Commit 872d277a authored by Bibo Mao's avatar Bibo Mao Committed by Huacai Chen
Browse files

LoongArch: KVM: Add paravirt vcpu_is_preempted() support in guest side 



Function vcpu_is_preempted() is used to check whether vCPU is preempted
or not. Here add the implementation with vcpu_is_preempted() when option
CONFIG_PARAVIRT is enabled.

Acked-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 9b486cdd

arch/loongarch/include/asm/qspinlock.h

+4 −0
Original line number Diff line number Diff line
@@ -34,6 +34,10 @@ static inline bool virt_spin_lock(struct qspinlock *lock) 
	return true;

}



#define vcpu_is_preempted vcpu_is_preempted



bool vcpu_is_preempted(int cpu);



#endif /* CONFIG_PARAVIRT */



#include <asm-generic/qspinlock.h>

arch/loongarch/kernel/paravirt.c

+20 −1
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ static int has_steal_clock; 
struct static_key paravirt_steal_enabled;

struct static_key paravirt_steal_rq_enabled;

static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64);

static DEFINE_STATIC_KEY_FALSE(virt_preempt_key);

DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key);



static u64 native_steal_clock(int cpu)
@@ -267,6 +268,18 @@ static int pv_time_cpu_down_prepare(unsigned int cpu) 


	return 0;

}



bool vcpu_is_preempted(int cpu)

{

	struct kvm_steal_time *src;



	if (!static_branch_unlikely(&virt_preempt_key))

		return false;



	src = &per_cpu(steal_time, cpu);

	return !!(src->preempted & KVM_VCPU_PREEMPTED);

}

EXPORT_SYMBOL(vcpu_is_preempted);

#endif



static void pv_cpu_reboot(void *unused)
@@ -308,6 +321,9 @@ int __init pv_time_init(void) 
		pr_err("Failed to install cpu hotplug callbacks\n");

		return r;

	}



	if (kvm_para_has_feature(KVM_FEATURE_PREEMPT))

		static_branch_enable(&virt_preempt_key);

#endif



	static_call_update(pv_steal_clock, paravt_steal_clock);
@@ -318,7 +334,10 @@ int __init pv_time_init(void) 
		static_key_slow_inc(&paravirt_steal_rq_enabled);

#endif



	pr_info("Using paravirt steal-time\n");

	if (static_key_enabled(&virt_preempt_key))

		pr_info("Using paravirt steal-time with preempt enabled\n");

	else

		pr_info("Using paravirt steal-time with preempt disabled\n");



	return 0;

}