From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6255-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 E12229860B4 for ; Thu, 24 Oct 2019 11:22:19 +0000 (UTC) From: Shahaf Shuler Date: Thu, 24 Oct 2019 11:22:16 +0000 Message-ID: Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_AM0PR0502MB37958EA359A04C0A67DB1A36C36A0AM0PR0502MB3795_" MIME-Version: 1.0 Subject: [virtio-dev] Virtio device specific MSIX arming To: Virtio-Dev , "Michael S . Tsirkin" Cc: Tzahi Oved , Alex Rosenbaum List-ID: --_000_AM0PR0502MB37958EA359A04C0A67DB1A36C36A0AM0PR0502MB3795_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Hi, Below question mainly raise when looking on the ways to have vDPA implement= ation of virtio-net device. One complexity we encounter is with the MSIX relay between the device and t= he guest. Reading the spec, and looking on the driver implementation, it seems there = is no way for the driver to re-arm the virtio device after MSIX was trigger= ed. There is a way to suppress interrupt by setting some flags on the available= rings, however it is hard to poll on it from a real (not emulated) PCI dev= ice. Is above correct? Or there is a way to re-arm virtio device for next interr= upt? If no way to re-arm, 1. are there any thoughts on adding such addition to spec? 2. What is the recommended approach for vDPA implementation? Use static interrupt moderation? --_000_AM0PR0502MB37958EA359A04C0A67DB1A36C36A0AM0PR0502MB3795_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hi,

 

Below question mainly raise when looking on the w= ays to have vDPA implementation of virtio-net device.

 

One complexity we encounter is with the MSIX rela= y between the device and the guest.

Reading the spec, and looking on the driver imple= mentation, it seems there is no way for the driver to re-arm the virtio dev= ice after MSIX was triggered.

 

There is a way to suppress interrupt by setting s= ome flags on the available rings, however it is hard to poll on it from a r= eal (not emulated) PCI device.

 

Is above correct? Or there is a way to re-arm vir= tio device for next interrupt?

 

If no way to re-arm,

1. are there any thoughts on adding such addition= to spec?

2. What is the recommended approach for vDPA impl= ementation? Use static

    interrupt moderation?

 

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