[xen master] x86/CPU: don't hard-code MTRR availability

[patchbot@xxxxxxx]

commit a56574f65d6ff7a92cd48f97ca1719eeb888498c
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Apr 3 09:39:35 2025 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Apr 3 09:39:35 2025 +0200

    x86/CPU: don't hard-code MTRR availability
    
    In particular if we're running virtualized, the underlying hypervisor
    (which may be another Xen) may not surface MTRRs, and offer PAT only.
    
    Fixes: 5a281883cdc3 ("Hardcode many cpu features for x86/64 -- we know 
64-bit")
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/include/asm/cpufeature.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/include/asm/cpufeature.h 
b/xen/arch/x86/include/asm/cpufeature.h
index 6935703e71..05399fb9c9 100644
--- a/xen/arch/x86/include/asm/cpufeature.h
+++ b/xen/arch/x86/include/asm/cpufeature.h
@@ -70,7 +70,7 @@ static inline bool boot_cpu_has(unsigned int feat)
 #define cpu_has_pse             1
 #define cpu_has_apic            boot_cpu_has(X86_FEATURE_APIC)
 #define cpu_has_sep             boot_cpu_has(X86_FEATURE_SEP)
-#define cpu_has_mtrr            1
+#define cpu_has_mtrr            boot_cpu_has(X86_FEATURE_MTRR)
 #define cpu_has_pge             1
 #define cpu_has_pse36           boot_cpu_has(X86_FEATURE_PSE36)
 #define cpu_has_clflush         boot_cpu_has(X86_FEATURE_CLFLUSH)
--
generated by git-patchbot for /home/xen/git/xen.git#master