emulator in kvm.
>
>   

I wrote a unit test for 'mov cr8', and it passes!

Seems we aren't trapping cr8 access at all for svm.

-- 
error compiling committee.c: too many arguments to function


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Re: [PATCH] x86: emulate read/write access to cr8

[Avi Kivity]

Avi Kivity wrote:
> Joerg Roedel wrote:
>   
>> From: Joerg Roedel <jroedel-Ug2OvFXVNAT2eFz/2MeuCQ@public.gmane.org>
>>
>> This patch adds code to emulate the access to the cr8 register to the x86
>> instruction emulator in kvm.
>>
>>   
>>     
>
> I wrote a unit test for 'mov cr8', and it passes!
>
> Seems we aren't trapping cr8 access at all for svm.
>
>   

Okay, I added mov cr8 trapping to svm.c.


-- 
error compiling committee.c: too many arguments to function


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Re: [PATCH] x86: emulate read/write access to cr8

[Joerg Roedel]

On Thu, Dec 06, 2007 at 07:51:49PM +0200, Avi Kivity wrote:
> Avi Kivity wrote:
> >Joerg Roedel wrote:
> >  
> >>From: Joerg Roedel <jroedel-Ug2OvFXVNAT2eFz/2MeuCQ@public.gmane.org>
> >>
> >>This patch adds code to emulate the access to the cr8 register to the x86
> >>instruction emulator in kvm.
> >>
> >>      
> >
> >I wrote a unit test for 'mov cr8', and it passes!
> >
> >Seems we aren't trapping cr8 access at all for svm.
> >
> >  
> 
> Okay, I added mov cr8 trapping to svm.c.

I have cr8 access intercepted here, but this is not sufficient for
getting Vista 64bit running. Therefore I have not sent the patch yet.

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