svn commit: r282336 - in head/sys/amd64/vmm: . amd intel

Neel Natu neel at FreeBSD.org
Sat May 2 04:19:13 UTC 2015


Author: neel
Date: Sat May  2 04:19:11 2015
New Revision: 282336
URL: https://svnweb.freebsd.org/changeset/base/282336

Log:
  Emulate machine check related MSRs to allow guest OSes like Windows to boot.
  
  Reported by:	Leon Dang (ldang at nahannisys.com)
  MFC after:	2 weeks

Modified:
  head/sys/amd64/vmm/amd/svm_msr.c
  head/sys/amd64/vmm/intel/vmx_msr.c
  head/sys/amd64/vmm/x86.c

Modified: head/sys/amd64/vmm/amd/svm_msr.c
==============================================================================
--- head/sys/amd64/vmm/amd/svm_msr.c	Sat May  2 03:25:24 2015	(r282335)
+++ head/sys/amd64/vmm/amd/svm_msr.c	Sat May  2 04:19:11 2015	(r282336)
@@ -110,6 +110,10 @@ svm_rdmsr(struct svm_softc *sc, int vcpu
 	int error = 0;
 
 	switch (num) {
+	case MSR_MCG_CAP:
+	case MSR_MCG_STATUS:
+		*result = 0;
+		break;
 	case MSR_MTRRcap:
 	case MSR_MTRRdefType:
 	case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
@@ -135,6 +139,9 @@ svm_wrmsr(struct svm_softc *sc, int vcpu
 	int error = 0;
 
 	switch (num) {
+	case MSR_MCG_CAP:
+	case MSR_MCG_STATUS:
+		break;		/* ignore writes */
 	case MSR_MTRRcap:
 		vm_inject_gp(sc->vm, vcpu);
 		break;

Modified: head/sys/amd64/vmm/intel/vmx_msr.c
==============================================================================
--- head/sys/amd64/vmm/intel/vmx_msr.c	Sat May  2 03:25:24 2015	(r282335)
+++ head/sys/amd64/vmm/intel/vmx_msr.c	Sat May  2 04:19:11 2015	(r282336)
@@ -395,6 +395,10 @@ vmx_rdmsr(struct vmx *vmx, int vcpuid, u
 	error = 0;
 
 	switch (num) {
+	case MSR_MCG_CAP:
+	case MSR_MCG_STATUS:
+		*val = 0;
+		break;
 	case MSR_MTRRcap:
 	case MSR_MTRRdefType:
 	case MSR_MTRR4kBase ... MSR_MTRR4kBase + 8:
@@ -433,6 +437,9 @@ vmx_wrmsr(struct vmx *vmx, int vcpuid, u
 	error = 0;
 
 	switch (num) {
+	case MSR_MCG_CAP:
+	case MSR_MCG_STATUS:
+		break;		/* ignore writes */
 	case MSR_MTRRcap:
 		vm_inject_gp(vmx->vm, vcpuid);
 		break;

Modified: head/sys/amd64/vmm/x86.c
==============================================================================
--- head/sys/amd64/vmm/x86.c	Sat May  2 03:25:24 2015	(r282335)
+++ head/sys/amd64/vmm/x86.c	Sat May  2 04:19:11 2015	(r282336)
@@ -285,17 +285,20 @@ x86_emulate_cpuid(struct vm *vm, int vcp
 			 * Hide thermal monitoring
 			 */
 			regs[3] &= ~(CPUID_ACPI | CPUID_TM);
-			
+
 			/*
-			 * Machine check handling is done in the host.
+			 * Hide the debug store capability.
 			 */
-			regs[3] &= ~(CPUID_MCA | CPUID_MCE);
-
-                        /*
-                        * Hide the debug store capability.
-                        */
 			regs[3] &= ~CPUID_DS;
 
+			/*
+			 * Advertise the Machine Check and MTRR capability.
+			 *
+			 * Some guest OSes (e.g. Windows) will not boot if
+			 * these features are absent.
+			 */
+			regs[3] |= (CPUID_MCA | CPUID_MCE | CPUID_MTRR);
+
 			logical_cpus = threads_per_core * cores_per_package;
 			regs[1] &= ~CPUID_HTT_CORES;
 			regs[1] |= (logical_cpus & 0xff) << 16;


More information about the svn-src-head mailing list