Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935356AbcLPMQI (ORCPT ); Fri, 16 Dec 2016 07:16:08 -0500 Received: from mx2.suse.de ([195.135.220.15]:60346 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934688AbcLPMQA (ORCPT ); Fri, 16 Dec 2016 07:16:00 -0500 Subject: Re: Can't boot as Xen dom0 due to commit fe055896 To: Borislav Petkov References: <20161215164635.thm7ruio2ddnxszw@pd.tnic> <20161215171755.xpfuax7a6q3jofet@pd.tnic> <20161215173609.ornfok6lk5oro2pj@pd.tnic> <20161216090228.ri4alokiaagqtibt@pd.tnic> <29d252b8-67ff-bd61-f274-0ed75708cd55@suse.com> <20161216094326.bnkr5a2k3njmdeyi@pd.tnic> <7ca8a9b9-e374-8052-6be3-d3eda78c891a@suse.com> <20161216104505.lk3s7fc7brrnmbq3@pd.tnic> Cc: Boris Ostrovsky , Linux Kernel Mailing List , xen-devel From: Juergen Gross Message-ID: <37c027ee-c6af-2aa2-364b-ed3dcdf8d966@suse.com> Date: Fri, 16 Dec 2016 13:15:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161216104505.lk3s7fc7brrnmbq3@pd.tnic> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2319 Lines: 96 On 16/12/16 11:45, Borislav Petkov wrote: > On Fri, Dec 16, 2016 at 11:00:29AM +0100, Juergen Gross wrote: >> Should work. I'm happy to test any patch. :-) > > I'm happy that you're happy to! :-) That makes me happy. :-D > Let's try this below. Okay. Results: Xen HVM domain is working. Xen dom0 is working. Bare metal is working, microcode has been loaded. So you can add my: Tested-by: Juergen Gross Acked-by: Juergen Gross Juergen > > Thanks! > > --- > diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c > index 6996413c78c3..c4bb2f7169f6 100644 > --- a/arch/x86/kernel/cpu/microcode/core.c > +++ b/arch/x86/kernel/cpu/microcode/core.c > @@ -44,7 +44,7 @@ > #define DRIVER_VERSION "2.2" > > static struct microcode_ops *microcode_ops; > -static bool dis_ucode_ldr; > +static bool dis_ucode_ldr = true; > > LIST_HEAD(microcode_cache); > > @@ -76,6 +76,7 @@ struct cpu_info_ctx { > static bool __init check_loader_disabled_bsp(void) > { > static const char *__dis_opt_str = "dis_ucode_ldr"; > + u32 a, b, c, d; > > #ifdef CONFIG_X86_32 > const char *cmdline = (const char *)__pa_nodebug(boot_command_line); > @@ -88,8 +89,23 @@ static bool __init check_loader_disabled_bsp(void) > bool *res = &dis_ucode_ldr; > #endif > > - if (cmdline_find_option_bool(cmdline, option)) > - *res = true; > + if (!have_cpuid_p()) > + return *res; > + > + a = 1; > + c = 0; > + native_cpuid(&a, &b, &c, &d); > + > + /* > + * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not > + * completely accurate as xen pv guests don't see that CPUID bit set but > + * that's good enough as they don't land on the BSP path anyway. > + */ > + if (c & BIT(31)) > + return *res; > + > + if (cmdline_find_option_bool(cmdline, option) <= 0) > + *res = false; > > return *res; > } > @@ -121,9 +137,6 @@ void __init load_ucode_bsp(void) > if (check_loader_disabled_bsp()) > return; > > - if (!have_cpuid_p()) > - return; > - > vendor = x86_cpuid_vendor(); > family = x86_cpuid_family(); > > @@ -157,9 +170,6 @@ void load_ucode_ap(void) > if (check_loader_disabled_ap()) > return; > > - if (!have_cpuid_p()) > - return; > - > vendor = x86_cpuid_vendor(); > family = x86_cpuid_family(); > >