linux-kernel - Re: [PATCH] KVM: x86: Add lowest-priority support for vt-d posted-interrupts

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: <5655C7C9.1010008@redhat.com>
Date:	Wed, 25 Nov 2015 15:38:01 +0100
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Radim Krcmár <rkrcmar@...hat.com>,
	"Wu, Feng" <feng.wu@...el.com>
Cc:	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] KVM: x86: Add lowest-priority support for vt-d
 posted-interrupts



On 25/11/2015 15:12, Radim Krcmár wrote:
> I think it's ok to pick any algorithm we like.  It's unlikely that
> software would recognize and take advantage of the hardware algorithm
> without adding a special treatment for KVM.
> (I'd vote for the simple pick-first-APIC lowest priority algorithm ...
>  I don't see much point in complicating lowest priority when it doesn't
>  deliver to lowest priority CPU anyway.)

Vector hashing is an improvement for the common case where all vectors
are set to all CPUs.  Sure you can get an unlucky assignment, but it's
still better than pick-first-APIC.

Paolo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/