From 196ea13104f802c508e57180b2a0d2b3418989a3 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Thu, 18 Jun 2015 18:47:20 +0200 Subject: memory: Add global-locking property to memory regions This introduces the memory region property "global_locking". It is true by default. By setting it to false, a device model can request BQL-free dispatching of region accesses to its r/w handlers. The actual BQL break-up will be provided in a separate patch. Signed-off-by: Jan Kiszka Cc: Frederic Konrad Signed-off-by: Paolo Bonzini Message-Id: <1434646046-27150-4-git-send-email-pbonzini@redhat.com> --- include/exec/memory.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'include/exec/memory.h') diff --git a/include/exec/memory.h b/include/exec/memory.h index 8ae004eb06..0ebdc55506 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -180,6 +180,7 @@ struct MemoryRegion { bool rom_device; bool warning_printed; /* For reservations */ bool flush_coalesced_mmio; + bool global_locking; MemoryRegion *alias; hwaddr alias_offset; int32_t priority; @@ -824,6 +825,31 @@ void memory_region_set_flush_coalesced(MemoryRegion *mr); */ void memory_region_clear_flush_coalesced(MemoryRegion *mr); +/** + * memory_region_set_global_locking: Declares the access processing requires + * QEMU's global lock. + * + * When this is invoked, accesses to the memory region will be processed while + * holding the global lock of QEMU. This is the default behavior of memory + * regions. + * + * @mr: the memory region to be updated. + */ +void memory_region_set_global_locking(MemoryRegion *mr); + +/** + * memory_region_clear_global_locking: Declares that access processing does + * not depend on the QEMU global lock. + * + * By clearing this property, accesses to the memory region will be processed + * outside of QEMU's global lock (unless the lock is held on when issuing the + * access request). In this case, the device model implementing the access + * handlers is responsible for synchronization of concurrency. + * + * @mr: the memory region to be updated. + */ +void memory_region_clear_global_locking(MemoryRegion *mr); + /** * memory_region_add_eventfd: Request an eventfd to be triggered when a word * is written to a location. -- cgit v1.2.3