From d89d04ab6030c73b24bbe032fb474e0fb74dd891 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 2 Feb 2021 10:44:23 -0500 Subject: [PATCH] KVM: move EXIT_FASTPATH_REENTER_GUEST to common code Now that KVM is using static calls, calling vmx_vcpu_run and vmx_sync_pir_to_irr does not incur anymore the cost of a retpoline. Therefore there is no need anymore to handle EXIT_FASTPATH_REENTER_GUEST in vendor code. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.c | 19 +------------------ arch/x86/kvm/x86.c | 17 ++++++++++++++--- arch/x86/kvm/x86.h | 1 - 3 files changed, 15 insertions(+), 22 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 02949a6..0cd24ae 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6711,11 +6711,9 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) { - 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)) @@ -6865,22 +6863,7 @@ reenter_guest: if (is_guest_mode(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. - */ - if (vcpu->arch.apicv_active) - vmx_sync_pir_to_irr(vcpu); - goto reenter_guest; - } - exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED; - } - - return exit_fastpath; + return vmx_exit_handlers_fastpath(vcpu); } static void vmx_free_vcpu(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4758afe..39f01a0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1796,12 +1796,11 @@ int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_emulate_wrmsr); -bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu) +static inline bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu) { return vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) || xfer_to_guest_mode_work_pending(); } -EXPORT_SYMBOL_GPL(kvm_vcpu_exit_request); /* * The fast path for frequent and performance sensitive wrmsr emulation, @@ -9044,7 +9043,19 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD; } - exit_fastpath = static_call(kvm_x86_run)(vcpu); + for (;;) { + exit_fastpath = static_call(kvm_x86_run)(vcpu); + if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST)) + break; + + if (unlikely(kvm_vcpu_exit_request(vcpu))) { + exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED; + break; + } + + if (vcpu->arch.apicv_active) + static_call(kvm_x86_sync_pir_to_irr)(vcpu); + } /* * Do this here before restoring debug registers on the host. And diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 5f7c224..cc652a3 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -395,7 +395,6 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu); void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu); int kvm_spec_ctrl_test_value(u64 value); bool kvm_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4); -bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu); int kvm_handle_memory_failure(struct kvm_vcpu *vcpu, int r, struct x86_exception *e); int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva); -- 2.7.4