[PATCH v2 1/2] xen: introduce PHYSDEVOP_pirq_eoi_gmfn_v2

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

PHYSDEVOP_pirq_eoi_gmfn changes the semantics of PHYSDEVOP_eoi.
In order to improve the interface this patch:

- renames PHYSDEVOP_pirq_eoi_gmfn to PHYSDEVOP_pirq_eoi_gmfn_v1;

- introduces PHYSDEVOP_pirq_eoi_gmfn_v2, that is like
  PHYSDEVOP_pirq_eoi_gmfn_v1 but it doesn't modify the behaviour of
  another hypercall;

- bump __XEN_LATEST_INTERFACE_VERSION__;

- #define PHYSDEVOP_pirq_eoi_gmfn to PHYSDEVOP_pirq_eoi_gmfn_v1 or
  PHYSDEVOP_pirq_eoi_gmfn_v2 depending on the __XEN_INTERFACE_VERSION.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 xen/arch/ia64/xen/domain.c      |    1 +
 xen/arch/ia64/xen/hypercall.c   |    7 +++++--
 xen/arch/x86/domain.c           |    1 +
 xen/arch/x86/physdev.c          |    7 +++++--
 xen/include/asm-ia64/domain.h   |    3 +++
 xen/include/asm-x86/domain.h    |    3 +++
 xen/include/public/physdev.h    |   16 +++++++++++++++-
 xen/include/public/xen-compat.h |    2 +-
 8 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/xen/arch/ia64/xen/domain.c b/xen/arch/ia64/xen/domain.c
index 1ea5a90..a31bd32 100644
--- a/xen/arch/ia64/xen/domain.c
+++ b/xen/arch/ia64/xen/domain.c
@@ -1731,6 +1731,7 @@ int domain_relinquish_resources(struct domain *d)
 		if (d->arch.pirq_eoi_map != NULL) {
 			put_page(virt_to_page(d->arch.pirq_eoi_map));
 			d->arch.pirq_eoi_map = NULL;
+			d->arch.auto_unmask = 0;
 		}
 
 		/* Tear down shadow mode stuff. */
diff --git a/xen/arch/ia64/xen/hypercall.c b/xen/arch/ia64/xen/hypercall.c
index 130675e..18930bf 100644
--- a/xen/arch/ia64/xen/hypercall.c
+++ b/xen/arch/ia64/xen/hypercall.c
@@ -65,7 +65,7 @@ static long __do_pirq_guest_eoi(struct domain *d, int pirq)
 {
 	if ( pirq < 0 || pirq >= NR_IRQS )
 		return -EINVAL;
-	if ( d->arch.pirq_eoi_map ) {
+	if ( d->arch.auto_unmask ) {
 		spin_lock(&d->event_lock);
 		evtchn_unmask(pirq_to_evtchn(d, pirq));
 		spin_unlock(&d->event_lock);
@@ -508,7 +508,8 @@ long do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         break;
     }
 
-    case PHYSDEVOP_pirq_eoi_gmfn: {
+    case PHYSDEVOP_pirq_eoi_gmfn_v1:
+    case PHYSDEVOP_pirq_eoi_gmfn_v2: {
         struct physdev_pirq_eoi_gmfn info;
         unsigned long mfn;
 
@@ -531,6 +532,8 @@ long do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         }
 
         current->domain->arch.pirq_eoi_map = mfn_to_virt(mfn);
+        if ( cmd == PHYSDEVOP_pirq_eoi_gmfn_v1 )
+            current->domain->arch.auto_unmask = 1;
         ret = 0;
         break;
     }
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 61d83c8..a540af7 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2125,6 +2125,7 @@ int domain_relinquish_resources(struct domain *d)
                 put_page_and_type(
                     mfn_to_page(d->arch.pv_domain.pirq_eoi_map_mfn));
                 d->arch.pv_domain.pirq_eoi_map = NULL;
+                d->arch.pv_domain.auto_unmask = 0;
             }
         }
 
diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index f280c28..df92cc7 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -271,7 +271,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
             break;
         }
         if ( !is_hvm_domain(v->domain) &&
-             v->domain->arch.pv_domain.pirq_eoi_map )
+             v->domain->arch.pv_domain.auto_unmask )
             evtchn_unmask(pirq->evtchn);
         if ( !is_hvm_domain(v->domain) ||
              domain_pirq_to_irq(v->domain, eoi.irq) > 0 )
@@ -293,7 +293,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         break;
     }
 
-    case PHYSDEVOP_pirq_eoi_gmfn: {
+    case PHYSDEVOP_pirq_eoi_gmfn_v2:
+    case PHYSDEVOP_pirq_eoi_gmfn_v1: {
         struct physdev_pirq_eoi_gmfn info;
         unsigned long mfn;
 
@@ -329,6 +330,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
             ret = -ENOSPC;
             break;
         }
+        if ( cmd == PHYSDEVOP_pirq_eoi_gmfn_v1 )
+            v->domain->arch.pv_domain.auto_unmask = 1;
 
         put_gfn(current->domain, info.gmfn);
         ret = 0;
diff --git a/xen/include/asm-ia64/domain.h b/xen/include/asm-ia64/domain.h
index 12dc3bd..31d7d32 100644
--- a/xen/include/asm-ia64/domain.h
+++ b/xen/include/asm-ia64/domain.h
@@ -186,6 +186,9 @@ struct arch_domain {
     /* Shared page for notifying that explicit PIRQ EOI is required. */
     unsigned long *pirq_eoi_map;
     unsigned long pirq_eoi_map_mfn;
+    /* set auto_unmask to 1 if you want PHYSDEVOP_eoi to automatically
+     * unmask the event channel */
+    bool_t auto_unmask;
 
     /* Address of efi_runtime_services_t (placed in domain memory)  */
     void *efi_runtime;
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 00bbaeb..fb2cfd2 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -231,6 +231,9 @@ struct pv_domain
     /* Shared page for notifying that explicit PIRQ EOI is required. */
     unsigned long *pirq_eoi_map;
     unsigned long pirq_eoi_map_mfn;
+    /* set auto_unmask to 1 if you want PHYSDEVOP_eoi to automatically
+     * unmask the event channel */
+    bool_t auto_unmask;
 
     /* Pseudophysical e820 map (XENMEM_memory_map).  */
     spinlock_t e820_lock;
diff --git a/xen/include/public/physdev.h b/xen/include/public/physdev.h
index 6e23295..16d800f 100644
--- a/xen/include/public/physdev.h
+++ b/xen/include/public/physdev.h
@@ -49,7 +49,15 @@ DEFINE_XEN_GUEST_HANDLE(physdev_eoi_t);
  * will automatically get unmasked. The page registered is used as a bit
  * array indexed by Xen's PIRQ value.
  */
-#define PHYSDEVOP_pirq_eoi_gmfn         17
+#define PHYSDEVOP_pirq_eoi_gmfn_v1       17
+/*
+ * Register a shared page for the hypervisor to indicate whether the
+ * guest must issue PHYSDEVOP_eoi. This hypercall is very similar to
+ * PHYSDEVOP_pirq_eoi_gmfn_v1 but it doesn't change the semantics of
+ * PHYSDEVOP_eoi. The page registered is used as a bit array indexed by
+ * Xen's PIRQ value.
+ */
+#define PHYSDEVOP_pirq_eoi_gmfn_v2       28
 struct physdev_pirq_eoi_gmfn {
     /* IN */
     xen_pfn_t gmfn;
@@ -325,6 +333,12 @@ DEFINE_XEN_GUEST_HANDLE(physdev_pci_device_t);
 #define PHYSDEVOP_IRQ_NEEDS_UNMASK_NOTIFY XENIRQSTAT_needs_eoi
 #define PHYSDEVOP_IRQ_SHARED             XENIRQSTAT_shared
 
+#if __XEN_INTERFACE_VERSION < 0x00040200
+#define PHYSDEVOP_pirq_eoi_gmfn PHYSDEVOP_pirq_eoi_gmfn_v1
+#else
+#define PHYSDEVOP_pirq_eoi_gmfn PHYSDEVOP_pirq_eoi_gmfn_v2
+#endif
+
 #endif /* __XEN_PUBLIC_PHYSDEV_H__ */
 
 /*
diff --git a/xen/include/public/xen-compat.h b/xen/include/public/xen-compat.h
index 2e38003..d8c55bf 100644
--- a/xen/include/public/xen-compat.h
+++ b/xen/include/public/xen-compat.h
@@ -27,7 +27,7 @@
 #ifndef __XEN_PUBLIC_XEN_COMPAT_H__
 #define __XEN_PUBLIC_XEN_COMPAT_H__
 
-#define __XEN_LATEST_INTERFACE_VERSION__ 0x0003020a
+#define __XEN_LATEST_INTERFACE_VERSION__ 0x00040200
 
 #if defined(__XEN__) || defined(__XEN_TOOLS__)
 /* Xen is built with matching headers and implements the latest interface. */
-- 
1.7.2.5