[Xen-devel] [PATCH v2] x86: drop cpu_has_sse{,2}

["Jan Beulich" <JBeulich@xxxxxxxx>]

Commit dc88221c97 ("x86: rename XMM* features to SSE*") pointlessly
added them - these features are always available on 64-bit CPUs. (Let's
not assume this for MMX though in at least the insn emulator.)

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
v2: Add a test harness comment clarifying host_and_vcpu_must_have() vs
    vcpu_must_have() use there.

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1326,6 +1326,11 @@ static bool vcpu_has(
     vcpu_must_have(feat); \
 })
 #else
+/*
+ * For the test harness both are fine to be used interchangeably, i.e.
+ * features known to always be available (e.g. SSE/SSE2) to (64-bit) Xen
+ * may be checked for by just vcpu_must_have().
+ */
 #define host_and_vcpu_must_have(feat) vcpu_must_have(feat)
 #endif
 
@@ -4910,9 +4915,9 @@ x86_emulate(
         if ( vex.opcx == vex_none )
         {
             if ( vex.pfx & VEX_PREFIX_DOUBLE_MASK )
-                host_and_vcpu_must_have(sse2);
+                vcpu_must_have(sse2);
             else
-                host_and_vcpu_must_have(sse);
+                vcpu_must_have(sse);
             ea.bytes = 16;
             SET_SSE_PREFIX(buf[0], vex.pfx);
             get_fpu(X86EMUL_FPU_xmm, &fic);
@@ -5183,7 +5188,7 @@ x86_emulate(
             {
             case vex_66:
             case vex_f3:
-                host_and_vcpu_must_have(sse2);
+                vcpu_must_have(sse2);
                 /* Converting movdqu to movdqa here: Our buffer is aligned. */
                 buf[0] = 0x66;
                 get_fpu(X86EMUL_FPU_xmm, &fic);
@@ -5193,7 +5198,7 @@ x86_emulate(
                 if ( b != 0xe7 )
                     host_and_vcpu_must_have(mmx);
                 else
-                    host_and_vcpu_must_have(sse);
+                    vcpu_must_have(sse);
                 get_fpu(X86EMUL_FPU_mmx, &fic);
                 ea.bytes = 8;
                 break;
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -38,8 +38,6 @@
 #define cpu_has_sep            boot_cpu_has(X86_FEATURE_SEP)
 #define cpu_has_mtrr           1
 #define cpu_has_mmx            1
-#define cpu_has_sse            boot_cpu_has(X86_FEATURE_SSE)
-#define cpu_has_sse2           boot_cpu_has(X86_FEATURE_SSE2)
 #define cpu_has_sse3           boot_cpu_has(X86_FEATURE_SSE3)
 #define cpu_has_sse4_2         boot_cpu_has(X86_FEATURE_SSE4_2)
 #define cpu_has_htt            boot_cpu_has(X86_FEATURE_HTT)

Attachment: x86-SSE-SSE2-always.patch
Description: Text document

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