| Message ID | 20221026072330.2248336-1-eesposit@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] KVM: nVMX: Advertise ENCLS_EXITING to L1 iff SGX is fully supported | expand |
On Wed, Oct 26, 2022, Emanuele Giuseppe Esposito wrote: > Clear enable_sgx if ENCLS-exiting is not supported, i.e. if SGX cannot be > virtualized. This fixes a bug where KVM would advertise ENCLS-exiting to > L1 and propagate the control from vmcs12 to vmcs02 even if ENCLS-exiting > isn't supported in secondary execution controls, e.g. because SGX isn't > fully enabled, and thus induce an unexpected VM-Fail in L1. > > Not updating enable_sgx is responsible for a second bug: > vmx_set_cpu_caps() doesn't clear the SGX bits when hardware support is > unavailable. This is a much less problematic bug as it only pops up > if SGX is soft-disabled (the case being handled by cpu_has_sgx()) or if > SGX is supported for bare metal but not in the VMCS (will never happen > when running on bare metal, but can theoertically happen when running in > a VM). > > Last but not least, KVM should ideally have module params reflect KVM's > actual configuration. > > RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2127128 > > Fixes: 72add915fbd5 ("KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC") > Cc: stable@vger.kernel.org > > Suggested-by: Sean Christopherson <seanjc@google.com> > Suggested-by: Bandan Das <bsd@redhat.com> > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> > --- Reviewed-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9dba04b6b019..ea0c65d3c08a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8263,6 +8263,11 @@ static __init int hardware_setup(void) if (!cpu_has_virtual_nmis()) enable_vnmi = 0; + #ifdef CONFIG_X86_SGX_KVM + if (!cpu_has_vmx_encls_vmexit()) + enable_sgx = false; + #endif + /* * set_apic_access_page_addr() is used to reload apic access * page upon invalidation. No need to do anything if not
Clear enable_sgx if ENCLS-exiting is not supported, i.e. if SGX cannot be virtualized. This fixes a bug where KVM would advertise ENCLS-exiting to L1 and propagate the control from vmcs12 to vmcs02 even if ENCLS-exiting isn't supported in secondary execution controls, e.g. because SGX isn't fully enabled, and thus induce an unexpected VM-Fail in L1. Not updating enable_sgx is responsible for a second bug: vmx_set_cpu_caps() doesn't clear the SGX bits when hardware support is unavailable. This is a much less problematic bug as it only pops up if SGX is soft-disabled (the case being handled by cpu_has_sgx()) or if SGX is supported for bare metal but not in the VMCS (will never happen when running on bare metal, but can theoertically happen when running in a VM). Last but not least, KVM should ideally have module params reflect KVM's actual configuration. RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2127128 Fixes: 72add915fbd5 ("KVM: VMX: Enable SGX virtualization for SGX1, SGX2 and LC") Cc: stable@vger.kernel.org Suggested-by: Sean Christopherson <seanjc@google.com> Suggested-by: Bandan Das <bsd@redhat.com> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> --- arch/x86/kvm/vmx/vmx.c | 5 +++++ 1 file changed, 5 insertions(+)