[RFC PATCH] x86: Add a new physdev_op PHYSDEVOP_nr_irqs_gsi

[Lin Ming <mlin@ss.pku.edu.cn>]

This new physdev_op is added for Linux guest kernel to get the correct
nr_irqs_gsi value.

See below Linux kernel patch for detail explanation.

[RFC PATCH] xen: get correct nr_irqs_gsi value from hypervisor
http://marc.info/?l=xen-devel&m=133407004503365&w=2

Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
---
 xen/arch/x86/physdev.c       |    8 ++++++++
 xen/include/public/physdev.h |    6 ++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index 05fff9e..0912db0 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -688,6 +688,14 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
                               setup_gsi.polarity);
         break; 
     }
+    case PHYSDEVOP_nr_irqs_gsi: {
+        struct physdev_nr_irqs_gsi out;
+
+        out.nr_irqs_gsi = nr_irqs_gsi;
+        ret = copy_to_guest(arg, &out, 1) ? -EFAULT : 0;
+
+        break;
+    }
     case PHYSDEVOP_get_free_pirq: {
         struct physdev_get_free_pirq out;
         struct domain *d;
diff --git a/xen/include/public/physdev.h b/xen/include/public/physdev.h
index b78eeba..7856fc2 100644
--- a/xen/include/public/physdev.h
+++ b/xen/include/public/physdev.h
@@ -312,6 +312,12 @@ struct physdev_pci_device {
 typedef struct physdev_pci_device physdev_pci_device_t;
 DEFINE_XEN_GUEST_HANDLE(physdev_pci_device_t);
 
+#define PHYSDEVOP_nr_irqs_gsi           29
+struct physdev_nr_irqs_gsi {
+    /* OUT */
+    uint32_t nr_irqs_gsi;
+};
+
 /*
  * Notify that some PIRQ-bound event channels have been unmasked.
  * ** This command is obsolete since interface version 0x00030202 and is **
-- 
1.7.2.5