Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
On Fri, Jan 11, 2013 at 08:46:35AM -0700, Alex Williamson wrote:
> On Fri, 2013-01-11 at 08:45 +, Pandarathil, Vijaymohan R wrote:
> >
> > > -Original Message-
> > > From: Alex Williamson [mailto:alex.william...@redhat.com]
> > > Sent: Wednesday, January 09, 2013 11:05 AM
> > > To: Pandarathil, Vijaymohan R
> > > Cc: Bjorn Helgaas; Gleb Natapov; k...@vger.kernel.org; qemu-
> > > de...@nongnu.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org
> > > Subject: Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting
> > > AER
> > >
> > > On Wed, 2013-01-09 at 10:52 -0700, Alex Williamson wrote:
> > > > On Wed, 2013-01-09 at 06:26 +, Pandarathil, Vijaymohan R wrote:
> > > > > - New ioctl which is used to pass the eventfd that is signaled
> > > > > when
> > > > > an error occurs in the vfio_pci_device
> > > > >
> > > > > - Register pci_error_handler for the vfio_pci driver
> > > > >
> > > > > - When the device encounters an error, the error handler
> > > > > registered
> > > by
> > > > > the vfio_pci driver gets invoked by the AER infrastructure
> > > > >
> > > > > - In the error handler, signal the eventfd registered for the
> > > > > device.
> > > > >
> > > > > - This results in the qemu eventfd handler getting invoked and
> > > > > appropriate action taken for the guest.
> > > > >
> > > > > Signed-off-by: Vijay Mohan Pandarathil
> > > > > ---
> > > > > drivers/vfio/pci/vfio_pci.c | 29
> > > > > +
> > > > > drivers/vfio/pci/vfio_pci_private.h | 1 +
> > > > > drivers/vfio/vfio.c | 8
> > > > > include/linux/vfio.h| 1 +
> > > > > include/uapi/linux/vfio.h | 9 +
> > > > > 5 files changed, 48 insertions(+)
> > > > >
> > > > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > > > > index 6c11994..4ae9526 100644
> > > > > --- a/drivers/vfio/pci/vfio_pci.c
> > > > > +++ b/drivers/vfio/pci/vfio_pci.c
> > > > > @@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
> > > > > if (vdev->reset_works)
> > > > > info.flags |= VFIO_DEVICE_FLAGS_RESET;
> > > > >
> > > > > + info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
> > > > > +
> > > >
> > > > This appears to be a PCI specific flag, so the name should include
> > > > _PCI_. We also support non-PCIe devices and it seems like it would be
> > > > possible to not have AER support available, so shouldn't this be
> > > > conditional?
> >
> > Will do that.
> >
> > > >
> > > > > info.num_regions = VFIO_PCI_NUM_REGIONS;
> > > > > info.num_irqs = VFIO_PCI_NUM_IRQS;
> > > > >
> > > > > @@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
> > > > >
> > > > > return ret;
> > > > >
> > > > > + } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
> > > > > + int32_t fd = (int32_t)arg;
> > > > > +
> > > > > + if (fd < 0)
> > > > > + return -EINVAL;
> > > > > +
> > > > > + vdev->err_trigger = eventfd_ctx_fdget(fd);
> > > > > +
> > > > > + if (IS_ERR(vdev->err_trigger))
> > > > > + return PTR_ERR(vdev->err_trigger);
> > > > > +
> > > > > + return 0;
> > > > > +
> > > >
> > > > I'm not sure why we wouldn't describe this as just another interrupt
> > > > from the device and configure it via SET_IRQ. This ioctl has very
> > > > limited use and doesn't follow any of the conventions of all the other
> > > > vfio ioctls.
> >
> > I thought this was a fairly simple ioctl to implement this way. Moreover,
> > there is no device interrupt involved. Let me know if you really want to
> > model it as a SET_IRQ ioctl.
>
> I'd like to see something else for sure. We're trying to do AER
> piecemeal but this ioctl leaves no room for anything else. Seems like a
> soon to be wasted ioctl number. Note that there isn't even a de-assign
> interface, nor a flag to set to indicate de-assignment. The SET_IRQ
> ioctl already handles these in a very similar way to how we'd want to
> handle it for error signaling. It doesn't seem like that much of a
> stretch to me to include it there, but I'd also entertain other ideas.
> Thanks,
>
> Alex
Yes it would be good to have a picture of the dependencies necessary to
implement passthrough, before introducing an incompatible interface.
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Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
On Fri, 2013-01-11 at 08:45 +, Pandarathil, Vijaymohan R wrote:
>
> > -Original Message-
> > From: Alex Williamson [mailto:alex.william...@redhat.com]
> > Sent: Wednesday, January 09, 2013 11:05 AM
> > To: Pandarathil, Vijaymohan R
> > Cc: Bjorn Helgaas; Gleb Natapov; k...@vger.kernel.org; qemu-
> > de...@nongnu.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting
> > AER
> >
> > On Wed, 2013-01-09 at 10:52 -0700, Alex Williamson wrote:
> > > On Wed, 2013-01-09 at 06:26 +, Pandarathil, Vijaymohan R wrote:
> > > > - New ioctl which is used to pass the eventfd that is signaled
> > > > when
> > > > an error occurs in the vfio_pci_device
> > > >
> > > > - Register pci_error_handler for the vfio_pci driver
> > > >
> > > > - When the device encounters an error, the error handler
> > > > registered
> > by
> > > > the vfio_pci driver gets invoked by the AER infrastructure
> > > >
> > > > - In the error handler, signal the eventfd registered for the
> > > > device.
> > > >
> > > > - This results in the qemu eventfd handler getting invoked and
> > > > appropriate action taken for the guest.
> > > >
> > > > Signed-off-by: Vijay Mohan Pandarathil
> > > > ---
> > > > drivers/vfio/pci/vfio_pci.c | 29 +
> > > > drivers/vfio/pci/vfio_pci_private.h | 1 +
> > > > drivers/vfio/vfio.c | 8
> > > > include/linux/vfio.h| 1 +
> > > > include/uapi/linux/vfio.h | 9 +
> > > > 5 files changed, 48 insertions(+)
> > > >
> > > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > > > index 6c11994..4ae9526 100644
> > > > --- a/drivers/vfio/pci/vfio_pci.c
> > > > +++ b/drivers/vfio/pci/vfio_pci.c
> > > > @@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
> > > > if (vdev->reset_works)
> > > > info.flags |= VFIO_DEVICE_FLAGS_RESET;
> > > >
> > > > + info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
> > > > +
> > >
> > > This appears to be a PCI specific flag, so the name should include
> > > _PCI_. We also support non-PCIe devices and it seems like it would be
> > > possible to not have AER support available, so shouldn't this be
> > > conditional?
>
> Will do that.
>
> > >
> > > > info.num_regions = VFIO_PCI_NUM_REGIONS;
> > > > info.num_irqs = VFIO_PCI_NUM_IRQS;
> > > >
> > > > @@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
> > > >
> > > > return ret;
> > > >
> > > > + } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
> > > > + int32_t fd = (int32_t)arg;
> > > > +
> > > > + if (fd < 0)
> > > > + return -EINVAL;
> > > > +
> > > > + vdev->err_trigger = eventfd_ctx_fdget(fd);
> > > > +
> > > > + if (IS_ERR(vdev->err_trigger))
> > > > + return PTR_ERR(vdev->err_trigger);
> > > > +
> > > > + return 0;
> > > > +
> > >
> > > I'm not sure why we wouldn't describe this as just another interrupt
> > > from the device and configure it via SET_IRQ. This ioctl has very
> > > limited use and doesn't follow any of the conventions of all the other
> > > vfio ioctls.
>
> I thought this was a fairly simple ioctl to implement this way. Moreover,
> there is no device interrupt involved. Let me know if you really want to
> model it as a SET_IRQ ioctl.
I'd like to see something else for sure. We're trying to do AER
piecemeal but this ioctl leaves no room for anything else. Seems like a
soon to be wasted ioctl number. Note that there isn't even a de-assign
interface, nor a flag to set to indicate de-assignment. The SET_IRQ
ioctl already handles these in a very similar way to how we'd want to
handle it for error signaling. It doesn't seem like that much of a
stretch to me to include it there, but I
RE: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
> -Original Message-
> From: Alex Williamson [mailto:alex.william...@redhat.com]
> Sent: Wednesday, January 09, 2013 11:05 AM
> To: Pandarathil, Vijaymohan R
> Cc: Bjorn Helgaas; Gleb Natapov; k...@vger.kernel.org; qemu-
> de...@nongnu.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting
> AER
>
> On Wed, 2013-01-09 at 10:52 -0700, Alex Williamson wrote:
> > On Wed, 2013-01-09 at 06:26 +, Pandarathil, Vijaymohan R wrote:
> > > - New ioctl which is used to pass the eventfd that is signaled when
> > > an error occurs in the vfio_pci_device
> > >
> > > - Register pci_error_handler for the vfio_pci driver
> > >
> > > - When the device encounters an error, the error handler registered
> by
> > > the vfio_pci driver gets invoked by the AER infrastructure
> > >
> > > - In the error handler, signal the eventfd registered for the device.
> > >
> > > - This results in the qemu eventfd handler getting invoked and
> > > appropriate action taken for the guest.
> > >
> > > Signed-off-by: Vijay Mohan Pandarathil
> > > ---
> > > drivers/vfio/pci/vfio_pci.c | 29 +
> > > drivers/vfio/pci/vfio_pci_private.h | 1 +
> > > drivers/vfio/vfio.c | 8
> > > include/linux/vfio.h| 1 +
> > > include/uapi/linux/vfio.h | 9 +
> > > 5 files changed, 48 insertions(+)
> > >
> > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > > index 6c11994..4ae9526 100644
> > > --- a/drivers/vfio/pci/vfio_pci.c
> > > +++ b/drivers/vfio/pci/vfio_pci.c
> > > @@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
> > > if (vdev->reset_works)
> > > info.flags |= VFIO_DEVICE_FLAGS_RESET;
> > >
> > > + info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
> > > +
> >
> > This appears to be a PCI specific flag, so the name should include
> > _PCI_. We also support non-PCIe devices and it seems like it would be
> > possible to not have AER support available, so shouldn't this be
> > conditional?
Will do that.
> >
> > > info.num_regions = VFIO_PCI_NUM_REGIONS;
> > > info.num_irqs = VFIO_PCI_NUM_IRQS;
> > >
> > > @@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
> > >
> > > return ret;
> > >
> > > + } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
> > > + int32_t fd = (int32_t)arg;
> > > +
> > > + if (fd < 0)
> > > + return -EINVAL;
> > > +
> > > + vdev->err_trigger = eventfd_ctx_fdget(fd);
> > > +
> > > + if (IS_ERR(vdev->err_trigger))
> > > + return PTR_ERR(vdev->err_trigger);
> > > +
> > > + return 0;
> > > +
> >
> > I'm not sure why we wouldn't describe this as just another interrupt
> > from the device and configure it via SET_IRQ. This ioctl has very
> > limited use and doesn't follow any of the conventions of all the other
> > vfio ioctls.
I thought this was a fairly simple ioctl to implement this way. Moreover,
there is no device interrupt involved. Let me know if you really want to
model it as a SET_IRQ ioctl.
> >
> > > } else if (cmd == VFIO_DEVICE_RESET)
> > > return vdev->reset_works ?
> > > pci_reset_function(vdev->pdev) : -EINVAL;
> > > @@ -527,11 +542,25 @@ static void vfio_pci_remove(struct pci_dev *pdev)
> > > kfree(vdev);
> > > }
> > >
> > > +static pci_ers_result_t vfio_err_detected(struct pci_dev *pdev,
> > > + pci_channel_state_t state)
> > > +{
> > > + struct vfio_pci_device *vdev = vfio_get_vdev(&pdev->dev);
> > > +
> > > + eventfd_signal(vdev->err_trigger, 1);
> > > + return PCI_ERS_RESULT_CAN_RECOVER;
> > > +}
> >
> > What if err_trigger hasn't been set?
Will fix that.
> >
> > > +
> > > +static const struct pci_error_handlers vfio_err_handlers = {
> > > + .error_detected = vfio_err_detected,
> > > +};
> > > +
> > > static struct pci_driver vfio_pci_driver = {
> > > .name = "vfio-pci",
> > >
Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
On Wed, 2013-01-09 at 10:52 -0700, Alex Williamson wrote:
> On Wed, 2013-01-09 at 06:26 +, Pandarathil, Vijaymohan R wrote:
> > - New ioctl which is used to pass the eventfd that is signaled when
> > an error occurs in the vfio_pci_device
> >
> > - Register pci_error_handler for the vfio_pci driver
> >
> > - When the device encounters an error, the error handler registered by
> > the vfio_pci driver gets invoked by the AER infrastructure
> >
> > - In the error handler, signal the eventfd registered for the device.
> >
> > - This results in the qemu eventfd handler getting invoked and
> > appropriate action taken for the guest.
> >
> > Signed-off-by: Vijay Mohan Pandarathil
> > ---
> > drivers/vfio/pci/vfio_pci.c | 29 +
> > drivers/vfio/pci/vfio_pci_private.h | 1 +
> > drivers/vfio/vfio.c | 8
> > include/linux/vfio.h| 1 +
> > include/uapi/linux/vfio.h | 9 +
> > 5 files changed, 48 insertions(+)
> >
> > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > index 6c11994..4ae9526 100644
> > --- a/drivers/vfio/pci/vfio_pci.c
> > +++ b/drivers/vfio/pci/vfio_pci.c
> > @@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
> > if (vdev->reset_works)
> > info.flags |= VFIO_DEVICE_FLAGS_RESET;
> >
> > + info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
> > +
>
> This appears to be a PCI specific flag, so the name should include
> _PCI_. We also support non-PCIe devices and it seems like it would be
> possible to not have AER support available, so shouldn't this be
> conditional?
>
> > info.num_regions = VFIO_PCI_NUM_REGIONS;
> > info.num_irqs = VFIO_PCI_NUM_IRQS;
> >
> > @@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
> >
> > return ret;
> >
> > + } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
> > + int32_t fd = (int32_t)arg;
> > +
> > + if (fd < 0)
> > + return -EINVAL;
> > +
> > + vdev->err_trigger = eventfd_ctx_fdget(fd);
> > +
> > + if (IS_ERR(vdev->err_trigger))
> > + return PTR_ERR(vdev->err_trigger);
> > +
> > + return 0;
> > +
>
> I'm not sure why we wouldn't describe this as just another interrupt
> from the device and configure it via SET_IRQ. This ioctl has very
> limited use and doesn't follow any of the conventions of all the other
> vfio ioctls.
>
> > } else if (cmd == VFIO_DEVICE_RESET)
> > return vdev->reset_works ?
> > pci_reset_function(vdev->pdev) : -EINVAL;
> > @@ -527,11 +542,25 @@ static void vfio_pci_remove(struct pci_dev *pdev)
> > kfree(vdev);
> > }
> >
> > +static pci_ers_result_t vfio_err_detected(struct pci_dev *pdev,
> > + pci_channel_state_t state)
> > +{
> > + struct vfio_pci_device *vdev = vfio_get_vdev(&pdev->dev);
> > +
> > + eventfd_signal(vdev->err_trigger, 1);
> > + return PCI_ERS_RESULT_CAN_RECOVER;
> > +}
>
> What if err_trigger hasn't been set?
>
> > +
> > +static const struct pci_error_handlers vfio_err_handlers = {
> > + .error_detected = vfio_err_detected,
> > +};
> > +
> > static struct pci_driver vfio_pci_driver = {
> > .name = "vfio-pci",
> > .id_table = NULL, /* only dynamic ids */
> > .probe = vfio_pci_probe,
> > .remove = vfio_pci_remove,
> > + .err_handler= &vfio_err_handlers,
> > };
> >
> > static void __exit vfio_pci_cleanup(void)
> > diff --git a/drivers/vfio/pci/vfio_pci_private.h
> > b/drivers/vfio/pci/vfio_pci_private.h
> > index 611827c..daee62f 100644
> > --- a/drivers/vfio/pci/vfio_pci_private.h
> > +++ b/drivers/vfio/pci/vfio_pci_private.h
> > @@ -55,6 +55,7 @@ struct vfio_pci_device {
> > boolbardirty;
> > struct pci_saved_state *pci_saved_state;
> > atomic_trefcnt;
> > + struct eventfd_ctx *err_trigger;
> > };
> >
> > #define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)
> > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> > index 56097c6..5ed5a54 100644
> > --- a/drivers/vfio/vfio.c
> > +++ b/drivers/vfio/vfio.c
> > @@ -693,6 +693,14 @@ void *vfio_del_group_dev(struct device *dev)
> > }
> > EXPORT_SYMBOL_GPL(vfio_del_group_dev);
> >
> > +void *vfio_get_vdev(struct device *dev)
> > +{
> > + struct vfio_device *device = dev_get_drvdata(dev);
> > +
> > + return device->device_data;
> > +}
> > +EXPORT_SYMBOL_GPL(vfio_get_vdev);
> > +
>
> This is unsafe. How do we know dev is a vfio device? How do we keep
> that drvdata valid while you're using it? I think you want to export
> the existing vfio_group_get_device() and vfio_device_put(). Thanks,
vfio_group_get_device() isn't quite what you want either since it
assumes a reference count on the group.
Re: [PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
On Wed, 2013-01-09 at 06:26 +, Pandarathil, Vijaymohan R wrote:
> - New ioctl which is used to pass the eventfd that is signaled when
> an error occurs in the vfio_pci_device
>
> - Register pci_error_handler for the vfio_pci driver
>
> - When the device encounters an error, the error handler registered by
> the vfio_pci driver gets invoked by the AER infrastructure
>
> - In the error handler, signal the eventfd registered for the device.
>
> - This results in the qemu eventfd handler getting invoked and
> appropriate action taken for the guest.
>
> Signed-off-by: Vijay Mohan Pandarathil
> ---
> drivers/vfio/pci/vfio_pci.c | 29 +
> drivers/vfio/pci/vfio_pci_private.h | 1 +
> drivers/vfio/vfio.c | 8
> include/linux/vfio.h| 1 +
> include/uapi/linux/vfio.h | 9 +
> 5 files changed, 48 insertions(+)
>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 6c11994..4ae9526 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
> if (vdev->reset_works)
> info.flags |= VFIO_DEVICE_FLAGS_RESET;
>
> + info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
> +
This appears to be a PCI specific flag, so the name should include
_PCI_. We also support non-PCIe devices and it seems like it would be
possible to not have AER support available, so shouldn't this be
conditional?
> info.num_regions = VFIO_PCI_NUM_REGIONS;
> info.num_irqs = VFIO_PCI_NUM_IRQS;
>
> @@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
>
> return ret;
>
> + } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
> + int32_t fd = (int32_t)arg;
> +
> + if (fd < 0)
> + return -EINVAL;
> +
> + vdev->err_trigger = eventfd_ctx_fdget(fd);
> +
> + if (IS_ERR(vdev->err_trigger))
> + return PTR_ERR(vdev->err_trigger);
> +
> + return 0;
> +
I'm not sure why we wouldn't describe this as just another interrupt
from the device and configure it via SET_IRQ. This ioctl has very
limited use and doesn't follow any of the conventions of all the other
vfio ioctls.
> } else if (cmd == VFIO_DEVICE_RESET)
> return vdev->reset_works ?
> pci_reset_function(vdev->pdev) : -EINVAL;
> @@ -527,11 +542,25 @@ static void vfio_pci_remove(struct pci_dev *pdev)
> kfree(vdev);
> }
>
> +static pci_ers_result_t vfio_err_detected(struct pci_dev *pdev,
> + pci_channel_state_t state)
> +{
> + struct vfio_pci_device *vdev = vfio_get_vdev(&pdev->dev);
> +
> + eventfd_signal(vdev->err_trigger, 1);
> + return PCI_ERS_RESULT_CAN_RECOVER;
> +}
What if err_trigger hasn't been set?
> +
> +static const struct pci_error_handlers vfio_err_handlers = {
> + .error_detected = vfio_err_detected,
> +};
> +
> static struct pci_driver vfio_pci_driver = {
> .name = "vfio-pci",
> .id_table = NULL, /* only dynamic ids */
> .probe = vfio_pci_probe,
> .remove = vfio_pci_remove,
> + .err_handler= &vfio_err_handlers,
> };
>
> static void __exit vfio_pci_cleanup(void)
> diff --git a/drivers/vfio/pci/vfio_pci_private.h
> b/drivers/vfio/pci/vfio_pci_private.h
> index 611827c..daee62f 100644
> --- a/drivers/vfio/pci/vfio_pci_private.h
> +++ b/drivers/vfio/pci/vfio_pci_private.h
> @@ -55,6 +55,7 @@ struct vfio_pci_device {
> boolbardirty;
> struct pci_saved_state *pci_saved_state;
> atomic_trefcnt;
> + struct eventfd_ctx *err_trigger;
> };
>
> #define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 56097c6..5ed5a54 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -693,6 +693,14 @@ void *vfio_del_group_dev(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(vfio_del_group_dev);
>
> +void *vfio_get_vdev(struct device *dev)
> +{
> + struct vfio_device *device = dev_get_drvdata(dev);
> +
> + return device->device_data;
> +}
> +EXPORT_SYMBOL_GPL(vfio_get_vdev);
> +
This is unsafe. How do we know dev is a vfio device? How do we keep
that drvdata valid while you're using it? I think you want to export
the existing vfio_group_get_device() and vfio_device_put(). Thanks,
Alex
> /**
> * VFIO base fd, /dev/vfio/vfio
> */
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index ab9e862..3c97b03 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -45,6 +45,7 @@ extern int vfio_add_group_dev(struct device *dev,
> void *device_data);
>
> extern void *vfi
[PATCH 1/2] VFIO-AER: Vfio-pci driver changes for supporting AER
- New ioctl which is used to pass the eventfd that is signaled when
an error occurs in the vfio_pci_device
- Register pci_error_handler for the vfio_pci driver
- When the device encounters an error, the error handler registered by
the vfio_pci driver gets invoked by the AER infrastructure
- In the error handler, signal the eventfd registered for the device.
- This results in the qemu eventfd handler getting invoked and
appropriate action taken for the guest.
Signed-off-by: Vijay Mohan Pandarathil
---
drivers/vfio/pci/vfio_pci.c | 29 +
drivers/vfio/pci/vfio_pci_private.h | 1 +
drivers/vfio/vfio.c | 8
include/linux/vfio.h| 1 +
include/uapi/linux/vfio.h | 9 +
5 files changed, 48 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 6c11994..4ae9526 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -207,6 +207,8 @@ static long vfio_pci_ioctl(void *device_data,
if (vdev->reset_works)
info.flags |= VFIO_DEVICE_FLAGS_RESET;
+ info.flags |= VFIO_DEVICE_FLAGS_AER_NOTIFY;
+
info.num_regions = VFIO_PCI_NUM_REGIONS;
info.num_irqs = VFIO_PCI_NUM_IRQS;
@@ -348,6 +350,19 @@ static long vfio_pci_ioctl(void *device_data,
return ret;
+ } else if (cmd == VFIO_DEVICE_SET_ERRFD) {
+ int32_t fd = (int32_t)arg;
+
+ if (fd < 0)
+ return -EINVAL;
+
+ vdev->err_trigger = eventfd_ctx_fdget(fd);
+
+ if (IS_ERR(vdev->err_trigger))
+ return PTR_ERR(vdev->err_trigger);
+
+ return 0;
+
} else if (cmd == VFIO_DEVICE_RESET)
return vdev->reset_works ?
pci_reset_function(vdev->pdev) : -EINVAL;
@@ -527,11 +542,25 @@ static void vfio_pci_remove(struct pci_dev *pdev)
kfree(vdev);
}
+static pci_ers_result_t vfio_err_detected(struct pci_dev *pdev,
+ pci_channel_state_t state)
+{
+ struct vfio_pci_device *vdev = vfio_get_vdev(&pdev->dev);
+
+ eventfd_signal(vdev->err_trigger, 1);
+ return PCI_ERS_RESULT_CAN_RECOVER;
+}
+
+static const struct pci_error_handlers vfio_err_handlers = {
+ .error_detected = vfio_err_detected,
+};
+
static struct pci_driver vfio_pci_driver = {
.name = "vfio-pci",
.id_table = NULL, /* only dynamic ids */
.probe = vfio_pci_probe,
.remove = vfio_pci_remove,
+ .err_handler= &vfio_err_handlers,
};
static void __exit vfio_pci_cleanup(void)
diff --git a/drivers/vfio/pci/vfio_pci_private.h
b/drivers/vfio/pci/vfio_pci_private.h
index 611827c..daee62f 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -55,6 +55,7 @@ struct vfio_pci_device {
boolbardirty;
struct pci_saved_state *pci_saved_state;
atomic_trefcnt;
+ struct eventfd_ctx *err_trigger;
};
#define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 56097c6..5ed5a54 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -693,6 +693,14 @@ void *vfio_del_group_dev(struct device *dev)
}
EXPORT_SYMBOL_GPL(vfio_del_group_dev);
+void *vfio_get_vdev(struct device *dev)
+{
+ struct vfio_device *device = dev_get_drvdata(dev);
+
+ return device->device_data;
+}
+EXPORT_SYMBOL_GPL(vfio_get_vdev);
+
/**
* VFIO base fd, /dev/vfio/vfio
*/
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index ab9e862..3c97b03 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -45,6 +45,7 @@ extern int vfio_add_group_dev(struct device *dev,
void *device_data);
extern void *vfio_del_group_dev(struct device *dev);
+extern void *vfio_get_vdev(struct device *dev);
/**
* struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 4758d1b..fa67213 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -147,6 +147,7 @@ struct vfio_device_info {
__u32 flags;
#define VFIO_DEVICE_FLAGS_RESET(1 << 0)/* Device supports
reset */
#define VFIO_DEVICE_FLAGS_PCI (1 << 1)/* vfio-pci device */
+#define VFIO_DEVICE_FLAGS_AER_NOTIFY (1 << 2) /* Supports aer notify */
__u32 num_regions;/* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
};
@@ -288,6 +289,14 @@ struct vfio_irq_set {
*/
#define VFIO_DEVICE_RESET _IO(VFIO_TYPE, VFIO_BASE + 11)
+/**
+ * VFIO_DEVICE_SET_ERRFD - _IO(VFIO_TYPE, VFIO_BASE + 12)
+ *
+
