KVM: MTRR support

Add emulation for the memory type range registers, needed by VMware esx 3.5,
and by pci device assignment.

Signed-off-by: Avi Kivity <avi@qumranet.com>

2 files changed, 51 insertions, 4 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 05b54976c891..5f67a7c54e82 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -611,6 +611,38 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
         mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
 }
 
+static bool msr_mtrr_valid(unsigned msr)
+{
+        switch (msr) {
+        case 0x200 ... 0x200 + 2 * KVM_NR_VAR_MTRR - 1:
+        case MSR_MTRRfix64K_00000:
+        case MSR_MTRRfix16K_80000:
+        case MSR_MTRRfix16K_A0000:
+        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:
+        case MSR_MTRRdefType:
+        case MSR_IA32_CR_PAT:
+                return true;
+        case 0x2f8:
+                return true;
+        }
+        return false;
+}
+
+static int set_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+        if (!msr_mtrr_valid(msr))
+                return 1;
+
+        vcpu->arch.mtrr[msr - 0x200] = data;
+        return 0;
+}
 
 int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 {
@@ -632,8 +664,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
                 break;
         case MSR_IA32_UCODE_REV:
         case MSR_IA32_UCODE_WRITE:
-        case 0x200 ... 0x2ff: /* MTRRs */
                 break;
+        case 0x200 ... 0x2ff:
+                return set_msr_mtrr(vcpu, msr, data);
         case MSR_IA32_APICBASE:
                 kvm_set_apic_base(vcpu, data);
                 break;
@@ -691,6 +724,15 @@ int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
         return kvm_x86_ops->get_msr(vcpu, msr_index, pdata);
 }
 
+static int get_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+{
+        if (!msr_mtrr_valid(msr))
+                return 1;
+
+        *pdata = vcpu->arch.mtrr[msr - 0x200];
+        return 0;
+}
+
 int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 {
         u64 data;
@@ -712,11 +754,13 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
         case MSR_IA32_MC0_MISC+16:
         case MSR_IA32_UCODE_REV:
         case MSR_IA32_EBL_CR_POWERON:
-                /* MTRR registers */
-        case 0xfe:
-        case 0x200 ... 0x2ff:
                 data = 0;
                 break;
+        case MSR_MTRRcap:
+                data = 0x500 | KVM_NR_VAR_MTRR;
+                break;
+        case 0x200 ... 0x2ff:
+                return get_msr_mtrr(vcpu, msr, pdata);
         case 0xcd: /* fsb frequency */
                 data = 3;
                 break;
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 075598b4e3f3..fc72bad878ed 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -79,6 +79,7 @@
 #define KVM_MIN_FREE_MMU_PAGES 5
 #define KVM_REFILL_PAGES 25
 #define KVM_MAX_CPUID_ENTRIES 40
+#define KVM_NR_VAR_MTRR 8
 
 extern spinlock_t kvm_lock;
 extern struct list_head vm_list;
@@ -290,6 +291,8 @@ struct kvm_vcpu_arch {
         struct page *time_page;
 
         bool nmi_pending;
+
+        u64 mtrr[0x100];
 };
 
 struct kvm_mem_alias {