[libvirt PATCH 2/3] cpu: Only retrieve AT_HWCAP once

No need to fetch the same information twice. As a side effect, this solves a bug where, on platforms where elf_aux_info() is used instead of getauxval(), we would not make sure the CPUID feature is available before attempting to use it. Signed-off-by: Andrea Bolognani <abologna(a)redhat.com&gt; --- src/cpu/cpu_arm.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/src/cpu/cpu_arm.c b/src/cpu/cpu_arm.c index aa3e5d8980..71702dbc91 100644 --- a/src/cpu/cpu_arm.c +++ b/src/cpu/cpu_arm.c @@ -557,12 +557,19 @@ virCPUarmCpuDataFromRegs(virCPUarmData *data) size_t i; # if defined(WITH_GETAUXVAL) - if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) { + hwcaps = getauxval(AT_HWCAP); +# elif defined(WITH_ELF_AUX_INFO) + elf_aux_info(AT_HWCAP, &hwcaps, sizeof(u_long)); +# else +# error No routines to retrieve a value from the auxiliary vector +# endif + VIR_DEBUG("CPU flags read from register: 0x%016lx", hwcaps); + + if (!(hwcaps & HWCAP_CPUID)) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("CPUID registers unavailable")); return -1; } -# endif /* read the cpuid data from MIDR_EL1 register */ asm("mrs %0, MIDR_EL1" : "=r" (cpuid)); @@ -573,15 +580,6 @@ virCPUarmCpuDataFromRegs(virCPUarmData *data) /* parse the corresponding vendor_id bits */ data->vendor_id = (cpuid >> 24) & 0xff; -# if defined(WITH_GETAUXVAL) - hwcaps = getauxval(AT_HWCAP); -# elif defined(WITH_ELF_AUX_INFO) - elf_aux_info(AT_HWCAP, &hwcaps, sizeof(u_long)); -# else -# error No routines to retrieve a value from the auxiliary vector -# endif - VIR_DEBUG("CPU flags read from register: 0x%016lx", hwcaps); - features = g_new0(char *, MAX_CPU_FLAGS + 1); /* shift bit map mask to parse for CPU flags */ -- 2.26.2