[RFC PATCH 3/5] KVM: x86: add msr_exits_supported to kvm_x86_ops

[Peter Hornyack <peterhornyack@google.com>]

msr_exits_supported will be checked when user space attempts to enable
the KVM_CAP_UNHANDLED_MSR_EXITS capability for the vm. This is needed
because MSR exit support will be implemented for vmx but not svm later
in this patchset.

Signed-off-by: Peter Hornyack <peterhornyack@google.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 6 ++++++
 arch/x86/kvm/vmx.c              | 6 ++++++
 3 files changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c12e845f59e6..a6e145b1e271 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -854,6 +854,7 @@ struct kvm_x86_ops {
 	void (*handle_external_intr)(struct kvm_vcpu *vcpu);
 	bool (*mpx_supported)(void);
 	bool (*xsaves_supported)(void);
+	bool (*msr_exits_supported)(void);
 
 	int (*check_nested_events)(struct kvm_vcpu *vcpu, bool external_intr);
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 74d825716f4f..bcbb56f49b9f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4249,6 +4249,11 @@ static bool svm_xsaves_supported(void)
 	return false;
 }
 
+static bool svm_msr_exits_supported(void)
+{
+	return false;
+}
+
 static bool svm_has_wbinvd_exit(void)
 {
 	return true;
@@ -4540,6 +4545,7 @@ static struct kvm_x86_ops svm_x86_ops = {
 	.invpcid_supported = svm_invpcid_supported,
 	.mpx_supported = svm_mpx_supported,
 	.xsaves_supported = svm_xsaves_supported,
+	.msr_exits_supported = svm_msr_exits_supported,
 
 	.set_supported_cpuid = svm_set_supported_cpuid,
 
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index acc38e27d221..27fec385d79d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8161,6 +8161,11 @@ static bool vmx_xsaves_supported(void)
 		SECONDARY_EXEC_XSAVES;
 }
 
+static bool vmx_msr_exits_supported(void)
+{
+	return false;
+}
+
 static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
 {
 	u32 exit_intr_info;
@@ -10413,6 +10418,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
 	.handle_external_intr = vmx_handle_external_intr,
 	.mpx_supported = vmx_mpx_supported,
 	.xsaves_supported = vmx_xsaves_supported,
+	.msr_exits_supported = vmx_msr_exits_supported,
 
 	.check_nested_events = vmx_check_nested_events,
 
-- 
2.5.0.276.gf5e568e