linux-kernel - Re: [PATCH] kvm: rename HINTS_DEDICATED to KVM_HINTS

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: <20180518154721-mutt-send-email-mst@kernel.org>
Date:   Fri, 18 May 2018 15:47:53 +0300
From:   "Michael S. Tsirkin" <mst@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Eduardo Habkost <ehabkost@...hat.com>,
        linux-kernel@...r.kernel.org,
        Radim Krčmář <rkrcmar@...hat.com>,
        Jonathan Corbet <corbet@....net>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        kvm@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH] kvm: rename HINTS_DEDICATED to KVM_HINTS_REALTIME

On Fri, May 18, 2018 at 11:41:23AM +0200, Paolo Bonzini wrote:
> On 17/05/2018 20:46, Eduardo Habkost wrote:
> > My understanding of the original patch is that the intention is
> > to tell the guest that it is very unlikely to be preempted, so it
> > can choose a more appropriate spinlock implementation.  This
> > description implies that the guest will never be preempted, which
> > is much stronger guarantee.
> > 
> > Isn't this new description incompatible with existing usage of
> > the hint, which might include people who just use vCPU pinning
> > but no mlock?
> 
> If you use hugetlbfs and vhost-user you don't really need mlock for the
> QEMU process, do you?  The QEMU process is not doing much in that case
> and hugetlbfs gives you pinned memory automatically.
> 
> Paolo

Same with PCI device passthrough: VFIO pins all guest memory right now.

-- 
MST