From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 3CE528DA4 for ; Thu, 1 Oct 2015 11:42:09 +0200 (CEST) Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 7888C461F0; Thu, 1 Oct 2015 09:42:08 +0000 (UTC) Received: from redhat.com (ovpn-116-83.ams2.redhat.com [10.36.116.83]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id t919g4lZ018795; Thu, 1 Oct 2015 05:42:06 -0400 Date: Thu, 1 Oct 2015 12:42:04 +0300 From: "Michael S. Tsirkin" To: Avi Kivity Message-ID: <20151001123335-mutt-send-email-mst@redhat.com> References: <560BDE24.8000308@scylladb.com> <20150930165359-mutt-send-email-mst@redhat.com> <560BF782.4070308@scylladb.com> <20150930175848-mutt-send-email-mst@redhat.com> <560C0171.7080507@scylladb.com> <20150930204016.GA29975@redhat.com> <20151001113828-mutt-send-email-mst@redhat.com> <560CF44A.60102@scylladb.com> <20151001120027-mutt-send-email-mst@redhat.com> <560CFB66.5050904@scylladb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <560CFB66.5050904@scylladb.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] Having troubles binding an SR-IOV VF to uio_pci_generic on Amazon instance X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Oct 2015 09:42:09 -0000 On Thu, Oct 01, 2015 at 12:22:46PM +0300, Avi Kivity wrote: > even when they are some users > prefer to avoid the performance penalty. I don't think there's a measureable penalty from passing through the IOMMU, as long as mappings are mostly static (i.e. iommu=pt). I sure never saw any numbers that show such. -- MST