host/include/i386: Implement clmul.h

Detect PCLMUL in cpuinfo; implement the accel hook.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

host/include/i386/host/cpuinfo.h

@@ -27,6 +27,7 @@
 #define CPUINFO_ATOMIC_VMOVDQA  (1u << 16)
 #define CPUINFO_ATOMIC_VMOVDQU  (1u << 17)
 #define CPUINFO_AES             (1u << 18)
+#define CPUINFO_PCLMUL          (1u << 19)
 
 /* Initialized with a constructor. */
 extern unsigned cpuinfo;

host/include/i386/host/crypto/clmul.h

@@ -0,0 +1,29 @@
+/*
+ * x86 specific clmul acceleration.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef X86_HOST_CRYPTO_CLMUL_H
+#define X86_HOST_CRYPTO_CLMUL_H
+
+#include "host/cpuinfo.h"
+#include <immintrin.h>
+
+#if defined(__PCLMUL__)
+# define HAVE_CLMUL_ACCEL  true
+# define ATTR_CLMUL_ACCEL
+#else
+# define HAVE_CLMUL_ACCEL  likely(cpuinfo & CPUINFO_PCLMUL)
+# define ATTR_CLMUL_ACCEL  __attribute__((target("pclmul")))
+#endif
+
+static inline Int128 ATTR_CLMUL_ACCEL
+clmul_64_accel(uint64_t n, uint64_t m)
+{
+    union { __m128i v; Int128 s; } u;
+
+    u.v = _mm_clmulepi64_si128(_mm_set_epi64x(0, n), _mm_set_epi64x(0, m), 0);
+    return u.s;
+}
+
+#endif /* X86_HOST_CRYPTO_CLMUL_H */

host/include/x86_64/host/crypto/clmul.h

@@ -0,0 +1 @@
+#include "host/include/i386/host/crypto/clmul.h"

include/qemu/cpuid.h

@@ -25,6 +25,9 @@
 #endif
 
 /* Leaf 1, %ecx */
+#ifndef bit_PCLMUL
+#define bit_PCLMUL      (1 << 1)
+#endif
 #ifndef bit_SSE4_1
 #define bit_SSE4_1      (1 << 19)
 #endif

util/cpuinfo-i386.c

@@ -39,6 +39,7 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
         info |= (c & bit_SSE4_1 ? CPUINFO_SSE4 : 0);
         info |= (c & bit_MOVBE ? CPUINFO_MOVBE : 0);
         info |= (c & bit_POPCNT ? CPUINFO_POPCNT : 0);
+        info |= (c & bit_PCLMUL ? CPUINFO_PCLMUL : 0);
 
         /* Our AES support requires PSHUFB as well. */
         info |= ((c & bit_AES) && (c & bit_SSSE3) ? CPUINFO_AES : 0);