From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iVQt9-00008c-Td for kexec@lists.infradead.org; Fri, 15 Nov 2019 01:59:10 +0000 Received: by mail-pl1-x641.google.com with SMTP id h13so3578664plr.1 for ; Thu, 14 Nov 2019 17:59:07 -0800 (PST) Date: Fri, 15 Nov 2019 11:00:00 +0900 From: AKASHI Takahiro Subject: Re: [PATCH v4 0/3] Append new variables to vmcoreinfo (TCR_EL1.T1SZ for arm64 and MAX_PHYSMEM_BITS for all archs) Message-ID: <20191115015959.GI22427@linaro.org> References: <1573459282-26989-1-git-send-email-bhsharma@redhat.com> <20191113063858.GE22427@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: Bhupesh Sharma Cc: Mark Rutland , Linux Doc Mailing List , Benjamin Herrenschmidt , Paul Mackerras , Will Deacon , Ingo Molnar , Jonathan Corbet , Michael Ellerman , x86@kernel.org, Catalin Marinas , Boris Petkov , Thomas Gleixner , Bhupesh SHARMA , linux-arm-kernel , Kazuhito Hagio , Ard Biesheuvel , Steve Capper , kexec mailing list , Linux Kernel Mailing List , James Morse , Dave Anderson , linuxppc-dev@lists.ozlabs.org Bhupesh, On Fri, Nov 15, 2019 at 01:24:17AM +0530, Bhupesh Sharma wrote: > Hi Akashi, > > On Wed, Nov 13, 2019 at 12:11 PM AKASHI Takahiro > wrote: > > > > Hi Bhupesh, > > > > Do you have a corresponding patch for userspace tools, > > including crash util and/or makedumpfile? > > Otherwise, we can't verify that a generated core file is > > correctly handled. > > Sure. I am still working on the crash-utility related changes, but you > can find the makedumpfile changes I posted a couple of days ago here > (see [0]) and the github link for the makedumpfile changes can be seen > via [1]. > > I will post the crash-util changes shortly as well. > Thanks for having a look at the same. Thank you. I have tested my kdump patch with a hacked version of crash where VA_BITS_ACTUAL is calculated from tcr_el1_t1sz in vmcoreinfo. -Takahiro Akashi > [0]. http://lists.infradead.org/pipermail/kexec/2019-November/023963.html > [1]. https://github.com/bhupesh-sharma/makedumpfile/tree/52-bit-va-support-via-vmcore-upstream-v4 > > Regards, > Bhupesh > > > > > Thanks, > > -Takahiro Akashi > > > > On Mon, Nov 11, 2019 at 01:31:19PM +0530, Bhupesh Sharma wrote: > > > Changes since v3: > > > ---------------- > > > - v3 can be seen here: > > > http://lists.infradead.org/pipermail/kexec/2019-March/022590.html > > > - Addressed comments from James and exported TCR_EL1.T1SZ in vmcoreinfo > > > instead of PTRS_PER_PGD. > > > - Added a new patch (via [PATCH 3/3]), which fixes a simple typo in > > > 'Documentation/arm64/memory.rst' > > > > > > Changes since v2: > > > ---------------- > > > - v2 can be seen here: > > > http://lists.infradead.org/pipermail/kexec/2019-March/022531.html > > > - Protected 'MAX_PHYSMEM_BITS' vmcoreinfo variable under CONFIG_SPARSEMEM > > > ifdef sections, as suggested by Kazu. > > > - Updated vmcoreinfo documentation to add description about > > > 'MAX_PHYSMEM_BITS' variable (via [PATCH 3/3]). > > > > > > Changes since v1: > > > ---------------- > > > - v1 was sent out as a single patch which can be seen here: > > > http://lists.infradead.org/pipermail/kexec/2019-February/022411.html > > > > > > - v2 breaks the single patch into two independent patches: > > > [PATCH 1/2] appends 'PTRS_PER_PGD' to vmcoreinfo for arm64 arch, whereas > > > [PATCH 2/2] appends 'MAX_PHYSMEM_BITS' to vmcoreinfo in core kernel code (all archs) > > > > > > This patchset primarily fixes the regression reported in user-space > > > utilities like 'makedumpfile' and 'crash-utility' on arm64 architecture > > > with the availability of 52-bit address space feature in underlying > > > kernel. These regressions have been reported both on CPUs which don't > > > support ARMv8.2 extensions (i.e. LVA, LPA) and are running newer kernels > > > and also on prototype platforms (like ARMv8 FVP simulator model) which > > > support ARMv8.2 extensions and are running newer kernels. > > > > > > The reason for these regressions is that right now user-space tools > > > have no direct access to these values (since these are not exported > > > from the kernel) and hence need to rely on a best-guess method of > > > determining value of 'vabits_actual' and 'MAX_PHYSMEM_BITS' supported > > > by underlying kernel. > > > > > > Exporting these values via vmcoreinfo will help user-land in such cases. > > > In addition, as per suggestion from makedumpfile maintainer (Kazu), > > > it makes more sense to append 'MAX_PHYSMEM_BITS' to > > > vmcoreinfo in the core code itself rather than in arm64 arch-specific > > > code, so that the user-space code for other archs can also benefit from > > > this addition to the vmcoreinfo and use it as a standard way of > > > determining 'SECTIONS_SHIFT' value in user-land. > > > > > > Cc: Boris Petkov > > > Cc: Ingo Molnar > > > Cc: Thomas Gleixner > > > Cc: Jonathan Corbet > > > Cc: James Morse > > > Cc: Mark Rutland > > > Cc: Will Deacon > > > Cc: Steve Capper > > > Cc: Catalin Marinas > > > Cc: Ard Biesheuvel > > > Cc: Michael Ellerman > > > Cc: Paul Mackerras > > > Cc: Benjamin Herrenschmidt > > > Cc: Dave Anderson > > > Cc: Kazuhito Hagio > > > Cc: x86@kernel.org > > > Cc: linuxppc-dev@lists.ozlabs.org > > > Cc: linux-arm-kernel@lists.infradead.org > > > Cc: linux-kernel@vger.kernel.org > > > Cc: linux-doc@vger.kernel.org > > > Cc: kexec@lists.infradead.org > > > > > > Bhupesh Sharma (3): > > > crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo > > > arm64/crash_core: Export TCR_EL1.T1SZ in vmcoreinfo > > > Documentation/arm64: Fix a simple typo in memory.rst > > > > > > Documentation/arm64/memory.rst | 2 +- > > > arch/arm64/include/asm/pgtable-hwdef.h | 1 + > > > arch/arm64/kernel/crash_core.c | 9 +++++++++ > > > kernel/crash_core.c | 1 + > > > 4 files changed, 12 insertions(+), 1 deletion(-) > > > > > > -- > > > 2.7.4 > > > > > > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec