From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>, kvm <kvm@vger.kernel.org>,
Eric Northup <digitaleric@google.com>
Subject: Re: [PATCH v4] KVM: Introduce direct MSI message injection for in-kernel irqchips
Date: Wed, 04 Apr 2012 14:50:11 +0300 [thread overview]
Message-ID: <4F7C3573.7080709@redhat.com> (raw)
In-Reply-To: <4F7C26F0.5090901@siemens.com>
On 04/04/2012 01:48 PM, Jan Kiszka wrote:
> >
> > I'm not so sure anymore. Sorry about the U turn, but remind me why? In
> > the long term it will be slower.
>
> Likely not measurably slower. If you look at a message through the arch
> glasses, you can usually spot the destination directly, specifically if
> a message targets a single processor - no need for hashing and table
> lookups in the common case.
Not on x86. The APIC ID is guest-provided. In x2apic mode it can be
quite large.
> In contrast, the maintenance costs for the current explicit route based
> model are significant as we see now.
>
You mean in amount of code in userspace? That doesn't get solved since
we need to keep compatibility.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2012-04-04 11:50 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-28 17:47 [PATCH v2] KVM: Introduce direct MSI message injection for in-kernel irqchips Jan Kiszka
2012-03-28 17:52 ` Jan Kiszka
2012-03-28 19:58 ` Eric Northup
2012-03-28 20:21 ` Jan Kiszka
2012-03-29 15:39 ` Michael S. Tsirkin
2012-03-29 15:43 ` Jan Kiszka
2012-03-29 16:15 ` [PATCH v3] " Jan Kiszka
2012-03-29 16:46 ` Michael S. Tsirkin
2012-03-29 16:50 ` Jan Kiszka
2012-03-29 18:25 ` Jan Kiszka
2012-03-29 19:14 ` [PATCH v4] " Jan Kiszka
2012-03-29 19:41 ` Michael S. Tsirkin
2012-03-30 7:45 ` Jan Kiszka
2012-03-30 12:45 ` Michael S. Tsirkin
2012-04-03 16:27 ` Avi Kivity
2012-04-03 16:47 ` Jan Kiszka
2012-04-03 16:54 ` Avi Kivity
2012-04-03 17:24 ` Jan Kiszka
2012-04-04 8:47 ` Avi Kivity
2012-04-04 8:38 ` Michael S. Tsirkin
2012-04-04 8:44 ` Avi Kivity
2012-04-04 8:53 ` Michael S. Tsirkin
2012-04-04 9:22 ` Jan Kiszka
2012-04-04 9:36 ` Avi Kivity
2012-04-04 9:38 ` Jan Kiszka
2012-04-04 9:55 ` Avi Kivity
2012-04-04 10:48 ` Jan Kiszka
2012-04-04 11:50 ` Avi Kivity [this message]
2012-04-04 12:01 ` Jan Kiszka
2012-04-10 18:30 ` [PATCH] KVM: Introduce generic interrupt " Jan Kiszka
2012-04-23 14:44 ` Jan Kiszka
2012-04-23 15:17 ` Avi Kivity
2012-04-23 15:32 ` Avi Kivity
2012-04-23 15:55 ` Jan Kiszka
2012-04-24 11:54 ` Avi Kivity
2012-04-24 11:57 ` [PATCH v4] KVM: Introduce direct MSI message " Avi Kivity
2012-04-24 12:07 ` Jan Kiszka
2012-04-24 12:59 ` Avi Kivity
2012-04-24 13:24 ` Jan Kiszka
2012-04-11 22:10 ` [PATCH v3] " Marcelo Tosatti
2012-04-12 9:28 ` Jan Kiszka
2012-04-12 22:38 ` Marcelo Tosatti
2012-04-13 13:45 ` Jan Kiszka
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