From patchwork Mon Oct 9 06:48:58 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: 13412996 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 74AA1E95A8E for ; Mon, 9 Oct 2023 06:50:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qpk50-0006Rb-Mh; Mon, 09 Oct 2023 02:49:26 -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 1qpk4y-0006Qk-SH for qemu-devel@nongnu.org; Mon, 09 Oct 2023 02:49:24 -0400 Received: from gandalf.ozlabs.org ([150.107.74.76]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qpk4w-0007HN-L9 for qemu-devel@nongnu.org; Mon, 09 Oct 2023 02:49:24 -0400 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4S3qQ84J32z4xWk; Mon, 9 Oct 2023 17:49:20 +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 4S3qQ62NsBz4xWP; Mon, 9 Oct 2023 17:49:18 +1100 (AEDT) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-devel@nongnu.org Cc: Alex Williamson , Jing Liu , Reinette Chatre , =?utf-8?q?C=C3=A9dric_Le_Goater?= Subject: [PULL 4/6] vfio/pci: enable vector on dynamic MSI-X allocation Date: Mon, 9 Oct 2023 08:48:58 +0200 Message-ID: <20231009064900.1465361-5-clg@redhat.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231009064900.1465361-1-clg@redhat.com> References: <20231009064900.1465361-1-clg@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=qD0P=FX=redhat.com=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no 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 The vector_use callback is used to enable vector that is unmasked in guest. The kernel used to only support static MSI-X allocation. When allocating a new interrupt using "static MSI-X allocation" kernels, QEMU first disables all previously allocated vectors and then re-allocates all including the new one. The nr_vectors of VFIOPCIDevice indicates that all vectors from 0 to nr_vectors are allocated (and may be enabled), which is used to loop all the possibly used vectors when e.g., disabling MSI-X interrupts. Extend the vector_use function to support dynamic MSI-X allocation when host supports the capability. QEMU therefore can individually allocate and enable a new interrupt without affecting others or causing interrupts lost during runtime. Utilize nr_vectors to calculate the upper bound of enabled vectors in dynamic MSI-X allocation mode since looping all msix_entries_nr is not efficient and unnecessary. Signed-off-by: Jing Liu Tested-by: Reinette Chatre Reviewed-by: Alex Williamson Signed-off-by: Cédric Le Goater --- hw/vfio/pci.c | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 86c92c51a46e2d1e9856c3cbcd7c47548daab422..eb7627c5f9fcd67f346595ebe73011cc3205b58e 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -470,6 +470,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr, VFIOPCIDevice *vdev = VFIO_PCI(pdev); VFIOMSIVector *vector; int ret; + bool resizing = !!(vdev->nr_vectors < nr + 1); trace_vfio_msix_vector_do_use(vdev->vbasedev.name, nr); @@ -512,33 +513,42 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr, } /* - * We don't want to have the host allocate all possible MSI vectors - * for a device if they're not in use, so we shutdown and incrementally - * increase them as needed. + * When dynamic allocation is not supported, we don't want to have the + * host allocate all possible MSI vectors for a device if they're not + * in use, so we shutdown and incrementally increase them as needed. + * nr_vectors represents the total number of vectors allocated. + * + * When dynamic allocation is supported, let the host only allocate + * and enable a vector when it is in use in guest. nr_vectors represents + * the upper bound of vectors being enabled (but not all of the ranges + * is allocated or enabled). */ - if (vdev->nr_vectors < nr + 1) { + if (resizing) { vdev->nr_vectors = nr + 1; - if (!vdev->defer_kvm_irq_routing) { + } + + if (!vdev->defer_kvm_irq_routing) { + if (vdev->msix->noresize && resizing) { vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX); ret = vfio_enable_vectors(vdev, true); if (ret) { error_report("vfio: failed to enable vectors, %d", ret); } - } - } else { - Error *err = NULL; - int32_t fd; - - if (vector->virq >= 0) { - fd = event_notifier_get_fd(&vector->kvm_interrupt); } else { - fd = event_notifier_get_fd(&vector->interrupt); - } + Error *err = NULL; + int32_t fd; - if (vfio_set_irq_signaling(&vdev->vbasedev, - VFIO_PCI_MSIX_IRQ_INDEX, nr, - VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) { - error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); + if (vector->virq >= 0) { + fd = event_notifier_get_fd(&vector->kvm_interrupt); + } else { + fd = event_notifier_get_fd(&vector->interrupt); + } + + if (vfio_set_irq_signaling(&vdev->vbasedev, + VFIO_PCI_MSIX_IRQ_INDEX, nr, + VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) { + error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); + } } }