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(+)

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