From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6362-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id CC0C3985E8D for ; Thu, 21 Nov 2019 09:04:10 +0000 (UTC) Date: Thu, 21 Nov 2019 10:04:03 +0100 From: Gerd Hoffmann Message-ID: <20191121090403.6vjnovlru4zrmzzs@sirius.home.kraxel.org> References: <6a4978e85505ae00ca9e2b170f5e893a064c03d2.camel@linux.intel.com> <568f32dc-8d82-a189-469f-5cb3a0140b8c@opensynergy.com> <0cc8007b70f4f5984223703313730d8e066006a7.camel@linux.intel.com> <20191112110937.GA4187507@lophozonia> <0c5939ad0b330bc4f42d63536340293745dce728.camel@linux.intel.com> <20191112160554.GA16008@lophozonia> <4ca16fb1d412bc92a2a65104680282b80742f6b1.camel@linux.intel.com> <21039a042ad38302e9dc9010014223d915704b91.camel@linux.intel.com> <07b9804d-2c20-9ff4-a375-2c65f1d27f63@opensynergy.com> MIME-Version: 1.0 In-Reply-To: <07b9804d-2c20-9ff4-a375-2c65f1d27f63@opensynergy.com> Subject: Re: [virtio-dev] [PATCH] snd: Add virtio sound device specification Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline To: Anton Yakovlev Cc: Liam Girdwood , Jean-Philippe Brucker , Mikhail Golubev , "virtio-dev@lists.oasis-open.org" , Takashi Iwai , Mark Brown List-ID: Hi, > > In general if I have guest core affinity then hypervisor context > > switching for that guest is in low 10s of uS (depends on hypervisor > > of course and HW). This is good enough for low latency audio. > That's why we are really curious how other people target such issues > with audio virtualization. And that's why I'm not sure about the spec > in this regard. We could say something like "you can activate > zero-copy mode, but it's up to your HW, OS and luck", but it does not > sound very nicely. real-time stuff in virtual machines is tricky, and real-time audio isn't special here. I don't think there is a need to discuss that in the device specification. The part which is important for the virtual hardware is to design the it in a way that the number of context switches (system calls, vmexits) is minimized. cheers, Gerd --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org