diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2020-03-18 23:48:04 +0100 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-05 11:27:50 +0200 |
commit | 394dcdbf4d9d628f8b7da64b2b0e049954e784db (patch) | |
tree | 08a03690c40fbeead04a60841f8830f3f4ffbd4d | |
parent | 61210b6895950326f15088fd085e4b1ea62d82e2 (diff) |
x86/kvm/svm: Move guest enter/exit into .noinstr.textentry-v4-part2
Move the functions which are inside the RCU off region into the
non-instrumentable text section.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
-rw-r--r-- | arch/x86/kvm/svm/svm.c | 102 | ||||
-rw-r--r-- | arch/x86/kvm/svm/vmenter.S | 2 |
2 files changed, 57 insertions, 47 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 29a13bf2442f..e68de114b832 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3278,6 +3278,61 @@ static void svm_cancel_injection(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(). + * + * 1) Trace interrupts on state + * 2) Prepare lockdep with RCU on + * 3) Invoke context tracking if enabled to adjust RCU state + * 4) Tell lockdep that interrupts are enabled + * + * This has to be after x86_spec_ctrl_set_guest() because that can + * take locks (lockdep needs RCU) and calls into world and some + * more. + */ + instr_begin(); + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(CALLER_ADDR0); + instr_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 + native_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, see the CLI in the ASM + * above), but tracing and lockdep have them in state 'on'. Same as + * enter_from_user_mode(). + * + * 1) Tell lockdep that interrupts are disabled + * 2) Invoke context tracking if enabled to reactivate RCU + * 3) Trace interrupts off state + * + * 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(); + instr_begin(); + trace_hardirqs_off_prepare(); + instr_end(); +} + static void svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -3330,52 +3385,7 @@ static void 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(). - * - * 1) Trace interrupts on state - * 2) Prepare lockdep with RCU on - * 3) Invoke context tracking if enabled to adjust RCU state - * 4) Tell lockdep that interrupts are enabled - * - * This has to be after x86_spec_ctrl_set_guest() because that can - * take locks (lockdep needs RCU) and calls into world and some - * more. - */ - 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, see the CLI in the ASM - * above), but tracing and lockdep have them in state 'on'. Same as - * enter_from_user_mode(). - * - * 1) Tell lockdep that interrupts are disabled - * 2) Invoke context tracking if enabled to reactivate RCU - * 3) Trace interrupts off state - * - * 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 |