Re: [GIT PULL] Last straggler for 4.20-rc8 or final

Paolo Bonzini
2018-12-23T08:45:29Z

On 22/12/18 21:59, Ingo Molnar wrote:
>
> * Paolo Bonzini <pbonzini@redhat.com> wrote:
>
>> On 21/12/18 23:40, Borislav Petkov wrote:
>>> + mingo.
>>>
>>> On Fri, Dec 21, 2018 at 02:09:02PM +0100, Paolo Bonzini wrote:
>>>> Linus,
>>>>
>>>> The following changes since commit 7566ec393f4161572ba6f11ad5171fd5d59b0fbd:
>>>>
>>>> Linux 4.20-rc7 (2018-12-16 15:46:55 -0800)
>>>>
>>>> are available in the git repository at:
>>>>
>>>> https://git.kernel.org/pub/scm/virt/kvm/kvm.git tags/for-linus
>>>>
>>>> for you to fetch changes up to 3cf85f9f6bd7b172122865432b4c6f0ec844e22a:
>>>>
>>>> KVM: x86: nSVM: fix switch to guest mmu (2018-12-19 22:19:22 +0100)
>>>>
>>>> A simple patch for a pretty bad bug. I haven't yet sent my 4.21 pull
>>>> request because currently I'm waiting for a patch to be removed from
>>>> tip (MPX removal breaks KVM live migration and was committed without
>>>> Cc or Ack from me) and until that happens I cannot finalize my
>>>> conflict resolution instructions.
>>>
>>> Lemme make sure I understand it correctly: you'd like us to not send
>>>
>>> https://git.kernel.org/tip/eb012ef3b4e331ae479dd7cd9378041d9b7f851c
>>>
>>> up now and delay it for 4.22, right?
>>
>> Right, and also I will have to provide you with a topic branch to base
>> that patch on.
>
> Ok - x86/mpx delayed for v4.22 at least.
>
> Can we turn off CONFIG_X86_INTEL_MPX configurability in the Kconfig, via
> a patch like below?
>
> Thanks,
>
> Ingo
>
> arch/x86/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 8689e794a43c..20fd5695f265 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1870,6 +1870,7 @@ config X86_INTEL_MPX
> def_bool n
> # Note: only available in 64-bit mode due to VMA flags shortage
> depends on CPU_SUP_INTEL && X86_64
> + depends on DEPRECATED
> select ARCH_USES_HIGH_VMA_FLAGS
> ---help---
> MPX provides hardware features that can be used in
>

I think so, you can even delete all X86_INTEL_MPX code already. All
that KVM still needs is that BNDCSR and BNDREGS remain in XCR0, I don't
see anything that affects that depending on X86_INTEL_MPX.

Thanks,

Paolo