From: "H.J. Lu" <hjl.tools@gmail.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Andi Kleen <ak@linux.intel.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
"Carlos O'Donell" <carlos@redhat.com>,
Marco Elver <elver@google.com>,
Taras Madan <tarasmadan@google.com>,
"xiang1...@intel.com" <xiang1.zhang@intel.com>
Subject: Re: [RFC 0/9] Linear Address Masking enabling
Date: Tue, 21 Sep 2021 10:15:39 -0700 [thread overview]
Message-ID: <CAMe9rOog08O8xmhhXuJ6aTO+ctv8D2yw1_vu8XjQWwsfw707Mg@mail.gmail.com> (raw)
In-Reply-To: <CACT4Y+YwUgksZBj4YpChqL8iac2us7mOkbVDLsib3Y+MVb31cw@mail.gmail.com>
On Tue, Sep 21, 2021 at 9:52 AM Dmitry Vyukov <dvyukov@google.com> wrote:
>
> On Sun, 7 Feb 2021 at 15:11, Kirill A. Shutemov <kirill@shutemov.name> wrote:
> >
> > On Sun, Feb 07, 2021 at 09:24:23AM +0100, Dmitry Vyukov wrote:
> > > On Fri, Feb 5, 2021 at 4:16 PM Kirill A. Shutemov
> > > <kirill.shutemov@linux.intel.com> wrote:
> > > >
> > > > Linear Address Masking[1] (LAM) modifies the checking that is applied to
> > > > 64-bit linear addresses, allowing software to use of the untranslated
> > > > address bits for metadata.
> > > >
> > > > The patchset brings support for LAM for userspace addresses.
> > > >
> > > > The most sensitive part of enabling is change in tlb.c, where CR3 flags
> > > > get set. Please take a look that what I'm doing makes sense.
> > > >
> > > > The patchset is RFC quality and the code requires more testing before it
> > > > can be applied.
> > > >
> > > > The userspace API is not finalized yet. The patchset extends API used by
> > > > ARM64: PR_GET/SET_TAGGED_ADDR_CTRL. The API is adjusted to not imply ARM
> > > > TBI: it now allows to request a number of bits of metadata needed and
> > > > report where these bits are located in the address.
> > > >
> > > > There's an alternative proposal[2] for the API based on Intel CET
> > > > interface. Please let us know if you prefer one over another.
> > > >
> > > > The feature competes for bits with 5-level paging: LAM_U48 makes it
> > > > impossible to map anything about 47-bits. The patchset made these
> > > > capability mutually exclusive: whatever used first wins. LAM_U57 can be
> > > > combined with mappings above 47-bits.
> > > >
> > > > I include QEMU patch in case if somebody wants to play with the feature.
> > >
> > > Exciting! Do you plan to send the QEMU patch to QEMU?
> >
> > Sure. After more testing, once I'm sure it's conforming to the hardware.
>
> A follow up after H.J.'s LPC talk:
> https://linuxplumbersconf.org/event/11/contributions/1010/
> (also +Carlos)
>
> As far as I understood, this kernel series depends on the Intel CET patches.
>
> Where are these compiler-rt patches that block gcc support?
Hi Xiang,
Please share your compiler-rt changes for LAM.
--
H.J.
next prev parent reply other threads:[~2021-09-21 17:16 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 15:16 [RFC 0/9] Linear Address Masking enabling Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 1/9] mm, arm64: Update PR_SET/GET_TAGGED_ADDR_CTRL interface Kirill A. Shutemov
2021-02-11 16:57 ` Catalin Marinas
2021-02-11 17:06 ` Dave Hansen
2021-02-11 18:26 ` Catalin Marinas
2021-02-05 15:16 ` [QEMU] x86: Implement Linear Address Masking support Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 2/9] x86/mm: Fix CR3_ADDR_MASK Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 3/9] x86: CPUID and CR3/CR4 flags for Linear Address Masking Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 4/9] x86/mm: Introduce TIF_LAM_U57 and TIF_LAM_U48 Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 5/9] x86/mm: Provide untagged_addr() helper Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 6/9] x86/uaccess: Remove tags from the address before checking Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 7/9] x86/mm: Handle tagged memory accesses from kernel threads Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 8/9] x86/mm: Make LAM_U48 and mappings above 47-bits mutually exclusive Kirill A. Shutemov
2021-02-05 15:16 ` [RFC 9/9] x86/mm: Implement PR_SET/GET_TAGGED_ADDR_CTRL with LAM Kirill A. Shutemov
2021-02-05 15:42 ` H.J. Lu
2021-02-07 8:07 ` Dmitry Vyukov
2021-02-07 14:09 ` Kirill A. Shutemov
2021-02-07 14:11 ` Dmitry Vyukov
2021-02-05 15:16 ` [QEMU] x86: Implement Linear Address Masking support Kirill A. Shutemov
2021-02-05 15:49 ` [RFC 0/9] Linear Address Masking enabling Peter Zijlstra
2021-02-05 16:01 ` Kirill A. Shutemov
2021-02-05 16:19 ` Peter Zijlstra
2021-02-07 8:24 ` Dmitry Vyukov
2021-02-07 14:11 ` Kirill A. Shutemov
2021-09-21 16:52 ` Dmitry Vyukov
2021-09-21 17:15 ` H.J. Lu [this message]
2021-09-22 1:15 ` Zhang, Xiang1
2021-09-22 12:54 ` Dmitry Vyukov
2021-09-22 20:03 ` Dmitry Vyukov
2021-09-22 21:33 ` Kirill A. Shutemov
2021-09-23 0:15 ` H.J. Lu
2021-09-23 5:35 ` Dmitry Vyukov
2021-09-23 0:07 ` H.J. Lu
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