Re: [PATCH 2/2] iommu/amd: Add support for AVIC when SNP is enabled

[Suravee Suthikulpanit]

On 7/26/22 10:32 PM, Jerry Snitselaar wrote:
> On Tue, Jul 26, 2022 at 08:43:48AM -0500, Suravee Suthikulpanit wrote:
> > In order to support AVIC on SNP-enabled system, The IOMMU driver needs to
> > check EFR2[SNPAVICSup] and enables the support by setting SNPAVICEn bit
> > in the IOMMU control register (MMIO offset 18h).
> >
> > For detail, please see section "SEV-SNP Guest Virtual APIC Support" of the
> > AMD I/O Virtualization Technology (IOMMU) Specification.
> > (https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.amd.com%2Fsystem%2Ffiles%2FTechDocs%2F48882_IOMMU.pdf&data=05%7C01%7Csuravee.suthikulpanit%40amd.com%7C844cc78ad4674484b1f208da6f1c0ee1%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637944463702725122%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=U%2Fe%2FxqqQ14UmlF5ThaB55Col4mbNzuqNj8IqEyxmsxo%3D&reserved=0)
> >
> > Signed-off-by: Suravee Suthikulpanit<suravee.suthikulpanit@xxxxxxx>
> Is this a typo in the 3.06 spec for SNPAVIC_EN?
>
> "001b-111b = Reserved."
>
> Or I guess maybe there is a newer revision that isn't available yet
> that describes 001b?

That's correct. The newer version should be coming out soon.

> Reviewed-by: Jerry Snitselaar<jsnitsel@xxxxxxxxxx>

Thank you,
Suravee