From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43291) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YbvsA-0000Q8-Tv for qemu-devel@nongnu.org; Sat, 28 Mar 2015 14:54:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ybvs5-0006nc-Iq for qemu-devel@nongnu.org; Sat, 28 Mar 2015 14:54:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39872) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ybvs5-0006n5-Bo for qemu-devel@nongnu.org; Sat, 28 Mar 2015 14:54:13 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2SIsBHo008902 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Sat, 28 Mar 2015 14:54:11 -0400 Date: Sat, 28 Mar 2015 19:54:09 +0100 From: "Michael S. Tsirkin" Message-ID: <20150328194809-mutt-send-email-mst@redhat.com> References: <1427391520-29497-1-git-send-email-pbonzini@redhat.com> <1427391520-29497-6-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427391520-29497-6-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH 05/22] memory: return bitmap from memory_region_is_logging List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org On Thu, Mar 26, 2015 at 06:38:23PM +0100, Paolo Bonzini wrote: > For now it only returns (1 << DIRTY_MEMORY_VGA) or 0, but this > will change soon so adjust the callers. > > Listeners check for "any bit except migration", which is handled > via the global start/stop listener callbacks. This in practice > means VGA because the code bitmap is TCG-specific; however, be > explicit, as for example things would be different if vhost ever > ran with TCG. > > Instead, the VMware VGA is looking explicitly for DIRTY_MEMORY_VGA. > > Cc: Michael S. Tsirkin > Signed-off-by: Paolo Bonzini > --- > This is the ugliest patch in the series. My long-term plan > is to get rid of the global start/stop hooks in the > MemoryListeners. > > hw/display/vmware_vga.c | 2 +- > hw/virtio/vhost.c | 3 ++- > include/exec/memory.h | 5 +++-- > kvm-all.c | 3 ++- > memory.c | 2 +- > xen-hvm.c | 3 ++- > 6 files changed, 11 insertions(+), 7 deletions(-) > > diff --git a/hw/display/vmware_vga.c b/hw/display/vmware_vga.c > index c17ddd1..93d7426 100644 > --- a/hw/display/vmware_vga.c > +++ b/hw/display/vmware_vga.c > @@ -1124,7 +1124,7 @@ static void vmsvga_update_display(void *opaque) > * Is it more efficient to look at vram VGA-dirty bits or wait > * for the driver to issue SVGA_CMD_UPDATE? > */ > - if (memory_region_is_logging(&s->vga.vram)) { > + if (memory_region_is_logging(&s->vga.vram) & (1 << DIRTY_MEMORY_VGA)) { > vga_sync_dirty_bitmap(&s->vga); > dirty = memory_region_get_dirty(&s->vga.vram, 0, > surface_stride(surface) * surface_height(surface), > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 5a12861..59321ee 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -377,7 +377,8 @@ static void vhost_set_memory(MemoryListener *listener, > memory_listener); > hwaddr start_addr = section->offset_within_address_space; > ram_addr_t size = int128_get64(section->size); > - bool log_dirty = memory_region_is_logging(section->mr); > + bool log_dirty = > + memory_region_is_logging(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); > int s = offsetof(struct vhost_memory, regions) + > (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; > void *ram; > diff --git a/include/exec/memory.h b/include/exec/memory.h > index 081f7d6..8d5feb2 100644 > --- a/include/exec/memory.h > +++ b/include/exec/memory.h > @@ -569,11 +569,12 @@ const char *memory_region_name(const MemoryRegion *mr); > /** > * memory_region_is_logging: return whether a memory region is logging writes > * > - * Returns %true if the memory region is logging writes > + * Returns a bitmap of clients for which the memory region is logging writes. > + * Right now this will be either 0 or (1 << DIRTY_MEMORY_VGA). > * > * @mr: the memory region being queried > */ > -bool memory_region_is_logging(MemoryRegion *mr); > +uint8_t memory_region_is_logging(MemoryRegion *mr); > > /** > * memory_region_is_rom: check whether a memory region is ROM > diff --git a/kvm-all.c b/kvm-all.c > index 335438a..6962653 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -663,7 +663,8 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) > KVMSlot *mem, old; > int err; > MemoryRegion *mr = section->mr; > - bool log_dirty = memory_region_is_logging(mr); > + bool log_dirty = > + memory_region_is_logging(mr) & ~(1 << DIRTY_MEMORY_MIGRATION); > bool writeable = !mr->readonly && !mr->rom_device; > bool readonly_flag = mr->readonly || memory_region_is_romd(mr); > hwaddr start_addr = section->offset_within_address_space; > diff --git a/memory.c b/memory.c > index e688f5e..45606bc 100644 > --- a/memory.c > +++ b/memory.c > @@ -1318,7 +1318,7 @@ bool memory_region_is_skip_dump(MemoryRegion *mr) > return mr->skip_dump; > } > > -bool memory_region_is_logging(MemoryRegion *mr) > +uint8_t memory_region_is_logging(MemoryRegion *mr) > { > return mr->dirty_log_mask; > } This API is pretty easy to misuse, and return value is completely undocumented. In fact, if I see "is" I assume a boolean return type. As you are touching all users anyway, how about wrappers that answer specific questions: memory_region_is_logging_dirty_memory_vga memory_region_is_logging_dirty_memory_migration memory_region_is_logging_dirty_memory_except_migration ? As a bonus, compiler will catch you if you forget to change some caller. > diff --git a/xen-hvm.c b/xen-hvm.c > index 315864c..acd89c8 100644 > --- a/xen-hvm.c > +++ b/xen-hvm.c > @@ -488,7 +488,8 @@ static void xen_set_memory(struct MemoryListener *listener, > XenIOState *state = container_of(listener, XenIOState, memory_listener); > hwaddr start_addr = section->offset_within_address_space; > ram_addr_t size = int128_get64(section->size); > - bool log_dirty = memory_region_is_logging(section->mr); > + bool log_dirty = > + memory_region_is_logging(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); > hvmmem_type_t mem_type; > > if (section->mr == &ram_memory) { > -- > 2.3.3 >