[Devel] [PATCH v3 4/6] KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus

[Roman Kagan]

From: Christoffer Dall <cdall at linaro.org>

There are occasional needs to use the index of vcpu in the kvm->vcpus
array to map something related to a VCPU.  For example, unlike the
vcpu->vcpu_id, the vcpu index is guaranteed to not be sparse across all
vcpus which is useful when allocating a memory area for each vcpu.

Signed-off-by: Christoffer Dall <cdall at linaro.org>
Reviewed-by: Eric Auger <eric.auger at redhat.com>
(cherry picked from commit 497d72d80a789501501cccabdad6b145f9e31371)
Signed-off-by: Roman Kagan <rkagan at virtuozzo.com>
---
 include/linux/kvm_host.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index de3cc6d91e2f..3d374feb9752 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -488,6 +488,17 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
 	return NULL;
 }
 
+static inline int kvm_vcpu_get_idx(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu *tmp;
+	int idx;
+
+	kvm_for_each_vcpu(idx, tmp, vcpu->kvm)
+		if (tmp == vcpu)
+			return idx;
+	BUG();
+}
+
 #define kvm_for_each_memslot(memslot, slots)	\
 	for (memslot = &slots->memslots[0];	\
 	      memslot < slots->memslots + KVM_MEM_SLOTS_NUM && memslot->npages;\
-- 
2.13.6