Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752288AbdI0WVC (ORCPT ); Wed, 27 Sep 2017 18:21:02 -0400 Received: from twosheds.infradead.org ([90.155.92.209]:49370 "EHLO twosheds.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752028AbdI0WVB (ORCPT ); Wed, 27 Sep 2017 18:21:01 -0400 Message-ID: <1506550852.7476.33.camel@infradead.org> Subject: Re: [PATCH] uio/uio_pci_generic: Add SR-IOV support From: David Woodhouse To: Bjorn Helgaas Cc: Greg Kroah-Hartman , linux-pci , linux-kernel , Donald Dutile , Alexander Duyck , "Bryant G. Ly" , Bodong Wang , Alex Williamson , "Michael S. Tsirkin" , kvm@vger.kernel.org In-Reply-To: <20170927220005.GB23674@bhelgaas-glaptop.roam.corp.google.com> References: <1506517162.30379.2.camel@infradead.org> <20170927220005.GB23674@bhelgaas-glaptop.roam.corp.google.com> Face: 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 Content-Type: multipart/signed; micalg="sha-256"; protocol="application/x-pkcs7-signature"; boundary="=-6HA7wm9Hvi4sPObu/XZT" Date: Wed, 27 Sep 2017 23:20:52 +0100 Mime-Version: 1.0 X-Mailer: Evolution 3.18.5.2-0ubuntu3.2 X-SRS-Rewrite: SMTP reverse-path rewritten from by twosheds.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7587 Lines: 115 --=-6HA7wm9Hvi4sPObu/XZT Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2017-09-27 at 17:00 -0500, Bjorn Helgaas wrote: >=20 >=20 > IIUC, this question is basically "why doesn't the PCI core enable IOV > automatically when it sees an IOV-capable device?" >=20 > I think one reason is that an admin might want to control the number > of VFs we enable (e.g., via 1789382a72a5 ("PCI: SRIOV control and > status via sysfs" [1]).=C2=A0 But I guess you already know about that, > since this patch uses that sysfs path, so maybe I don't understand > your question. I mean, why doesn't the PCI core *allow* SR-IOV to be enabled via sysfs, unless the driver does this? --=-6HA7wm9Hvi4sPObu/XZT Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCDzUw ggSvMIIDl6ADAgECAhEA4CPLFRKDU4mtYW56VGdrITANBgkqhkiG9w0BAQsFADBvMQswCQYDVQQG EwJTRTEUMBIGA1UEChMLQWRkVHJ1c3QgQUIxJjAkBgNVBAsTHUFkZFRydXN0IEV4dGVybmFsIFRU UCBOZXR3b3JrMSIwIAYDVQQDExlBZGRUcnVzdCBFeHRlcm5hbCBDQSBSb290MB4XDTE0MTIyMjAw MDAwMFoXDTIwMDUzMDEwNDgzOFowgZsxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1h bmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGjAYBgNVBAoTEUNPTU9ETyBDQSBMaW1pdGVkMUEw PwYDVQQDEzhDT01PRE8gU0hBLTI1NiBDbGllbnQgQXV0aGVudGljYXRpb24gYW5kIFNlY3VyZSBF bWFpbCBDQTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAImxDdp6UxlOcFIdvFamBia3 uEngludRq/HwWhNJFaO0jBtgvHpRQqd5jKQi3xdhTpHVdiMKFNNKAn+2HQmAbqUEPdm6uxb+oYep 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