From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753919AbdHUNSN (ORCPT ); Mon, 21 Aug 2017 09:18:13 -0400 Received: from verein.lst.de ([213.95.11.211]:33788 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753524AbdHUNSK (ORCPT ); Mon, 21 Aug 2017 09:18:10 -0400 Date: Mon, 21 Aug 2017 15:18:09 +0200 From: Christoph Hellwig To: Marc Zyngier Cc: YASUAKI ISHIMATSU , tglx@linutronix.de, axboe@kernel.dk, mpe@ellerman.id.au, keith.busch@intel.com, peterz@infradead.org, LKML , Christoph Hellwig Subject: Re: system hung up when offlining CPUs Message-ID: <20170821131809.GA17564@lst.de> References: <20170809124213.0d9518bb@why.wild-wind.fr.eu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Can you try the patch below please? --- >>From d5f59cb7a629de8439b318e1384660e6b56e7dd8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 21 Aug 2017 14:24:11 +0200 Subject: virtio_pci: fix cpu affinity support Commit 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues"") removed the adjustment of the pre_vectors for the virtio MSI-X vector allocation which was added in commit fb5e31d9 ("virtio: allow drivers to request IRQ affinity when creating VQs"). This will lead to an incorrect assignment of MSI-X vectors, and potential deadlocks when offlining cpus. Signed-off-by: Christoph Hellwig Fixes: 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues") Reported-by: YASUAKI ISHIMATSU --- drivers/virtio/virtio_pci_common.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index 007a4f366086..1c4797e53f68 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -107,6 +107,7 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, { struct virtio_pci_device *vp_dev = to_vp_device(vdev); const char *name = dev_name(&vp_dev->vdev.dev); + unsigned flags = PCI_IRQ_MSIX; unsigned i, v; int err = -ENOMEM; @@ -126,10 +127,13 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, GFP_KERNEL)) goto error; + if (desc) { + flags |= PCI_IRQ_AFFINITY; + desc->pre_vectors++; /* virtio config vector */ + } + err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors, - nvectors, PCI_IRQ_MSIX | - (desc ? PCI_IRQ_AFFINITY : 0), - desc); + nvectors, flags, desc); if (err < 0) goto error; vp_dev->msix_enabled = 1; -- 2.11.0