From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: 2f47e7e19f ("x86/mm/kaiser: Use PCID feature to make user and .."): WARNING: CPU: 0 PID: 1 at mm/early_ioremap.c:114 __early_ioremap Date: Mon, 27 Nov 2017 10:28:35 -0800 Message-ID: References: <5a1aaa36.CWNgvwmmRFzeAlPc%fengguang.wu@intel.com> <20171127101814.jsglrh7typy3pxxp@gmail.com> <20171127180328.GA12661@u40b0340c692b58f6553c.ant.amazon.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Ingo Molnar , kernel test robot , LKP , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , wfg@linux.intel.com, aliguori@amazon.com To: Eduardo Valentin Return-path: In-Reply-To: <20171127180328.GA12661@u40b0340c692b58f6553c.ant.amazon.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 11/27/2017 10:03 AM, Eduardo Valentin wrote: > On top of VM crashes, on your branch: > https://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-kaiser.git/log/?h=kaiser-414-tipwip-20171123 > > I am also getting crashes in early userspace, during tlb flushes. When KAISER is enabled and whenever userspace is loaded, I get a stack trace around __do_page_fault() called from restore_regs_and_return_to_kernel(). I saw this very same behavior in your v3 branch (kaiser-414-tipwip-20171121) too. > > The crashes are followed by a machine halt via NMI. They also get the following warning: > WARNING: can't dereference iret registers at fffffffffe198048 for ip page_fault+0x11/0x60 There was a known bug in my branch with not mapping some of the interrupt entry routines. Random alignment makes it break or work. Ingo/Thomas, correct me if I'm wrong, but I think we need folks testing here at the moment: > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/log/?h=auto-latest My tree from last week is ancient gunk at this point. :)