From mboxrd@z Thu Jan  1 00:00:00 1970
From: Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
Subject: Re: [RFC][PATCH] KVM: SVM: Sync g_pat with guest-written PAT value
Date: Mon, 20 Apr 2015 18:14:02 +0200
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Cc: kvm <kvm@vger.kernel.org>, Joel Schopp <joel.schopp@amd.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
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2015-04-13 08:58+0200, Jan Kiszka:
> When hardware supports the g_pat VMCB field, we can use it for emulat=
ing
> the PAT configuration that the guest configures by writing to the
> corresponding MSR.
>=20
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>=20
> RFC because it is only compile-tested.
>=20
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> @@ -3245,6 +3245,15 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, =
struct msr_data *msr)
>  	case MSR_VM_IGNNE:
>  		vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, =
data);
>  		break;
> +	case MSR_IA32_CR_PAT:
> +		if (npt_enabled) {
> +			if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
> +				return 1;
> +			svm->vmcb->save.g_pat =3D data;
> +			vcpu->arch.pat =3D data;

Disregarding my Reviewed-by, the code is missing:

  mark_dirty(svm->vmcb, VMCB_NPT);

Also,

Tested-by: Radim Kr=C4=8Dm=C3=A1=C5=99 <rkrcmar@redhat.com>