This is a note to let you know that I've just added the patch titled KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-register-processor-trace-interrupt-hook-iff-pt-enabled-in-guest.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f4b027c5c8199abd4fb6f00d67d380548dbfdfa8 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc@xxxxxxxxxx> Date: Thu, 11 Nov 2021 02:07:24 +0000 Subject: KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest From: Sean Christopherson <seanjc@xxxxxxxxxx> commit f4b027c5c8199abd4fb6f00d67d380548dbfdfa8 upstream. Override the Processor Trace (PT) interrupt handler for guest mode if and only if PT is configured for host+guest mode, i.e. is being used independently by both host and guest. If PT is configured for system mode, the host fully controls PT and must handle all events. Fixes: 8479e04e7d6b ("KVM: x86: Inject PMI for KVM guest") Reported-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Reported-by: Artem Kashkanov <artem.kashkanov@xxxxxxxxx> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20211111020738.2512932-4-seanjc@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx/vmx.c | 1 + arch/x86/kvm/x86.c | 5 ++++- 3 files changed, 6 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1306,6 +1306,7 @@ struct kvm_x86_init_ops { int (*disabled_by_bios)(void); int (*check_processor_compatibility)(void); int (*hardware_setup)(void); + bool (*intel_pt_intr_in_guest)(void); struct kvm_x86_ops *runtime_ops; }; --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7915,6 +7915,7 @@ static struct kvm_x86_init_ops vmx_init_ .disabled_by_bios = vmx_disabled_by_bios, .check_processor_compatibility = vmx_check_processor_compat, .hardware_setup = hardware_setup, + .intel_pt_intr_in_guest = vmx_pt_mode_is_host_guest, .runtime_ops = &vmx_x86_ops, }; --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7882,7 +7882,7 @@ static struct perf_guest_info_callbacks .is_in_guest = kvm_is_in_guest, .is_user_mode = kvm_is_user_mode, .get_guest_ip = kvm_get_guest_ip, - .handle_intel_pt_intr = kvm_handle_intel_pt_intr, + .handle_intel_pt_intr = NULL, }; #ifdef CONFIG_X86_64 @@ -8005,6 +8005,8 @@ int kvm_arch_init(void *opaque) PT_PRESENT_MASK, 0, sme_me_mask); kvm_timer_init(); + if (ops->intel_pt_intr_in_guest && ops->intel_pt_intr_in_guest()) + kvm_guest_cbs.handle_intel_pt_intr = kvm_handle_intel_pt_intr; perf_register_guest_info_callbacks(&kvm_guest_cbs); if (boot_cpu_has(X86_FEATURE_XSAVE)) { @@ -8042,6 +8044,7 @@ void kvm_arch_exit(void) #endif kvm_lapic_exit(); perf_unregister_guest_info_callbacks(&kvm_guest_cbs); + kvm_guest_cbs.handle_intel_pt_intr = NULL; if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block, Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are queue-5.10/kvm-x86-register-processor-trace-interrupt-hook-iff-pt-enabled-in-guest.patch queue-5.10/perf-protect-perf_guest_cbs-with-rcu.patch