From: dv <dv@openbsd.org>
Date: Wed, 7 Sep 2022 18:44:09 +0000 (+0000)
Subject: vmm(4): allow reading MSR_TSC on Intel hosts.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=73fb78b9c841b10161de16a561d7714609733e3a;p=openbsd

vmm(4): allow reading MSR_TSC on Intel hosts.

Add's MSR_TSC to the read bitmap for msr access. This was added to
AMD/SVM in Feb 2020, but never added to Intel VMX. Some guests use
rdmsr instead of rdtsc, so this prevents a #GP exception.

ok mlarkin@
---

diff --git a/sys/arch/amd64/amd64/vmm.c b/sys/arch/amd64/amd64/vmm.c
index c3d957cfb90..51378f4a798 100644
--- a/sys/arch/amd64/amd64/vmm.c
+++ b/sys/arch/amd64/amd64/vmm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmm.c,v 1.322 2022/09/02 17:46:37 dv Exp $	*/
+/*	$OpenBSD: vmm.c,v 1.323 2022/09/07 18:44:09 dv Exp $	*/
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
  *
@@ -3522,7 +3522,9 @@ vcpu_reset_regs_vmx(struct vcpu *vcpu, struct vcpu_reg_state *vrs)
 	vmx_setmsrbrw(vcpu, MSR_FSBASE);
 	vmx_setmsrbrw(vcpu, MSR_GSBASE);
 	vmx_setmsrbrw(vcpu, MSR_KERNELGSBASE);
+	
 	vmx_setmsrbr(vcpu, MSR_MISC_ENABLE);
+	vmx_setmsrbr(vcpu, MSR_TSC);
 
 	/* XXX CR0 shadow */
 	/* XXX CR4 shadow */