linux-kernel - Re: Re: [RFC PATCH v4 0/6] arm64: tlb: add support for TTL feature

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200325133201.GI20713@hirez.programming.kicks-ass.net>
Date:   Wed, 25 Mar 2020 14:32:01 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Zhenyu Ye <yezhenyu2@...wei.com>
Cc:     mark.rutland@....com, catalin.marinas@....com, linux-mm@...ck.org,
        guohanjun@...wei.com, will@...nel.org, linux-arch@...r.kernel.org,
        yuzhao@...gle.com, maz@...nel.org, steven.price@....com,
        arm@...nel.org, Dave.Martin@....com, arnd@...db.de,
        suzuki.poulose@....com, npiggin@...il.com,
        zhangshaokun@...ilicon.com, broonie@...nel.org,
        rostedt@...dmis.org, prime.zeng@...ilicon.com, tglx@...utronix.de,
        linux-arm-kernel@...ts.infradead.org, xiexiangyou@...wei.com,
        linux-kernel@...r.kernel.org, aneesh.kumar@...ux.ibm.com,
        akpm@...ux-foundation.org
Subject: Re: Re: [RFC PATCH v4 0/6] arm64: tlb: add support for TTL feature

On Wed, Mar 25, 2020 at 12:49:45PM +0800, Zhenyu Ye wrote:
> Hi Peter,
> 
> On 2020/3/24 23:01, Peter Zijlstra wrote:
> > On Tue, Mar 24, 2020 at 09:45:28PM +0800, Zhenyu Ye wrote:
> >> In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL
> >> feature allows TLBs to be issued with a level allowing for quicker
> >> invalidation.  This series provide support for this feature. 
> >>
> >> Patch 1 and Patch 2 was provided by Marc on his NV series[1] patches,
> >> which detect the TTL feature and add __tlbi_level interface.
> > 
> > I realy hate how it makes vma->vm_flags more important for tlbi.
> > 
> 
> Thanks for your review.
> 
> The tlbi interfaces only have two parameters: vma and addr. If we
> try to not use vma->vm_flags, we may should have to add a parameter
> to some of these interfaces(such as flush_tlb_range), which are
> common to all architectures.
> 
> I'm not sure if this is feasible, because this feature is only
> supported by ARM64 currently.

Power (p9-radix) also has level dependent invalidation instructions, so
at the very least you can hook them up as well.