Juergen Gross
2022-Apr-27 06:40 UTC
[PATCH 2/2] virtio: replace arch_has_restricted_virtio_memory_access()
On 26.04.22 21:51, Heiko Carstens wrote:> On Tue, Apr 26, 2022 at 07:35:43PM +0200, Borislav Petkov wrote: >> On Tue, Apr 26, 2022 at 03:40:21PM +0200, Juergen Gross wrote: >>> /* protected virtualization */ >>> static void pv_init(void) >>> { >>> if (!is_prot_virt_guest()) >>> return; >>> >>> + platform_set_feature(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); >> >> Kinda long-ish for my taste. I'll probably call it: >> >> platform_set() >> >> as it is implicit that it sets a feature bit. > > ...and platform_clear(), instead of platform_reset_feature() please.Fine with me.> >> In any case, yeah, looks ok at a quick glance. It would obviously need >> for more people to look at it and say whether it makes sense to them and >> whether that's fine to have in generic code but so far, the experience >> with cc_platform_* says that it seems to work ok in generic code. > > We _could_ convert s390's machine flags to this mechanism. Those flags > are historically per-cpu, but if I'm not mistaken none of them is > performance critical anymore, and those who are could/should probably > transformed to jump labels or alternatives anyway.I was planning to look at the x86 cpu features to see whether some of those might be candidates to be switched to platform features instead. Juergen -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_0xB0DE9DD628BF132F.asc Type: application/pgp-keys Size: 3098 bytes Desc: OpenPGP public key URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20220427/a4576f16/attachment.bin> -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature Type: application/pgp-signature Size: 495 bytes Desc: OpenPGP digital signature URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20220427/a4576f16/attachment.sig>
Borislav Petkov
2022-Apr-27 12:26 UTC
[PATCH 2/2] virtio: replace arch_has_restricted_virtio_memory_access()
On Wed, Apr 27, 2022 at 08:40:08AM +0200, Juergen Gross wrote:> I was planning to look at the x86 cpu features to see whether some of > those might be candidates to be switched to platform features instead.I'd say "never touch a running system" unless the platform features are of an advantage... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette