From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fix3w-0001Wt-53 for kexec@lists.infradead.org; Fri, 27 Jul 2018 07:21:21 +0000 Received: by mail-pg1-x541.google.com with SMTP id p23-v6so2701158pgv.13 for ; Fri, 27 Jul 2018 00:21:10 -0700 (PDT) Date: Fri, 27 Jul 2018 16:22:43 +0900 From: AKASHI Takahiro Subject: Re: [PATCH v12 13/16] arm64: kexec_file: invoke the kernel without purgatory Message-ID: <20180727072242.GH11258@linaro.org> References: <20180724065759.19186-1-takahiro.akashi@linaro.org> <20180724065759.19186-14-takahiro.akashi@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: James Morse Cc: herbert@gondor.apana.org.au, bhe@redhat.com, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, bhsharma@redhat.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, heiko.carstens@de.ibm.com, dhowells@redhat.com, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, kexec@lists.infradead.org, schwidefsky@de.ibm.com, dyoung@redhat.com, davem@davemloft.net, vgoyal@redhat.com On Thu, Jul 26, 2018 at 02:36:07PM +0100, James Morse wrote: > Hi Akashi, > > On 24/07/18 07:57, AKASHI Takahiro wrote: > > On arm64, purgatory would do almost nothing. So just invoke secondary > > kernel directly by jumping into its entry code. > > > > While, in this case, cpu_soft_restart() must be called with dtb address > > in the fifth argument, the behavior still stays compatible with kexec_load > > case as long as the argument is null. > > This patch conflicts with commit 76f4e2da45b4 ("arm64: kexec: always reset to > EL2 if present") in the arm64 tree. I haven't noticed Mark's patch. I'm going to have to refresh my memory regarding why I introduced el2_switch when I implemented kdump. According to my current memory, however, I added kvm_arch_hardware_enable/disable(), and associated functions, to gracefully shutdown EL2 in case of kexec. Since we have no chance to call reset function (via notifier) at kdump, I believed that el2_switch was necessary for better chance of successful kdump. Thanks, -Takahiro AKASHI > Thanks, > > James > > > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > > index f76ea92dff91..830a5063e09d 100644 > > --- a/arch/arm64/kernel/machine_kexec.c > > +++ b/arch/arm64/kernel/machine_kexec.c > > @@ -205,10 +205,18 @@ void machine_kexec(struct kimage *kimage) > > * uses physical addressing to relocate the new image to its final > > * position and transfers control to the image entry point when the > > * relocation is complete. > > + * In kexec case, kimage->start points to purgatory assuming that > > + * kernel entry and dtb address are embedded in purgatory by > > + * userspace (kexec-tools). > > + * In kexec_file case, the kernel starts directly without purgatory. > > */ > > - > > cpu_soft_restart(kimage != kexec_crash_image, > > - reboot_code_buffer_phys, kimage->head, kimage->start, 0); > > + reboot_code_buffer_phys, kimage->head, kimage->start, > > +#ifdef CONFIG_KEXEC_FILE > > + kimage->arch.dtb_mem); > > +#else > > + 0); > > +#endif > > > > BUG(); /* Should never get here. */ > > } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec