Commit 404d5d7b authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
Browse files

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: default avatarHaiwei Li <lihaiwei@tencent.com>
Cc: Haiwei Li <lihaiwei@tencent.com>
Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
Message-Id: <1588055009-12677-4-git-send-email-wanpengli@tencent.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5a9f5443

arch/x86/include/asm/kvm_host.h

+3 −1
Original line number Diff line number Diff line
@@ -182,8 +182,10 @@ enum { 


enum exit_fastpath_completion {

	EXIT_FASTPATH_NONE,

	EXIT_FASTPATH_SKIP_EMUL_INS,

	EXIT_FASTPATH_REENTER_GUEST,

	EXIT_FASTPATH_EXIT_HANDLED,

};

typedef enum exit_fastpath_completion fastpath_t;



struct x86_emulate_ctxt;

struct x86_exception;

arch/x86/kvm/svm/svm.c

+7 −8
Original line number Diff line number Diff line
@@ -2893,8 +2893,7 @@ static void svm_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2) 
	*info2 = control->exit_info_2;

}



static int handle_exit(struct kvm_vcpu *vcpu,

	enum exit_fastpath_completion exit_fastpath)

static int handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)

{

	struct vcpu_svm *svm = to_svm(vcpu);

	struct kvm_run *kvm_run = vcpu->run;
@@ -2952,10 +2951,10 @@ static int handle_exit(struct kvm_vcpu *vcpu, 
		       __func__, svm->vmcb->control.exit_int_info,

		       exit_code);



	if (exit_fastpath == EXIT_FASTPATH_SKIP_EMUL_INS) {

		kvm_skip_emulated_instruction(vcpu);

	if (exit_fastpath != EXIT_FASTPATH_NONE)

		return 1;

	} else if (exit_code >= ARRAY_SIZE(svm_exit_handlers)



	if (exit_code >= ARRAY_SIZE(svm_exit_handlers)

	    || !svm_exit_handlers[exit_code]) {

		vcpu_unimpl(vcpu, "svm: unexpected exit reason 0x%x\n", exit_code);

		dump_vmcb(vcpu);
@@ -3324,7 +3323,7 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu) 
	svm_complete_interrupts(svm);

}



static enum exit_fastpath_completion svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)

static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)

{

	if (!is_guest_mode(vcpu) &&

	    to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR &&
@@ -3336,9 +3335,9 @@ static enum exit_fastpath_completion svm_exit_handlers_fastpath(struct kvm_vcpu 


void __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);



static enum exit_fastpath_completion svm_vcpu_run(struct kvm_vcpu *vcpu)

static fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)

{

	enum exit_fastpath_completion exit_fastpath;

	fastpath_t exit_fastpath;

	struct vcpu_svm *svm = to_svm(vcpu);



	svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];

arch/x86/kvm/vmx/vmx.c

+18 −8
Original line number Diff line number Diff line
@@ -5926,8 +5926,7 @@ void dump_vmcs(void) 
 * The guest has exited.  See if we can fix it or if we need userspace

 * assistance.

 */

static int vmx_handle_exit(struct kvm_vcpu *vcpu,

	enum exit_fastpath_completion exit_fastpath)

static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	u32 exit_reason = vmx->exit_reason;
@@ -6034,10 +6033,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, 
		}

	}



	if (exit_fastpath == EXIT_FASTPATH_SKIP_EMUL_INS) {

		kvm_skip_emulated_instruction(vcpu);

	if (exit_fastpath != EXIT_FASTPATH_NONE)

		return 1;

	}



	if (exit_reason >= kvm_vmx_max_exit_handlers)

		goto unexpected_vmexit;
@@ -6628,7 +6625,7 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp) 
	}

}



static enum exit_fastpath_completion vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)

static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)

{

	switch (to_vmx(vcpu)->exit_reason) {

	case EXIT_REASON_MSR_WRITE:
@@ -6640,12 +6637,13 @@ static enum exit_fastpath_completion vmx_exit_handlers_fastpath(struct kvm_vcpu 


bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);



static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu)

static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)

{

	enum exit_fastpath_completion exit_fastpath;

	fastpath_t exit_fastpath;

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	unsigned long cr3, cr4;



reenter_guest:

	/* Record the guest's net vcpu time for enforced NMI injections. */

	if (unlikely(!enable_vnmi &&

		     vmx->loaded_vmcs->soft_vnmi_blocked))
@@ -6807,6 +6805,18 @@ static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu) 
		return EXIT_FASTPATH_NONE;



	exit_fastpath = vmx_exit_handlers_fastpath(vcpu);

	if (exit_fastpath == EXIT_FASTPATH_REENTER_GUEST) {

		if (!kvm_vcpu_exit_request(vcpu)) {

			/*

			 * FIXME: this goto should be a loop in vcpu_enter_guest,

			 * but it would incur the cost of a retpoline for now.

			 * Revisit once static calls are available.

			 */

			goto reenter_guest;

		}

		exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED;

	}



	return exit_fastpath;

}

arch/x86/kvm/x86.c

+10 −9
Original line number Diff line number Diff line
@@ -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;

arch/x86/kvm/x86.h

+1 −1
Original line number Diff line number Diff line
@@ -274,7 +274,7 @@ bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, 
bool kvm_vector_hashing_enabled(void);

int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,

			    int emulation_type, void *insn, int insn_len);

enum exit_fastpath_completion handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);

fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu);



extern u64 host_xcr0;

extern u64 supported_xcr0;