x86/vtx: Remove opencoded MSR_ARCH_CAPS check

MSR_ARCH_CAPS data is now included in featureset information.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 8f6bc7f9b7)

xen/arch/x86/hvm/vmx/vmx.c

@@ -2640,8 +2640,6 @@ static void __init ler_to_fixup_check(void);
  */
 static bool __init has_if_pschange_mc(void)
 {
-    uint64_t caps = 0;
-
     /*
      * If we are virtualised, there is nothing we can do.  Our EPT tables are
      * shadowed by our hypervisor, and not walked by hardware.
@@ -2649,10 +2647,8 @@ static bool __init has_if_pschange_mc(void)
     if ( cpu_has_hypervisor )
         return false;
 
-    if ( cpu_has_arch_caps )
-        rdmsrl(MSR_ARCH_CAPABILITIES, caps);
-
-    if ( caps & ARCH_CAPS_IF_PSCHANGE_MC_NO )
+    /* Hardware reports itself as fixed. */
+    if ( cpu_has_if_pschange_mc_no )
         return false;
 
     /*

xen/include/asm-x86/cpufeature.h

@@ -146,6 +146,9 @@
 #define cpu_has_avx_vnni        boot_cpu_has(X86_FEATURE_AVX_VNNI)
 #define cpu_has_avx512_bf16     boot_cpu_has(X86_FEATURE_AVX512_BF16)
 
+/* MSR_ARCH_CAPS */
+#define cpu_has_if_pschange_mc_no boot_cpu_has(X86_FEATURE_IF_PSCHANGE_MC_NO)
+
 /* Synthesized. */
 #define cpu_has_arch_perfmon    boot_cpu_has(X86_FEATURE_ARCH_PERFMON)
 #define cpu_has_cpuid_faulting  boot_cpu_has(X86_FEATURE_CPUID_FAULTING)