From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753914AbeE3Qyn (ORCPT ); Wed, 30 May 2018 12:54:43 -0400 Received: from mga07.intel.com ([134.134.136.100]:24566 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753670AbeE3Qyk (ORCPT ); Wed, 30 May 2018 12:54:40 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,461,1520924400"; d="scan'208";a="45449353" From: "Duyck, Alexander H" To: "Rustad, Mark D" , "mst@redhat.com" CC: "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "virtio-dev@lists.oasis-open.org" , "Daly, Dan" , "Bie, Tiwei" , "linux-pci@vger.kernel.org" , "bhelgaas@google.com" , "Liang, Cunming" , "Wang, Zhihong" Subject: Re: [PATCH] virtio_pci: support enabling VFs Thread-Topic: [PATCH] virtio_pci: support enabling VFs Thread-Index: AQHT9/P5uaO7GXR/D0ickSAfuvKJDaRI6igAgAAGIoCAAALrgA== Date: Wed, 30 May 2018 16:54:35 +0000 Message-ID: <1527699273.29907.2.camel@intel.com> References: <20180530085521.26583-1-tiwei.bie@intel.com> <20180530192010-mutt-send-email-mst@kernel.org> <414C18B1-30FA-4AC0-B47D-F0FBF9832737@intel.com> In-Reply-To: <414C18B1-30FA-4AC0-B47D-F0FBF9832737@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [134.134.177.79] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w4UGspnX002814 On Wed, 2018-05-30 at 09:44 -0700, Rustad, Mark D wrote: > On May 30, 2018, at 9:22 AM, Michael S. Tsirkin wrote: > > > > +static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int > > > num_vfs) > > > +{ > > > + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); > > > + struct virtio_device *vdev = &vp_dev->vdev; > > > + int (*sriov_configure)(struct pci_dev *pci_dev, int num_vfs); > > > + > > > + if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK)) > > > + return -EBUSY; > > > + > > > + if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV)) > > > + return -EINVAL; > > > + > > > + sriov_configure = pci_sriov_configure_simple; > > > + if (sriov_configure == NULL) > > > + return -ENOENT; > > > > BTW what is all this trickery in aid of? > > When SR-IOV support is not compiled into the kernel, > pci_sriov_configure_simple is #defined as NULL. This allows it to compile > in that case, even though there is utterly no way for it to be called in > that case. It is an alternative to #ifs in the code. Why even have the call though? I would wrap all of this in an #ifdef and strip it out since you couldn't support SR-IOV if it isn't present in the kernel anyway. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com ([134.134.136.100]:24566 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753670AbeE3Qyk (ORCPT ); Wed, 30 May 2018 12:54:40 -0400 From: "Duyck, Alexander H" To: "Rustad, Mark D" , "mst@redhat.com" CC: "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "virtio-dev@lists.oasis-open.org" , "Daly, Dan" , "Bie, Tiwei" , "linux-pci@vger.kernel.org" , "bhelgaas@google.com" , "Liang, Cunming" , "Wang, Zhihong" Subject: Re: [PATCH] virtio_pci: support enabling VFs Date: Wed, 30 May 2018 16:54:35 +0000 Message-ID: <1527699273.29907.2.camel@intel.com> References: <20180530085521.26583-1-tiwei.bie@intel.com> <20180530192010-mutt-send-email-mst@kernel.org> <414C18B1-30FA-4AC0-B47D-F0FBF9832737@intel.com> In-Reply-To: <414C18B1-30FA-4AC0-B47D-F0FBF9832737@intel.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org List-ID: T24gV2VkLCAyMDE4LTA1LTMwIGF0IDA5OjQ0IC0wNzAwLCBSdXN0YWQsIE1hcmsgRCB3cm90ZToN Cj4gT24gTWF5IDMwLCAyMDE4LCBhdCA5OjIyIEFNLCBNaWNoYWVsIFMuIFRzaXJraW4gPG1zdEBy ZWRoYXQuY29tPiB3cm90ZToNCj4gDQo+ID4gPiArc3RhdGljIGludCB2aXJ0aW9fcGNpX3NyaW92 X2NvbmZpZ3VyZShzdHJ1Y3QgcGNpX2RldiAqcGNpX2RldiwgaW50ICANCj4gPiA+IG51bV92ZnMp DQo+ID4gPiArew0KPiA+ID4gKwlzdHJ1Y3QgdmlydGlvX3BjaV9kZXZpY2UgKnZwX2RldiA9IHBj aV9nZXRfZHJ2ZGF0YShwY2lfZGV2KTsNCj4gPiA+ICsJc3RydWN0IHZpcnRpb19kZXZpY2UgKnZk ZXYgPSAmdnBfZGV2LT52ZGV2Ow0KPiA+ID4gKwlpbnQgKCpzcmlvdl9jb25maWd1cmUpKHN0cnVj dCBwY2lfZGV2ICpwY2lfZGV2LCBpbnQgbnVtX3Zmcyk7DQo+ID4gPiArDQo+ID4gPiArCWlmICgh KHZkZXYtPmNvbmZpZy0+Z2V0X3N0YXR1cyh2ZGV2KSAmIFZJUlRJT19DT05GSUdfU19EUklWRVJf T0spKQ0KPiA+ID4gKwkJcmV0dXJuIC1FQlVTWTsNCj4gPiA+ICsNCj4gPiA+ICsJaWYgKCFfX3Zp cnRpb190ZXN0X2JpdCh2ZGV2LCBWSVJUSU9fRl9TUl9JT1YpKQ0KPiA+ID4gKwkJcmV0dXJuIC1F SU5WQUw7DQo+ID4gPiArDQo+ID4gPiArCXNyaW92X2NvbmZpZ3VyZSA9IHBjaV9zcmlvdl9jb25m aWd1cmVfc2ltcGxlOw0KPiA+ID4gKwlpZiAoc3Jpb3ZfY29uZmlndXJlID09IE5VTEwpDQo+ID4g PiArCQlyZXR1cm4gLUVOT0VOVDsNCj4gPiANCj4gPiBCVFcgd2hhdCBpcyBhbGwgdGhpcyB0cmlj a2VyeSBpbiBhaWQgb2Y/DQo+IA0KPiBXaGVuIFNSLUlPViBzdXBwb3J0IGlzIG5vdCBjb21waWxl ZCBpbnRvIHRoZSBrZXJuZWwsICANCj4gcGNpX3NyaW92X2NvbmZpZ3VyZV9zaW1wbGUgaXMgI2Rl ZmluZWQgYXMgTlVMTC4gVGhpcyBhbGxvd3MgaXQgdG8gY29tcGlsZSAgDQo+IGluIHRoYXQgY2Fz ZSwgZXZlbiB0aG91Z2ggdGhlcmUgaXMgdXR0ZXJseSBubyB3YXkgZm9yIGl0IHRvIGJlIGNhbGxl ZCBpbiAgDQo+IHRoYXQgY2FzZS4gSXQgaXMgYW4gYWx0ZXJuYXRpdmUgdG8gI2lmcyBpbiB0aGUg Y29kZS4NCg0KV2h5IGV2ZW4gaGF2ZSB0aGUgY2FsbCB0aG91Z2g/IEkgd291bGQgd3JhcCBhbGwg b2YgdGhpcyBpbiBhbiAjaWZkZWYNCmFuZCBzdHJpcCBpdCBvdXQgc2luY2UgeW91IGNvdWxkbid0 IHN1cHBvcnQgU1ItSU9WIGlmIGl0IGlzbid0IHByZXNlbnQNCmluIHRoZSBrZXJuZWwgYW55d2F5 Lg==