From: Sedat Dilek <sedat.dilek@gmail.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Brian Gerst <brgerst@gmail.com>, Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH v2 1/2] x86/stackprotector/32: Make the canary into a regular percpu variable
Date: Tue, 16 Feb 2021 21:23:20 +0100 [thread overview]
Message-ID: <CA+icZUXmPXyVHdFwuunZfxtOid78Y_s2z=UuTfvzoNxu1F+DTw@mail.gmail.com> (raw)
In-Reply-To: <YCvw99dIJ9C90Q6R@google.com>
On Tue, Feb 16, 2021 at 5:21 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Sat, Feb 13, 2021, Andy Lutomirski wrote:
> > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> > index f923e14e87df..ec39073b4897 100644
> > --- a/arch/x86/kvm/svm/svm.c
> > +++ b/arch/x86/kvm/svm/svm.c
> > @@ -1467,12 +1467,8 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
> > #ifdef CONFIG_X86_64
> > loadsegment(fs, svm->host.fs);
> > wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase);
> > - load_gs_index(svm->host.gs);
> > -#else
> > -#ifdef CONFIG_X86_32_LAZY_GS
> > - loadsegment(gs, svm->host.gs);
> > -#endif
>
> This manually GS crud is gone as of commit e79b91bb3c91 ("KVM: SVM: use
> vmsave/vmload for saving/restoring additional host state"), which is queued for
> 5.12.
>
Link to the above KVM patch see [1].
As said the base for this patchset should be changed - for example it
conflicts with [2].
Maybe wait for Linux v5.12-rc1?
- Sedat -
[1] https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?h=tags/kvm-5.12-1&id=e79b91bb3c916a52ce823ab60489c717c925c49f
[2] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/tag/?h=x86-entry-2021-02-15
> > #endif
> > + load_gs_index(svm->host.gs);
> >
> > for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
> > wrmsrl(host_save_user_msrs[i].index,
> > @@ -3705,13 +3701,11 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu,
> > } else {
> > __svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs);
> >
> > + /* Restore the percpu segment immediately. */
> > #ifdef CONFIG_X86_64
> > native_wrmsrl(MSR_GS_BASE, svm->host.gs_base);
> > #else
> > loadsegment(fs, svm->host.fs);
> > -#ifndef CONFIG_X86_32_LAZY_GS
> > - loadsegment(gs, svm->host.gs);
> > -#endif
> > #endif
> > }
next prev parent reply other threads:[~2021-02-16 20:24 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-13 19:19 [PATCH v2 0/2] Clean up x86_32 stackprotector Andy Lutomirski
2021-02-13 19:19 ` [PATCH v2 1/2] x86/stackprotector/32: Make the canary into a regular percpu variable Andy Lutomirski
2021-02-13 19:49 ` Sedat Dilek
2021-02-16 16:21 ` Sean Christopherson
2021-02-16 20:23 ` Sedat Dilek [this message]
2021-02-16 18:45 ` Nick Desaulniers
2021-02-16 20:29 ` Sedat Dilek
2021-03-08 13:14 ` [tip: x86/core] " tip-bot2 for Andy Lutomirski
2022-09-29 13:56 ` [PATCH v2 1/2] " Andy Shevchenko
2022-09-29 14:20 ` Andy Shevchenko
2022-09-30 20:30 ` Ferry Toth
2022-09-30 21:18 ` Ferry Toth
2022-11-09 14:50 ` Andy Shevchenko
2022-11-09 22:33 ` Brian Gerst
2022-11-10 14:02 ` Andy Shevchenko
2022-11-10 19:36 ` Ferry Toth
2022-11-14 21:43 ` Brian Gerst
2022-11-14 22:16 ` Ferry Toth
2022-11-17 19:28 ` Ferry Toth
2021-02-13 19:19 ` [PATCH v2 2/2] x86/entry/32: Remove leftover macros after stackprotector cleanups Andy Lutomirski
2021-03-08 13:14 ` [tip: x86/core] " tip-bot2 for Andy Lutomirski
2021-02-13 19:33 ` [PATCH v2 0/2] Clean up x86_32 stackprotector Sedat Dilek
2021-02-14 14:42 ` Sedat Dilek
2021-02-16 18:13 ` Nick Desaulniers
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