Function kvm_para_has_feature() is to detect supported paravirt features, it can be used by device driver to detect and enable paravirt features, such as extioi irqchip driver can detect KVM_FEATURE_VIRT_EXTIOI and do some optimization. Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx> --- arch/loongarch/include/asm/kvm_para.h | 10 +++++++++ arch/loongarch/kernel/paravirt.c | 31 ++++++++++++++------------- 2 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h index 39d7483ab8fd..2174fb53c2e7 100644 --- a/arch/loongarch/include/asm/kvm_para.h +++ b/arch/loongarch/include/asm/kvm_para.h @@ -155,10 +155,20 @@ static __always_inline long kvm_hypercall5(u64 fid, return ret; } +#ifdef CONFIG_PARAVIRT +bool kvm_para_available(void); +unsigned int kvm_arch_para_features(void); +#else +static inline bool kvm_para_available(void) +{ + return false; +} + static inline unsigned int kvm_arch_para_features(void) { return 0; } +#endif static inline unsigned int kvm_arch_para_hints(void) { diff --git a/arch/loongarch/kernel/paravirt.c b/arch/loongarch/kernel/paravirt.c index cc6bf096cb88..dc3cebcb550a 100644 --- a/arch/loongarch/kernel/paravirt.c +++ b/arch/loongarch/kernel/paravirt.c @@ -151,11 +151,14 @@ static void pv_init_ipi(void) } #endif -static bool kvm_para_available(void) +bool kvm_para_available(void) { int config; static int hypervisor_type; + if (!cpu_has_hypervisor) + return false; + if (!hypervisor_type) { config = read_cpucfg(CPUCFG_KVM_SIG); if (!memcmp(&config, KVM_SIGNATURE, 4)) @@ -165,17 +168,21 @@ static bool kvm_para_available(void) return hypervisor_type == HYPERVISOR_KVM; } -int __init pv_ipi_init(void) +unsigned int kvm_arch_para_features(void) { - int feature; + static int feature; - if (!cpu_has_hypervisor) - return 0; if (!kvm_para_available()) return 0; - feature = read_cpucfg(CPUCFG_KVM_FEATURE); - if (!(feature & BIT(KVM_FEATURE_IPI))) + if (!feature) + feature = read_cpucfg(CPUCFG_KVM_FEATURE); + return feature; +} + +int __init pv_ipi_init(void) +{ + if (!kvm_para_has_feature(KVM_FEATURE_IPI)) return 0; #ifdef CONFIG_SMP @@ -258,15 +265,9 @@ static struct notifier_block pv_reboot_nb = { int __init pv_time_init(void) { - int r, feature; - - if (!cpu_has_hypervisor) - return 0; - if (!kvm_para_available()) - return 0; + int r; - feature = read_cpucfg(CPUCFG_KVM_FEATURE); - if (!(feature & BIT(KVM_FEATURE_STEAL_TIME))) + if (!kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) return 0; has_steal_clock = 1; -- 2.39.3