Re: [PATCH kernel 7/9] coco/sev-guest: Implement the guest support for SEV TIO (phase2)

Alexey Kardashevskiy
2026-02-26T03:39:58Z

On 25/2/26 17:00, Borislav Petkov wrote:
> On February 25, 2026 5:37:50 AM UTC, Alexey Kardashevskiy <aik@amd.com> wrote:
>> Implement the SEV-TIO (Trusted I/O) support in for AMD SEV-SNP guests.
>>
>> The implementation includes Device Security Manager (DSM) operations
>> for:
>> - binding a PCI function (GHCB extension) to a VM and locking
>> the device configuration;
>> - receiving TDI report and configuring MMIO and DMA/sDTE;
>> - accepting the device into the guest TCB.
>>
>> Detect the SEV-TIO support (reported via GHCB HV features) and install
>> the SEV-TIO TSM ops.
>>
>> Implement lock/accept/unlock TSM ops.
>>
>> Define 2 new VMGEXIT codes for GHCB:
>> - TIO Guest Request to provide secure communication between a VM and
>> the FW (for configuring MMIO and DMA);
>> - TIO Op for requesting the HV to bind a TDI to the VM and for
>> starting/stopping a TDI.
>
> Just from staring at that huuuge diff, those bullets and things above are basically begging to be separate patches...

I struggle to separate these more without making individual patches useless for any purpose, even splitting between maintainership area. People often define things in separate patches and then use them and I dislike such approach for reviewing purposes - hard to follow. I can ditch more stuff (like TIO_GUID_CERTIFICATES - just noticed) but it is not much :-/

--
Alexey