[PATCH v3 7/9] vpci: add a priority field to the vPCI register initializer

[Roger Pau Monne <roger.pau@citrix.com>]

And mark the capability and header vPCI register initializers as high priority,
so that they are initialized first.

This is needed for MSI-X, since MSI-X needs to know the position of the BARs in
order to perform it's initialization, and in order to mask or enable the
MSI/MSI-X functionality on demand.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
---
 tools/tests/vpci/Makefile       |  4 ++--
 xen/drivers/vpci/capabilities.c |  2 +-
 xen/drivers/vpci/header.c       |  2 +-
 xen/drivers/vpci/vpci.c         | 14 ++++++++++++--
 xen/include/xen/vpci.h          | 13 +++++++++++--
 5 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/tools/tests/vpci/Makefile b/tools/tests/vpci/Makefile
index 7969fcbd82..e5edc4f512 100644
--- a/tools/tests/vpci/Makefile
+++ b/tools/tests/vpci/Makefile
@@ -31,8 +31,8 @@ vpci.c: $(XEN_ROOT)/xen/drivers/vpci/vpci.c
 	# Trick the compiler so it doesn't complain about missing symbols
 	sed -e '/#include/d' \
 	    -e '1s;^;#include "emul.h"\
-	             const vpci_register_init_t __start_vpci_array[1]\;\
-	             const vpci_register_init_t __end_vpci_array[1]\;\
+	             const struct vpci_register_init __start_vpci_array[1]\;\
+	             const struct vpci_register_init __end_vpci_array[1]\;\
 	             ;' <$< >$@
 
 rbtree.h: $(XEN_ROOT)/xen/include/xen/rbtree.h
diff --git a/xen/drivers/vpci/capabilities.c b/xen/drivers/vpci/capabilities.c
index b2a3326aa7..204355e673 100644
--- a/xen/drivers/vpci/capabilities.c
+++ b/xen/drivers/vpci/capabilities.c
@@ -145,7 +145,7 @@ static int vpci_capabilities_init(struct pci_dev *pdev)
     return 0;
 }
 
-REGISTER_VPCI_INIT(vpci_capabilities_init);
+REGISTER_VPCI_INIT(vpci_capabilities_init, true);
 
 /*
  * Local variables:
diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index a401cf6915..3deec53efd 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -278,7 +278,7 @@ static int vpci_init_bars(struct pci_dev *pdev)
     return 0;
 }
 
-REGISTER_VPCI_INIT(vpci_init_bars);
+REGISTER_VPCI_INIT(vpci_init_bars, true);
 
 /*
  * Local variables:
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index b159f0db80..e6154b742e 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -20,7 +20,7 @@
 #include <xen/sched.h>
 #include <xen/vpci.h>
 
-extern const vpci_register_init_t __start_vpci_array[], __end_vpci_array[];
+extern const struct vpci_register_init __start_vpci_array[], __end_vpci_array[];
 #define NUM_VPCI_INIT (__end_vpci_array - __start_vpci_array)
 #define vpci_init __start_vpci_array
 
@@ -37,6 +37,7 @@ struct vpci_register {
 int xen_vpci_add_handlers(struct pci_dev *pdev)
 {
     int i, rc = 0;
+    bool priority = true;
 
     if ( !has_vpci(pdev->domain) )
         return 0;
@@ -47,9 +48,13 @@ int xen_vpci_add_handlers(struct pci_dev *pdev)
 
     pdev->vpci->handlers = RB_ROOT;
 
+ again:
     for ( i = 0; i < NUM_VPCI_INIT; i++ )
     {
-        rc = vpci_init[i](pdev);
+        if ( priority != vpci_init[i].priority )
+            continue;
+
+        rc = vpci_init[i].init(pdev);
         if ( rc )
             break;
     }
@@ -69,6 +74,11 @@ int xen_vpci_add_handlers(struct pci_dev *pdev)
         }
         xfree(pdev->vpci);
     }
+    else if ( priority )
+    {
+        priority = false;
+        goto again;
+    }
 
     return rc;
 }
diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h
index d41277f39b..2bf61d6c15 100644
--- a/xen/include/xen/vpci.h
+++ b/xen/include/xen/vpci.h
@@ -29,8 +29,17 @@ typedef int (*vpci_write_t)(struct pci_dev *pdev, unsigned int reg,
 
 typedef int (*vpci_register_init_t)(struct pci_dev *dev);
 
-#define REGISTER_VPCI_INIT(x) \
-  static const vpci_register_init_t x##_entry __used_section(".data.vpci") = x
+struct vpci_register_init {
+    vpci_register_init_t init;
+    bool priority;
+};
+
+#define REGISTER_VPCI_INIT(f, p)                                        \
+  static const struct vpci_register_init                                \
+                      x##_entry __used_section(".data.vpci") = {        \
+    .init = f,                                                          \
+    .priority = p,                                                      \
+}
 
 /* Add vPCI handlers to device. */
 int xen_vpci_add_handlers(struct pci_dev *dev);
-- 
2.11.0 (Apple Git-81)


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