Revert "x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR"

CVE-2017-5753 (revert embargoed)
CVE-2017-5715 (revert embargoed)

This reverts commit 44c314e1.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/include/asm/msr-index.h

@@ -332,7 +332,6 @@
 #define MSR_F15H_PERF_CTR		0xc0010201
 #define MSR_F15H_NB_PERF_CTL		0xc0010240
 #define MSR_F15H_NB_PERF_CTR		0xc0010241
-#define MSR_F15H_IC_CFG			0xc0011021
 
 /* Fam 10h MSRs */
 #define MSR_FAM10H_MMIO_CONF_BASE	0xc0010058

arch/x86/kernel/cpu/amd.c

@@ -685,9 +685,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
 	 * Disable it on the affected CPUs.
 	 */
 	if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
-		if (!rdmsrl_safe(MSR_F15H_IC_CFG, &value) && !(value & 0x1E)) {
+		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
 			value |= 0x1E;
-			wrmsrl_safe(MSR_F15H_IC_CFG, value);
+			wrmsrl_safe(0xc0011021, value);
 		}
 	}
 }

arch/x86/kvm/cpuid.h

 #ifndef ARCH_X86_KVM_CPUID_H
 #define ARCH_X86_KVM_CPUID_H
 
-#include <asm/microcode.h>
-
 #include "x86.h"
 
 int kvm_update_cpuid(struct kvm_vcpu *vcpu);
@@ -121,28 +119,6 @@ static inline bool guest_cpuid_is_amd(struct kvm_vcpu *vcpu)
 	return best && best->ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx;
 }
 
-static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
-{
-	struct kvm_cpuid_entry2 *best;
-
-	best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
-	if (!best)
-		return -1;
-
-	return __x86_family(best->eax);
-}
-
-static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
-{
-	struct kvm_cpuid_entry2 *best;
-
-	best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
-	if (!best)
-		return -1;
-
-	return x86_model(best->eax);
-}
-
 static inline bool guest_cpuid_has_gbpages(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best;

arch/x86/kvm/svm.c

@@ -3053,23 +3053,6 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_UCODE_REV:
 		msr_info->data = 0x01000065;
 		break;
-	case MSR_F15H_IC_CFG: {
-
-		int family, model;
-
-		family = guest_cpuid_family(vcpu);
-		model  = guest_cpuid_model(vcpu);
-
-		if (family < 0 || model < 0)
-			return kvm_get_msr_common(vcpu, msr_info);
-
-		msr_info->data = 0;
-
-		if (family == 0x15 &&
-		    (model >= 0x2 && model < 0x20))
-			msr_info->data = 0x1E;
-		}
-		break;
 	default:
 		return kvm_get_msr_common(vcpu, msr_info);
 	}