2 files changed, 21 insertions, 8 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3ad10f634d4c..8e90488c3d56 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1455,7 +1455,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
 void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu);
 
 int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
-                    unsigned long ipi_bitmap_high, int min,
+                    unsigned long ipi_bitmap_high, u32 min,
                     unsigned long icr, int op_64_bit);
 
 u64 kvm_get_arch_capabilities(void);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 0cefba28c864..17c0472c5b34 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -548,7 +548,7 @@ int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
 }
 
 int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
-                    unsigned long ipi_bitmap_high, int min,
+                    unsigned long ipi_bitmap_high, u32 min,
                     unsigned long icr, int op_64_bit)
 {
         int i;
@@ -571,18 +571,31 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
         rcu_read_lock();
         map = rcu_dereference(kvm->arch.apic_map);
 
+        if (min > map->max_apic_id)
+                goto out;
         /* Bits above cluster_size are masked in the caller.  */
-        for_each_set_bit(i, &ipi_bitmap_low, BITS_PER_LONG) {
-                vcpu = map->phys_map[min + i]->vcpu;
-                count += kvm_apic_set_irq(vcpu, &irq, NULL);
+        for_each_set_bit(i, &ipi_bitmap_low,
+                min((u32)BITS_PER_LONG, (map->max_apic_id - min + 1))) {
+                if (map->phys_map[min + i]) {
+                        vcpu = map->phys_map[min + i]->vcpu;
+                        count += kvm_apic_set_irq(vcpu, &irq, NULL);
+                }
         }
 
         min += cluster_size;
-        for_each_set_bit(i, &ipi_bitmap_high, BITS_PER_LONG) {
-                vcpu = map->phys_map[min + i]->vcpu;
-                count += kvm_apic_set_irq(vcpu, &irq, NULL);
+
+        if (min > map->max_apic_id)
+                goto out;
+
+        for_each_set_bit(i, &ipi_bitmap_high,
+                min((u32)BITS_PER_LONG, (map->max_apic_id - min + 1))) {
+                if (map->phys_map[min + i]) {
+                        vcpu = map->phys_map[min + i]->vcpu;
+                        count += kvm_apic_set_irq(vcpu, &irq, NULL);
+                }
         }
 
+out:
         rcu_read_unlock();
         return count;
 }