On 22/11/19 14:01, Brijesh Singh wrote:
>
> On 11/21/19 2:33 PM, Peter Gonda wrote:
>> Only pass through guest relevant CPUID information: Cbit location and
>> SEV bit. The kernel does not support nested SEV guests so the other data
>> in this CPUID leaf is unneeded by the guest.
>>
>> Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
>> Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
>> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
>> ---
>> arch/x86/kvm/cpuid.c | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>> index 946fa9cb9dd6..6439fb1dbe76 100644
>> --- a/arch/x86/kvm/cpuid.c
>> +++ b/arch/x86/kvm/cpuid.c
>> @@ -780,8 +780,14 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
>> break;
>> /* Support memory encryption cpuid if host supports it */
>> case 0x8000001F:
>> - if (!boot_cpu_has(X86_FEATURE_SEV))
>> + if (boot_cpu_has(X86_FEATURE_SEV)) {
>> + /* Expose only SEV bit and CBit location */
>> + entry->eax &= F(SEV);
>
>
> I know SEV-ES patches are not accepted yet, but can I ask to pass the
> SEV-ES bit in eax?
I think it shouldn't be passed, since KVM does not support SEV-ES.
Paolo
>
>> + entry->ebx &= GENMASK(5, 0);
>> + entry->edx = entry->ecx = 0;
>> + } else {
>> entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
>> + }
>> break;
>> /*Add support for Centaur's CPUID instruction*/
>> case 0xC0000000:
>
