KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest

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@linux.intel.com>
Reported-by: Artem Kashkanov <artem.kashkanov@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211111020738.2512932-4-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 75e21715ecb462ff73efed6c98ec5c7cb215fd78..77ab14bcd47779f610a38f1685e8c4830dd5ba1a 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1509,6 +1509,7 @@ 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;
 };

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7d280e6f5488ab75c558b1a5edd3877a21fc198e..2ab0e997e39fa80953bf2446ca82696752ea5464 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7899,6 +7899,7 @@ static struct kvm_x86_init_ops vmx_init_ops __initdata = {
        .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,
 };

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d59e521f602386f155f96a8c798880b8e824a8bc..695dca37f46b45f7bb078f0046f26b3bf4c48eb5 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8430,7 +8430,7 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = {
        .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
@@ -11183,6 +11183,8 @@ int kvm_arch_hardware_setup(void *opaque)
        memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));
        kvm_ops_static_call_update();
 
+       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 (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
@@ -11213,6 +11215,7 @@ int kvm_arch_hardware_setup(void *opaque)
 void kvm_arch_hardware_unsetup(void)
 {
        perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
+       kvm_guest_cbs.handle_intel_pt_intr = NULL;
 
        static_call(kvm_x86_hardware_unsetup)();
 }