From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: Re: [PATCH v5 4/9] i386: Add new property to control cache info Date: Mon, 9 Apr 2018 17:07:06 -0300 Message-ID: <20180409200706.GB29865@localhost.localdomain> References: <1522186271-27743-1-git-send-email-babu.moger@amd.com> <1522186271-27743-5-git-send-email-babu.moger@amd.com> <867epg48oh.fsf@profitbricks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "kvm@vger.kernel.org" , "mst@redhat.com" , "kash@tripleback.net" , "mtosatti@redhat.com" , Alexandr Iarygin , "qemu-devel@nongnu.org" , "marcel@redhat.com" , "pbonzini@redhat.com" , "rth@twiddle.net" To: "Moger, Babu" Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel2=m.gmane.org@nongnu.org Sender: "Qemu-devel" List-Id: kvm.vger.kernel.org On Mon, Apr 09, 2018 at 07:51:24PM +0000, Moger, Babu wrote: [...] > > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > > > index 67faa53..f4fbe3a 100644 > > > --- a/target/i386/cpu.c > > > +++ b/target/i386/cpu.c > > > @@ -5132,6 +5132,7 @@ static Property x86_cpu_properties[] = { > > > false), > > > DEFINE_PROP_BOOL("vmware-cpuid-freq", X86CPU, > > vmware_cpuid_freq, true), > > > DEFINE_PROP_BOOL("tcg-cpuid", X86CPU, expose_tcg, true), > > > + DEFINE_PROP_BOOL("legacy-cache", X86CPU, legacy_cache, false), > > > > I'm wondering the reason why Intel L1 caches aren't shared per threads, > > L2 not shared per threads/cores etc? I mean, changing that will also > > require new compat flag with very similar name. > > I am not an expert on this topic. But, yes, If there is any future change in cache topology > then it would require similar change. In the future I really hope we manage to represent cache information in a more structured way, so other incompatible changes could be represented by more descriptive options like "l1-cache-size=N", "l2-sharing=cores", etc. -- Eduardo