x86/kvm/svm: Move guest enter/exit into .noinstr.text (135961e0) · Commits · 戴 / test

arch/x86/kvm/svm/svm.c

+55 −43

Original line number	Diff line number	Diff line
		@@ -3343,6 +3343,60 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)

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

		static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu,
		struct vcpu_svm *svm)
		{
		/*
		* VMENTER enables interrupts (host state), but the kernel state is
		* interrupts disabled when this is invoked. Also tell RCU about
		* it. This is the same logic as for exit_to_user_mode().
		*
		* This ensures that e.g. latency analysis on the host observes
		* guest mode as interrupt enabled.
		*
		* guest_enter_irqoff() informs context tracking about the
		* transition to guest mode and if enabled adjusts RCU state
		* accordingly.
		*/
		instrumentation_begin();
		trace_hardirqs_on_prepare();
		lockdep_hardirqs_on_prepare(CALLER_ADDR0);
		instrumentation_end();

		guest_enter_irqoff();
		lockdep_hardirqs_on(CALLER_ADDR0);

		__svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs);

		#ifdef CONFIG_X86_64
		wrmsrl(MSR_GS_BASE, svm->host.gs_base);
		#else
		loadsegment(fs, svm->host.fs);
		#ifndef CONFIG_X86_32_LAZY_GS
		loadsegment(gs, svm->host.gs);
		#endif
		#endif

		/*
		* VMEXIT disables interrupts (host state), but tracing and lockdep
		* have them in state 'on' as recorded before entering guest mode.
		* Same as enter_from_user_mode().
		*
		* guest_exit_irqoff() restores host context and reinstates RCU if
		* enabled and required.
		*
		* This needs to be done before the below as native_read_msr()
		* contains a tracepoint and x86_spec_ctrl_restore_host() calls
		* into world and some more.
		*/
		lockdep_hardirqs_off(CALLER_ADDR0);
		guest_exit_irqoff();

		instrumentation_begin();
		trace_hardirqs_off_finish();
		instrumentation_end();
		}

		static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
		{
		fastpath_t exit_fastpath;
		@@ -3398,49 +3452,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
		*/
		x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl);

		/*
		* VMENTER enables interrupts (host state), but the kernel state is
		* interrupts disabled when this is invoked. Also tell RCU about
		* it. This is the same logic as for exit_to_user_mode().
		*
		* This ensures that e.g. latency analysis on the host observes
		* guest mode as interrupt enabled.
		*
		* guest_enter_irqoff() informs context tracking about the
		* transition to guest mode and if enabled adjusts RCU state
		* accordingly.
		*/
		trace_hardirqs_on_prepare();
		lockdep_hardirqs_on_prepare(CALLER_ADDR0);
		guest_enter_irqoff();
		lockdep_hardirqs_on(CALLER_ADDR0);

		__svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs);

		#ifdef CONFIG_X86_64
		wrmsrl(MSR_GS_BASE, svm->host.gs_base);
		#else
		loadsegment(fs, svm->host.fs);
		#ifndef CONFIG_X86_32_LAZY_GS
		loadsegment(gs, svm->host.gs);
		#endif
		#endif

		/*
		* VMEXIT disables interrupts (host state), but tracing and lockdep
		* have them in state 'on' as recorded before entering guest mode.
		* Same as enter_from_user_mode().
		*
		* guest_exit_irqoff() restores host context and reinstates RCU if
		* enabled and required.
		*
		* This needs to be done before the below as native_read_msr()
		* contains a tracepoint and x86_spec_ctrl_restore_host() calls
		* into world and some more.
		*/
		lockdep_hardirqs_off(CALLER_ADDR0);
		guest_exit_irqoff();
		trace_hardirqs_off_finish();
		svm_vcpu_enter_exit(vcpu, svm);

		/*
		* We do not use IBRS in the kernel. If this vCPU has used the

arch/x86/kvm/svm/vmenter.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -27,7 +27,7 @@
		#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE
		#endif

		.text
		.section .noinstr.text, "ax"

		/**
		* __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode

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