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Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3

From Boris Ostrovsky <boris.ostrovsky@oracle.com>
Newsgroups linux.kernel
Subject Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3
Date 2017-06-08 23:20 +0200
Message-ID <tQd0u-11f-11@gated-at.bofh.it> (permalink)
References (1 earlier) <tPRjk-44i-21@gated-at.bofh.it> <tPRjk-44i-17@gated-at.bofh.it> <tQcH7-FJ-21@gated-at.bofh.it> <tQcH7-FJ-19@gated-at.bofh.it> <tQd0u-11f-13@gated-at.bofh.it>
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On 06/08/2017 05:02 PM, Tom Lendacky wrote:
> On 6/8/2017 3:51 PM, Boris Ostrovsky wrote:
>>
>>>
>>>> What may be needed is making sure X86_FEATURE_SME is not set for PV
>>>> guests.
>>>
>>> And that may be something that Xen will need to control through either
>>> CPUID or MSR support for the PV guests.
>>
>>
>> Only on newer versions of Xen. On earlier versions (2-3 years old) leaf
>> 0x80000007 is passed to the guest unchanged. And so is MSR_K8_SYSCFG.
>
> The SME feature is in leaf 0x8000001f, is that leaf passed to the guest
> unchanged?

Oh, I misread the patch where X86_FEATURE_SME is defined. Then all
versions, including the current one, pass it unchanged.

All that's needed is setup_clear_cpu_cap(X86_FEATURE_SME) in
xen_init_capabilities().


-boris

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Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against  just the physical address in cr3 Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-06-08 00:10 +0200
  Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against  just the physical address in cr3 Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-06-08 23:00 +0200
    Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against  just the physical address in cr3 Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-06-08 23:20 +0200
      Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use  __va() against just the physical address in cr3 Andrew Cooper <andrew.cooper3@citrix.com> - 2017-06-09 00:10 +0200
        Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use  __va() against just the physical address in cr3 Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-06-09 20:50 +0200
          Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use  __va() against just the physical address in cr3 Andrew Cooper <andrew.cooper3@citrix.com> - 2017-06-09 21:00 +0200
          Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use  __va() against just the physical address in cr3 Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-06-09 21:50 +0200

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