[PATCH 2/6] svm: Improve type of cpu_has_svm_feature

[George Dunlap <george.dunlap@xxxxxxxxx>]

The "effective type" of the cpu_has_svm_feature macro is effectively
an unsigned log with one bit set (or not); at least one place someone
felt compelled to do a !! to make sure that they got a boolean out of
it.

Ideally the whole of this would be folded into the cpufeature.h
infrastructure.  But for now, duplicate the more type-safe static
inlines in that file, and remove the !!.

Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxx>
---
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
---
 xen/arch/x86/hvm/svm/svm.c             | 2 +-
 xen/arch/x86/include/asm/hvm/svm/svm.h | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 5741287355..40bc1ffbc6 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2580,7 +2580,7 @@ const struct hvm_function_table * __init start_svm(void)
     if ( !printed )
         printk(" - none\n");
 
-    svm_function_table.hap_supported = !!cpu_has_svm_npt;
+    svm_function_table.hap_supported = cpu_has_svm_npt;
     svm_function_table.caps.hap_superpage_2mb = true;
     svm_function_table.caps.hap_superpage_1gb = cpu_has_page1gb;
 
diff --git a/xen/arch/x86/include/asm/hvm/svm/svm.h 
b/xen/arch/x86/include/asm/hvm/svm/svm.h
index 687d35be40..9e9a148845 100644
--- a/xen/arch/x86/include/asm/hvm/svm/svm.h
+++ b/xen/arch/x86/include/asm/hvm/svm/svm.h
@@ -38,7 +38,10 @@ extern u32 svm_feature_flags;
 #define SVM_FEATURE_SSS           19 /* NPT Supervisor Shadow Stacks */
 #define SVM_FEATURE_SPEC_CTRL     20 /* MSR_SPEC_CTRL virtualisation */
 
-#define cpu_has_svm_feature(f) (svm_feature_flags & (1u << (f)))
+static inline bool cpu_has_svm_feature(unsigned int feat)
+{
+    return svm_feature_flags & (1u << (feat));
+}
 #define cpu_has_svm_npt       cpu_has_svm_feature(SVM_FEATURE_NPT)
 #define cpu_has_svm_lbrv      cpu_has_svm_feature(SVM_FEATURE_LBRV)
 #define cpu_has_svm_svml      cpu_has_svm_feature(SVM_FEATURE_SVML)
-- 
2.25.1