Re: [XEN PATCH v16 1/3] x86/irq: allow setting IRQ permissions from GSI instead of pIRQ

[Jan Beulich <jbeulich@xxxxxxxx>]

On 30.09.2024 05:42, Jiqian Chen wrote:
> Some domains are not aware of the pIRQ abstraction layer that maps
> interrupt sources into Xen space interrupt numbers.  pIRQs values are
> only exposed to domains that have the option to route physical
> interrupts over event channels.
> 
> This creates issues for PCI-passthrough from a PVH domain, as some of
> the passthrough related hypercalls use pIRQ as references to physical
> interrupts on the system.  One of such interfaces is
> XEN_DOMCTL_irq_permission, used to grant or revoke access to
> interrupts, takes a pIRQ as the reference to the interrupt to be
> adjusted.
> 
> Since PVH doesn't manage interrupts in terms of pIRQs, introduce a new
> hypercall that allows setting interrupt permissions based on GSI value
> rather than pIRQ.
> 
> Note the GSI hypercall parameters is translated to an IRQ value (in
> case there are ACPI overrides) before doing the checks.
> 
> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
> Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
> Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>

Acked-by: Jan Beulich <jbeulich@xxxxxxxx>