KVM: x86: Directly return __vmalloc() result in ->vm_alloc()

Directly return the __vmalloc() result in {svm,vmx}_vm_alloc() to pave
the way for handling VM alloc/free in common x86 code, and to obviate
the need to check the result of __vmalloc() in vendor specific code.
Add a build-time assertion to ensure each structs' "kvm" field stays at
offset 0, which allows interpreting a "struct kvm_{svm,vmx}" as a
"struct kvm".

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-01-26 16:41:12 -08:00 committed by Paolo Bonzini
parent d18b2f43b9
commit 1a625056cc
2 changed files with 8 additions and 16 deletions

View File

@ -1946,19 +1946,15 @@ static void __unregister_enc_region_locked(struct kvm *kvm,
static struct kvm *svm_vm_alloc(void)
{
struct kvm_svm *kvm_svm = __vmalloc(sizeof(struct kvm_svm),
GFP_KERNEL_ACCOUNT | __GFP_ZERO,
PAGE_KERNEL);
BUILD_BUG_ON(offsetof(struct kvm_svm, kvm) != 0);
if (!kvm_svm)
return NULL;
return &kvm_svm->kvm;
return __vmalloc(sizeof(struct kvm_svm),
GFP_KERNEL_ACCOUNT | __GFP_ZERO, PAGE_KERNEL);
}
static void svm_vm_free(struct kvm *kvm)
{
vfree(to_kvm_svm(kvm));
vfree(kvm);
}
static void sev_vm_destroy(struct kvm *kvm)

View File

@ -6681,20 +6681,16 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
static struct kvm *vmx_vm_alloc(void)
{
struct kvm_vmx *kvm_vmx = __vmalloc(sizeof(struct kvm_vmx),
GFP_KERNEL_ACCOUNT | __GFP_ZERO,
PAGE_KERNEL);
BUILD_BUG_ON(offsetof(struct kvm_vmx, kvm) != 0);
if (!kvm_vmx)
return NULL;
return &kvm_vmx->kvm;
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(to_kvm_vmx(kvm));
vfree(kvm);
}
static void vmx_free_vcpu(struct kvm_vcpu *vcpu)