From 13060b64b819c194909121b90b5f8dd9abb5ea4e Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 6 Feb 2015 15:05:07 -0700 Subject: vfio: Add and use device request op for vfio bus drivers When a request is made to unbind a device from a vfio bus driver, we need to wait for the device to become unused, ie. for userspace to release the device. However, we have a long standing TODO in the code to do something proactive to make that happen. To enable this, we add a request callback on the vfio bus driver struct, which is intended to signal the user through the vfio device interface to release the device. Instead of passively waiting for the device to become unused, we can now pester the user to give it up. Signed-off-by: Alex Williamson --- include/linux/vfio.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/vfio.h b/include/linux/vfio.h index d3204115f15d..2d67b8998fd8 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -26,6 +26,7 @@ * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_* * operations documented below * @mmap: Perform mmap(2) on a region of the device file descriptor + * @request: Request for the bus driver to release the device */ struct vfio_device_ops { char *name; @@ -38,6 +39,7 @@ struct vfio_device_ops { long (*ioctl)(void *device_data, unsigned int cmd, unsigned long arg); int (*mmap)(void *device_data, struct vm_area_struct *vma); + void (*request)(void *device_data, unsigned int count); }; extern int vfio_add_group_dev(struct device *dev, -- cgit v1.3-18-gd494 From 6140a8f5623820cec7f56c63444b9551d8d35775 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 6 Feb 2015 15:05:08 -0700 Subject: vfio-pci: Add device request interface Userspace can opt to receive a device request notification, indicating that the device should be released. This is setup the same way as the error IRQ and also supports eventfd signaling. Future support may forcefully remove the device from the user if the request is ignored. Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci.c | 21 ++++++++++++++++++++- drivers/vfio/pci/vfio_pci_intrs.c | 16 ++++++++++++++++ drivers/vfio/pci/vfio_pci_private.h | 1 + include/uapi/linux/vfio.h | 1 + 4 files changed, 38 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 7cc0122a18ce..f8a186381ae8 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -239,9 +239,12 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type) return (flags & PCI_MSIX_FLAGS_QSIZE) + 1; } - } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) + } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) { if (pci_is_pcie(vdev->pdev)) return 1; + } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) { + return 1; + } return 0; } @@ -464,6 +467,7 @@ static long vfio_pci_ioctl(void *device_data, switch (info.index) { case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX: + case VFIO_PCI_REQ_IRQ_INDEX: break; case VFIO_PCI_ERR_IRQ_INDEX: if (pci_is_pcie(vdev->pdev)) @@ -828,6 +832,20 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) req_len, vma->vm_page_prot); } +static void vfio_pci_request(void *device_data, unsigned int count) +{ + struct vfio_pci_device *vdev = device_data; + + mutex_lock(&vdev->igate); + + if (vdev->req_trigger) { + dev_dbg(&vdev->pdev->dev, "Requesting device from user\n"); + eventfd_signal(vdev->req_trigger, 1); + } + + mutex_unlock(&vdev->igate); +} + static const struct vfio_device_ops vfio_pci_ops = { .name = "vfio-pci", .open = vfio_pci_open, @@ -836,6 +854,7 @@ static const struct vfio_device_ops vfio_pci_ops = { .read = vfio_pci_read, .write = vfio_pci_write, .mmap = vfio_pci_mmap, + .request = vfio_pci_request, }; static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index b134befbfd0e..f88bfdf5b6a0 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -817,6 +817,16 @@ static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev, return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data); } +static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev, + unsigned index, unsigned start, + unsigned count, uint32_t flags, void *data) +{ + if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1) + return -EINVAL; + + return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data); +} + int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags, unsigned index, unsigned start, unsigned count, void *data) @@ -858,6 +868,12 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags, func = vfio_pci_set_err_trigger; break; } + case VFIO_PCI_REQ_IRQ_INDEX: + switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) { + case VFIO_IRQ_SET_ACTION_TRIGGER: + func = vfio_pci_set_req_trigger; + break; + } } if (!func) diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 671c17a6e6d0..c9f9b323f152 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -58,6 +58,7 @@ struct vfio_pci_device { struct pci_saved_state *pci_saved_state; int refcnt; struct eventfd_ctx *err_trigger; + struct eventfd_ctx *req_trigger; }; #define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 29715d27548f..82889c30f4f5 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -333,6 +333,7 @@ enum { VFIO_PCI_MSI_IRQ_INDEX, VFIO_PCI_MSIX_IRQ_INDEX, VFIO_PCI_ERR_IRQ_INDEX, + VFIO_PCI_REQ_IRQ_INDEX, VFIO_PCI_NUM_IRQS }; -- cgit v1.3-18-gd494