KVM: X86: Introduce more exit_fastpath_completion enum values

Adds a fastpath_t typedef since enum lines are a bit long, and replace
EXIT_FASTPATH_SKIP_EMUL_INS with two new exit_fastpath_completion enum values.

- EXIT_FASTPATH_EXIT_HANDLED  kvm will still go through it's full run loop,
                              but it would skip invoking the exit handler.

- EXIT_FASTPATH_REENTER_GUEST complete fastpath, guest can be re-entered
                              without invoking the exit handler or going
                              back to vcpu_run

Tested-by: Haiwei Li <lihaiwei@tencent.com>
Cc: Haiwei Li <lihaiwei@tencent.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1588055009-12677-4-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 29a41aa98929..71749fcb229e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1608,27 +1608,28 @@ static int handle_fastpath_set_x2apic_icr_irqoff(struct kvm_vcpu *vcpu, u64 data
 	return 1;
 }
 
-enum exit_fastpath_completion handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
+fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
 {
 	u32 msr = kvm_rcx_read(vcpu);
 	u64 data;
-	int ret = 0;
+	fastpath_t ret = EXIT_FASTPATH_NONE;
 
 	switch (msr) {
 	case APIC_BASE_MSR + (APIC_ICR >> 4):
 		data = kvm_read_edx_eax(vcpu);
-		ret = handle_fastpath_set_x2apic_icr_irqoff(vcpu, data);
+		if (!handle_fastpath_set_x2apic_icr_irqoff(vcpu, data)) {
+			kvm_skip_emulated_instruction(vcpu);
+			ret = EXIT_FASTPATH_EXIT_HANDLED;
+               }
 		break;
 	default:
-		return EXIT_FASTPATH_NONE;
+		break;
 	}
 
-	if (!ret) {
+	if (ret != EXIT_FASTPATH_NONE)
 		trace_kvm_msr_write(msr, data);
-		return EXIT_FASTPATH_SKIP_EMUL_INS;
-	}
 
-	return EXIT_FASTPATH_NONE;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(handle_fastpath_set_msr_irqoff);
 
@@ -8205,7 +8206,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	bool req_int_win =
 		dm_request_for_irq_injection(vcpu) &&
 		kvm_cpu_accept_dm_intr(vcpu);
-	enum exit_fastpath_completion exit_fastpath;
+	fastpath_t exit_fastpath;
 
 	bool req_immediate_exit = false;