Re: [PATCH v6 00/12] SVM cleanup and INVPCID feature support

From: Babu Moger
Date: Wed Mar 10 2021 - 20:22:19 EST




On 3/10/21 9:31 AM, Paolo Bonzini wrote:
> On 10/03/21 15:58, Babu Moger wrote:
>> There is no upstream version 4.9.258.
>
> Sure there is, check out
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcdn.kernel.org%2Fpub%2Flinux%2Fkernel%2Fv4.x%2F&data=04%7C01%7Cbabu.moger%40amd.com%7Caeefc58416ed490faa7f08d8e3d99d72%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637509871127634618%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=re2Jj5P7IjN2UdmPTjTuKd1KIJLek84KlcnsXxgKYRc%3D&reserved=0
>
>
> The easiest way to do it is to bisect on the linux-4.9.y branch of
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git.
>
Paolo, Thanks for pointing that out. Bisected linux-4.9.y branch.
It is pointing at

# git bisect good
59094faf3f618b2d2b2a45acb916437d611cede6 is the first bad commit
commit 59094faf3f618b2d2b2a45acb916437d611cede6
Author: Borislav Petkov <bp@xxxxxxx>
Date: Mon Dec 25 13:57:16 2017 +0100

x86/kaiser: Move feature detection up


... before the first use of kaiser_enabled as otherwise funky
things happen:

about to get started...
(XEN) d0v0 Unhandled page fault fault/trap [#14, ec=0000]
(XEN) Pagetable walk from ffff88022a449090:
(XEN) L4[0x110] = 0000000229e0e067 0000000000001e0e
(XEN) L3[0x008] = 0000000000000000 ffffffffffffffff
(XEN) domain_crash_sync called from entry.S: fault at ffff82d08033fd08
entry.o#create_bounce_frame+0x135/0x14d
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.9.1_02-3.21 x86_64 debug=n Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e033:[<ffffffff81007460>]
(XEN) RFLAGS: 0000000000000286 EM: 1 CONTEXT: pv guest (d0v0)

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

:040000 040000 e56bbc975c3fd1a774b6cc0d6699c0c24e66be1c
e06231dccc8589b4baa0cd5759a37899b7ec71c1 M arch

Not sure what is going on with this commit. Still looking.