From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH 2/3] KVM: arm64: Correctly handle zero register in system register accesses Date: Thu, 03 Dec 2015 13:12:38 +0000 Message-ID: <56603FC6.20200@arm.com> References: <56601E36.5070700@arm.com> <00cd01d12dba$f14ac070$d3e04150$@samsung.com> <56602951.1040305@arm.com> <00e001d12dc1$812a34e0$837e9ea0$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <00e001d12dc1$812a34e0$837e9ea0$@samsung.com> Sender: kvm-owner@vger.kernel.org To: Pavel Fedin , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: christoffer.dall@linaro.org List-Id: kvmarm@lists.cs.columbia.edu On 03/12/15 11:55, Pavel Fedin wrote: > Hello! > >>> It's simply more convenient to use a pointer for exchange with >>> userspace, see vgic_v3_cpu_regs_access() and callers. I wouldn't like >>> to refactor the code again. What's your opinion on this? >> >> I still don't think this is a good idea. You can still store the value >> as an integer in vgic_v3_cpu_regs_access(), and check the write property >> to do the writeback on read. Which is the same thing I asked for in this >> patch. > > Started doing this and found one more (big) reason against. All sysreg handlers have 'const struct sys_reg_params' declaration, and > callers, and their callers... This 'const' is all around the code, and it would take a separate huge patch to un-const'ify all this. > Does it worth that? maz@approximate:~/Work/arm-platforms$ git diff --stat arch/arm64/kvm/sys_regs.c | 36 ++++++++++++++++++------------------ arch/arm64/kvm/sys_regs.h | 2 +- 2 files changed, 19 insertions(+), 19 deletions(-) Hardly a big deal... You can have that as a separate patch. Thanks, M. -- Jazz is not dead. It just smells funny...