x86: add a shared page indicating the need for an EOI notification

Index: 2008-11-20/xen/arch/x86/domain.c
===================================================================
@@ -1823,6 +1823,14 @@ int domain_relinquish_resources(struct d
             unmap_vcpu_info(v);
         }
 
+        if ( d->arch.pirq_eoi_map )
+        {
+            unsigned long mfn = unmap_domain_page_global(d->arch.pirq_eoi_map);
+
+            d->arch.pirq_eoi_map = NULL;
+            put_page_and_type(mfn_to_page(mfn));
+        }
+
         d->arch.relmem = RELMEM_xen;
         /* fallthrough */
 

100 lines not on this page · raw message

Index: 2008-11-20/xen/arch/x86/physdev.c
===================================================================
@@ -191,10 +191,41 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         ret = -EFAULT;
         if ( copy_from_guest(&eoi, arg, 1) != 0 )
             break;
+        ret = -EINVAL;
+        if ( eoi.irq < 0 || eoi.irq >= NR_IRQS )
+            break;
+        if ( v->domain->arch.pirq_eoi_map )
+            evtchn_unmask(v->domain->pirq_to_evtchn[eoi.irq]);
         ret = pirq_guest_eoi(v->domain, eoi.irq);
         break;
     }
 
+    case PHYSDEVOP_pirq_eoi_mfn: {
+        struct physdev_pirq_eoi_mfn info;
+
+        BUILD_BUG_ON(NR_IRQS > PAGE_SIZE * 8);
+        ret = -EFAULT;
+        if ( copy_from_guest(&info, arg, 1) != 0 )
+            break;
+        ret = -EBUSY;
+        if ( v->domain->arch.pirq_eoi_map )
+            break;
+        ret = -EINVAL;
+        if ( !mfn_valid(info.mfn) ||
+             !get_page_and_type(mfn_to_page(info.mfn), v->domain,
+                                PGT_writable_page) )
+            break;
+        v->domain->arch.pirq_eoi_map = map_domain_page_global(info.mfn);
+        if ( v->domain->arch.pirq_eoi_map )
+            ret = 0;
+        else
+        {
+            put_page_and_type(mfn_to_page(info.mfn));
+            ret = -ENOSPC;
+        }
+        break;
+    }
+
     /* Legacy since 0x00030202. */
     case PHYSDEVOP_IRQ_UNMASK_NOTIFY: {
         ret = pirq_guest_unmask(v->domain);

Index: 2008-11-20/xen/arch/x86/x86_32/domain_page.c
===================================================================
@@ -241,9 +241,9 @@ void *map_domain_page_global(unsigned lo
     return (void *)va;
 }
 
-void unmap_domain_page_global(const void *va)
+unsigned long unmap_domain_page_global(const void *va)
 {
-    unsigned long __va = (unsigned long)va;
+    unsigned long __va = (unsigned long)va, mfn;
     l2_pgentry_t *pl2e;
     l1_pgentry_t *pl1e;
     unsigned int idx;

@@ -253,9 +253,12 @@ void unmap_domain_page_global(const void
     /* /First/, we zap the PTE. */
     pl2e = virt_to_xen_l2e(__va);
     pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(__va);
+    mfn = l1e_get_pfn(*pl1e);
     l1e_write(pl1e, l1e_empty());
 
     /* /Second/, we add to the garbage map. */
     idx = (__va - IOREMAP_VIRT_START) >> PAGE_SHIFT;
     set_bit(idx, garbage);
+
+    return mfn;
 }

Index: 2008-11-20/xen/arch/x86/x86_64/physdev.c
===================================================================
@@ -18,6 +18,9 @@
 #define physdev_eoi                compat_physdev_eoi
 #define physdev_eoi_t              physdev_eoi_compat_t
 
+#define physdev_pirq_eoi_mfn       compat_physdev_pirq_eoi_mfn
+#define physdev_pirq_eoi_mfn_t     physdev_pirq_eoi_mfn_compat_t
+
 #define physdev_set_iobitmap       compat_physdev_set_iobitmap
 #define physdev_set_iobitmap_t     physdev_set_iobitmap_compat_t
 

Index: 2008-11-20/xen/common/event_channel.c
===================================================================
@@ -762,10 +762,9 @@ long evtchn_bind_vcpu(unsigned int port,
 }
 
 
-static long evtchn_unmask(evtchn_unmask_t *unmask)
+int evtchn_unmask(unsigned int port)
 {
     struct domain *d = current->domain;
-    int            port = unmask->port;
     struct vcpu   *v;
 
     spin_lock(&d->event_lock);

@@ -916,7 +915,7 @@ long do_event_channel_op(int cmd, XEN_GU
         struct evtchn_unmask unmask;
         if ( copy_from_guest(&unmask, arg, 1) != 0 )
             return -EFAULT;
-        rc = evtchn_unmask(&unmask);
+        rc = evtchn_unmask(unmask.port);
         break;
     }
 

Index: 2008-11-20/xen/include/asm-x86/domain.h
===================================================================
@@ -238,6 +238,8 @@ struct arch_domain
     int vector_pirq[NR_VECTORS];
     s16 pirq_vector[NR_IRQS];
 
+    unsigned long *pirq_eoi_map;
+
     /* Pseudophysical e820 map (XENMEM_memory_map).  */
     struct e820entry e820[3];
     unsigned int nr_e820;

Index: 2008-11-20/xen/include/public/physdev.h
===================================================================
@@ -41,6 +41,21 @@ typedef struct physdev_eoi physdev_eoi_t
 DEFINE_XEN_GUEST_HANDLE(physdev_eoi_t);
 
 /*
+ * Register a shared page for the hypervisor to indicate whether the guest
+ * must issue PHYSDEVOP_eoi. The semantics of PHYSDEVOP_eoi change slightly
+ * once the guest used this function in that the associated event channel
+ * will automatically get unmasked. The page registered is used as a bit
+ * array indexed by Xen's PIRQ value.
+ */
+#define PHYSDEVOP_pirq_eoi_mfn          17
+struct physdev_pirq_eoi_mfn {
+    /* IN */
+    xen_pfn_t mfn;
+};
+typedef struct physdev_pirq_eoi_mfn physdev_pirq_eoi_mfn_t;
+DEFINE_XEN_GUEST_HANDLE(physdev_pirq_eoi_mfn_t);
+
+/*
  * Query the status of an IRQ line.
  * @arg == pointer to physdev_irq_status_query structure.
  */

Index: 2008-11-20/xen/include/xen/domain_page.h
===================================================================
@@ -32,7 +32,7 @@ void unmap_domain_page(const void *va);
  * mappings can also be unmapped from any context.
  */
 void *map_domain_page_global(unsigned long mfn);
-void unmap_domain_page_global(const void *va);
+unsigned long unmap_domain_page_global(const void *va);
 
 #define DMCACHE_ENTRY_VALID 1U
 #define DMCACHE_ENTRY_HELD  2U

@@ -99,8 +99,15 @@ domain_mmap_cache_destroy(struct domain_
 #define map_domain_page(mfn)                mfn_to_virt(mfn)
 #define unmap_domain_page(va)               ((void)(va))
 
-#define map_domain_page_global(mfn)         mfn_to_virt(mfn)
-#define unmap_domain_page_global(va)        ((void)(va))
+static inline void *map_domain_page_global(unsigned long mfn)
+{
+    return mfn_to_virt(mfn);
+}
+
+static inline unsigned long unmap_domain_page_global(void *va)
+{
+    return virt_to_mfn(va);
+}
 
 struct domain_mmap_cache { 
 };

Index: 2008-11-20/xen/include/xen/event.h
===================================================================
@@ -44,6 +44,9 @@ int evtchn_send(struct domain *d, unsign
 /* Bind a local event-channel port to the specified VCPU. */
 long evtchn_bind_vcpu(unsigned int port, unsigned int vcpu_id);
 
+/* unmask the current domain's event-channel port. */
+int evtchn_unmask(unsigned int port);
+
 /* Allocate/free a Xen-attached event channel port. */
 int alloc_unbound_xen_event_channel(
     struct vcpu *local_vcpu, domid_t remote_domid);

Index: 2008-11-20/xen/include/xen/irq.h
===================================================================
@@ -22,6 +22,7 @@ struct irqaction
 #define IRQ_PENDING	4	/* IRQ pending - replay on enable */
 #define IRQ_REPLAY	8	/* IRQ has been replayed but not acked yet */
 #define IRQ_GUEST       16      /* IRQ is handled by guest OS(es) */
+#define IRQ_GUEST_EOI_PENDING 32 /* IRQ was disabled, pending a guest EOI */
 #define IRQ_PER_CPU     256     /* IRQ is per CPU */
 
 /*