| Message ID | 1456184436-31168-1-git-send-email-pfeiner@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 23/02/2016 00:40, Peter Feiner wrote: > Was defined as 0x1 when it should have been 0x2000 (13th bit of CR4). > See Intel manual 23.7. 0x1 is the VME 'Virtual-8086 Mode Extensions' > bit, which the vmx tests don't exercise. > > The correct bit was being set thanks to IA32_VMX_CR4_FIXED{0,1} MSRs > forcing it. > > I hacked the test setup to forcibly un-set the bit and observed the > correct #UD VMXON behavior. Adding a test to verify the #UD behavior > is follow-up work. > > Signed-off-by: Peter Feiner <pfeiner@google.com> > --- > lib/x86/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/x86/processor.h b/lib/x86/processor.h > index 95cea1a..dff1689 100644 > --- a/lib/x86/processor.h > +++ b/lib/x86/processor.h > @@ -21,7 +21,7 @@ > #define X86_CR0_WP 0x00010000 > #define X86_CR0_AM 0x00040000 > #define X86_CR0_PG 0x80000000 > -#define X86_CR4_VMXE 0x00000001 > +#define X86_CR4_VMXE 0x00002000 > #define X86_CR4_TSD 0x00000004 > #define X86_CR4_DE 0x00000008 > #define X86_CR4_PSE 0x00000010 > Thanks, applying both patches. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/x86/processor.h b/lib/x86/processor.h index 95cea1a..dff1689 100644 --- a/lib/x86/processor.h +++ b/lib/x86/processor.h @@ -21,7 +21,7 @@ #define X86_CR0_WP 0x00010000 #define X86_CR0_AM 0x00040000 #define X86_CR0_PG 0x80000000 -#define X86_CR4_VMXE 0x00000001 +#define X86_CR4_VMXE 0x00002000 #define X86_CR4_TSD 0x00000004 #define X86_CR4_DE 0x00000008 #define X86_CR4_PSE 0x00000010
Was defined as 0x1 when it should have been 0x2000 (13th bit of CR4). See Intel manual 23.7. 0x1 is the VME 'Virtual-8086 Mode Extensions' bit, which the vmx tests don't exercise. The correct bit was being set thanks to IA32_VMX_CR4_FIXED{0,1} MSRs forcing it. I hacked the test setup to forcibly un-set the bit and observed the correct #UD VMXON behavior. Adding a test to verify the #UD behavior is follow-up work. Signed-off-by: Peter Feiner <pfeiner@google.com> --- lib/x86/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)