1 files changed, 133 insertions, 0 deletions
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
new file mode 100644
index 000000000..c4ec02494
--- /dev/null
+++ b/arch/x86/kvm/mtrr.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * vMTRR implementation
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright 2010 Red Hat, Inc. and/or its affiliates.
+ * Copyright(C) 2015 Intel Corporation.
+ *
+ * Authors:
+ *   Yaniv Kamay  <yaniv@qumranet.com>
+ *   Avi Kivity   <avi@qumranet.com>
+ *   Marcelo Tosatti <mtosatti@redhat.com>
+ *   Paolo Bonzini <pbonzini@redhat.com>
+ *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kvm_host.h>
+#include <asm/mtrr.h>
+
+#include "cpuid.h"
+#include "msrs.h"
+
+static u64 *find_mtrr(struct kvm_vcpu *vcpu, unsigned int msr)
+{
+	int index;
+
+	switch (msr) {
+	case MTRRphysBase_MSR(0) ... MTRRphysMask_MSR(KVM_NR_VAR_MTRR - 1):
+		index = msr - MTRRphysBase_MSR(0);
+		return &vcpu->arch.mtrr_state.var[index];
+	case MSR_MTRRfix64K_00000:
+		return &vcpu->arch.mtrr_state.fixed_64k;
+	case MSR_MTRRfix16K_80000:
+	case MSR_MTRRfix16K_A0000:
+		index = msr - MSR_MTRRfix16K_80000;
+		return &vcpu->arch.mtrr_state.fixed_16k[index];
+	case MSR_MTRRfix4K_C0000:
+	case MSR_MTRRfix4K_C8000:
+	case MSR_MTRRfix4K_D0000:
+	case MSR_MTRRfix4K_D8000:
+	case MSR_MTRRfix4K_E0000:
+	case MSR_MTRRfix4K_E8000:
+	case MSR_MTRRfix4K_F0000:
+	case MSR_MTRRfix4K_F8000:
+		index = msr - MSR_MTRRfix4K_C0000;
+		return &vcpu->arch.mtrr_state.fixed_4k[index];
+	case MSR_MTRRdefType:
+		return &vcpu->arch.mtrr_state.deftype;
+	default:
+		break;
+	}
+	return NULL;
+}
+
+static bool valid_mtrr_type(unsigned t)
+{
+	return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */
+}
+
+static bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+	int i;
+	u64 mask;
+
+	if (msr == MSR_MTRRdefType) {
+		if (data & ~0xcff)
+			return false;
+		return valid_mtrr_type(data & 0xff);
+	} else if (msr >= MSR_MTRRfix64K_00000 && msr <= MSR_MTRRfix4K_F8000) {
+		for (i = 0; i < 8 ; i++)
+			if (!valid_mtrr_type((data >> (i * 8)) & 0xff))
+				return false;
+		return true;
+	}
+
+	/* variable MTRRs */
+	if (WARN_ON_ONCE(!(msr >= MTRRphysBase_MSR(0) &&
+			   msr <= MTRRphysMask_MSR(KVM_NR_VAR_MTRR - 1))))
+		return false;
+
+	mask = kvm_vcpu_reserved_gpa_bits_raw(vcpu);
+	if ((msr & 1) == 0) {
+		/* MTRR base */
+		if (!valid_mtrr_type(data & 0xff))
+			return false;
+		mask |= 0xf00;
+	} else {
+		/* MTRR mask */
+		mask |= 0x7ff;
+	}
+
+	return (data & mask) == 0;
+}
+
+int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+	u64 *mtrr;
+
+	mtrr = find_mtrr(vcpu, msr);
+	if (!mtrr)
+		return 1;
+
+	if (!kvm_mtrr_valid(vcpu, msr, data))
+		return 1;
+
+	*mtrr = data;
+	return 0;
+}
+
+int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+{
+	u64 *mtrr;
+
+	/* MSR_MTRRcap is a readonly MSR. */
+	if (msr == MSR_MTRRcap) {
+		/*
+		 * SMRR = 0
+		 * WC = 1
+		 * FIX = 1
+		 * VCNT = KVM_NR_VAR_MTRR
+		 */
+		*pdata = 0x500 | KVM_NR_VAR_MTRR;
+		return 0;
+	}
+
+	mtrr = find_mtrr(vcpu, msr);
+	if (!mtrr)
+		return 1;
+
+	*pdata = *mtrr;
+	return 0;
+}