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From: Zhao Liu <zhao1.liu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
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	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	kvm@vger.kernel.org,
	linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	x86@kernel.org
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
	Len Brown <len.brown@intel.com>,
	Zhang Rui <rui.zhang@intel.com>,
	Zhenyu Wang <zhenyu.z.wang@intel.com>,
	Zhuocheng Ding <zhuocheng.ding@intel.com>,
	Dapeng Mi <dapeng1.mi@intel.com>,
	Yanting Jiang <yanting.jiang@intel.com>,
	Yongwei Ma <yongwei.ma@intel.com>,
	Vineeth Pillai <vineeth@bitbyteword.org>,
	Suleiman Souhlal <suleiman@google.com>,
	Masami Hiramatsu <mhiramat@google.com>,
	David Dai <davidai@google.com>,
	Saravana Kannan <saravanak@google.com>,
	Zhao Liu <zhao1.liu@intel.com>
Subject: [RFC 04/26] KVM: Add kvm_arch_sched_out() hook
Date: Sat,  3 Feb 2024 17:11:52 +0800
Message-Id: <20240203091214.411862-5-zhao1.liu@linux.intel.com>
In-Reply-To: <20240203091214.411862-1-zhao1.liu@linux.intel.com>
References: <20240203091214.411862-1-zhao1.liu@linux.intel.com>
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From: Zhao Liu <zhao1.liu@intel.com>

x86 needs to reset classification history when vCPU is scheduled out.

Add the kvm_arch_sched_out() hook to allow x86 implements its own
history reset logic at sched_out.

Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 arch/arm64/include/asm/kvm_host.h   | 1 +
 arch/mips/include/asm/kvm_host.h    | 1 +
 arch/powerpc/include/asm/kvm_host.h | 1 +
 arch/riscv/include/asm/kvm_host.h   | 1 +
 arch/s390/include/asm/kvm_host.h    | 1 +
 arch/x86/include/asm/kvm_host.h     | 2 ++
 include/linux/kvm_host.h            | 1 +
 virt/kvm/kvm_main.c                 | 1 +
 8 files changed, 9 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 21c57b812569..a7898fceb761 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1127,6 +1127,7 @@ static inline bool kvm_system_needs_idmapped_vectors(void)
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 
 void kvm_arm_init_debug(void);
 void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu);
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 179f320cc231..2bcd462db11a 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -891,6 +891,7 @@ static inline void kvm_arch_free_memslot(struct kvm *kvm,
 					 struct kvm_memory_slot *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 8abac532146e..96bcf62439b2 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -898,6 +898,7 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 484d04a92fa6..a395a366f034 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -273,6 +273,7 @@ struct kvm_vcpu_arch {
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 
 #define KVM_RISCV_GSTAGE_TLB_MIN_ORDER		12
 
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 52664105a473..6e03188d11b0 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1045,6 +1045,7 @@ extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc);
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
 					 struct kvm_memory_slot *slot) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b5b2d0fde579..2be78549bec8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2280,6 +2280,8 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
 
 int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
 
+static inline void kvm_arch_sched_out(struct kvm_vcpu *vcpu) {}
+
 #define KVM_CLOCK_VALID_FLAGS						\
 	(KVM_CLOCK_TSC_STABLE | KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC)
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7e7fd25b09b3..3aabd3813de0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1478,6 +1478,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu);
 
 void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
+void kvm_arch_sched_out(struct kvm_vcpu *vcpu);
 
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 10bfc88a69f7..671f88dff006 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -6317,6 +6317,7 @@ static void kvm_sched_out(struct preempt_notifier *pn,
 		WRITE_ONCE(vcpu->ready, true);
 	}
 	kvm_arch_vcpu_put(vcpu);
+	kvm_arch_sched_out(vcpu);
 	__this_cpu_write(kvm_running_vcpu, NULL);
 }
 
-- 
2.34.1