From: Stefan Hajnoczi <stefanha@redhat.com>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: virtio-dev@lists.oasis-open.org,
Zha Bin <zhabin@linux.alibaba.com>,
Jing Liu <jing2.liu@linux.intel.com>,
Chao Peng <chao.p.peng@linux.intel.com>
Subject: Re: [virtio-dev] On doorbells (queue notifications)
Date: Wed, 15 Jul 2020 12:48:55 +0100 [thread overview]
Message-ID: <20200715114855.GF18817@stefanha-x1.localdomain> (raw)
In-Reply-To: <87r1tdydpz.fsf@linaro.org>
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On Tue, Jul 14, 2020 at 10:43:36PM +0100, Alex Bennée wrote:
> I'm slightly confused by the MSI terminology because this only seems to
> be relevant for the PCI legacy interface and AFAICT only touch the
> outgoing path in setup and del_vq. Do incoming MSI interrupts just get
> mapped directly to the appropriate handler function to process the
> queues or the config?
When MSI is used the VIRTIO ISR register does not need to be read by the
guest interrupt handler.
> Finally I'm curious if this is just a problem avoided by the s390
> channel approach? Does the use of messages over a channel just avoid the
> sort of bouncing back and forth that other hypervisors have to do when
> emulating a device?
What does "bouncing back and forth" mean exactly?
Stefan
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next prev parent reply other threads:[~2020-07-15 11:49 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 21:43 [virtio-dev] On doorbells (queue notifications) Alex Bennée
2020-07-15 11:48 ` Stefan Hajnoczi [this message]
2020-07-15 13:29 ` Alex Bennée
2020-07-15 15:47 ` Stefan Hajnoczi
2020-07-15 16:40 ` Alex Bennée
2020-07-15 17:09 ` Cornelia Huck
2020-07-16 10:00 ` Stefan Hajnoczi
2020-07-16 11:25 ` Christophe de Dinechin
2020-07-16 14:19 ` Stefan Hajnoczi
2020-07-16 14:31 ` Christophe de Dinechin
2020-07-16 14:34 ` Christophe de Dinechin
2020-07-17 8:42 ` Stefan Hajnoczi
2020-07-15 17:01 ` Cornelia Huck
2020-07-15 17:25 ` Alex Bennée
2020-07-15 20:04 ` Halil Pasic
2020-07-16 9:41 ` Cornelia Huck
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