From: Vitaly Kuznetsov vkuznets@redhat.com
commit ea1529873ab18c204688cf31746df851c098cbea upstream.
If kvm_intel is loaded with nested=0 parameter an attempt to perform KVM_GET_SUPPORTED_HV_CPUID results in OOPS as nested_get_evmcs_version hook in kvm_x86_ops is NULL (we assign it in nested_vmx_hardware_setup() and this only happens in case nested is enabled).
Check that kvm_x86_ops->nested_get_evmcs_version is not NULL before calling it. With this, we can remove the stub from svm as it is no longer needed.
Cc: stable@vger.kernel.org Fixes: e2e871ab2f02 ("x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper") Signed-off-by: Vitaly Kuznetsov vkuznets@redhat.com Reviewed-by: Jim Mattson jmattson@google.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/hyperv.c | 5 ++++- arch/x86/kvm/svm.c | 8 +------- arch/x86/kvm/vmx/vmx.c | 1 + 3 files changed, 6 insertions(+), 8 deletions(-)
--- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1783,7 +1783,7 @@ int kvm_vm_ioctl_hv_eventfd(struct kvm * int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries) { - uint16_t evmcs_ver = kvm_x86_ops->nested_get_evmcs_version(vcpu); + uint16_t evmcs_ver = 0; struct kvm_cpuid_entry2 cpuid_entries[] = { { .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS }, { .function = HYPERV_CPUID_INTERFACE }, @@ -1795,6 +1795,9 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct k }; int i, nent = ARRAY_SIZE(cpuid_entries);
+ if (kvm_x86_ops->nested_get_evmcs_version) + evmcs_ver = kvm_x86_ops->nested_get_evmcs_version(vcpu); + /* Skip NESTED_FEATURES if eVMCS is not supported */ if (!evmcs_ver) --nent; --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7107,12 +7107,6 @@ failed: return ret; }
-static uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu) -{ - /* Not supported */ - return 0; -} - static int nested_enable_evmcs(struct kvm_vcpu *vcpu, uint16_t *vmcs_version) { @@ -7283,7 +7277,7 @@ static struct kvm_x86_ops svm_x86_ops __ .mem_enc_unreg_region = svm_unregister_enc_region,
.nested_enable_evmcs = nested_enable_evmcs, - .nested_get_evmcs_version = nested_get_evmcs_version, + .nested_get_evmcs_version = NULL,
.need_emulation_on_page_fault = svm_need_emulation_on_page_fault, }; --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7733,6 +7733,7 @@ static struct kvm_x86_ops vmx_x86_ops __ .set_nested_state = NULL, .get_vmcs12_pages = NULL, .nested_enable_evmcs = NULL, + .nested_get_evmcs_version = NULL, .need_emulation_on_page_fault = vmx_need_emulation_on_page_fault, };