{
struct domain *d = v->domain;
- v->vcpu_info = ((v->vcpu_id < XEN_LEGACY_MAX_VCPUS)
- ? (vcpu_info_t *)&shared_info(d, vcpu_info[v->vcpu_id])
- : &dummy_vcpu_info);
- v->vcpu_info_mfn = INVALID_MFN;
+ v->vcpu_info_area.map =
+ ((v->vcpu_id < XEN_LEGACY_MAX_VCPUS)
+ ? (vcpu_info_t *)&shared_info(d, vcpu_info[v->vcpu_id])
+ : &dummy_vcpu_info);
}
static void vmtrace_free_buffer(struct vcpu *v)
return -ERESTART;
for_each_vcpu ( d, v )
{
- unmap_vcpu_info(v);
+ unmap_guest_area(v, &v->vcpu_info_area);
unmap_guest_area(v, &v->runstate_guest_area);
}
d->is_dying = DOMDYING_dead;
for_each_vcpu ( d, v )
{
set_xen_guest_handle(runstate_guest(v), NULL);
- unmap_vcpu_info(v);
+ unmap_guest_area(v, &v->vcpu_info_area);
unmap_guest_area(v, &v->runstate_guest_area);
}
return rc;
}
-/*
- * Map a guest page in and point the vcpu_info pointer at it. This
- * makes sure that the vcpu_info is always pointing at a valid piece
- * of memory, and it sets a pending event to make sure that a pending
- * event doesn't get missed.
- */
-int map_vcpu_info(struct vcpu *v, unsigned long gfn, unsigned int offset)
-{
- struct domain *d = v->domain;
- void *mapping;
- vcpu_info_t *new_info;
- struct page_info *page;
- unsigned int align;
-
- if ( offset > (PAGE_SIZE - sizeof(*new_info)) )
- return -ENXIO;
-
-#ifdef CONFIG_COMPAT
- BUILD_BUG_ON(sizeof(*new_info) != sizeof(new_info->compat));
- if ( has_32bit_shinfo(d) )
- align = alignof(new_info->compat);
- else
-#endif
- align = alignof(*new_info);
- if ( offset & (align - 1) )
- return -ENXIO;
-
- if ( !mfn_eq(v->vcpu_info_mfn, INVALID_MFN) )
- return -EINVAL;
-
- /* Run this command on yourself or on other offline VCPUS. */
- if ( (v != current) && !(v->pause_flags & VPF_down) )
- return -EINVAL;
-
- page = get_page_from_gfn(d, gfn, NULL, P2M_UNSHARE);
- if ( !page )
- return -EINVAL;
-
- if ( !get_page_type(page, PGT_writable_page) )
- {
- put_page(page);
- return -EINVAL;
- }
-
- mapping = __map_domain_page_global(page);
- if ( mapping == NULL )
- {
- put_page_and_type(page);
- return -ENOMEM;
- }
-
- new_info = (vcpu_info_t *)(mapping + offset);
-
- if ( v->vcpu_info == &dummy_vcpu_info )
- {
- memset(new_info, 0, sizeof(*new_info));
-#ifdef XEN_HAVE_PV_UPCALL_MASK
- __vcpu_info(v, new_info, evtchn_upcall_mask) = 1;
-#endif
- }
- else
- {
- memcpy(new_info, v->vcpu_info, sizeof(*new_info));
- }
-
- v->vcpu_info = new_info;
- v->vcpu_info_mfn = page_to_mfn(page);
-
- /* Set new vcpu_info pointer /before/ setting pending flags. */
- smp_wmb();
-
- /*
- * Mark everything as being pending just to make sure nothing gets
- * lost. The domain will get a spurious event, but it can cope.
- */
-#ifdef CONFIG_COMPAT
- if ( !has_32bit_shinfo(d) )
- write_atomic(&new_info->native.evtchn_pending_sel, ~0);
- else
-#endif
- write_atomic(&vcpu_info(v, evtchn_pending_sel), ~0);
- vcpu_mark_events_pending(v);
-
- return 0;
-}
-
-/*
- * Unmap the vcpu info page if the guest decided to place it somewhere
- * else. This is used from domain_kill() and domain_soft_reset().
- */
-void unmap_vcpu_info(struct vcpu *v)
-{
- mfn_t mfn = v->vcpu_info_mfn;
-
- if ( mfn_eq(mfn, INVALID_MFN) )
- return;
-
- unmap_domain_page_global((void *)
- ((unsigned long)v->vcpu_info & PAGE_MASK));
-
- vcpu_info_reset(v); /* NB: Clobbers v->vcpu_info_mfn */
-
- put_page_and_type(mfn_to_page(mfn));
-}
-
int map_guest_area(struct vcpu *v, paddr_t gaddr, unsigned int size,
struct guest_area *area,
void (*populate)(void *dst, struct vcpu *v))
domain_lock(d);
- if ( map && populate )
- populate(map, v);
+ /* No re-registration of the vCPU info area. */
+ if ( area != &v->vcpu_info_area || !area->pg )
+ {
+ if ( map && populate )
+ populate(map, v);
- SWAP(area->pg, pg);
- SWAP(area->map, map);
+ SWAP(area->pg, pg);
+ SWAP(area->map, map);
+ }
+ else
+ rc = -EBUSY;
domain_unlock(d);
+ /* Set pending flags /after/ new vcpu_info pointer was set. */
+ if ( area == &v->vcpu_info_area && !rc )
+ {
+ /*
+ * Mark everything as being pending just to make sure nothing gets
+ * lost. The domain will get a spurious event, but it can cope.
+ */
+#ifdef CONFIG_COMPAT
+ if ( !has_32bit_shinfo(d) )
+ {
+ vcpu_info_t *info = area->map;
+
+ /* For VCPUOP_register_vcpu_info handling in common_vcpu_op(). */
+ BUILD_BUG_ON(sizeof(*info) != sizeof(info->compat));
+ write_atomic(&info->native.evtchn_pending_sel, ~0);
+ }
+ else
+#endif
+ write_atomic(&vcpu_info(v, evtchn_pending_sel), ~0);
+ vcpu_mark_events_pending(v);
+
+ force_update_vcpu_system_time(v);
+ }
+
if ( v != current )
vcpu_unpause(v);
domain_lock(d);
map = area->map;
- area->map = NULL;
+ if ( area == &v->vcpu_info_area )
+ vcpu_info_reset(v);
+ else
+ area->map = NULL;
pg = area->pg;
area->pg = NULL;
domain_unlock(d);
return rc;
}
+/*
+ * This makes sure that the vcpu_info is always pointing at a valid piece of
+ * memory, and it sets a pending event to make sure that a pending event
+ * doesn't get missed.
+ */
+static void cf_check
+vcpu_info_populate(void *map, struct vcpu *v)
+{
+ vcpu_info_t *info = map;
+
+ if ( v->vcpu_info_area.map == &dummy_vcpu_info )
+ {
+ memset(info, 0, sizeof(*info));
+#ifdef XEN_HAVE_PV_UPCALL_MASK
+ __vcpu_info(v, info, evtchn_upcall_mask) = 1;
+#endif
+ }
+ else
+ memcpy(info, v->vcpu_info_area.map, sizeof(*info));
+}
+
static void cf_check
runstate_area_populate(void *map, struct vcpu *v)
{
switch ( cmd )
{
case VCPUOP_initialise:
- if ( v->vcpu_info == &dummy_vcpu_info )
+ if ( v->vcpu_info_area.map == &dummy_vcpu_info )
return -EINVAL;
rc = arch_initialise_vcpu(v, arg);
case VCPUOP_register_vcpu_info:
{
struct vcpu_register_vcpu_info info;
+ paddr_t gaddr;
rc = -EFAULT;
if ( copy_from_guest(&info, arg, 1) )
break;
- domain_lock(d);
- rc = map_vcpu_info(v, info.mfn, info.offset);
- domain_unlock(d);
+ rc = -EINVAL;
+ gaddr = gfn_to_gaddr(_gfn(info.mfn)) + info.offset;
+ if ( !~gaddr ||
+ gfn_x(gaddr_to_gfn(gaddr)) != info.mfn )
+ break;
- force_update_vcpu_system_time(v);
+ /* Preliminary check only; see map_guest_area(). */
+ rc = -EBUSY;
+ if ( v->vcpu_info_area.pg )
+ break;
+
+ /* See the BUILD_BUG_ON() in vcpu_info_populate(). */
+ rc = map_guest_area(v, gaddr, sizeof(vcpu_info_t),
+ &v->vcpu_info_area, vcpu_info_populate);
+ if ( rc == -ERESTART )
+ rc = hypercall_create_continuation(__HYPERVISOR_vcpu_op, "iih",
+ cmd, vcpuid, arg);
break;
}
projects / people / royger / xen.git / commitdiff