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SubjectRe: [PATCH] PCI: Device specific reset function
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On Mon, 2012-03-12 at 16:55 +0000, Tadeusz Struk wrote:
> I have a use case where I need to cleanup resource allocated for Virtual
> Functions after a guest OS that used it crashed. This cleanup needs to
> be done before the VF is being FLRed. The only possible way to do this
> seems to be by using pci_dev_specific_reset() function.
> This patch adds specific reset function to the pci_driver struct.
> Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
> ---
> drivers/pci/quirks.c | 4 ++++
> include/linux/pci.h | 1 +
> 2 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 6476547..13d224b 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3081,8 +3081,12 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
>
> int pci_dev_specific_reset(struct pci_dev *dev, int probe)
> {
> + struct pci_driver *drv = dev->driver;
> const struct pci_dev_reset_methods *i;
>
> + if (drv && drv->reset)
> + return drv->reset(dev, probe);
> +

Isn't this exactly what the below code is for (pci_dev_reset_methods)?
In the case of KVM device assignment, the device should be reset via
this path if the guest crashes, but it may or may not be attached to
pci-stub at the time. I assume you're not adding a reset handler to
pci-stub, so we'll pass through here and use FLR, violating the premise
of the patch. Thanks,

Alex

> for (i = pci_dev_reset_methods; i->reset; i++) {
> if ((i->vendor == dev->vendor ||
> i->vendor == (u16)PCI_ANY_ID) &&
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index a16b1df..2ccd838 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -560,6 +560,7 @@ struct pci_driver {
> int (*resume_early) (struct pci_dev *dev);
> int (*resume) (struct pci_dev *dev); /* Device woken up */
> void (*shutdown) (struct pci_dev *dev);
> + int (*reset) (struct pci_dev *dev, int probe);
> struct pci_error_handlers *err_handler;
> struct device_driver driver;
> struct pci_dynids dynids;





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