git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From ea1529873ab18c204688cf31746df851c098cbea Mon Sep 17 00:00:00 2001
   2 From: Vitaly Kuznetsov <vkuznets@redhat.com>
   3 Date: Tue, 27 Aug 2019 18:04:02 +0200
   4 Subject: KVM: x86: hyper-v: don't crash on KVM_GET_SUPPORTED_HV_CPUID when kvm_intel.nested is disabled
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 From: Vitaly Kuznetsov <vkuznets@redhat.com>
  10
  11 commit ea1529873ab18c204688cf31746df851c098cbea upstream.
  12
  13 If kvm_intel is loaded with nested=0 parameter an attempt to perform
  14 KVM_GET_SUPPORTED_HV_CPUID results in OOPS as nested_get_evmcs_version hook
  15 in kvm_x86_ops is NULL (we assign it in nested_vmx_hardware_setup() and
  16 this only happens in case nested is enabled).
  17
  18 Check that kvm_x86_ops->nested_get_evmcs_version is not NULL before
  19 calling it. With this, we can remove the stub from svm as it is no
  20 longer needed.
  21
  22 Cc: <stable@vger.kernel.org>
  23 Fixes: e2e871ab2f02 ("x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper")
  24 Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
  25 Reviewed-by: Jim Mattson <jmattson@google.com>
  26 Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28
  29 ---
  30  arch/x86/kvm/hyperv.c  |    5 ++++-
  31  arch/x86/kvm/svm.c     |    8 +-------
  32  arch/x86/kvm/vmx/vmx.c |    1 +
  33  3 files changed, 6 insertions(+), 8 deletions(-)
  34
  35 --- a/arch/x86/kvm/hyperv.c
  36 +++ b/arch/x86/kvm/hyperv.c
  37 @@ -1783,7 +1783,7 @@ int kvm_vm_ioctl_hv_eventfd(struct kvm *
  38  int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
  39                                 struct kvm_cpuid_entry2 __user *entries)
  40  {
  41 -       uint16_t evmcs_ver = kvm_x86_ops->nested_get_evmcs_version(vcpu);
  42 +       uint16_t evmcs_ver = 0;
  43         struct kvm_cpuid_entry2 cpuid_entries[] = {
  44                 { .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
  45                 { .function = HYPERV_CPUID_INTERFACE },
  46 @@ -1795,6 +1795,9 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct k
  47         };
  48         int i, nent = ARRAY_SIZE(cpuid_entries);
  49
  50 +       if (kvm_x86_ops->nested_get_evmcs_version)
  51 +               evmcs_ver = kvm_x86_ops->nested_get_evmcs_version(vcpu);
  52 +
  53         /* Skip NESTED_FEATURES if eVMCS is not supported */
  54         if (!evmcs_ver)
  55                 --nent;
  56 --- a/arch/x86/kvm/svm.c
  57 +++ b/arch/x86/kvm/svm.c
  58 @@ -7107,12 +7107,6 @@ failed:
  59         return ret;
  60  }
  61
  62 -static uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
  63 -{
  64 -       /* Not supported */
  65 -       return 0;
  66 -}
  67 -
  68  static int nested_enable_evmcs(struct kvm_vcpu *vcpu,
  69                                    uint16_t *vmcs_version)
  70  {
  71 @@ -7283,7 +7277,7 @@ static struct kvm_x86_ops svm_x86_ops __
  72         .mem_enc_unreg_region = svm_unregister_enc_region,
  73
  74         .nested_enable_evmcs = nested_enable_evmcs,
  75 -       .nested_get_evmcs_version = nested_get_evmcs_version,
  76 +       .nested_get_evmcs_version = NULL,
  77
  78         .need_emulation_on_page_fault = svm_need_emulation_on_page_fault,
  79  };
  80 --- a/arch/x86/kvm/vmx/vmx.c
  81 +++ b/arch/x86/kvm/vmx/vmx.c
  82 @@ -7733,6 +7733,7 @@ static struct kvm_x86_ops vmx_x86_ops __
  83         .set_nested_state = NULL,
  84         .get_vmcs12_pages = NULL,
  85         .nested_enable_evmcs = NULL,
  86 +       .nested_get_evmcs_version = NULL,
  87         .need_emulation_on_page_fault = vmx_need_emulation_on_page_fault,
  88  };
  89