Re: [PATCH v3 1/1] xen/pci: Install vpci handlers on x86 and fix error paths

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Wed, Oct 20, 2021 at 11:05:37AM +0100, Bertrand Marquis wrote:
> Xen might not be able to discover at boot time all devices or some devices
> might appear after specific actions from dom0.
> In this case dom0 can use the PHYSDEVOP_pci_device_add to signal some
> PCI devices to Xen.
> As those devices where not known from Xen before, the vpci handlers must
> be properly installed during pci_device_add for x86 PVH Dom0, in the
> same way as what is done currently on arm (where Xen does not detect PCI
> devices but relies on Dom0 to declare them all the time).
> 
> So this patch is removing the ifdef protecting the call to
> vpci_add_handlers and the comment which was arm specific.
> 
> vpci_add_handlers is called on during pci_device_add which can be called
> at runtime through hypercall physdev_op.
> Remove __hwdom_init as the call is not limited anymore to hardware
> domain init and fix linker script to only keep vpci_array in rodata
> section.
> 
> Add missing vpci handlers cleanup during pci_device_remove and in case
> of error with iommu during pci_device_add.
> 
> Move code adding the domain to the pdev domain_list as vpci_add_handlers
> needs this to be set and remove it from the list in the error path.
> 
> Exit early of vpci_remove_device if the domain has no vpci support.
> 
> Add empty static inline for vpci_remove_device when CONFIG_VPCI is not
> defined.
> 
> Add an ASSERT in vpci_add_handlers to check that the function is not
> called twice for the same device.
> 
> Fixes: d59168dc05 ("xen/arm: Enable the existing x86 virtual PCI support
> for ARM")
> Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks!