Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752975AbaJ0SKa (ORCPT ); Mon, 27 Oct 2014 14:10:30 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:50571 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752934AbaJ0SKZ (ORCPT ); Mon, 27 Oct 2014 14:10:25 -0400 From: Antonios Motakis To: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, alex.williamson@redhat.com Cc: will.deacon@arm.com, tech@virtualopensystems.com, christoffer.dall@linaro.org, eric.auger@linaro.org, kim.phillips@freescale.com, marc.zyngier@arm.com, Antonios Motakis , Bjorn Helgaas , Alexander Gordeev , kvm@vger.kernel.org (open list:VFIO DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v9 15/19] vfio: add local lock in virqfd instead of depending on VFIO PCI Date: Mon, 27 Oct 2014 19:08:00 +0100 Message-Id: <1414433284-31719-16-git-send-email-a.motakis@virtualopensystems.com> X-Mailer: git-send-email 2.1.1 In-Reply-To: <1414433284-31719-1-git-send-email-a.motakis@virtualopensystems.com> References: <1414433284-31719-1-git-send-email-a.motakis@virtualopensystems.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Virqfd just needs to keep accesses to any struct *virqfd safe, but this comes into play only when creating or destroying eventfds, so sharing the same spinlock with the VFIO bus driver is not necessary. Signed-off-by: Antonios Motakis --- drivers/vfio/pci/vfio_pci_intrs.c | 10 +++++----- drivers/vfio/virqfd.c | 24 +++++++++++++----------- include/linux/vfio.h | 3 +-- 3 files changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 3f909bb..e56c814 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -226,8 +226,8 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd) static void vfio_intx_disable(struct vfio_pci_device *vdev) { vfio_intx_set_signal(vdev, -1); - virqfd_disable(vdev, &vdev->ctx[0].unmask); - virqfd_disable(vdev, &vdev->ctx[0].mask); + virqfd_disable(&vdev->ctx[0].unmask); + virqfd_disable(&vdev->ctx[0].mask); vdev->irq_type = VFIO_PCI_NUM_IRQS; vdev->num_ctx = 0; kfree(vdev->ctx); @@ -377,8 +377,8 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix) vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix); for (i = 0; i < vdev->num_ctx; i++) { - virqfd_disable(vdev, &vdev->ctx[i].unmask); - virqfd_disable(vdev, &vdev->ctx[i].mask); + virqfd_disable(&vdev->ctx[i].unmask); + virqfd_disable(&vdev->ctx[i].mask); } if (msix) { @@ -415,7 +415,7 @@ static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev, vfio_send_intx_eventfd, NULL, &vdev->ctx[0].unmask, fd); - virqfd_disable(vdev, &vdev->ctx[0].unmask); + virqfd_disable(&vdev->ctx[0].unmask); } return 0; diff --git a/drivers/vfio/virqfd.c b/drivers/vfio/virqfd.c index 243eb61..27fa2f0 100644 --- a/drivers/vfio/virqfd.c +++ b/drivers/vfio/virqfd.c @@ -17,6 +17,7 @@ #include "pci/vfio_pci_private.h" static struct workqueue_struct *vfio_irqfd_cleanup_wq; +static spinlock_t lock; int __init vfio_pci_virqfd_init(void) { @@ -25,6 +26,8 @@ int __init vfio_pci_virqfd_init(void) if (!vfio_irqfd_cleanup_wq) return -ENOMEM; + spin_lock_init(&lock); + return 0; } @@ -53,21 +56,21 @@ static int virqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key) if (flags & POLLHUP) { unsigned long flags; - spin_lock_irqsave(&virqfd->vdev->irqlock, flags); + spin_lock_irqsave(&lock, flags); /* * The eventfd is closing, if the virqfd has not yet been * queued for release, as determined by testing whether the - * vdev pointer to it is still valid, queue it now. As + * virqfd pointer to it is still valid, queue it now. As * with kvm irqfds, we know we won't race against the virqfd - * going away because we hold wqh->lock to get here. + * going away because we hold the lock to get here. */ if (*(virqfd->pvirqfd) == virqfd) { *(virqfd->pvirqfd) = NULL; virqfd_deactivate(virqfd); } - spin_unlock_irqrestore(&virqfd->vdev->irqlock, flags); + spin_unlock_irqrestore(&lock, flags); } return 0; @@ -143,16 +146,16 @@ int virqfd_enable(struct vfio_pci_device *vdev, * we update the pointer to the virqfd under lock to avoid * pushing multiple jobs to release the same virqfd. */ - spin_lock_irq(&vdev->irqlock); + spin_lock_irq(&lock); if (*pvirqfd) { - spin_unlock_irq(&vdev->irqlock); + spin_unlock_irq(&lock); ret = -EBUSY; goto err_busy; } *pvirqfd = virqfd; - spin_unlock_irq(&vdev->irqlock); + spin_unlock_irq(&lock); /* * Install our own custom wake-up handling so we are notified via @@ -190,19 +193,18 @@ err_fd: } EXPORT_SYMBOL_GPL(virqfd_enable); -void virqfd_disable(struct vfio_pci_device *vdev, - struct virqfd **pvirqfd) +void virqfd_disable(struct virqfd **pvirqfd) { unsigned long flags; - spin_lock_irqsave(&vdev->irqlock, flags); + spin_lock_irqsave(&lock, flags); if (*pvirqfd) { virqfd_deactivate(*pvirqfd); *pvirqfd = NULL; } - spin_unlock_irqrestore(&vdev->irqlock, flags); + spin_unlock_irqrestore(&lock, flags); /* * Block until we know all outstanding shutdown jobs have completed. diff --git a/include/linux/vfio.h b/include/linux/vfio.h index a077c48..fb6037b 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -146,7 +146,6 @@ extern int virqfd_enable(struct vfio_pci_device *vdev, int (*handler)(struct vfio_pci_device *, void *), void (*thread)(struct vfio_pci_device *, void *), void *data, struct virqfd **pvirqfd, int fd); -extern void virqfd_disable(struct vfio_pci_device *vdev, - struct virqfd **pvirqfd); +extern void virqfd_disable(struct virqfd **pvirqfd); #endif /* VFIO_H */ -- 2.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/