include/qemu/cpuid: Introduce xgetbv_low

Replace the two uses of asm to expand xgetbv with an inline function.
Since one of the two has been using the mnemonic, assume that the
comment about "older versions of the assember" is obsolete, as even
that is 4 years old.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 4 insertions, 7 deletions

diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index 883ced8..028ece6 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -4156,12 +4156,9 @@ static void tcg_target_init(TCGContext *s)
         /* There are a number of things we must check before we can be
            sure of not hitting invalid opcode.  */
         if (c & bit_OSXSAVE) {
-            unsigned xcrl, xcrh;
-            /* The xgetbv instruction is not available to older versions of
-             * the assembler, so we encode the instruction manually.
-             */
-            asm(".byte 0x0f, 0x01, 0xd0" : "=a" (xcrl), "=d" (xcrh) : "c" (0));
-            if ((xcrl & 6) == 6) {
+            unsigned bv = xgetbv_low(0);
+
+            if ((bv & 6) == 6) {
                 have_avx1 = (c & bit_AVX) != 0;
                 have_avx2 = (b7 & bit_AVX2) != 0;
 
@@ -4172,7 +4169,7 @@ static void tcg_target_init(TCGContext *s)
                  * check that OPMASK and all extended ZMM state are enabled
                  * even if we're not using them -- the insns will fault.
                  */
-                if ((xcrl & 0xe0) == 0xe0
+                if ((bv & 0xe0) == 0xe0
                     && (b7 & bit_AVX512F)
                     && (b7 & bit_AVX512VL)) {
                     have_avx512vl = true;