linux-kernel - Re: [PATCH v7 02/12] KVM: arm64: Use kvm_arch_flush_remote

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]

Date:   Tue, 8 Aug 2023 09:19:53 -0700
From:   Raghavendra Rao Ananta <rananta@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Marc Zyngier <maz@...nel.org>,
        Oliver Upton <oliver.upton@...ux.dev>,
        James Morse <james.morse@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Huacai Chen <chenhuacai@...nel.org>,
        Zenghui Yu <yuzenghui@...wei.com>,
        Anup Patel <anup@...infault.org>,
        Atish Patra <atishp@...shpatra.org>,
        Jing Zhang <jingzhangos@...gle.com>,
        Reiji Watanabe <reijiw@...gle.com>,
        Colton Lewis <coltonlewis@...gle.com>,
        David Matlack <dmatlack@...gle.com>,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
        linux-mips@...r.kernel.org, kvm-riscv@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Subject: Re: [PATCH v7 02/12] KVM: arm64: Use kvm_arch_flush_remote_tlbs()

On Tue, Aug 8, 2023 at 8:07 AM Sean Christopherson <seanjc@...gle.com> wrote:
>
> On Fri, Aug 04, 2023, Raghavendra Rao Ananta wrote:
> > On Wed, Aug 2, 2023 at 4:28 PM Raghavendra Rao Ananta
> > <rananta@...gle.com> wrote:
> > >
> > > Sure, I'll change it to kvm_arch_flush_vm_tlbs() in v8.
> > >
> > While working on the renaming, I realized that since this function is
> > called from kvm_main.c's kvm_flush_remote_tlbs(). Do we want to rename
> > this and the other kvm_flush_*() functions that the series introduces
> > to match their kvm_arch_flush_*() counterparts?
>
> Hmm, if we're going to rename one arch hook, then yes, I think it makes sense to
> rename all the common APIs and arch hooks to match.
>
> However, x86 is rife with the "remote_tlbs" nomenclature, and renaming the common
> APIs will just push the inconsistencies into x86.  While I 100% agree that the
> current naming is flawed, I am not willing to end up with x86 being partially
> converted.
>
> I think I'm ok renaming all of x86's many hooks?  But I'd definitely want input
> from more x86 folks, and the size and scope of this series would explode.  Unless
> Marc objects and/or has a better idea, the least awful option is probably to ignore
> the poor "remote_tlbs" naming and tackle it in a separate series.
>
Sure, I think it's better to do it in a separate series as well. I'm
happy to carry out the task after this one gets merged. But, let's
wait for Marc and others' opinion on the matter.

Thank you.
Raghavendra
> Sorry for not noticiing this earlier, I didn't realize just how much x86 uses
> remote_tlbs.
>
> > (spiraling more into this, we also have the 'remote_tlb_flush_requests' and
> > 'remote_tlb_flush' stats)
>
> Regardless of what we decide for the APIs, definitely leave the stats alone.  The
> names are ABI.  We could preserve the names and changes the struct fields, but that
> would be a net negative IMO.