[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Mon, 20 Feb 2017 09:39:21 -0800
From: Thomas Garnier <thgarnie@...gle.com>
To: Andy Lutomirski <luto@...capital.net>
Cc: Jim Mattson <jmattson@...gle.com>, Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, "H . Peter Anvin" <hpa@...or.com>,
Andrey Ryabinin <aryabinin@...tuozzo.com>, Alexander Potapenko <glider@...gle.com>,
Dmitry Vyukov <dvyukov@...gle.com>, Kees Cook <keescook@...omium.org>,
Andy Lutomirski <luto@...nel.org>, Borislav Petkov <bp@...e.de>,
Paul Gortmaker <paul.gortmaker@...driver.com>, "Rafael J . Wysocki" <rjw@...ysocki.net>,
Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>, Jiri Kosina <jikos@...nel.org>,
Matt Fleming <matt@...eblueprint.co.uk>, Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>, Juergen Gross <jgross@...e.com>,
Rusty Russell <rusty@...tcorp.com.au>, Peter Zijlstra <peterz@...radead.org>,
Christian Borntraeger <borntraeger@...ibm.com>, "Luis R . Rodriguez" <mcgrof@...nel.org>,
He Chen <he.chen@...ux.intel.com>, Brian Gerst <brgerst@...il.com>,
Stanislaw Gruszka <sgruszka@...hat.com>, Arnd Bergmann <arnd@...db.de>,
Adam Buchbinder <adam.buchbinder@...il.com>, Dave Hansen <dave.hansen@...el.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>, Josh Poimboeuf <jpoimboe@...hat.com>,
Tim Chen <tim.c.chen@...ux.intel.com>, Rik van Riel <riel@...hat.com>,
Andi Kleen <ak@...ux.intel.com>, Jiri Olsa <jolsa@...hat.com>,
Michael Ellerman <mpe@...erman.id.au>, Joerg Roedel <joro@...tes.org>,
Paolo Bonzini <pbonzini@...hat.com>, Radim Krčmář <rkrcmar@...hat.com>,
"the arch/x86 maintainers" <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
kasan-dev <kasan-dev@...glegroups.com>, Linux PM list <linux-pm@...r.kernel.org>,
"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
"xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>, lguest@...ts.ozlabs.org,
kvm list <kvm@...r.kernel.org>,
Kernel Hardening <kernel-hardening@...ts.openwall.com>
Subject: Re: [PATCH v3 4/4] KVM: VMX: Simplify segment_base
On Mon, Feb 20, 2017 at 9:28 AM, Thomas Garnier <thgarnie@...gle.com> wrote:
> On Mon, Feb 20, 2017 at 8:56 AM, Andy Lutomirski <luto@...capital.net> wrote:
>> On Fri, Feb 17, 2017 at 2:01 PM, Thomas Garnier <thgarnie@...gle.com> wrote:
>>> On Fri, Feb 17, 2017 at 1:00 PM, Jim Mattson <jmattson@...gle.com> wrote:
>>>> On Fri, Feb 17, 2017 at 12:11 PM, Thomas Garnier <thgarnie@...gle.com> wrote:
>>>>> On Fri, Feb 17, 2017 at 9:49 AM, Jim Mattson <jmattson@...gle.com> wrote:
>>>>>>
>>>>>> Can we use the read-only GDT here? When expanding the virtual address
>>>>>> for 64-bit system descriptors, isn't it sufficient to check (d->s == 0
>>>>>> && d->type != 0)?
>>>>>
>>>>> We can use the readonly GDT but I think doesn't matter one or the
>>>>> other here. We have to check specific types for LDT or TSS, other
>>>>> values describe other entries (cf Intel volume 3, 3.5) (for example 14
>>>>> & 15 on 64-bits are for trap & interrupt gates).
>>>>
>>>> According to volume 3 of the SDM, section 3.5.2:
>>>>
>>>> The following system descriptors expand to 16 bytes:
>>>> — Call gate descriptors (see Section 5.8.3.1, “IA-32e Mode Call Gates”)
>>>> — IDT gate descriptors (see Section 6.14.1, “64-Bit Mode IDT”)
>>>> — LDT and TSS descriptors (see Section 7.2.3, “TSS Descriptor in 64-bit mode”).
>>>>
>>>> All legal system descriptor types (except for 0: Upper 8 bytes of an 16-byte
>>>> descriptor) should get the high 32 bits of the base address from the next 8-byte
>>>> descriptor.
>>>>
>>>
>>> Ok, then I will test an updated version next week.
>>>
>>
>> I'm going to send out some preliminary patches that just get rid of
>> this problem entirely.
>
> Okay, I guess I will have to wait for it to be integrated to
> linux-next then. Or would you rather to it after this patch set is
> added?
>
Read your summary for the patchset of KVM cleanup, I will wait for it
to reach linux-next to rebase and send the new iteration.
Thanks for working on the clean-up.
> --
> Thomas
--
Thomas
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
