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FAILED: patch "[PATCH] KVM: x86: Register Processor Trace interrupt hook iff PT" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message Jan 18, 2022

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The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f4b027c5c8199abd4fb6f00d67d380548dbfdfa8 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <[email protected]>
Date: Thu, 11 Nov 2021 02:07:24 +0000
Subject: [PATCH] KVM: x86: Register Processor Trace interrupt hook iff PT
enabled in guest

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 <[email protected]>
Reported-by Artem Kashkanov <[email protected]>
Signed-off-by Sean Christopherson <[email protected]>
Signed-off-by Peter Zijlstra (Intel) <[email protected]>
Acked-by Paolo Bonzini <[email protected]>
Cc [email protected]
Link https://lore.kernel.org/r/[email protected] open here
arch/x86/include/asm/kvm_host.h +1 -0
index e5d8700319cc..41e858df5795 100644
@@ -1516,6 +1516,7 @@ 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;
 };
arch/x86/kvm/vmx/vmx.c +1 -0
index ba66c171d951..7d90c8d443ac 100644
@@ -7865,6 +7865,7 @@ 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,
 };
arch/x86/kvm/x86.c +4 -1
index 50f0cd16f2d4..760c4e3a8326 100644
@@ -8510,7 +8510,7 @@ 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

@@ -11222,6 +11222,8 @@ 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))

@@ -11252,6 +11254,7 @@ 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)();
 }