[PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[Rusty Russell]

Intel manual (and KVM definition) say it's TPR is 4 bits wide.  Also fix
CR8_RESEVED_BITS typo.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff -r 6ef0b4c0d6f7 drivers/kvm/kvm_main.c
--- a/drivers/kvm/kvm_main.c	Tue Jul 17 18:07:48 2007 +1000
+++ b/drivers/kvm/kvm_main.c	Tue Jul 17 18:20:22 2007 +1000
@@ -92,7 +92,7 @@ static struct dentry *debugfs_dir;
 			  | X86_CR4_PGE | X86_CR4_PCE | X86_CR4_OSFXSR	\
 			  | X86_CR4_OSXMMEXCPT | X86_CR4_VMXE))
 
-#define CR8_RESEVED_BITS (~0x0fULL)
+#define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR)
 #define EFER_RESERVED_BITS 0xfffffffffffff2fe
 
 #ifdef CONFIG_X86_64
@@ -633,7 +633,7 @@ EXPORT_SYMBOL_GPL(set_cr3);
 
 void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
 {
-	if ( cr8 & CR8_RESEVED_BITS) {
+	if (cr8 & CR8_RESERVED_BITS) {
 		printk(KERN_DEBUG "set_cr8: #GP, reserved bits 0x%lx\n", cr8);
 		inject_gp(vcpu);
 		return;
diff -r 6ef0b4c0d6f7 include/asm-i386/processor-flags.h
--- a/include/asm-i386/processor-flags.h	Tue Jul 17 18:07:48 2007 +1000
+++ b/include/asm-i386/processor-flags.h	Tue Jul 17 18:12:54 2007 +1000
@@ -63,7 +63,7 @@
 /*
  * x86-64 Task Priority Register, CR8
  */
-#define X86_CR8_TPR	0x00000007 /* task priority register */
+#define X86_CR8_TPR	0x0000000F /* task priority register */
 
 /*
  * AMD and Transmeta use MSRs for configuration; see <asm/msr-index.h>

Re: [PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[Avi Kivity]

Rusty Russell wrote:
> Intel manual (and KVM definition) say it's TPR is 4 bits wide.  Also fix
> CR8_RESEVED_BITS typo.
>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> diff -r 6ef0b4c0d6f7 include/asm-i386/processor-flags.h
> --- a/include/asm-i386/processor-flags.h	Tue Jul 17 18:07:48 2007 +1000
> +++ b/include/asm-i386/processor-flags.h	Tue Jul 17 18:12:54 2007 +1000
> @@ -63,7 +63,7 @@
>  /*
>   * x86-64 Task Priority Register, CR8
>   */
> -#define X86_CR8_TPR	0x00000007 /* task priority register */
> +#define X86_CR8_TPR	0x0000000F /* task priority register */
>  
>  /*
>   * AMD and Transmeta use MSRs for configuration; see <asm/msr-index.h>
>
>
>   


X86_CR8_TPR is not used in the kernel.  But is this meant to be a mask, 
or something else?

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

Re: [PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[H. Peter Anvin]

Rusty Russell wrote:
> Intel manual (and KVM definition) say it's TPR is 4 bits wide.  Also fix
> CR8_RESEVED_BITS typo.
> 
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Indeed it is.

Acked-by: H. Peter Anvin <hpa@zytor.com>

	-hpa

Re: [PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[H. Peter Anvin]

Avi Kivity wrote:
> 
> X86_CR8_TPR is not used in the kernel.  But is this meant to be a mask,
> or something else?
> 

Yes, a mask.

And no, it's not used, except for KVM...

	-hpa

Re: [PATCH 10/10] Use standard CR8 flags, and fix TPR definition

[Avi Kivity]

H. Peter Anvin wrote:
> Rusty Russell wrote:
>   
>> Intel manual (and KVM definition) say it's TPR is 4 bits wide.  Also fix
>> CR8_RESEVED_BITS typo.
>>
>> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
>>     
>
> Indeed it is.
>
> Acked-by: H. Peter Anvin <hpa@zytor.com>
>
>   

Applied-by: Avi Kivity <avi@qumranet.com>

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.