Re: [RFC v2-fix-v2 1/1] x86: Introduce generic protected guest abstractionn

From: Kuppuswamy, Sathyanarayanan
Date: Fri Jun 04 2021 - 18:14:01 EST




On 6/4/21 3:01 PM, Tom Lendacky wrote:
*/
- if (sme_active())
+ if (protected_guest_has(VM_HOST_MEM_ENCRYPT))
swiotlb = 1;
I still feel this is confusing. SME is a host/bare-metal technology, so
calling protected_guest_has() seems odd and using VM_HOST_MEM_ENCRYPT,
where I assume VM is short for virtual machine, also seems odd.

How about just protected_os_has()? Then you could have
- HOST_MEM_ENCRYPT for host memory encryption
- GUEST_MEM_ENCRYPT for guest memory encryption
- MEM_ENCRYPT for either host or guest memory encryption.

The first is analogous to sme_active(), the second to sev_active() and the
third to mem_encrypt_active(). Just my opinion, though...


I am not sure whether OS makes sense here. But I am fine with it if
it is maintainers choice.

Other option could be protected_boot_has()?

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer