On Mon, Jun 14, 2010, Avi Kivity wrote about "Re: [PATCH 2/24] Add VMX and SVM to list of supported cpuid features":
> > const u32 kvm_supported_word4_x86_features =
> > F(XMM3) | 0 /* Reserved, DTES64, MONITOR */ |
> >- 0 /* DS-CPL, VMX, SMX, EST */ |
> >+ 0 /* DS-CPL */ | (nested ? F(VMX) : 0) | 0 /* SMX, EST */ |
> > 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
> > 0 /* Reserved */ | F(CX16) | 0 /* xTPR Update, PDCM */ |
> > 0 /* Reserved, DCA */ | F(XMM4_1) |
> >
>
> You can use kvm_x86_ops->set_supported_cpuid() to alter features.
You're right, that's indeed much cleaner! Thanks.
This also prevents me from needing the "nested" parameter in x86.c (which I
don't have now that I've moved it to vmx.c).
The fixed patch:
-------
Subject: [PATCH 2/24] Add VMX and SVM to list of supported cpuid features
Add the "VMX" CPU feature to the list of CPU featuress KVM advertises with
the KVM_GET_SUPPORTED_CPUID ioctl (unless the "nested" module option is off).
Qemu uses this ioctl, and intersects KVM's list with its own list of desired
cpu features (depending on the -cpu option given to qemu) to determine the
final list of features presented to the guest.
Signed-off-by: Nadav Har'El <nyh@xxxxxxxxxx>
---
--- .before/arch/x86/kvm/vmx.c 2010-06-15 17:20:01.000000000 +0300
+++ .after/arch/x86/kvm/vmx.c 2010-06-15 17:20:01.000000000 +0300
@@ -4236,6 +4236,8 @@ static void vmx_cpuid_update(struct kvm_
static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
{
+ if (func == 1 && nested)
+ entry->ecx |= bit(X86_FEATURE_VMX);
}
static struct kvm_x86_ops vmx_x86_ops = {
--
Nadav Har'El | Tuesday, Jun 15 2010, 3 Tammuz 5770
nyh@xxxxxxxxxxxxxxxxxxx |-----------------------------------------
Phone +972-523-790466, ICQ 13349191 |Time is the best teacher. Unfortunately
http://nadav.harel.org.il |it kills all its students.
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