On Thu, Nov 25, 2021 at 01:02:50PM +0200, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
>
> At the moment, we always allocate an extra 16 slots for IO handlers
> (see MAX_IO_HANDLER). So while adding IO trap handlers for the emulated
> MSI-X registers we need to explicitly tell that we have additional IO
> handlers, so those are accounted.
>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
LGTM, just one comment below. This will require an Ack from the Arm
guys.
> ---
> Cc: Julien Grall <jul...@xen.org>
> Cc: Stefano Stabellini <sstabell...@kernel.org>
> ---
> This actually moved here from the part 2 of the prep work for PCI
> passthrough on Arm as it seems to be the proper place for it.
>
> New in v5
> ---
> xen/arch/arm/vpci.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c
> index 3d134f42d07e..902f8491e030 100644
> --- a/xen/arch/arm/vpci.c
> +++ b/xen/arch/arm/vpci.c
> @@ -134,6 +134,8 @@ static int vpci_get_num_handlers_cb(struct domain *d,
>
> unsigned int domain_vpci_get_num_mmio_handlers(struct domain *d)
> {
> + unsigned int count;
> +
> if ( !has_vpci(d) )
> return 0;
>
> @@ -145,7 +147,18 @@ unsigned int domain_vpci_get_num_mmio_handlers(struct
> domain *d)
> }
>
> /* For a single emulated host bridge's configuration space. */
> - return 1;
> + count = 1;
> +
> +#ifdef CONFIG_HAS_PCI_MSI
> + /*
> + * There's a single MSI-X MMIO handler that deals with both PBA
> + * and MSI-X tables per each PCI device being passed through.
> + * Maximum number of emulated virtual devices is VPCI_MAX_VIRT_DEV.
> + */
> + count += VPCI_MAX_VIRT_DEV;
You could also use IS_ENABLED(CONFIG_HAS_PCI_MSI) since
VPCI_MAX_VIRT_DEV is defined unconditionally.
Thanks, Roger.
