From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39082) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7y67-00048y-86 for qemu-devel@nongnu.org; Wed, 24 Jun 2015 23:45:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z7y63-0002AH-US for qemu-devel@nongnu.org; Wed, 24 Jun 2015 23:45:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46685) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7y63-00029b-MX for qemu-devel@nongnu.org; Wed, 24 Jun 2015 23:45:03 -0400 Date: Thu, 25 Jun 2015 11:44:57 +0800 From: Fam Zheng Message-ID: <20150625034457.GH17695@ad.nay.redhat.com> References: <1435163110-2724-1-git-send-email-pbonzini@redhat.com> <1435163110-2724-4-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435163110-2724-4-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: borntraeger@de.ibm.com, Frederic Konrad , qemu-devel@nongnu.org, Jan Kiszka On Wed, 06/24 18:25, 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 > Cc: Frederic Konrad > Signed-off-by: Paolo Bonzini > Message-Id: <1434646046-27150-4-git-send-email-pbonzini@redhat.com> > --- > 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 8ae004e..fc33348 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; > @@ -825,6 +826,31 @@ 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 Inconsistent with singlar form (access) in the previous one. Otherwise, Reviewed-by: Fam Zheng > + * 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 3ac0bd2..b0b8860 100644 > --- a/memory.c > +++ b/memory.c > @@ -1012,6 +1012,7 @@ static void memory_region_initfn(Object *obj) > mr->ram_addr = RAM_ADDR_INVALID; > 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); > @@ -1646,6 +1647,16 @@ 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 > >