From 3abb708ec0be25da16a1ee9f1ab5cbc93f3256f3 Mon Sep 17 00:00:00 2001 From: Bibo Mao Date: Thu, 12 Sep 2024 22:56:14 +0800 Subject: LoongArch: KVM: Implement function kvm_para_has_feature() Implement function kvm_para_has_feature() to detect supported paravirt features. It can be used by device driver to detect and enable paravirt features, such as the EIOINTC irqchip driver is able to detect feature KVM_FEATURE_VIRT_EXTIOI and do some optimization. Signed-off-by: Bibo Mao Signed-off-by: Huacai Chen --- arch/loongarch/include/asm/kvm_para.h | 10 ++++++++++ arch/loongarch/kernel/paravirt.c | 32 +++++++++++++++++--------------- 2 files changed, 27 insertions(+), 15 deletions(-) (limited to 'arch') diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h index d0f087870628..c4e84227280d 100644 --- a/arch/loongarch/include/asm/kvm_para.h +++ b/arch/loongarch/include/asm/kvm_para.h @@ -156,10 +156,20 @@ 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 1306ad830ae2..708eda025ed8 100644 --- a/arch/loongarch/kernel/paravirt.c +++ b/arch/loongarch/kernel/paravirt.c @@ -152,11 +152,14 @@ 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)) @@ -166,17 +169,22 @@ 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 unsigned 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 @@ -259,15 +267,9 @@ 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; -- cgit