File xsa435-0-08.patch of Package xen.32200
From 94c3df9188d6deed6fe213754492b11b9d409262 Mon Sep 17 00:00:00 2001
From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Wed, 15 Dec 2021 16:30:25 +0000
Subject: x86/cpuid: Factor common parsing out of parse_xen_cpuid()
dom0-cpuid= is going to want to reuse the common parsing loop, so factor it
out into parse_cpuid().
Irritatingly, despite being static const, the features[] array gets duplicated
each time parse_cpuid() is inlined. As it is a large (and ever growing with
new CPU features) datastructure, move it to being file scope so all inlines
use the same single object.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -18,17 +18,26 @@ static const uint32_t hvm_shadow_feature
static const uint32_t hvm_hap_featuremask[] = INIT_HVM_HAP_FEATURES;
static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
-static int __init parse_xen_cpuid(const char *s)
+static const struct feature_name {
+ const char *name;
+ unsigned int bit;
+} feature_names[] __initconstrel = INIT_FEATURE_NAMES;
+
+/*
+ * Parse a list of cpuid feature names -> bool, calling the callback for any
+ * matches found.
+ *
+ * always_inline, because this is init code only and we really don't want a
+ * function pointer call in the middle of the loop.
+ */
+static int __init always_inline parse_cpuid(
+ const char *s, void (*callback)(unsigned int feat, bool val))
{
const char *ss;
int val, rc = 0;
do {
- static const struct feature {
- const char *name;
- unsigned int bit;
- } features[] __initconstrel = INIT_FEATURE_NAMES;
- const struct feature *lhs, *mid, *rhs;
+ const struct feature_name *lhs, *rhs, *mid = NULL /* GCC... */;
const char *feat;
ss = strchr(s, ',');
@@ -41,8 +50,8 @@ static int __init parse_xen_cpuid(const
feat += 3;
/* (Re)initalise lhs and rhs for binary search. */
- lhs = features;
- rhs = features + ARRAY_SIZE(features);
+ lhs = feature_names;
+ rhs = feature_names + ARRAY_SIZE(feature_names);
while ( lhs < rhs )
{
@@ -64,11 +73,7 @@ static int __init parse_xen_cpuid(const
if ( (val = parse_boolean(mid->name, s, ss)) >= 0 )
{
- if ( !val )
- setup_clear_cpu_cap(mid->bit);
- else if ( mid->bit == X86_FEATURE_RDRAND &&
- (cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_RDRAND)) )
- setup_force_cpu_cap(X86_FEATURE_RDRAND);
+ callback(mid->bit, val);
mid = NULL;
}
@@ -87,6 +92,20 @@ static int __init parse_xen_cpuid(const
return rc;
}
+
+static void __init _parse_xen_cpuid(unsigned int feat, bool val)
+{
+ if ( !val )
+ setup_clear_cpu_cap(feat);
+ else if ( feat == X86_FEATURE_RDRAND &&
+ (cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_RDRAND)) )
+ setup_force_cpu_cap(X86_FEATURE_RDRAND);
+}
+
+static int __init parse_xen_cpuid(const char *s)
+{
+ return parse_cpuid(s, _parse_xen_cpuid);
+}
custom_param("cpuid", parse_xen_cpuid);
#define EMPTY_LEAF ((struct cpuid_leaf){})