Re: [RFC PATCH v8 19/35] x86/apic: Initialize Secure AVIC APIC backing page

[Tianyu Lan <ltykernel@gmail.com>]

On Wed, Jul 9, 2025 at 11:40 AM Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> wrote:
>
> With Secure AVIC, the APIC backing page is owned and managed by guest.
> Allocate and initialize APIC backing page for all guest CPUs.
>
> The NPT entry for a vCPU's APIC backing page must always be present
> when the vCPU is running, in order for Secure AVIC to function. A
> VMEXIT_BUSY is returned on VMRUN and the vCPU cannot be resumed if
> the NPT entry for the APIC backing page is not present. To handle this,
> notify GPA of the vCPU's APIC backing page to the hypervisor by using the
> SVM_VMGEXIT_SECURE_AVIC GHCB protocol event. Before executing VMRUN,
> the hypervisor makes use of this information to make sure the APIC backing
> page is mapped in NPT.
>
> Co-developed-by: Kishon Vijay Abraham I <kvijayab@amd.com>
> Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com>
> Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
> ---
> Changes since v7:
>  - No change.

Reviewed-by: Tianyu Lan <tiala@microsoft.com>

-- 
Thanks
Tianyu Lan