From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45987) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8OuD-00039N-Cm for qemu-devel@nongnu.org; Tue, 17 Apr 2018 07:36:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8OuC-00059H-Bi for qemu-devel@nongnu.org; Tue, 17 Apr 2018 07:36:13 -0400 Date: Tue, 17 Apr 2018 13:35:44 +0200 From: Igor Mammedov Message-ID: <20180417133544.0102ef0b@redhat.com> In-Reply-To: References: <1523551221-11612-1-git-send-email-imammedo@redhat.com> <1523551221-11612-4-git-send-email-imammedo@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-arm] [PATCH for-2.13 3/4] arm: always start from first_cpu when registering loader cpu reset callback List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: QEMU Developers , qemu-arm , Eric Auger , "Edgar E. Iglesias" On Mon, 16 Apr 2018 18:17:51 +0100 Peter Maydell wrote: > On 12 April 2018 at 19:29, Peter Maydell wrote: > > On 12 April 2018 at 17:40, Igor Mammedov wrote: > >> if arm_load_kernel() were passed non first_cpu, QEMU would end up > >> with partially set do_cpu_reset() callback leaving some CPUs without it. > >> > >> Make sure that do_cpu_reset() is registered for all CPUs by enumerating > >> CPUs from first_cpu. > >> > >> Signed-off-by: Igor Mammedov > >> --- > >> hw/arm/boot.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/hw/arm/boot.c b/hw/arm/boot.c > >> index 2f464ca..2591fee 100644 > >> --- a/hw/arm/boot.c > >> +++ b/hw/arm/boot.c > >> @@ -1188,7 +1188,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info) > >> * actually loading a kernel, the handler is also responsible for > >> * arranging that we start it correctly. > >> */ > >> - for (cs = CPU(cpu); cs; cs = CPU_NEXT(cs)) { > >> + for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) { > >> qemu_register_reset(do_cpu_reset, ARM_CPU(cs)); > >> } > >> } > > > > Definitely a bug fix, so: > > Reviewed-by: Peter Maydell > > > > I think though that in at least some cases we'll still mishandle > > being passed anything other than first_cpu as the CPU pointer, > > because in do_cpu_reset() we do some checks for "do this if > > cs == first_cpu", on the assumption that first_cpu is the > > primary CPU that we're booting. We should instead I suppose > > be checking against the CPU pointer we're given as the > > arm_load_kernel() argument (which I think do_cpu_reset() can > > get at via info->load_kernel_notifier.cpu). > > > > We should probably analyse which boards actually pass anything > > other than first_cpu -- I suspect it will end up just being > > the xilinx board which has both A and R profile cores... > > I did the check, and in fact all of our boards always pass the > first CPU as the boot CPU. Xilinx comes the closest, in that > the SoC object has a boot-cpu property to pick a boot CPU, but > since none of our boards set that it defaults to the first CPU. > > Since this patch isn't very related to the rest of the series > I've just applied it to target-arm.next ready for 2.13 (with > a note in the commit message that in practice it isn't a behaviour > change). Let me know if that's awkward for you and you'd prefer > to keep it in this series, in which case I'll drop it. That's fine, I'll just rebase v2 on top of it. > > thanks > -- PMM