kvm hypervisor: Add directed yield in vcpu block path
From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
We use the improved PLE handler logic in vcpu block patch for
scheduling rather than plain schedule, so that we can make
intelligent decisions.
Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
---
arch/ia64/include/asm/kvm_host.h | 5 +++++
arch/powerpc/include/asm/kvm_host.h | 5 +++++
arch/s390/include/asm/kvm_host.h | 5 +++++
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/x86.c | 8 ++++++++
include/linux/kvm_host.h | 2 +-
virt/kvm/kvm_main.c | 6 ++++--
7 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
index 989dd3f..999ab15 100644
--- a/arch/ia64/include/asm/kvm_host.h
+++ b/arch/ia64/include/asm/kvm_host.h
@@ -595,6 +595,11 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu);
int kvm_pal_emul(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run);
void kvm_sal_emul(struct kvm_vcpu *vcpu);
+static inline void kvm_do_schedule(struct kvm_vcpu *vcpu)
+{
+ schedule();
+}
+
#define __KVM_HAVE_ARCH_VM_ALLOC 1
struct kvm *kvm_arch_alloc_vm(void);
void kvm_arch_free_vm(struct kvm *kvm);
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index af326cd..1aeecc0 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -628,4 +628,9 @@ struct kvm_vcpu_arch {
#define __KVM_HAVE_ARCH_WQP
#define __KVM_HAVE_CREATE_DEVICE
+static inline void kvm_do_schedule(struct kvm_vcpu *vcpu)
+{
+ schedule();
+}
+
#endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 16bd5d1..db09a56 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -266,4 +266,9 @@ struct kvm_arch{
};
extern int sie64a(struct kvm_s390_sie_block *, u64 *);
+static inline void kvm_do_schedule(struct kvm_vcpu *vcpu)
+{
+ schedule();
+}
+
#endif
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 95702de..72ff791 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1042,5 +1042,5 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
void kvm_handle_pmu_event(struct kvm_vcpu *vcpu);
void kvm_deliver_pmi(struct kvm_vcpu *vcpu);
-
+void kvm_do_schedule(struct kvm_vcpu *vcpu);
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b963c86..84a4eb2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7281,6 +7281,14 @@ bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu)
kvm_x86_ops->interrupt_allowed(vcpu);
}
+void kvm_do_schedule(struct kvm_vcpu *vcpu)
+{
+ /* We try to yield to a kicked vcpu else do a schedule */
+ if (kvm_vcpu_on_spin(vcpu) <= 0)
+ schedule();
+}
+EXPORT_SYMBOL_GPL(kvm_do_schedule);
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f0eea07..39efc18 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -565,7 +565,7 @@ void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
void kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
bool kvm_vcpu_yield_to(struct kvm_vcpu *target);
-void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
+bool kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
void kvm_resched(struct kvm_vcpu *vcpu);
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 302681c..8387247 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1685,7 +1685,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
if (signal_pending(current))
break;
- schedule();
+ kvm_do_schedule(vcpu);
}
finish_wait(&vcpu->wq, &wait);
@@ -1786,7 +1786,7 @@ bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
}
#endif
-void kvm_vcpu_on_spin(struct kvm_vcpu *me)
+bool kvm_vcpu_on_spin(struct kvm_vcpu *me)
{
struct kvm *kvm = me->kvm;
struct kvm_vcpu *vcpu;
@@ -1835,6 +1835,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me)
/* Ensure vcpu is not eligible during next spinloop */
kvm_vcpu_set_dy_eligible(me, false);
+
+ return yielded;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
--
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