From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49616) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkRp-0003kh-I0 for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:29:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzkRk-0000wR-91 for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:29:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27251) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkRk-0000wD-0a for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:28:56 -0400 Date: Wed, 25 Jun 2014 12:46:24 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625094624.GC6357@redhat.com> References: <1403686864-13567-1-git-send-email-hutao@cn.fujitsu.com> <20140625091757.GK32652@redhat.com> <20140625093331.GA8022@G08FNSTD100614.fnst.cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140625093331.GA8022@G08FNSTD100614.fnst.cn.fujitsu.com> Subject: Re: [Qemu-devel] [PATCH] check if we have space left for hotplugged memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hu Tao Cc: Igor Mammedov , qemu-devel@nongnu.org, Yasunori Goto On Wed, Jun 25, 2014 at 05:33:31PM +0800, Hu Tao wrote: > On Wed, Jun 25, 2014 at 12:17:57PM +0300, Michael S. Tsirkin wrote: > > On Wed, Jun 25, 2014 at 05:01:04PM +0800, Hu Tao wrote: > > > If pc-dimm is specified on qemu command line, but only with > > > -m size (aka not -m size,maxmem,slots) then qemu will core dump. > > > > > > This patch fixes the problem. > > > > > > Signed-off-by: Hu Tao > > > --- > > > hw/i386/pc.c | 5 +++++ > > > hw/mem/pc-dimm.c | 5 +++++ > > > 2 files changed, 10 insertions(+) > > > > > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > > index 2cf22b1..1a0d96e 100644 > > > --- a/hw/i386/pc.c > > > +++ b/hw/i386/pc.c > > > @@ -1566,6 +1566,11 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev, > > > goto out; > > > } > > > > > > + if (memory_region_size(&pcms->hotplug_memory) == 0) { > > > + error_setg(&local_err, "no space left for hotplugged memory."); > > > + goto out; > > > + } > > > + > > > addr = pc_dimm_get_free_addr(pcms->hotplug_memory_base, > > > memory_region_size(&pcms->hotplug_memory), > > > !addr ? NULL : &addr, > > > > > > Why two errors in two places? > > This is what Igor suggested(IIUC) which I think is reasonable. The check > here prevents further operation even if there is no call to > pc_dimm_get_free_addr. > > > > > > diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c > > > index ad176b7..59ed9c0 100644 > > > --- a/hw/mem/pc-dimm.c > > > +++ b/hw/mem/pc-dimm.c > > > @@ -146,6 +146,11 @@ uint64_t pc_dimm_get_free_addr(uint64_t address_space_start, > > > uint64_t new_addr, ret = 0; > > > uint64_t address_space_end = address_space_start + address_space_size; > > > > > > + if (address_space_size == 0) { > > > + error_setg(errp, "no space left for hotplugged memory."); > > > + goto out; > > > + } > > > + > > > assert(address_space_end > address_space_size); > > > object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &list); > > > > > > > > > Didn't we want a more specific message? > > What about: > > no space left for hotplugged memory, please check maxmem option > > ? Maybe "please increase the maxmem value"? > > Igor pointed out that explicitly state "-m maxmem=maxmem" here may not > sync with future -m change. > > > Hu