From bd20817f733ceb0291e0449106307ffc939006ba Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 15 Nov 2011 10:13:24 +0100 Subject: virtio: add HAS_IOMEM dependency to MMIO platform bus driver Fix this compile error on s390: CC [M] drivers/virtio/virtio_mmio.o drivers/virtio/virtio_mmio.c: In function 'vm_get_features': drivers/virtio/virtio_mmio.c:107:2: error: implicit declaration of function 'writel' Cc: Christian Borntraeger Signed-off-by: Heiko Carstens Acked-by: Pawel Moll Signed-off-by: Rusty Russell --- drivers/virtio/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 816ed08e7cf3..1a61939b85fc 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -37,7 +37,7 @@ config VIRTIO_BALLOON config VIRTIO_MMIO tristate "Platform bus driver for memory mapped virtio devices (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on HAS_IOMEM && EXPERIMENTAL select VIRTIO select VIRTIO_RING ---help--- -- cgit v1.2.3 From fe1a7fe2c4456679b3402f04268bdfafca7b127a Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Tue, 15 Nov 2011 16:17:18 +0200 Subject: virtio-mmio: Correct the name of the guest features selector Guest features selector spelling mistake. Cc: Pawel Moll Cc: Rusty Russell Cc: virtualization@lists.linux-foundation.org Signed-off-by: Sasha Levin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_mmio.c | 2 +- include/linux/virtio_mmio.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index acc5e43c373e..7317dc2ec426 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -118,7 +118,7 @@ static void vm_finalize_features(struct virtio_device *vdev) vring_transport_features(vdev); for (i = 0; i < ARRAY_SIZE(vdev->features); i++) { - writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SET); + writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL); writel(vdev->features[i], vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES); } diff --git a/include/linux/virtio_mmio.h b/include/linux/virtio_mmio.h index 27c7edefbc86..5c7b6f0daef8 100644 --- a/include/linux/virtio_mmio.h +++ b/include/linux/virtio_mmio.h @@ -63,7 +63,7 @@ #define VIRTIO_MMIO_GUEST_FEATURES 0x020 /* Activated features set selector - Write Only */ -#define VIRTIO_MMIO_GUEST_FEATURES_SET 0x024 +#define VIRTIO_MMIO_GUEST_FEATURES_SEL 0x024 /* Guest's memory page size in bytes - Write Only */ #define VIRTIO_MMIO_GUEST_PAGE_SIZE 0x028 -- cgit v1.2.3 From e6af578c5305be693a1bc7f4dc7b51dd82d41425 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 17 Nov 2011 17:41:15 +0200 Subject: virtio-pci: make reset operation safer virtio pci device reset actually just does an I/O write, which in PCI is really posted, that is it can complete on CPU before the device has received it. Further, interrupts might have been pending on another CPU, so device callback might get invoked after reset. This conflicts with how drivers use reset, which is typically: reset unregister a callback running after reset completed can race with unregister, potentially leading to use after free bugs. Fix by flushing out the write, and flushing pending interrupts. This assumes that device is never reset from its vq/config callbacks, or in parallel with being added/removed, document this assumption. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 18 ++++++++++++++++++ include/linux/virtio_config.h | 2 ++ 2 files changed, 20 insertions(+) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 3d1bf41e8892..03d1984bd363 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -169,11 +169,29 @@ static void vp_set_status(struct virtio_device *vdev, u8 status) iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS); } +/* wait for pending irq handlers */ +static void vp_synchronize_vectors(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + int i; + + if (vp_dev->intx_enabled) + synchronize_irq(vp_dev->pci_dev->irq); + + for (i = 0; i < vp_dev->msix_vectors; ++i) + synchronize_irq(vp_dev->msix_entries[i].vector); +} + static void vp_reset(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* 0 status means a reset. */ iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS); + /* Flush out the status write, and flush in device writes, + * including MSi-X interrupts, if any. */ + ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS); + /* Flush pending VQ/configuration callbacks. */ + vp_synchronize_vectors(vdev); } /* the notify function used when creating a virt queue */ diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index add4790b21fe..e9e72bda1b72 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -85,6 +85,8 @@ * @reset: reset the device * vdev: the virtio device * After this, status and feature negotiation must be done again + * Device must not be reset from its vq/config callbacks, or in + * parallel with being added/removed. * @find_vqs: find virtqueues and instantiate them. * vdev: the virtio_device * nvqs: the number of virtqueues to find -- cgit v1.2.3