| Message ID | 20110419203234.4254.94914.stgit@s20.home |
|---|---|
| State | New |
| Headers | show |
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 <alex.williamson@redhat.com> > --- > > 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 (rdunlap@xenotime.net) 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 (alex.williamson@redhat.com) 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 (alex.williamson@redhat.com) 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 (alex.williamson@redhat.com) wrote: > On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote: > > * Alex Williamson (alex.williamson@redhat.com) 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 (alex.williamson@redhat.com) wrote: > > On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote: > > > * Alex Williamson (alex.williamson@redhat.com) 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 (alex.williamson@redhat.com) wrote: > On Tue, 2011-04-19 at 15:26 -0700, Chris Wright wrote: > > * Alex Williamson (alex.williamson@redhat.com) wrote: > > > On Tue, 2011-04-19 at 15:07 -0700, Chris Wright wrote: > > > > * Alex Williamson (alex.williamson@redhat.com) 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 <alex.williamson@redhat.com> > --- > > 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.
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
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@redhat.com> --- 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(-)