From: Prarit Bhargava <prarit@redhat.com>
Date: Fri, 25 Sep 2009 11:12:54 -0400
Subject: [x86] xen: add 'ida' flag
Message-id: 20090925151236.9162.91772.sendpatchset@prarit.bos.redhat.com
O-Subject: [RHEL5 PATCH] add "ida" flag on i386 and x86_64 xen
Bugzilla: 522846
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>
RH-Acked-by: Chris Lalancette <clalance@redhat.com>

32 and 64 bit x86 xen kernels do not output the "ida" flag in /proc/cpuinfo.

>From the BZ:

"We need a way to know if Turbo Boost is active, because it
messes with our certification results. The time it takes for us to calculate
test workloads is less than can be accounted for by the displayed clock speed.
If we had the 'ida' flag, we would know to expect discrepancies due to the
automatic overclocking that occurs with Turbo Boost."

2.6.18-166.el5

flags           : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush
dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor
ds_cpl vmx est tm2 cx16 xtpr lahf_lm

2.6.18-166.el5 + patch

flags           : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush
dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc ida pni monitor
ds_cpl vmx est tm2 cx16 xtpr lahf_lm

Successfully compiled and tested on i686 and x86_64.

Resolves BZ 522846.

diff --git a/arch/i386/kernel/cpu/common-xen.c b/arch/i386/kernel/cpu/common-xen.c
index 1dc3163..71865d9 100644
--- a/arch/i386/kernel/cpu/common-xen.c
+++ b/arch/i386/kernel/cpu/common-xen.c
@@ -317,6 +317,8 @@ void __cpuinit generic_identify(struct cpuinfo_x86 * c)
 			if ( xlvl >= 0x80000004 )
 				get_model_name(c); /* Default name */
 		}
+
+		init_scattered_cpuid_features(c);
 	}
 
 	early_intel_workaround(c);
diff --git a/arch/x86_64/kernel/setup-xen.c b/arch/x86_64/kernel/setup-xen.c
index 72f73ed..83d8992 100644
--- a/arch/x86_64/kernel/setup-xen.c
+++ b/arch/x86_64/kernel/setup-xen.c
@@ -1416,6 +1416,8 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 			c->x86_capability[2] = cpuid_edx(0x80860001);
 	}
 
+	init_scattered_cpuid_features(c);
+
 	c->apicid = phys_pkg_id(0);
 
 	/*
@@ -1520,8 +1522,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		/* Other (Linux-defined) */
 		"cxmmx", NULL, "cyrix_arr", "centaur_mcr", NULL,
 		"constant_tsc", NULL, NULL,
-		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 		"up", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+		"ida", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 
 		/* Intel-defined (#2) */
diff --git a/include/asm-i386/mach-xen/asm/processor.h b/include/asm-i386/mach-xen/asm/processor.h
index 8f1eae3..2f725a1 100644
--- a/include/asm-i386/mach-xen/asm/processor.h
+++ b/include/asm-i386/mach-xen/asm/processor.h
@@ -124,6 +124,7 @@ extern char ignore_fpu_irq;
 
 extern void identify_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
+extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern unsigned short num_cache_leaves;
 
diff --git a/include/asm-x86_64/mach-xen/asm/processor.h b/include/asm-x86_64/mach-xen/asm/processor.h
index 9b5b225..c75e458 100644
--- a/include/asm-x86_64/mach-xen/asm/processor.h
+++ b/include/asm-x86_64/mach-xen/asm/processor.h
@@ -106,6 +106,7 @@ extern char ignore_irq13;
 
 extern void identify_cpu(struct cpuinfo_x86 *);
 extern void print_cpu_info(struct cpuinfo_x86 *);
+extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern unsigned short num_cache_leaves;