Current versions of Intel's SDM incorrectly state that "bits 31:15 of the VM-Entry exception error-code field" must be zero. In reality, bits 31:16 must be zero, i.e. error codes are 16-bit values.
The bogus error code check manifests as an unexpected VM-Entry failure due to an invalid code field (error number 7) in L1, e.g. when injecting a #GP with error_code=0x9f00. Nadav previously reported the bug[*], both to KVM and Intel, and fixed the associated kvm-unit-test. [*] https://patchwork.kernel.org/patch/11124749/ Reported-by: Nadav Amit <[email protected]> Cc: [email protected] Signed-off-by: Sean Christopherson <[email protected]> --- arch/x86/kvm/vmx/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 41abc62c9a8a..e76eb4f07f6c 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2610,7 +2610,7 @@ static int nested_check_vm_entry_controls(struct kvm_vcpu *vcpu, /* VM-entry exception error code */ if (CC(has_error_code && - vmcs12->vm_entry_exception_error_code & GENMASK(31, 15))) + vmcs12->vm_entry_exception_error_code & GENMASK(31, 16))) return -EINVAL; /* VM-entry interruption-info field: reserved bits */ -- 2.22.0
