When using VFIO to assign a device to a guest, we want to make sure the device is quiesced on VM reset to stop all DMA within the guest mapped memory. Add an ioctl which just calls pci_reset_function() and returns whether it succeeds. Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- We've recently needed to add this functionality for current KVM based device assignment, VFIO should provide a way to do this too. An example of it being used in the Qemu VFIO driver can be found here: https://github.com/awilliam/qemu-vfio/blob/vfio/hw/vfio.c drivers/vfio/vfio_main.c | 4 ++++ include/linux/vfio.h | 3 +++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 7e427fc..b9bb692 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -490,6 +490,10 @@ static long vfio_unl_ioctl(struct file *filep, ret = vfio_irq_eoi_eventfd(vdev, fd); break; + case VFIO_RESET_FUNCTION: + ret = pci_reset_function(vdev->pdev); + break; + default: return -EINVAL; } diff --git a/include/linux/vfio.h b/include/linux/vfio.h index f07d8fe..47d9bb9 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -215,6 +215,9 @@ struct vfio_dma_map { /* Re-enable INTx via eventfd */ #define VFIO_IRQ_EOI_EVENTFD _IOW(';', 110, int) +/* Reset PCI function */ +#define VFIO_RESET_FUNCTION _IO(';', 111) + /* * Reads, writes, and mmaps determine which PCI BAR (or config space) * from the high level bits of the file offset -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
