Re: [PATCH RFC v1 1/2] iommu: Introduce iommu_dev_reset_prepare() and iommu_dev_reset_done()

[Nicolin Chen <nicolinc@nvidia.com>]

On Tue, Jun 10, 2025 at 01:43:06PM -0300, Jason Gunthorpe wrote:
> On Tue, Jun 10, 2025 at 05:31:09PM +0100, Robin Murphy wrote:
> > From a quick skim I suspect it's probably OK - at least device_del() gets to
> > bus_remove_device()->device_remove_groups() well enough before the
> > BUS_NOTIFY_REMOVED_DEVICE call that triggers iommu_release_device().
> 
> Make sense, Nicolin, a well placed comment explaining this would be
> good

Ack.

> > And on an unrelated thought that's just come to mind, if we ever did FLR
> > with PASIDs enabled, presumably that's going to wipe out the PASID
> > configuration,
> 
> I've always been expecting the PCI FLR code to preserve the config
> space that belongs the iommu subsystem. PASID, ATS, PRI, etc. Never
> looked into it... Nicolin??

Those are the flags in struct pci_dev right?
unsigned int    ats_enabled:1;          /* Address Translation Svc */
unsigned int    pasid_enabled:1;        /* Process Address Space ID */
unsigned int    pri_enabled:1;          /* Page Request Interface */

And pci_restore_state() does the recovery of these bits.

Thanks
Nicolin