From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF476C64E8A for ; Mon, 30 Nov 2020 14:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97E2A20715 for ; Mon, 30 Nov 2020 14:29:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="dfMrMYg+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727664AbgK3O3d (ORCPT ); Mon, 30 Nov 2020 09:29:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727605AbgK3O3c (ORCPT ); Mon, 30 Nov 2020 09:29:32 -0500 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E97DCC061A49 for ; Mon, 30 Nov 2020 06:28:24 -0800 (PST) Received: by mail-wm1-x341.google.com with SMTP id g185so17371924wmf.3 for ; Mon, 30 Nov 2020 06:28:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=eHLcaoGR3OBMxI8Ka9Vg7O4WIQrlDq3JLjO4ywGlLGY=; b=dfMrMYg+Imtd1PT+Ug3KAxUR66mYTe9vAIQKEVg0p13ToattxxKgowHojH4QkVsl8o qWCIFLhhk7c1mD01OWMkZ5hkSkRlkmPm+bVkb34eSimeJ1VnWw2ym78YElm9GSziyfkJ EEgXBw3Tprvet3blzGCzAx/h7Dl9EX4sL5AEk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=eHLcaoGR3OBMxI8Ka9Vg7O4WIQrlDq3JLjO4ywGlLGY=; b=nBAUMlsbj78raz075cj4tLx3Ha42PZu3aSRIDrchJ+4tn4OkG7/B2xI0/XiMuy1oDE yAanZfYDpR3BJurCiNmfIYHh9uvSFqQszhPKUyw9dP8W2ODbpx0DjXdZxR1ctgrtkUsP l/vNIJt7W3zZUyK0bM1STO2Hl+befFdyBFun5andGoajnLvGR7ieQ6CH3JT5BNfwAaWP hhI+G8Zp+jkhZ2JT/mrzxJK9N+gHMGZ+rUFXBQ3t9Ia3ANGIkGGKF0afyqJQvH9/TRjz olCVum0YRskus5HKFx15lKw4tQqMwkeon3OZazqZpWFtJGBQSG/5t4yOq6wubbMED/Qa x9bg== X-Gm-Message-State: AOAM530Xfco4BYWO0g3mALNRNafDIG/byfGu6FLlji5Gx5754/zPiw11 NF6mGQ/WIkrSmmLS02J3WHui8A== X-Google-Smtp-Source: ABdhPJw0HCNBfCYYbfgmPNymctRPGyVxi7hp50ZBAm3Q4du98rsXy8jIiPNtdF8UeMGO2YaRzuWbEw== X-Received: by 2002:a7b:c05a:: with SMTP id u26mr23719527wmc.159.1606746503617; Mon, 30 Nov 2020 06:28:23 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id v3sm270080wrq.72.2020.11.30.06.28.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Nov 2020 06:28:22 -0800 (PST) Date: Mon, 30 Nov 2020 15:28:20 +0100 From: Daniel Vetter To: kernel test robot Cc: Daniel Vetter , DRI Development , LKML , kbuild-all@lists.01.org, clang-built-linux@googlegroups.com, kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Christoph Hellwig , Jason Gunthorpe Subject: Re: [PATCH v7 17/17] mm: add mmu_notifier argument to follow_pfn Message-ID: <20201130142820.GN401619@phenom.ffwll.local> Mail-Followup-To: kernel test robot , DRI Development , LKML , kbuild-all@lists.01.org, clang-built-linux@googlegroups.com, kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Christoph Hellwig , Jason Gunthorpe References: <20201127164131.2244124-18-daniel.vetter@ffwll.ch> <202011280356.rPWHFNW4-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202011280356.rPWHFNW4-lkp@intel.com> X-Operating-System: Linux phenom 5.7.0-1-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org So I guess kvm platforms that don't set KVM_ARCH_WANT_MMU_NOTIFIER exist, and at least on powerpc they're consistent with KVM_CAP_SYNC_MMU signalling that the guest pagetables stays in sync automatically with any updates. So for that case I guess we could use unsafe_follow_pfn. But on s390 this seems different: No mmu notifier, but KVM_CAP_SYNC_MMU is set. So I guess there's some hardware magic on s390 that I don't know about. Not sure what to do with this now here ... -Daniel On Sat, Nov 28, 2020 at 03:10:40AM +0800, kernel test robot wrote: > Hi Daniel, > > I love your patch! Yet something to improve: > > [auto build test ERROR on linuxtv-media/master] > [also build test ERROR on char-misc/char-misc-testing v5.10-rc5] > [cannot apply to hnaz-linux-mm/master next-20201127] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch] > > url: https://github.com/0day-ci/linux/commits/Daniel-Vetter/follow_pfn-and-other-iomap-races/20201128-004421 > base: git://linuxtv.org/media_tree.git master > config: s390-randconfig-r032-20201127 (attached as .config) > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project f095ac11a9550530a4a54298debb8b04b36422be) > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # install s390 cross compiling tool for clang build > # apt-get install binutils-s390x-linux-gnu > # https://github.com/0day-ci/linux/commit/d76a3489433ce67d45da86aa12953385427f0ac9 > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review Daniel-Vetter/follow_pfn-and-other-iomap-races/20201128-004421 > git checkout d76a3489433ce67d45da86aa12953385427f0ac9 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot > > All errors (new ones prefixed by >>): > > In file included from arch/s390/include/asm/kvm_para.h:25: > In file included from arch/s390/include/asm/diag.h:12: > In file included from include/linux/if_ether.h:19: > In file included from include/linux/skbuff.h:31: > In file included from include/linux/dma-mapping.h:10: > In file included from include/linux/scatterlist.h:9: > In file included from arch/s390/include/asm/io.h:80: > include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); > ~~~~~~~~~~ ^ > include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' > #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) > ^ > include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' > ___constant_swab32(x) : \ > ^ > include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32' > (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ > ^ > In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18: > In file included from include/linux/kvm_host.h:32: > In file included from include/linux/kvm_para.h:5: > In file included from include/uapi/linux/kvm_para.h:36: > In file included from arch/s390/include/asm/kvm_para.h:25: > In file included from arch/s390/include/asm/diag.h:12: > In file included from include/linux/if_ether.h:19: > In file included from include/linux/skbuff.h:31: > In file included from include/linux/dma-mapping.h:10: > In file included from include/linux/scatterlist.h:9: > In file included from arch/s390/include/asm/io.h:80: > include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); > ~~~~~~~~~~ ^ > include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' > #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) > ^ > include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' > ___constant_swab32(x) : \ > ^ > include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32' > (((__u32)(x) & (__u32)0xff000000UL) >> 24))) > ^ > In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18: > In file included from include/linux/kvm_host.h:32: > In file included from include/linux/kvm_para.h:5: > In file included from include/uapi/linux/kvm_para.h:36: > In file included from arch/s390/include/asm/kvm_para.h:25: > In file included from arch/s390/include/asm/diag.h:12: > In file included from include/linux/if_ether.h:19: > In file included from include/linux/skbuff.h:31: > In file included from include/linux/dma-mapping.h:10: > In file included from include/linux/scatterlist.h:9: > In file included from arch/s390/include/asm/io.h:80: > include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); > ~~~~~~~~~~ ^ > include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' > #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) > ^ > include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32' > __fswab32(x)) > ^ > In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18: > In file included from include/linux/kvm_host.h:32: > In file included from include/linux/kvm_para.h:5: > In file included from include/uapi/linux/kvm_para.h:36: > In file included from arch/s390/include/asm/kvm_para.h:25: > In file included from arch/s390/include/asm/diag.h:12: > In file included from include/linux/if_ether.h:19: > In file included from include/linux/skbuff.h:31: > In file included from include/linux/dma-mapping.h:10: > In file included from include/linux/scatterlist.h:9: > In file included from arch/s390/include/asm/io.h:80: > include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writeb(value, PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > readsb(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > readsw(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > readsl(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > writesb(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > writesw(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > writesl(PCI_IOBASE + addr, buffer, count); > ~~~~~~~~~~ ^ > >> arch/s390/kvm/../../../virt/kvm/kvm_main.c:1894:40: error: no member named 'mmu_notifier' in 'struct kvm' > r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier); > ~~~ ^ > arch/s390/kvm/../../../virt/kvm/kvm_main.c:1909:41: error: no member named 'mmu_notifier' in 'struct kvm' > r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier); > ~~~ ^ > 20 warnings and 2 errors generated. > > vim +1894 arch/s390/kvm/../../../virt/kvm/kvm_main.c > > 1885 > 1886 static int hva_to_pfn_remapped(struct kvm *kvm, struct vm_area_struct *vma, > 1887 unsigned long addr, bool *async, > 1888 bool write_fault, bool *writable, > 1889 kvm_pfn_t *p_pfn) > 1890 { > 1891 unsigned long pfn; > 1892 int r; > 1893 > > 1894 r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier); > 1895 if (r) { > 1896 /* > 1897 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does > 1898 * not call the fault handler, so do it here. > 1899 */ > 1900 bool unlocked = false; > 1901 r = fixup_user_fault(current->mm, addr, > 1902 (write_fault ? FAULT_FLAG_WRITE : 0), > 1903 &unlocked); > 1904 if (unlocked) > 1905 return -EAGAIN; > 1906 if (r) > 1907 return r; > 1908 > 1909 r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier); > 1910 if (r) > 1911 return r; > 1912 > 1913 } > 1914 > 1915 if (writable) > 1916 *writable = true; > 1917 > 1918 /* > 1919 * Get a reference here because callers of *hva_to_pfn* and > 1920 * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the > 1921 * returned pfn. This is only needed if the VMA has VM_MIXEDMAP > 1922 * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will > 1923 * simply do nothing for reserved pfns. > 1924 * > 1925 * Whoever called remap_pfn_range is also going to call e.g. > 1926 * unmap_mapping_range before the underlying pages are freed, > 1927 * causing a call to our MMU notifier. > 1928 */ > 1929 kvm_get_pfn(pfn); > 1930 > 1931 *p_pfn = pfn; > 1932 return 0; > 1933 } > 1934 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch