[PATCH v3 3/5] xen/arm: make has_vpci() depend on d->arch.has_vpci

[Stewart Hildebrand <stewart.hildebrand@xxxxxxx>]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

VPCI is disabled on ARM. Make it depend on d->arch.has_vpci to enable the PCI
passthrough support on ARM.

While here, remove the comment on the preceding line.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx>
---
There are two downstreams [1] [2] that have independently made a version this
change, each with different Signed-off-by's. I simply picked one at random for
the Author: field, and added both Signed-off-by lines. Please let me know if
there are any objections.

v2->v3:
* use d->arch.has_vpci since plumbing struct arch_domain with a vPCI flag

v1->v2:
* add is_hardware_domain check. This will need to be removed after the vPCI
  series [3] is merged.

downstream->v1:
* change to IS_ENABLED(CONFIG_HAS_VPCI) instead of hardcoded to true
* remove the comment on the preceding line

[1] 
https://gitlab.com/xen-project/people/bmarquis/xen-arm-poc/-/commit/27be1729ce8128dbe37275ce7946b2fbd2e5a382
[2] 
https://github.com/xen-troops/xen/commit/bf12185e6fb2e31db0d8e6ea9ccd8a02abadec17
[3] https://lists.xenproject.org/archives/html/xen-devel/2023-08/msg02361.html
---
 xen/arch/arm/include/asm/domain.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/xen/arch/arm/include/asm/domain.h 
b/xen/arch/arm/include/asm/domain.h
index 0a66ed09a617..ebba2c25dceb 100644
--- a/xen/arch/arm/include/asm/domain.h
+++ b/xen/arch/arm/include/asm/domain.h
@@ -300,8 +300,7 @@ static inline void arch_vcpu_block(struct vcpu *v) {}
 
 #define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag)
 
-/* vPCI is not available on Arm */
-#define has_vpci(d)    ({ (void)(d); false; })
+#define has_vpci(d) ( (d)->arch.has_vpci )
 
 struct arch_vcpu_io {
     struct instr_details dabt_instr; /* when the instruction is decoded */
-- 
2.42.0