Re: [PATCH v4 1/5] x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit

Jon Doron
2020-03-10T17:14:18Z

On 10/03/2020, Vitaly Kuznetsov wrote:
>Jon Doron <arilou@gmail.com> writes:
>
>> Signed-off-by: Jon Doron <arilou@gmail.com>
>> ---
>> include/uapi/linux/kvm.h | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index 4b95f9a31a2f..7acfd6a2569a 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -189,6 +189,7 @@ struct kvm_hyperv_exit {
>> #define KVM_EXIT_HYPERV_SYNIC 1
>> #define KVM_EXIT_HYPERV_HCALL 2
>> __u32 type;
>> + __u32 pad;
>> union {
>> struct {
>> __u32 msr;
>
>Sorry if I missed something but I think the suggestion was to pad this
>'msr' too (in case we're aiming at making padding explicit for the whole
>structure). Or is there any reason to not do that?
>
>Also, I just noticed that we have a copy of this definition in
>Documentation/virt/kvm/api.rst - it will need to be updated (and sorry
>for not noticing it earlier).
>
>--
>Vitaly
>

Heh sure no problem will fix in v5, but going to wait for a verdict on
the location for the new CPUID leafs and MSRs for the synthetic
debugger.

-- Jon.