lkml.org 
[lkml]   [2023]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC][PATCH 07/17] x86/cpu/kvm: Provide UNTRAIN_RET_VM
On Wed, Aug 09, 2023 at 09:50:04AM -0400, Josh Poimboeuf wrote:
> On Wed, Aug 09, 2023 at 09:12:25AM +0200, Peter Zijlstra wrote:
> > With the difference being that UNTRAIN_RET_VM uses
> > X86_FEATURE_IBPB_ON_VMEXIT instead of X86_FEATURE_ENTRY_IBPB.
> >
> > This cures VMEXIT doing potentially unret+IBPB or double IBPB.
> >
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > ---
> > arch/x86/include/asm/nospec-branch.h | 11 +++++++++++
> > arch/x86/kernel/cpu/bugs.c | 17 ++++++++++++++++-
> > arch/x86/kvm/svm/vmenter.S | 7 ++-----
> > 3 files changed, 29 insertions(+), 6 deletions(-)
> >
> > --- a/arch/x86/include/asm/nospec-branch.h
> > +++ b/arch/x86/include/asm/nospec-branch.h
> > @@ -299,6 +299,17 @@
> > #endif
> > .endm
> >
> > +.macro UNTRAIN_RET_VM
> > +#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \
> > + defined(CONFIG_CALL_DEPTH_TRACKING) || defined(CONFIG_CPU_SRSO)
>
> Maybe can be simplified?
>

See patches 9 and 10 :-)

\
 
 \ /
  Last update: 2023-08-09 16:07    [W:0.103 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site