Re: [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support
From: Joerg Roedel <hidden>
Date: 2021-11-25 10:07:59
Also in:
kvm, linux-crypto, linux-mm, lkml
On Wed, Nov 24, 2021 at 09:48:14AM -0800, Dave Hansen wrote:
That covers things like copy_from_user(). It does not account for things where kernel mappings are used, like where a get_user_pages()/kmap() is in play.
The kmap case is guarded by KVM code, which locks the page first so that the guest can't change the page state, then checks the page state, and if it is shared does the kmap and the access. This should turn an RMP fault in the kernel which is not covered in the uaccess exception table into a fatal error. Regards, -- Jörg Rödel jroedel@suse.de SUSE Software Solutions Germany GmbH Maxfeldstr. 5 90409 Nürnberg Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev