linux-kernel - [PATCH v4 22/26] KVM: x86: Make x86 processor compat check callback empty

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Message-Id: <fc3c8c0a3bb5a5aa38a8c261e992ac636de4da3c.1662679124.git.isaku.yamahata@intel.com>
Date:   Thu,  8 Sep 2022 16:25:38 -0700
From:   isaku.yamahata@...el.com
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Marc Zyngier <maz@...nel.org>, Will Deacon <will@...nel.org>,
        Yuan Yao <yuan.yao@...ux.intel.com>
Cc:     isaku.yamahata@...el.com, isaku.yamahata@...il.com,
        Kai Huang <kai.huang@...el.com>, Chao Gao <chao.gao@...el.com>,
        Atish Patra <atishp@...shpatra.org>,
        Shaokun Zhang <zhangshaokun@...ilicon.com>,
        Qi Liu <liuqi115@...wei.com>,
        John Garry <john.garry@...wei.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Huang Ying <ying.huang@...el.com>,
        Huacai Chen <chenhuacai@...nel.org>
Subject: [PATCH v4 22/26] KVM: x86: Make x86 processor compat check callback empty

From: Isaku Yamahata <isaku.yamahata@...el.com>

Move processor compatibility check on all processors into
kvm_arch_hardware_setup() and make kvm_arch_check_processor_compat{,_all}()
empty.  This is a preparation step to eliminate them.

Suggested-by: Sean Christopherson <seanjc@...gle.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
---
 arch/x86/kvm/x86.c | 47 +++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0c9d965859c6..9dd90f0521c3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -129,6 +129,8 @@ static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu);
 static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);
 static void __get_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);
 
+static int kvm_check_processor_compatibility(void);
+
 struct kvm_x86_ops kvm_x86_ops __read_mostly;
 
 #define KVM_X86_OP(func)					     \
@@ -11911,21 +11913,8 @@ int kvm_arch_del_vm(int usage_count)
 	return 0;
 }
 
-static void check_processor_compat(void *rtn)
-{
-	*(int *)rtn = kvm_arch_check_processor_compat();
-}
-
 int kvm_arch_check_processor_compat_all(void)
 {
-	int cpu;
-	int r;
-
-	for_each_online_cpu(cpu) {
-		smp_call_function_single(cpu, check_processor_compat, &r, 1);
-		if (r < 0)
-			return r;
-	}
 	return 0;
 }
 
@@ -11933,7 +11922,7 @@ int kvm_arch_online_cpu(unsigned int cpu, int usage_count)
 {
 	int ret;
 
-	ret = kvm_arch_check_processor_compat();
+	ret = kvm_check_processor_compatibility();
 	if (ret)
 		return ret;
 
@@ -11997,7 +11986,7 @@ void kvm_arch_resume(int usage_count)
 	u64 max_tsc = 0;
 	bool stable, backwards_tsc = false;
 
-	if (kvm_arch_check_processor_compat())
+	if (kvm_check_processor_compatibility())
 		return; /* FIXME: disable KVM. */
 
 	if (!usage_count)
@@ -12103,6 +12092,24 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
 	kvm_pmu_ops_update(ops->pmu_ops);
 }
 
+static void check_processor_compat(void *rtn)
+{
+	*(int *)rtn = kvm_check_processor_compatibility();
+}
+
+static int kvm_check_processor_compatibility_all(void)
+{
+	int cpu;
+	int r;
+
+	for_each_online_cpu(cpu) {
+		smp_call_function_single(cpu, check_processor_compat, &r, 1);
+		if (r < 0)
+			return r;
+	}
+	return 0;
+}
+
 int kvm_arch_hardware_setup(void *opaque)
 {
 	struct kvm_x86_init_ops *ops = opaque;
@@ -12143,7 +12150,8 @@ int kvm_arch_hardware_setup(void *opaque)
 	}
 	kvm_caps.default_tsc_scaling_ratio = 1ULL << kvm_caps.tsc_scaling_ratio_frac_bits;
 	kvm_init_msr_list();
-	return 0;
+
+	return kvm_check_processor_compatibility_all();
 }
 
 void kvm_arch_hardware_unsetup(void)
@@ -12155,7 +12163,7 @@ void kvm_arch_hardware_unsetup(void)
 	static_call(kvm_x86_hardware_unsetup)();
 }
 
-int kvm_arch_check_processor_compat(void)
+static int kvm_check_processor_compatibility(void)
 {
 	int cpu = smp_processor_id();
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -12175,6 +12183,11 @@ int kvm_arch_check_processor_compat(void)
 	return static_call(kvm_x86_check_processor_compatibility)();
 }
 
+int kvm_arch_check_processor_compat(void)
+{
+	return 0;
+}
+
 bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
 {
 	return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
-- 
2.25.1