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 <[email protected]>
---
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
On Tue, 19 Apr 2011 14:32:59 -0600 Alex Williamson wrote:
> 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 <[email protected]>
> ---
>
> 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
I can't find include/linux/vfio.h in linux-next or mainline git, but
ioctls need to be documented in Documentation/ioctl/ioctl-number.txt....
---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
* Randy Dunlap ([email protected]) wrote:
> I can't find include/linux/vfio.h in linux-next or mainline git, but
> ioctls need to be documented in Documentation/ioctl/ioctl-number.txt....
It is in the full patchset: https://github.com/pugs/vfio-linux-2.6
* Alex Williamson ([email protected]) wrote:
> 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.
Shouldn't there be a reset when binding/unbinding vfio to/from a pci
device?
On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote:
> * Alex Williamson ([email protected]) wrote:
> > 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.
>
> Shouldn't there be a reset when binding/unbinding vfio to/from a pci
> device?
There's already one when the /dev/vfioX file is opened, we should add
another on release, and probably add the same PCI save state store/load
that I'm proposing for KVM across those. Thanks,
Alex
* Alex Williamson ([email protected]) wrote:
> On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote:
> > * Alex Williamson ([email protected]) wrote:
> > > 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.
> >
> > Shouldn't there be a reset when binding/unbinding vfio to/from a pci
> > device?
>
> There's already one when the /dev/vfioX file is opened, we should add
> another on release, and probably add the same PCI save state store/load
> that I'm proposing for KVM across those. Thanks,
Hmm, I looked and didn't see it, hence the question.
On Tue, 2011-04-19 at 15:26 -0700, Chris Wright wrote:
> * Alex Williamson ([email protected]) wrote:
> > On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote:
> > > * Alex Williamson ([email protected]) wrote:
> > > > 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.
> > >
> > > Shouldn't there be a reset when binding/unbinding vfio to/from a pci
> > > device?
> >
> > There's already one when the /dev/vfioX file is opened, we should add
> > another on release, and probably add the same PCI save state store/load
> > that I'm proposing for KVM across those. Thanks,
>
> Hmm, I looked and didn't see it, hence the question.
vfio_open() -> pci_reset_function()
https://github.com/pugs/vfio-linux-2.6/blob/vfio/drivers/vfio/vfio_main.c
* Alex Williamson ([email protected]) wrote:
> On Tue, 2011-04-19 at 15:26 -0700, Chris Wright wrote:
> > * Alex Williamson ([email protected]) wrote:
> > > On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote:
> > > > * Alex Williamson ([email protected]) wrote:
> > > > > 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.
> > > >
> > > > Shouldn't there be a reset when binding/unbinding vfio to/from a pci
> > > > device?
> > >
> > > There's already one when the /dev/vfioX file is opened, we should add
> > > another on release, and probably add the same PCI save state store/load
> > > that I'm proposing for KVM across those. Thanks,
> >
> > Hmm, I looked and didn't see it, hence the question.
>
> vfio_open() -> pci_reset_function()
> https://github.com/pugs/vfio-linux-2.6/blob/vfio/drivers/vfio/vfio_main.c
Got it, thanks Alex.
On Tuesday, April 19, 2011 01:32:59 pm Alex Williamson wrote:
> 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 <[email protected]>
> ---
>
> 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
Applied.