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-rw-r--r--include/xen/interface/memory.h50
1 files changed, 50 insertions, 0 deletions
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index af36ead1681..d3938d3e71f 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -9,6 +9,8 @@
#ifndef __XEN_PUBLIC_MEMORY_H__
#define __XEN_PUBLIC_MEMORY_H__
+#include <linux/spinlock.h>
+
/*
* Increase or decrease the specified domain's memory reservation. Returns a
* -ve errcode on failure, or the # extents successfully allocated or freed.
@@ -53,6 +55,48 @@ struct xen_memory_reservation {
DEFINE_GUEST_HANDLE_STRUCT(xen_memory_reservation);
/*
+ * An atomic exchange of memory pages. If return code is zero then
+ * @out.extent_list provides GMFNs of the newly-allocated memory.
+ * Returns zero on complete success, otherwise a negative error code.
+ * On complete success then always @nr_exchanged == @in.nr_extents.
+ * On partial success @nr_exchanged indicates how much work was done.
+ */
+#define XENMEM_exchange 11
+struct xen_memory_exchange {
+ /*
+ * [IN] Details of memory extents to be exchanged (GMFN bases).
+ * Note that @in.address_bits is ignored and unused.
+ */
+ struct xen_memory_reservation in;
+
+ /*
+ * [IN/OUT] Details of new memory extents.
+ * We require that:
+ * 1. @in.domid == @out.domid
+ * 2. @in.nr_extents << @in.extent_order ==
+ * @out.nr_extents << @out.extent_order
+ * 3. @in.extent_start and @out.extent_start lists must not overlap
+ * 4. @out.extent_start lists GPFN bases to be populated
+ * 5. @out.extent_start is overwritten with allocated GMFN bases
+ */
+ struct xen_memory_reservation out;
+
+ /*
+ * [OUT] Number of input extents that were successfully exchanged:
+ * 1. The first @nr_exchanged input extents were successfully
+ * deallocated.
+ * 2. The corresponding first entries in the output extent list correctly
+ * indicate the GMFNs that were successfully exchanged.
+ * 3. All other input and output extents are untouched.
+ * 4. If not all input exents are exchanged then the return code of this
+ * command will be non-zero.
+ * 5. THIS FIELD MUST BE INITIALISED TO ZERO BY THE CALLER!
+ */
+ unsigned long nr_exchanged;
+};
+
+DEFINE_GUEST_HANDLE_STRUCT(xen_memory_exchange);
+/*
* Returns the maximum machine frame number of mapped RAM in this system.
* This command always succeeds (it never returns an error code).
* arg == NULL.
@@ -142,4 +186,10 @@ struct xen_translate_gpfn_list {
};
DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list);
+
+/*
+ * Prevent the balloon driver from changing the memory reservation
+ * during a driver critical region.
+ */
+extern spinlock_t xen_reservation_lock;
#endif /* __XEN_PUBLIC_MEMORY_H__ */