linux-kernel - [PATCH 3/3] KVM: x86: Consolidate VM allocation and free for VMX and SVM

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Date:   Sun, 26 Jan 2020 16:41:13 -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
Subject: [PATCH 3/3] KVM: x86: Consolidate VM allocation and free for VMX and SVM

Move the VM allocation and free code to common x86 as the logic is
more or less identical across SVM and VMX.

Note, although hyperv.hv_pa_pg is part of the common kvm->arch, it's
(currently) only allocated by VMX VMs.  But, since kfree() plays nice
when passed a NULL pointer, the superfluous call for SVM is harmless
and avoids future churn if SVM gains support for HyperV's direct TLB
flush.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/include/asm/kvm_host.h | 12 ++++--------
 arch/x86/kvm/svm.c              | 13 +++----------
 arch/x86/kvm/vmx/vmx.c          | 14 +++-----------
 arch/x86/kvm/x86.c              |  7 +++++++
 4 files changed, 17 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 77d206a93658..06f48d3efa0a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1053,8 +1053,7 @@ struct kvm_x86_ops {
 	bool (*has_emulated_msr)(int index);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
-	struct kvm *(*vm_alloc)(void);
-	void (*vm_free)(struct kvm *);
+	unsigned int (*vm_size)(void);
 	int (*vm_init)(struct kvm *kvm);
 	void (*vm_destroy)(struct kvm *kvm);
 
@@ -1271,13 +1270,10 @@ extern struct kmem_cache *x86_fpu_cache;
 #define __KVM_HAVE_ARCH_VM_ALLOC
 static inline struct kvm *kvm_arch_alloc_vm(void)
 {
-	return kvm_x86_ops->vm_alloc();
-}
-
-static inline void kvm_arch_free_vm(struct kvm *kvm)
-{
-	return kvm_x86_ops->vm_free(kvm);
+	return __vmalloc(kvm_x86_ops->vm_size(),
+			 GFP_KERNEL_ACCOUNT | __GFP_ZERO, PAGE_KERNEL);
 }
+void kvm_arch_free_vm(struct kvm *kvm);
 
 #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
 static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4fff99722487..e72e209e7254 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1946,17 +1946,11 @@ static void __unregister_enc_region_locked(struct kvm *kvm,
 	kfree(region);
 }
 
-static struct kvm *svm_vm_alloc(void)
+static unsigned int svm_vm_size(void)
 {
 	BUILD_BUG_ON(offsetof(struct kvm_svm, kvm) != 0);
 
-	return __vmalloc(sizeof(struct kvm_svm),
-			 GFP_KERNEL_ACCOUNT | __GFP_ZERO, PAGE_KERNEL);
-}
-
-static void svm_vm_free(struct kvm *kvm)
-{
-	vfree(kvm);
+	return sizeof(struct kvm_svm);
 }
 
 static void sev_vm_destroy(struct kvm *kvm)
@@ -7385,8 +7379,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.vcpu_free = svm_free_vcpu,
 	.vcpu_reset = svm_vcpu_reset,
 
-	.vm_alloc = svm_vm_alloc,
-	.vm_free = svm_vm_free,
+	.vm_size = svm_vm_size,
 	.vm_init = svm_vm_init,
 	.vm_destroy = svm_vm_destroy,
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 17e449330c8a..17ae291122e5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6657,18 +6657,11 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	vmx_complete_interrupts(vmx);
 }
 
-static struct kvm *vmx_vm_alloc(void)
+static unsigned int vmx_vm_size(void)
 {
 	BUILD_BUG_ON(offsetof(struct kvm_vmx, kvm) != 0);
 
-	return __vmalloc(sizeof(struct kvm_vmx),
-			 GFP_KERNEL_ACCOUNT | __GFP_ZERO, PAGE_KERNEL);
-}
-
-static void vmx_vm_free(struct kvm *kvm)
-{
-	kfree(kvm->arch.hyperv.hv_pa_pg);
-	vfree(kvm);
+	return sizeof(struct kvm_vmx);
 }
 
 static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
@@ -7756,9 +7749,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_accelerated_tpr = report_flexpriority,
 	.has_emulated_msr = vmx_has_emulated_msr,
 
+	.vm_size = vmx_vm_size,
 	.vm_init = vmx_vm_init,
-	.vm_alloc = vmx_vm_alloc,
-	.vm_free = vmx_vm_free,
 
 	.vcpu_create = vmx_create_vcpu,
 	.vcpu_free = vmx_free_vcpu,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7e3f1d937224..f57a0bcd0e45 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9653,6 +9653,13 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
 	kvm_x86_ops->sched_in(vcpu, cpu);
 }
 
+void kvm_arch_free_vm(struct kvm *kvm)
+{
+	kfree(kvm->arch.hyperv.hv_pa_pg);
+	vfree(kvm);
+}
+
+
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	if (type)
-- 
2.24.1