linux-kernel - [PATCH v2 24/66] KVM: x86: Drop explicit @func param from ->set_supported

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Date:   Mon,  2 Mar 2020 15:56:27 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Xiaoyao Li <xiaoyao.li@...el.com>
Subject: [PATCH v2 24/66] KVM: x86: Drop explicit @func param from ->set_supported_cpuid()

Drop the explicit @func param from ->set_supported_cpuid() and instead
pull the CPUID function from the relevant entry.  This sets the stage
for hardening guest CPUID updates in future patches, e.g. allows adding
run-time assertions that the CPUID feature being changed is actually
a bit in the referenced CPUID entry.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/include/asm/kvm_host.h | 2 +-
 arch/x86/kvm/cpuid.c            | 2 +-
 arch/x86/kvm/svm.c              | 4 ++--
 arch/x86/kvm/vmx/vmx.c          | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9a4ae6ef0d7a..b0bd6bd3838a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1154,7 +1154,7 @@ struct kvm_x86_ops {
 
 	void (*set_tdp_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
 
-	void (*set_supported_cpuid)(u32 func, struct kvm_cpuid_entry2 *entry);
+	void (*set_supported_cpuid)(struct kvm_cpuid_entry2 *entry);
 
 	bool (*has_wbinvd_exit)(void);
 
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c194e49622b9..ffcf647b8fb4 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -784,7 +784,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		break;
 	}
 
-	kvm_x86_ops->set_supported_cpuid(function, entry);
+	kvm_x86_ops->set_supported_cpuid(entry);
 
 	r = 0;
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 16c4b7eb6312..0d7bdbb94643 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6029,9 +6029,9 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
 
 #define F feature_bit
 
-static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
+static void svm_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
 {
-	switch (func) {
+	switch (entry->function) {
 	case 0x1:
 		if (avic)
 			entry->ecx &= ~F(X2APIC);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 17dc4dc2a7f9..44724e8d0b88 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7124,9 +7124,9 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 	}
 }
 
-static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
+static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
 {
-	if (func == 1 && nested)
+	if (entry->function == 1 && nested)
 		entry->ecx |= feature_bit(VMX);
 }
 
-- 
2.24.1