From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36950) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1wB5-0003u9-73 for qemu-devel@nongnu.org; Tue, 10 Oct 2017 11:10:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1wAz-0001X4-Lb for qemu-devel@nongnu.org; Tue, 10 Oct 2017 11:10:39 -0400 Message-ID: <1507648227.3683.24.camel@redhat.com> From: Andrea Bolognani Date: Tue, 10 Oct 2017 17:10:27 +0200 In-Reply-To: <20171010132159.15787-1-david@gibson.dropbear.id.au> References: <20171010132159.15787-1-david@gibson.dropbear.id.au> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH] spapr: Correct RAM size calculation for HPT resizing List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson , lvivier@redhat.com, groug@kaod.org, clg@kaod.org Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org On Wed, 2017-10-11 at 00:21 +1100, David Gibson wrote: > In order to prevent the guest from forcing the allocation of large amounts > of qemu memory (or host kernel memory, in the case of KVM HV), we limit > the size of Hashed Page Table (HPT) it is allowed to allocated, based on > its RAM size. > > However, the current calculation is not correct: it only adds up the size > of plugged memory, ignoring the base memory size. This patch corrects it. > > While we're there, use get_plugged_memory_size() instead of directly > calling pc_existing_dimms_capacity(). The only difference is that it > will abort on failure, which is right: a failure here indicates something > wrong within qemu. Does this change invalidate in any way the calculation performed by libvirt to figure out the memory locking limit for guests? -- Andrea Bolognani / Red Hat / Virtualization