From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55529) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a09jd-0004PS-Fz for qemu-devel@nongnu.org; Sat, 21 Nov 2015 10:05:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a09jc-00076B-IC for qemu-devel@nongnu.org; Sat, 21 Nov 2015 10:05:53 -0500 Date: Sat, 21 Nov 2015 10:05:37 -0500 From: Andrew Jones Message-ID: <20151121150537.GA3701@hawk.localdomain> References: <1447944817-13286-1-git-send-email-drjones@redhat.com> <1447944817-13286-6-git-send-email-drjones@redhat.com> <20151120214121.GC20402@hawk.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151120214121.GC20402@hawk.localdomain> Subject: Re: [Qemu-devel] [PATCH 5/5] target-arm: support QMP dump-guest-memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Alexander Graf , QEMU Developers , Markus Armbruster , qemu-arm@nongnu.org, "qemu-ppc@nongnu.org" , Andreas =?iso-8859-1?Q?F=E4rber?= , Richard Henderson On Fri, Nov 20, 2015 at 04:41:21PM -0500, Andrew Jones wrote: > On Fri, Nov 20, 2015 at 06:19:14PM +0000, Peter Maydell wrote: > > On 19 November 2015 at 14:53, Andrew Jones wrote: > > > + > > > + if (is_a64(env)) { > > > > Are you really sure you want the core dump format to depend on > > whether the CPU happens to be in 32-bit or 64-bit format at > > the point in time we write it out? (Consider a 64-bit kernel > > which happens to be running a 32-bit userspace binary.) > > I simply forgot to consider the case where a 64-bit kernel would > run a 32-bit userspace binary. I'm actually quite sure we would > want 64-bit in that case, as crash is the only tool we're able to > generate dumps for at this time (gdb requires the 'paging' option > of dump-guest-memory to work). Is there something in the env I can > look at to determine that we have a 64-bit kernel? (Sorry for being > lazy and just asking, rather than reading...) Duh, I momentarily forgot about arm_el_is_aa64(env, 1). I see we unset ARM_FEATURE_AARCH64 in aarch64_cpu_set_aarch64, so that should work fine for our 32bit guests on 64bit hosts. > > > + if (is_a64(env)) { > > > + info->d_machine = EM_AARCH64; > > > + info->d_class = ELFCLASS64; > > > + if (cur_el == 0) { > > > + be = (env->cp15.sctlr_el[1] & SCTLR_E0E) != 0; > > > + } else { > > > + be = (env->cp15.sctlr_el[cur_el] & SCTLR_EE) != 0; > > > + } > > > > Again, are you sure you want the core dump format to depend on > > whether we currently happen to be executing a BE userspace > > process? > > We'll want to match the kernel. Hopefully we can determine it. Here's a bigger, duh. I guess I just need to drop all the cur_el stuff and stick to el==1. I'll wait to hear back on the 'should we add ptrace.h to linux-headers', and 'should we add floating point registers, even though crash won't care' questions before sending a v2. Thanks, drew