Re: ** POTENTIAL FRAUD ALERT - RED HAT ** RE: [PATCH v2 8/8] KVM: x86: Add checks for reserved-to-zero Hyper-V hypercall fields

Vitaly Kuznetsov
2021-12-03T14:09:37Z

"Michael Kelley (LINUX)" <mikelley@microsoft.com> writes:

> From: Sean Christopherson <seanjc@google.com> Sent: Wednesday, December 1, 2021 6:13 PM
>>
>> On Mon, Nov 01, 2021, Vitaly Kuznetsov wrote:
>> > Sean Christopherson <seanjc@google.com> writes:
>> >
>> > > Add checks for the three fields in Hyper-V's hypercall params that must
>> > > be zero. Per the TLFS, HV_STATUS_INVALID_HYPERCALL_INPUT is returned if
>> > > "A reserved bit in the specified hypercall input value is non-zero."
>> > >
>> > > Note, the TLFS has an off-by-one bug for the last reserved field, which
>> > > it defines as being bits 64:60. The same section states "The input field
>> > > 64-bit value called a hypercall input value.", i.e. bit 64 doesn't
>> > > exist.
>> >
>> > This version are you looking at? I can't see this issue in 6.0b
>>
>> It's the web-based documentation, the 6.0b PDF indeed does not have the same bug.
>>
>> https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hypercall-interface#hypercall-inputs
>
> Did you (or Vitaly) file a bug report on this doc issue? If not, I can do so.
>

Done, https://github.com/MicrosoftDocs/Virtualization-Documentation/pull/1682

--
Vitaly