Move the functions which are inside the RCU off region into the non-instrumentable text section.
Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Acked-by: Paolo Bonzini <[email protected]> Link: https://lkml.kernel.org/r/[email protected] diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 46d69567faab..35bd95dd64dd 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3327,6 +3327,60 @@ 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_prepare(); + instrumentation_end(); +} + static fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) { fastpath_t exit_fastpath; @@ -3389,49 +3443,7 @@ static 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_prepare(); + svm_vcpu_enter_exit(vcpu, svm); /* * We do not use IBRS in the kernel. If this vCPU has used the diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index bf944334003a..1ec1ac40e328 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -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
