From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56039) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7JvU-0007HQ-Ro for qemu-devel@nongnu.org; Tue, 23 Jun 2015 04:51:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z7JvQ-0002K6-Nz for qemu-devel@nongnu.org; Tue, 23 Jun 2015 04:51:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58479) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7JvQ-0002K2-Gt for qemu-devel@nongnu.org; Tue, 23 Jun 2015 04:51:24 -0400 Date: Tue, 23 Jun 2015 16:51:21 +0800 From: Fam Zheng Message-ID: <20150623085121.GB2028@ad.nay.redhat.com> References: <1434646046-27150-1-git-send-email-pbonzini@redhat.com> <1434646046-27150-4-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1434646046-27150-4-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH 3/9] memory: Add global-locking property to memory regions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: jan.kiszka@siemens.com, qemu-devel@nongnu.org On Thu, 06/18 18:47, Paolo Bonzini wrote: > From: Jan Kiszka > > 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 > Signed-off-by: Paolo Bonzini > --- > include/exec/memory.h | 26 ++++++++++++++++++++++++++ > memory.c | 11 +++++++++++ > 2 files changed, 37 insertions(+) > > diff --git a/include/exec/memory.h b/include/exec/memory.h > index b61c84f..61791f8 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; > @@ -812,6 +813,31 @@ 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, access to this memory regions 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. > * > diff --git a/memory.c b/memory.c > index 03c536b..6b77354 100644 > --- a/memory.c > +++ b/memory.c > @@ -1004,6 +1004,7 @@ static void memory_region_initfn(Object *obj) > mr->ops = &unassigned_mem_ops; > mr->enabled = true; > mr->romd_mode = true; > + mr->global_locking = true; > mr->destructor = memory_region_destructor_none; > QTAILQ_INIT(&mr->subregions); > QTAILQ_INIT(&mr->coalesced); > @@ -1627,6 +1628,16 @@ void memory_region_clear_flush_coalesced(MemoryRegion *mr) > } > } > > +void memory_region_set_global_locking(MemoryRegion *mr) > +{ > + mr->global_locking = true; > +} > + > +void memory_region_clear_global_locking(MemoryRegion *mr) > +{ > + mr->global_locking = false; > +} > + > void memory_region_add_eventfd(MemoryRegion *mr, > hwaddr addr, > unsigned size, > -- > 1.8.3.1 > > > Reviewed-by: Fam Zheng