From 8b27ee60bfd6bbb84d2df28fa706c5c5081066ca Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 4 Sep 2013 11:28:04 -0600 Subject: vfio-pci: PCI hot reset interface The current VFIO_DEVICE_RESET interface only maps to PCI use cases where we can isolate the reset to the individual PCI function. This means the device must support FLR (PCIe or AF), PM reset on D3hot->D0 transition, device specific reset, or be a singleton device on a bus for a secondary bus reset. FLR does not have widespread support, PM reset is not very reliable, and bus topology is dictated by the system and device design. We need to provide a means for a user to induce a bus reset in cases where the existing mechanisms are not available or not reliable. This device specific extension to VFIO provides the user with this ability. Two new ioctls are introduced: - VFIO_DEVICE_PCI_GET_HOT_RESET_INFO - VFIO_DEVICE_PCI_HOT_RESET The first provides the user with information about the extent of devices affected by a hot reset. This is essentially a list of devices and the IOMMU groups they belong to. The user may then initiate a hot reset by calling the second ioctl. We must be careful that the user has ownership of all the affected devices found via the first ioctl, so the second ioctl takes a list of file descriptors for the VFIO groups affected by the reset. Each group must have IOMMU protection established for the ioctl to succeed. Signed-off-by: Alex Williamson --- include/uapi/linux/vfio.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 916e444e6f74..0fd47f5bc146 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -324,6 +324,44 @@ enum { VFIO_PCI_NUM_IRQS }; +/** + * VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IORW(VFIO_TYPE, VFIO_BASE + 12, + * struct vfio_pci_hot_reset_info) + * + * Return: 0 on success, -errno on failure: + * -enospc = insufficient buffer, -enodev = unsupported for device. + */ +struct vfio_pci_dependent_device { + __u32 group_id; + __u16 segment; + __u8 bus; + __u8 devfn; /* Use PCI_SLOT/PCI_FUNC */ +}; + +struct vfio_pci_hot_reset_info { + __u32 argsz; + __u32 flags; + __u32 count; + struct vfio_pci_dependent_device devices[]; +}; + +#define VFIO_DEVICE_GET_PCI_HOT_RESET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12) + +/** + * VFIO_DEVICE_PCI_HOT_RESET - _IOW(VFIO_TYPE, VFIO_BASE + 13, + * struct vfio_pci_hot_reset) + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_pci_hot_reset { + __u32 argsz; + __u32 flags; + __u32 count; + __s32 group_fds[]; +}; + +#define VFIO_DEVICE_PCI_HOT_RESET _IO(VFIO_TYPE, VFIO_BASE + 13) + /* -------- API for Type1 VFIO IOMMU -------- */ /** -- cgit v1.2.2