From patchwork Wed Apr 6 12:40:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 65177 Delivered-To: patch@linaro.org Received: by 10.112.199.169 with SMTP id jl9csp1027746lbc; Wed, 6 Apr 2016 05:41:20 -0700 (PDT) X-Received: by 10.66.231.100 with SMTP id tf4mr70851490pac.44.1459946465194; Wed, 06 Apr 2016 05:41:05 -0700 (PDT) Return-Path: Received: from ml01.01.org (ml01.01.org. [2001:19d0:306:5::1]) by mx.google.com with ESMTPS id g29si4431872pfj.135.2016.04.06.05.41.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Apr 2016 05:41:05 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 2001:19d0:306:5::1 as permitted sender) client-ip=2001:19d0:306:5::1; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of edk2-devel-bounces@lists.01.org designates 2001:19d0:306:5::1 as permitted sender) smtp.mailfrom=edk2-devel-bounces@lists.01.org Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id E68FF1A1FD1; Wed, 6 Apr 2016 05:40:56 -0700 (PDT) X-Original-To: edk2-devel@ml01.01.org Delivered-To: edk2-devel@ml01.01.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id A283A1A1FAD for ; Wed, 6 Apr 2016 05:40:55 -0700 (PDT) Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3EBEF7F6B4; Wed, 6 Apr 2016 12:40:55 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com ([10.3.113.15]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u36CeV8X027635; Wed, 6 Apr 2016 08:40:54 -0400 From: Laszlo Ersek To: edk2-devel-01 Date: Wed, 6 Apr 2016 14:40:22 +0200 Message-Id: <1459946427-15771-13-git-send-email-lersek@redhat.com> In-Reply-To: <1459946427-15771-1-git-send-email-lersek@redhat.com> References: <1459946427-15771-1-git-send-email-lersek@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Subject: [edk2] [wave 3 PATCH v2 12/17] OvmfPkg: VirtioRngDxe: adapt feature negotiation to virtio-1.0 X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Jordan Justen , Ard Biesheuvel MIME-Version: 1.0 Errors-To: edk2-devel-bounces@lists.01.org Sender: "edk2-devel" Relative to virtio-0.9.5, virtio-1.0 reverses the order of queue discovery and feature negotiation. In virtio-1.0, feature negotiation has to complete first, and the device can also reject a self-inconsistent feature request through the new VSTAT_FEATURES_OK status bit. (For example if the driver requests a higher level feature but clears a prerequisite feature.) Furthermore, we retain the VIRTIO_F_VERSION_1 feature bit if the VIRTIO_DEVICE_PROTOCOL provider has high enough revision. Cc: Ard Biesheuvel Cc: Jordan Justen Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek Tested-by: Ard Biesheuvel Reviewed-by: Jordan Justen --- OvmfPkg/VirtioRngDxe/VirtioRng.c | 27 +++++++++++++++----- 1 file changed, 20 insertions(+), 7 deletions(-) -- 1.8.3.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c index d916534aac63..1a186d04082a 100644 --- a/OvmfPkg/VirtioRngDxe/VirtioRng.c +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c @@ -238,14 +238,27 @@ VirtioRngInit ( // step 4a -- retrieve and validate features // Status = Dev->VirtIo->GetDeviceFeatures (Dev->VirtIo, &Features); if (EFI_ERROR (Status)) { goto Failed; } + Features &= VIRTIO_F_VERSION_1; + + // + // In virtio-1.0, feature negotiation is expected to complete before queue + // discovery, and the device can also reject the selected set of features. + // + if (Dev->VirtIo->Revision >= VIRTIO_SPEC_REVISION (1, 0, 0)) { + Status = Virtio10WriteFeatures (Dev->VirtIo, Features, &NextDevStat); + if (EFI_ERROR (Status)) { + goto Failed; + } + } + // // step 4b -- allocate request virtqueue, just use #0 // Status = Dev->VirtIo->SetQueueSel (Dev->VirtIo, 0); if (EFI_ERROR (Status)) { goto Failed; } @@ -286,22 +299,22 @@ VirtioRngInit ( // Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, &Dev->Ring); if (EFI_ERROR (Status)) { goto ReleaseQueue; } // - // step 5 -- Report understood features and guest-tuneables. None are - // currently defined for VirtioRng, and no generic features are needed by - // this driver. + // step 5 -- Report understood features and guest-tuneables. // - Features &= 0; - Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); - if (EFI_ERROR (Status)) { - goto ReleaseQueue; + if (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) { + Features &= ~(UINT64)VIRTIO_F_VERSION_1; + Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); + if (EFI_ERROR (Status)) { + goto ReleaseQueue; + } } // // step 6 -- initialization complete // NextDevStat |= VSTAT_DRIVER_OK; Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat);