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| author | Sean Christopherson <seanjc@google.com> | 2022-08-30 15:37:09 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-09-26 12:02:39 -0400 |
| commit | 3be29eb7b5251a772e2033761a9b67981fdfb0f7 (patch) | |
| tree | e64cf41fda9f452339347a2851d1e55b7fd95ddd /arch/x86/kvm/hyperv.h | |
| parent | 1cac8d9f6bd25df3713103e44e2d9ca0c2e03c33 (diff) | |
| download | linux-3be29eb7b5251a772e2033761a9b67981fdfb0f7.tar.gz linux-3be29eb7b5251a772e2033761a9b67981fdfb0f7.tar.bz2 linux-3be29eb7b5251a772e2033761a9b67981fdfb0f7.zip | |
KVM: x86: Report error when setting CPUID if Hyper-V allocation fails
Return -ENOMEM back to userspace if allocating the Hyper-V vCPU struct
fails when enabling Hyper-V in guest CPUID. Silently ignoring failure
means that KVM will not have an up-to-date CPUID cache if allocating the
struct succeeds later on, e.g. when activating SynIC.
Rejecting the CPUID operation also guarantess that vcpu->arch.hyperv is
non-NULL if hyperv_enabled is true, which will allow for additional
cleanup, e.g. in the eVMCS code.
Note, the initialization needs to be done before CPUID is set, and more
subtly before kvm_check_cpuid(), which potentially enables dynamic
XFEATURES. Sadly, there's no easy way to avoid exposing Hyper-V details
to CPUID or vice versa. Expose kvm_hv_vcpu_init() and the Hyper-V CPUID
signature to CPUID instead of exposing cpuid_entry2_find() outside of
CPUID code. It's hard to envision kvm_hv_vcpu_init() being misused,
whereas cpuid_entry2_find() absolutely shouldn't be used outside of core
CPUID code.
Fixes: 10d7bf1e46dc ("KVM: x86: hyper-v: Cache guest CPUID leaves determining features availability")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830133737.1539624-6-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/hyperv.h')
| -rw-r--r-- | arch/x86/kvm/hyperv.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h index da2737f2a956..1030b1b50552 100644 --- a/arch/x86/kvm/hyperv.h +++ b/arch/x86/kvm/hyperv.h @@ -23,6 +23,9 @@ #include <linux/kvm_host.h> +/* "Hv#1" signature */ +#define HYPERV_CPUID_SIGNATURE_EAX 0x31237648 + /* * The #defines related to the synthetic debugger are required by KDNet, but * they are not documented in the Hyper-V TLFS because the synthetic debugger @@ -141,7 +144,8 @@ void kvm_hv_request_tsc_page_update(struct kvm *kvm); void kvm_hv_init_vm(struct kvm *kvm); void kvm_hv_destroy_vm(struct kvm *kvm); -void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu); +int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu); +void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled); int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce); int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args); int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, |