From: Oleksandr Andrushchenko
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
---
Cc: Julien Grall
Cc: Stefano Stabellini
---
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.
Since v5:
- optimize with IS_ENABLED(CONFIG_HAS_PCI_MSI) since VPCI_MAX_VIRT_DEV is
defined unconditionally
New in v5
---
xen/arch/arm/vpci.c | 14 +-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c
index 84b2b068a0fe..c5902cb9d34d 100644
--- a/xen/arch/arm/vpci.c
+++ b/xen/arch/arm/vpci.c
@@ -131,6 +131,8 @@ 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;
@@ -151,7 +153,17 @@ unsigned int domain_vpci_get_num_mmio_handlers(struct
domain *d)
* For guests each host bridge requires one region to cover the
* configuration space. At the moment, we only expose a single host bridge.
*/
-return 1;
+count = 1;
+
+/*
+ * 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.
+ */
+if ( IS_ENABLED(CONFIG_HAS_PCI_MSI) )
+count += VPCI_MAX_VIRT_DEV;
+
+return count;
}
/*
--
2.25.1
