2 * SPDX-License-Identifier: GPL-2.0-or-later
3 * Host specific cpu identification for AArch64.
6 #include "qemu/osdep.h"
7 #include "host/cpuinfo.h"
10 # ifdef CONFIG_GETAUXVAL
11 # include <sys/auxv.h>
13 # include <asm/hwcap.h>
17 # define HWCAP2_BTI 0 /* added in glibc 2.32 */
21 # include <sys/sysctl.h>
27 static bool sysctl_for_bool(const char *name)
30 size_t len = sizeof(val);
32 if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
37 * We might in the future ask for properties not present in older kernels,
38 * but we're only asking about static properties, all of which should be
39 * 'int'. So we shouldn't see ENOMEM (val too small), or any of the other
42 assert(errno == ENOENT);
47 /* Called both as constructor and (possibly) via other constructors. */
48 unsigned __attribute__((constructor)) cpuinfo_init(void)
50 unsigned info = cpuinfo;
56 info = CPUINFO_ALWAYS;
59 unsigned long hwcap = qemu_getauxval(AT_HWCAP);
60 info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
61 info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
62 info |= (hwcap & HWCAP_AES ? CPUINFO_AES : 0);
63 info |= (hwcap & HWCAP_PMULL ? CPUINFO_PMULL : 0);
65 unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
66 info |= (hwcap2 & HWCAP2_BTI ? CPUINFO_BTI : 0);
69 info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
70 info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
71 info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
72 info |= sysctl_for_bool("hw.optional.arm.FEAT_PMULL") * CPUINFO_PMULL;
73 info |= sysctl_for_bool("hw.optional.arm.FEAT_BTI") * CPUINFO_BTI;