Messages in this thread Patch in this message | | | Date | Tue, 05 May 2020 15:41:27 +0200 | From | Thomas Gleixner <> | Subject | [patch V4 part 2 15/18] x86/kvm/svm: Handle hardirqs proper on guest enter/exit |
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Add hardirq tracing to guest enter/exit functions in the same way as it is done in the user mode enter/exit code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/svm/svm.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-)
--- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3331,12 +3331,23 @@ static void svm_vcpu_run(struct kvm_vcpu x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl); /* - * Tell context tracking that this CPU is about to enter guest - * mode. 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. + * 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); @@ -3348,14 +3359,23 @@ static void svm_vcpu_run(struct kvm_vcpu loadsegment(gs, svm->host.gs); #endif #endif + /* - * Tell context tracking that this CPU is back. + * 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(); /* * We do not use IBRS in the kernel. If this vCPU has used the
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