From patchwork Fri Oct 6 06:19:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 13410977 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 529DFE92FEA for ; Fri, 6 Oct 2023 06:22:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qoeCS-0005CG-9d; Fri, 06 Oct 2023 02:20:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qoeCO-00059M-Ir for qemu-devel@nongnu.org; Fri, 06 Oct 2023 02:20:32 -0400 Received: from mail.ozlabs.org ([2404:9400:2221:ea00::3] helo=gandalf.ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qoeCL-0002ql-QI for qemu-devel@nongnu.org; Fri, 06 Oct 2023 02:20:32 -0400 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4S1yw81HpFz4xQZ; Fri, 6 Oct 2023 17:20:24 +1100 (AEDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4S1yw64Kb9z4xQV; Fri, 6 Oct 2023 17:20:22 +1100 (AEDT) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-devel@nongnu.org Cc: Alex Williamson , Jing Liu , =?utf-8?q?C=C3=A9dric_Le_Goater?= Subject: [PULL 06/21] vfio/pci: enable MSI-X in interrupt restoring on dynamic allocation Date: Fri, 6 Oct 2023 08:19:50 +0200 Message-ID: <20231006062005.1040296-7-clg@redhat.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231006062005.1040296-1-clg@redhat.com> References: <20231006062005.1040296-1-clg@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2404:9400:2221:ea00::3; envelope-from=SRS0=cI0A=FU=redhat.com=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -39 X-Spam_score: -4.0 X-Spam_bar: ---- X-Spam_report: (-4.0 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Jing Liu During migration restoring, vfio_enable_vectors() is called to restore enabling MSI-X interrupts for assigned devices. It sets the range from 0 to nr_vectors to kernel to enable MSI-X and the vectors unmasked in guest. During the MSI-X enabling, all the vectors within the range are allocated according to the VFIO_DEVICE_SET_IRQS ioctl. When dynamic MSI-X allocation is supported, we only want the guest unmasked vectors being allocated and enabled. Use vector 0 with an invalid fd to get MSI-X enabled, after that, all the vectors can be allocated in need. Signed-off-by: Jing Liu Reviewed-by: Cédric Le Goater Reviewed-by: Alex Williamson Signed-off-by: Cédric Le Goater --- hw/vfio/pci.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index ad508abd6f382d518871191017859c4c4c8fd4f9..898296fd5441b07fded7e50a53b2927683dd4b1a 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -402,6 +402,23 @@ static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix) int ret = 0, i, argsz; int32_t *fds; + /* + * If dynamic MSI-X allocation is supported, the vectors to be allocated + * and enabled can be scattered. Before kernel enabling MSI-X, setting + * nr_vectors causes all these vectors to be allocated on host. + * + * To keep allocation as needed, use vector 0 with an invalid fd to get + * MSI-X enabled first, then set vectors with a potentially sparse set of + * eventfds to enable interrupts only when enabled in guest. + */ + if (msix && !vdev->msix->noresize) { + ret = vfio_enable_msix_no_vec(vdev); + + if (ret) { + return ret; + } + } + argsz = sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds)); irq_set = g_malloc0(argsz);