From patchwork Mon Feb 5 18:58:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 869457 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3zZxrz19BSz9t2c for ; Tue, 6 Feb 2018 06:06:27 +1100 (AEDT) Received: from localhost ([::1]:51783 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eim5x-0008GR-5C for incoming@patchwork.ozlabs.org; Mon, 05 Feb 2018 14:06:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35968) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eilyN-0002Nc-F1 for qemu-devel@nongnu.org; Mon, 05 Feb 2018 13:58:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eilyK-0004pe-Dx for qemu-devel@nongnu.org; Mon, 05 Feb 2018 13:58:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39940) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eilyK-0004pO-4a for qemu-devel@nongnu.org; Mon, 05 Feb 2018 13:58:32 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5170C28204 for ; Mon, 5 Feb 2018 18:58:31 +0000 (UTC) Received: from gimli.home (ovpn-117-203.phx2.redhat.com [10.3.117.203]) by smtp.corp.redhat.com (Postfix) with ESMTP id 17ADD5EE01; Mon, 5 Feb 2018 18:58:19 +0000 (UTC) From: Alex Williamson To: qemu-devel@nongnu.org Date: Mon, 05 Feb 2018 11:58:18 -0700 Message-ID: <20180205185818.14391.75315.stgit@gimli.home> In-Reply-To: <20180205185416.14391.5739.stgit@gimli.home> References: <20180205185416.14391.5739.stgit@gimli.home> User-Agent: StGit/0.18-101-g8fa6 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 05 Feb 2018 18:58:31 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 11/11] vfio/pci: Add option to disable GeForce quirks X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" These quirks are necessary for GeForce, but not for Quadro/GRID/Tesla assignment. Leaving them enabled is fully functional and provides the most compatibility, but due to the unique NVIDIA MSI ACK behavior[1], it also introduces latency in re-triggering the MSI interrupt. This overhead is typically negligible, but has been shown to adversely affect some (very) high interrupt rate applications. This adds the vfio-pci device option "x-no-geforce-quirks=" which can be set to "on" to disable this additional overhead. A follow-on optimization for GeForce might be to make use of an ioeventfd to allow KVM to trigger an irqfd in the kernel vfio-pci driver, avoiding the bounce through userspace to handle this device write. [1] Background: the NVIDIA driver has been observed to issue a write to the MMIO mirror of PCI config space in BAR0 in order to allow the MSI interrupt for the device to retrigger. Older reports indicated a write of 0xff to the (read-only) MSI capability ID register, while more recently a write of 0x0 is observed at config space offset 0x704, non-architected, extended config space of the device (BAR0 offset 0x88704). Virtualization of this range is only required for GeForce. Signed-off-by: Alex Williamson --- hw/vfio/pci-quirks.c | 9 ++++++--- hw/vfio/pci.c | 2 ++ hw/vfio/pci.h | 1 + 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c index 60ad5fb91a83..e5779a7ad35b 100644 --- a/hw/vfio/pci-quirks.c +++ b/hw/vfio/pci-quirks.c @@ -542,7 +542,8 @@ static void vfio_vga_probe_nvidia_3d0_quirk(VFIOPCIDevice *vdev) VFIOQuirk *quirk; VFIONvidia3d0Quirk *data; - if (!vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || + if (vdev->no_geforce_quirks || + !vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || !vdev->bars[1].region.size) { return; } @@ -660,7 +661,8 @@ static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr) VFIONvidiaBAR5Quirk *bar5; VFIOConfigWindowQuirk *window; - if (!vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || + if (vdev->no_geforce_quirks || + !vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || !vdev->vga || nr != 5 || !vdev->bars[5].ioport) { return; } @@ -754,7 +756,8 @@ static void vfio_probe_nvidia_bar0_quirk(VFIOPCIDevice *vdev, int nr) VFIOQuirk *quirk; VFIOConfigMirrorQuirk *mirror; - if (!vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || + if (vdev->no_geforce_quirks || + !vfio_pci_is(vdev, PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID) || !vfio_is_vga(vdev) || nr != 0) { return; } diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index cab2aecb8094..879510c046cd 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3130,6 +3130,8 @@ static Property vfio_pci_dev_properties[] = { DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false), DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false), DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false), + DEFINE_PROP_BOOL("x-no-geforce-quirks", VFIOPCIDevice, + no_geforce_quirks, false), DEFINE_PROP_UINT32("x-pci-vendor-id", VFIOPCIDevice, vendor_id, PCI_ANY_ID), DEFINE_PROP_UINT32("x-pci-device-id", VFIOPCIDevice, device_id, PCI_ANY_ID), DEFINE_PROP_UINT32("x-pci-sub-vendor-id", VFIOPCIDevice, diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h index 588381f201b4..f4aa13e021fa 100644 --- a/hw/vfio/pci.h +++ b/hw/vfio/pci.h @@ -146,6 +146,7 @@ typedef struct VFIOPCIDevice { bool no_kvm_intx; bool no_kvm_msi; bool no_kvm_msix; + bool no_geforce_quirks; } VFIOPCIDevice; uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);