From: Bernhard Beschow <shentey@gmail.com>

The only user of xen_set_pci_link_route() is
xen_piix_pci_write_config_client() which implements PIIX-specific logic in
the xen namespace. This makes xen-hvm depend on PIIX which could be
avoided if xen_piix_pci_write_config_client() was implemented in PIIX. In
order to do this, xen_set_pci_link_route() needs to be stubbable which
this patch addresses.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20220626094656.15673-2-shentey@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 hw/i386/xen/xen-hvm.c       | 7 ++++++-
 include/hw/xen/xen.h        | 1 +
 include/hw/xen/xen_common.h | 6 ------
 stubs/xen-hw-stub.c         | 5 +++++
 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
index 0731f7041069..204fda7949d9 100644
--- a/hw/i386/xen/xen-hvm.c
+++ b/hw/i386/xen/xen-hvm.c
@@ -161,11 +161,16 @@ void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
         }
         v &= 0xf;
         if (((address + i) >= PIIX_PIRQCA) && ((address + i) <= PIIX_PIRQCD)) {
-            xen_set_pci_link_route(xen_domid, address + i - PIIX_PIRQCA, v);
+            xen_set_pci_link_route(address + i - PIIX_PIRQCA, v);
         }
     }
 }
 
+int xen_set_pci_link_route(uint8_t link, uint8_t irq)
+{
+    return xendevicemodel_set_pci_link_route(xen_dmod, xen_domid, link, irq);
+}
+
 int xen_is_pirq_msi(uint32_t msi_data)
 {
     /* If vector is 0, the msi is remapped into a pirq, passed as
diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h
index 0f9962b1c190..13bffaef531f 100644
--- a/include/hw/xen/xen.h
+++ b/include/hw/xen/xen.h
@@ -21,6 +21,7 @@ extern enum xen_mode xen_mode;
 extern bool xen_domid_restrict;
 
 int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num);
+int xen_set_pci_link_route(uint8_t link, uint8_t irq);
 void xen_piix3_set_irq(void *opaque, int irq_num, int level);
 void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len);
 void xen_hvm_inject_msi(uint64_t addr, uint32_t data);
diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index 179741ff791c..77ce17d8a4f7 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -316,12 +316,6 @@ static inline int xen_set_pci_intx_level(domid_t domid, uint16_t segment,
                                              device, intx, level);
 }
 
-static inline int xen_set_pci_link_route(domid_t domid, uint8_t link,
-                                         uint8_t irq)
-{
-    return xendevicemodel_set_pci_link_route(xen_dmod, domid, link, irq);
-}
-
 static inline int xen_inject_msi(domid_t domid, uint64_t msi_addr,
                                  uint32_t msi_data)
 {
diff --git a/stubs/xen-hw-stub.c b/stubs/xen-hw-stub.c
index 15f3921a76b0..743967623f00 100644
--- a/stubs/xen-hw-stub.c
+++ b/stubs/xen-hw-stub.c
@@ -23,6 +23,11 @@ void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
 {
 }
 
+int xen_set_pci_link_route(uint8_t link, uint8_t irq)
+{
+    return -1;
+}
+
 void xen_hvm_inject_msi(uint64_t addr, uint32_t data)
 {
 }
-- 
2.36.1