KVM: x86: Mark GPRs dirty when written

When performing VMGEXIT processing for an SEV-ES guest, register values
will be synced between KVM and the GHCB. Prepare for detecting when a GPR
has been updated (marked dirty) in order to determine whether to sync the
register to the GHCB.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <7ca2a1cdb61456f2fe9c64193e34d601e395c133.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/kvm_cache_regs.h

@@ -9,6 +9,31 @@
 	(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR  \
 	 | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)
 
+static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
+					     enum kvm_reg reg)
+{
+	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
+					 enum kvm_reg reg)
+{
+	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
+static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
+					       enum kvm_reg reg)
+{
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
+					   enum kvm_reg reg)
+{
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
 #define BUILD_KVM_GPR_ACCESSORS(lname, uname)				      \
 static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
 {									      \
@@ -18,6 +43,7 @@ static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu,	      \
 						unsigned long val)	      \
 {									      \
 	vcpu->arch.regs[VCPU_REGS_##uname] = val;			      \
+	kvm_register_mark_dirty(vcpu, VCPU_REGS_##uname);		      \
 }
 BUILD_KVM_GPR_ACCESSORS(rax, RAX)
 BUILD_KVM_GPR_ACCESSORS(rbx, RBX)
@@ -37,31 +63,6 @@ BUILD_KVM_GPR_ACCESSORS(r14, R14)
 BUILD_KVM_GPR_ACCESSORS(r15, R15)
 #endif
 
-static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
-					     enum kvm_reg reg)
-{
-	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
-}
-
-static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
-					 enum kvm_reg reg)
-{
-	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
-}
-
-static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
-					       enum kvm_reg reg)
-{
-	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
-}
-
-static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
-					   enum kvm_reg reg)
-{
-	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
-	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
-}
-
 static inline unsigned long kvm_register_read(struct kvm_vcpu *vcpu, int reg)
 {
 	if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))