From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH v3 1/9] x86: define CPUINFO_features used as the base offset for cpu features Date: Mon, 28 Apr 2014 10:13:54 +0100 Message-ID: <535E37F2020000780000CBC8@nat28.tlf.novell.com> References: <1398654829-5887-1-git-send-email-feng.wu@intel.com> <535E1788.5080901@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <535E1788.5080901@citrix.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper , Feng Wu Cc: kevin.tian@intel.com, eddie.dong@intel.com, ian.campbell@citrix.com, jun.nakajima@intel.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org >>> On 28.04.14 at 10:55, wrote: > On 28/04/14 04:13, Feng Wu wrote: >> This patch defines CPUINFO_features which can be used as the base of >> the offset for cpu features. >> >> Signed-off-by: Feng Wu >> --- >> xen/arch/x86/boot/head.S | 2 +- >> xen/arch/x86/x86_64/asm-offsets.c | 2 +- >> xen/include/asm-x86/asm_defns.h | 2 ++ >> 3 files changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S >> index 1777c17..2b5b26a 100644 >> --- a/xen/arch/x86/boot/head.S >> +++ b/xen/arch/x86/boot/head.S >> @@ -131,7 +131,7 @@ __start: >> mov $0x80000001,%eax >> cpuid >> 1: mov %edx,sym_phys(cpuid_ext_features) >> - mov %edx,sym_phys(boot_cpu_data)+CPUINFO86_ext_features >> + mov %edx,sym_phys(boot_cpu_data)+CPUINFO_ext_features > > Personally I feel this would be better as CPUINFO_features + 4, rather > than having another #define in asm_defn.h solely for this purpose. It should indeed be done here, without the extra #define, but also without the literal 4. Our main goal here is to collect the LM bit, so just calculate the number from X86_FEATURE_LM. Jan