Commit 3abb708e authored by Bibo Mao's avatar Bibo Mao Committed by Huacai Chen
Browse files

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: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent cdc118f8

arch/loongarch/include/asm/kvm_para.h

+10 −0
Original line number Diff line number Diff line
@@ -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)

{

arch/loongarch/kernel/paravirt.c

+17 −15
Original line number Diff line number Diff line
@@ -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;



	if (!feature)

		feature = read_cpucfg(CPUCFG_KVM_FEATURE);

	if (!(feature & BIT(KVM_FEATURE_IPI)))



	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;