kvm: nVMX: Shadow "high" parts of shadowed 64-bit VMCS fields

Inconsistencies result from shadowing only accesses to the full
64-bits of a 64-bit VMCS field, but not shadowing accesses to the high
32-bits of the field. The "high" part of a 64-bit field should be
shadowed whenever the full 64-bit field is shadowed.

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 34 insertions, 26 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e02c7004b64b..32db3f5dce7f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3764,6 +3764,25 @@ static void free_kvm_area(void)
 	}
 }
 
+enum vmcs_field_type {
+	VMCS_FIELD_TYPE_U16 = 0,
+	VMCS_FIELD_TYPE_U64 = 1,
+	VMCS_FIELD_TYPE_U32 = 2,
+	VMCS_FIELD_TYPE_NATURAL_WIDTH = 3
+};
+
+static inline int vmcs_field_type(unsigned long field)
+{
+	if (0x1 & field)	/* the *_HIGH fields are all 32 bit */
+		return VMCS_FIELD_TYPE_U32;
+	return (field >> 13) & 0x3 ;
+}
+
+static inline int vmcs_field_readonly(unsigned long field)
+{
+	return (((field >> 10) & 0x3) == 1);
+}
+
 static void init_vmcs_shadow_fields(void)
 {
 	int i, j;
@@ -3789,14 +3808,22 @@ static void init_vmcs_shadow_fields(void)
 
 	/* shadowed fields guest access without vmexit */
 	for (i = 0; i < max_shadow_read_write_fields; i++) {
-		clear_bit(shadow_read_write_fields[i],
-			  vmx_vmwrite_bitmap);
-		clear_bit(shadow_read_write_fields[i],
-			  vmx_vmread_bitmap);
+		unsigned long field = shadow_read_write_fields[i];
+
+		clear_bit(field, vmx_vmwrite_bitmap);
+		clear_bit(field, vmx_vmread_bitmap);
+		if (vmcs_field_type(field) == VMCS_FIELD_TYPE_U64) {
+			clear_bit(field + 1, vmx_vmwrite_bitmap);
+			clear_bit(field + 1, vmx_vmread_bitmap);
+		}
+	}
+	for (i = 0; i < max_shadow_read_only_fields; i++) {
+		unsigned long field = shadow_read_only_fields[i];
+
+		clear_bit(field, vmx_vmread_bitmap);
+		if (vmcs_field_type(field) == VMCS_FIELD_TYPE_U64)
+			clear_bit(field + 1, vmx_vmread_bitmap);
 	}
-	for (i = 0; i < max_shadow_read_only_fields; i++)
-		clear_bit(shadow_read_only_fields[i],
-			  vmx_vmread_bitmap);
 }
 
 static __init int alloc_kvm_area(void)
@@ -7219,25 +7246,6 @@ static int handle_vmresume(struct kvm_vcpu *vcpu)
 	return nested_vmx_run(vcpu, false);
 }
 
-enum vmcs_field_type {
-	VMCS_FIELD_TYPE_U16 = 0,
-	VMCS_FIELD_TYPE_U64 = 1,
-	VMCS_FIELD_TYPE_U32 = 2,
-	VMCS_FIELD_TYPE_NATURAL_WIDTH = 3
-};
-
-static inline int vmcs_field_type(unsigned long field)
-{
-	if (0x1 & field)	/* the *_HIGH fields are all 32 bit */
-		return VMCS_FIELD_TYPE_U32;
-	return (field >> 13) & 0x3 ;
-}
-
-static inline int vmcs_field_readonly(unsigned long field)
-{
-	return (((field >> 10) & 0x3) == 1);
-}
-
 /*
  * Read a vmcs12 field. Since these can have varying lengths and we return
  * one type, we chose the biggest type (u64) and zero-extend the return value