From ea1529873ab18c204688cf31746df851c098cbea Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 27 Aug 2019 18:04:02 +0200 Subject: [PATCH] KVM: x86: hyper-v: don't crash on KVM_GET_SUPPORTED_HV_CPUID when kvm_intel.nested is disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Fixes: e2e871ab2f02 ("x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper") Signed-off-by: Vitaly Kuznetsov Reviewed-by: Jim Mattson Signed-off-by: Radim Krčmář --- 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(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index c10a8b10b203..fff790a3f4ee 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1781,7 +1781,7 @@ int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args) 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 }, @@ -1793,6 +1793,9 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, }; 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; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index e3d3b2128f2b..e0368076a1ef 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7128,12 +7128,6 @@ static int svm_unregister_enc_region(struct kvm *kvm, 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) { @@ -7332,7 +7326,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .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, }; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 42ed3faa6af8..c030c96fc81a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7797,6 +7797,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .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, }; -- GitLab