From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: Re: [PATCH v7 7/9] i386: Add support for CPUID_8000_001E for AMD Date: Fri, 11 May 2018 11:59:35 -0300 Message-ID: <20180511145935.GO25013@localhost.localdomain> References: <1524760009-24710-1-git-send-email-babu.moger@amd.com> <1524760009-24710-8-git-send-email-babu.moger@amd.com> <20180507193944.GF13350@localhost.localdomain> <20180508141632.GJ25013@localhost.localdomain> <20180511141201.GK25013@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "geoff@hostfission.com" , "kvm@vger.kernel.org" , "mst@redhat.com" , "kash@tripleback.net" , "mtosatti@redhat.com" , "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 Fri, May 11, 2018 at 02:44:11PM +0000, Moger, Babu wrote: > > > > -----Original Message----- > > From: Eduardo Habkost [mailto:ehabkost@redhat.com] > > Sent: Friday, May 11, 2018 9:12 AM > > To: Moger, Babu > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com; > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com; > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for > > CPUID_8000_001E for AMD > > > > On Tue, May 08, 2018 at 03:02:07PM +0000, Moger, Babu wrote: > > > > > > > -----Original Message----- > > > > From: Eduardo Habkost [mailto:ehabkost@redhat.com] > > > > Sent: Tuesday, May 8, 2018 9:17 AM > > > > To: Moger, Babu > > > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com; > > > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com; > > > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org > > > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for > > > > CPUID_8000_001E for AMD > > > > > > > > On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote: > > > > [...] > > > > > > > + > > > > > > > /* > > > > > > > * Encode cache info for CPUID[0x80000006].ECX and > > > > > > CPUID[0x80000006].EDX > > > > > > > * @l3 can be NULL. > > > > > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env, > > > > > > uint32_t index, uint32_t count, > > > > > > > break; > > > > > > > } > > > > > > > break; > > > > > > > + case 0x8000001E: > > > > > > > + assert(cpu->core_id <= 255); > > > > > > > > > > > > Where's the code that ensures this assert() line can't be > > > > > > triggered by any command-line configuration? > > > > > > > > > > I did not understand this. Can you please elaborate. Thanks > > > > > > > > The user must not be able to trigger an assert(), so we need to > > > > ensure that core_id will never be larger than 255. Is there > > > > existing code that ensures that? > > > > > > I see that max_cpus is set to 255 and also there are checks to make sure > > core_id does not go above 255. > > > I verified it while testing. So, probably we don't need assert here. Radim > > asked me to add this assert. > > > I can remove it if no abjections. > > > > Sorry for not replying to this before: no objection to the > > assert(), especially considering it will trigger very early on > > initialization if we break it one day. > > Ok. No problem. I will add it back and send a v9 version. > Please let me know if you have any other feedback for v8 version(sent yesterday). Thanks, I just saw v8 on my mailbox. No need to send v9 just because of the assert(), I can re-add it while committing if necessary. -- Eduardo From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36710) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fH9WP-0005CN-Ui for qemu-devel@nongnu.org; Fri, 11 May 2018 10:59:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fH9WM-0006qx-3j for qemu-devel@nongnu.org; Fri, 11 May 2018 10:59:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48708) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fH9WL-0006ql-Sa for qemu-devel@nongnu.org; Fri, 11 May 2018 10:59:46 -0400 Date: Fri, 11 May 2018 11:59:35 -0300 From: Eduardo Habkost Message-ID: <20180511145935.GO25013@localhost.localdomain> References: <1524760009-24710-1-git-send-email-babu.moger@amd.com> <1524760009-24710-8-git-send-email-babu.moger@amd.com> <20180507193944.GF13350@localhost.localdomain> <20180508141632.GJ25013@localhost.localdomain> <20180511141201.GK25013@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for CPUID_8000_001E for AMD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Moger, Babu" Cc: "mst@redhat.com" , "marcel@redhat.com" , "pbonzini@redhat.com" , "rth@twiddle.net" , "mtosatti@redhat.com" , "geoff@hostfission.com" , "kash@tripleback.net" , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" On Fri, May 11, 2018 at 02:44:11PM +0000, Moger, Babu wrote: > > > > -----Original Message----- > > From: Eduardo Habkost [mailto:ehabkost@redhat.com] > > Sent: Friday, May 11, 2018 9:12 AM > > To: Moger, Babu > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com; > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com; > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for > > CPUID_8000_001E for AMD > > > > On Tue, May 08, 2018 at 03:02:07PM +0000, Moger, Babu wrote: > > > > > > > -----Original Message----- > > > > From: Eduardo Habkost [mailto:ehabkost@redhat.com] > > > > Sent: Tuesday, May 8, 2018 9:17 AM > > > > To: Moger, Babu > > > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com; > > > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com; > > > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org > > > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for > > > > CPUID_8000_001E for AMD > > > > > > > > On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote: > > > > [...] > > > > > > > + > > > > > > > /* > > > > > > > * Encode cache info for CPUID[0x80000006].ECX and > > > > > > CPUID[0x80000006].EDX > > > > > > > * @l3 can be NULL. > > > > > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env, > > > > > > uint32_t index, uint32_t count, > > > > > > > break; > > > > > > > } > > > > > > > break; > > > > > > > + case 0x8000001E: > > > > > > > + assert(cpu->core_id <= 255); > > > > > > > > > > > > Where's the code that ensures this assert() line can't be > > > > > > triggered by any command-line configuration? > > > > > > > > > > I did not understand this. Can you please elaborate. Thanks > > > > > > > > The user must not be able to trigger an assert(), so we need to > > > > ensure that core_id will never be larger than 255. Is there > > > > existing code that ensures that? > > > > > > I see that max_cpus is set to 255 and also there are checks to make sure > > core_id does not go above 255. > > > I verified it while testing. So, probably we don't need assert here. Radim > > asked me to add this assert. > > > I can remove it if no abjections. > > > > Sorry for not replying to this before: no objection to the > > assert(), especially considering it will trigger very early on > > initialization if we break it one day. > > Ok. No problem. I will add it back and send a v9 version. > Please let me know if you have any other feedback for v8 version(sent yesterday). Thanks, I just saw v8 on my mailbox. No need to send v9 just because of the assert(), I can re-add it while committing if necessary. -- Eduardo