Hi Rahul,
> On 28 Sep 2021, at 19:18, Rahul Singh <rahul.si...@arm.com> wrote:
>
> If the property is not present in the device tree node for host bridge,
> XEN while creating the dtb for hwdom will create this property and
> assigns the already allocated segment to the host bridge
> so that XEN and linux will have the same segment for the host bridges.
>
> Signed-off-by: Rahul Singh <rahul.si...@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com>
Cheers
Bertrand
> ---
> Change in v3:
> - Use is_pci_passthrough_enabled()
> Change in v2:
> - Add linux,pci-domain only when pci-passthrough command line option is
> enabeld
> ---
> xen/arch/arm/domain_build.c | 16 ++++++++++++++++
> xen/arch/arm/pci/pci-host-common.c | 21 +++++++++++++++++++++
> xen/include/asm-arm/pci.h | 9 +++++++++
> 3 files changed, 46 insertions(+)
>
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 1731ae2028..026c9e5c6c 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -743,6 +743,22 @@ static int __init write_properties(struct domain *d,
> struct kernel_info *kinfo,
> return res;
> }
>
> + if ( is_pci_passthrough_enabled() && dt_device_type_is_equal(node,
> "pci") )
> + {
> + if ( !dt_find_property(node, "linux,pci-domain", NULL) )
> + {
> + uint16_t segment;
> +
> + res = pci_get_host_bridge_segment(node, &segment);
> + if ( res < 0 )
> + return res;
> +
> + res = fdt_property_cell(kinfo->fdt, "linux,pci-domain", segment);
> + if ( res )
> + return res;
> + }
> + }
> +
> /*
> * Override the property "status" to disable the device when it's
> * marked for passthrough.
> diff --git a/xen/arch/arm/pci/pci-host-common.c
> b/xen/arch/arm/pci/pci-host-common.c
> index c5941b10e9..593beeb48c 100644
> --- a/xen/arch/arm/pci/pci-host-common.c
> +++ b/xen/arch/arm/pci/pci-host-common.c
> @@ -255,6 +255,27 @@ struct pci_host_bridge *pci_find_host_bridge(uint16_t
> segment, uint8_t bus)
>
> return NULL;
> }
> +
> +/*
> + * This function will lookup an hostbridge based on config space address.
> + */
> +int pci_get_host_bridge_segment(const struct dt_device_node *node,
> + uint16_t *segment)
> +{
> + struct pci_host_bridge *bridge;
> +
> + list_for_each_entry( bridge, &pci_host_bridges, node )
> + {
> + if ( bridge->dt_node != node )
> + continue;
> +
> + *segment = bridge->segment;
> + return 0;
> + }
> +
> + return -EINVAL;
> +}
> +
> /*
> * Local variables:
> * mode: C
> diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
> index 5532ce3977..7cb2e2f1ed 100644
> --- a/xen/include/asm-arm/pci.h
> +++ b/xen/include/asm-arm/pci.h
> @@ -90,6 +90,8 @@ int pci_generic_config_write(struct pci_host_bridge
> *bridge, pci_sbdf_t sbdf,
> void __iomem *pci_ecam_map_bus(struct pci_host_bridge *bridge,
> pci_sbdf_t sbdf, uint32_t where);
> struct pci_host_bridge *pci_find_host_bridge(uint16_t segment, uint8_t bus);
> +int pci_get_host_bridge_segment(const struct dt_device_node *node,
> + uint16_t *segment);
>
> static always_inline bool is_pci_passthrough_enabled(void)
> {
> @@ -104,5 +106,12 @@ static always_inline bool
> is_pci_passthrough_enabled(void)
> return false;
> }
>
> +static inline int pci_get_host_bridge_segment(const struct dt_device_node
> *node,
> + uint16_t *segment)
> +{
> + ASSERT_UNREACHABLE();
> + return -EINVAL;
> +}
> +
> #endif /*!CONFIG_HAS_PCI*/
> #endif /* __ARM_PCI_H__ */
> --
> 2.17.1
>
