Re: [RFC v2 14/17] x86/apic: Add kexec support for Secure AVIC

Thomas Gleixner
2025-04-01T18:31:11Z

On Tue, Apr 01 2025 at 16:05, Neeraj Upadhyay wrote:

> On 3/21/2025 9:18 PM, Thomas Gleixner wrote:
>> On Wed, Feb 26 2025 at 14:35, Neeraj Upadhyay wrote:
>>>
>>> +/*
>>> + * Unregister GPA of the Secure AVIC backing page.
>>> + *
>>> + * @apic_id: APIC ID of the vCPU. Use -1ULL for the current vCPU
>>
>> Yes, -1ULL is really a sensible value - NOT. Ever thought about
>> signed/unsigned?
>
>
> In table "Table 7: List of Supported Non-Automatic Events" of GHCB spec [1],
> 0xffff_ffff_ffff_ffff is used for Secure AVIC GHCB event
>
> "RAX will have the APIC ID of the target vCPU or 0xffff_ffff_ffff_ffff
> for the vCPU doing the call"
>
> I am using -1ULL for that here.

Which is a horrible construct, while ~0ULL is not.