1 files changed, 10 insertions, 5 deletions

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index dba629c5f8ac..a4c1b76240df 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -63,7 +63,7 @@ static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_arm_running_vcpu);
 static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
 static u32 kvm_next_vmid;
 static unsigned int kvm_vmid_bits __read_mostly;
-static DEFINE_SPINLOCK(kvm_vmid_lock);
+static DEFINE_RWLOCK(kvm_vmid_lock);
 
 static bool vgic_present;
 
@@ -473,11 +473,16 @@ static void update_vttbr(struct kvm *kvm)
 {
         phys_addr_t pgd_phys;
         u64 vmid;
+        bool new_gen;
 
-        if (!need_new_vmid_gen(kvm))
+        read_lock(&kvm_vmid_lock);
+        new_gen = need_new_vmid_gen(kvm);
+        read_unlock(&kvm_vmid_lock);
+
+        if (!new_gen)
                 return;
 
-        spin_lock(&kvm_vmid_lock);
+        write_lock(&kvm_vmid_lock);
 
         /*
          * We need to re-check the vmid_gen here to ensure that if another vcpu
@@ -485,7 +490,7 @@ static void update_vttbr(struct kvm *kvm)
          * use the same vmid.
          */
         if (!need_new_vmid_gen(kvm)) {
-                spin_unlock(&kvm_vmid_lock);
+                write_unlock(&kvm_vmid_lock);
                 return;
         }
 
@@ -519,7 +524,7 @@ static void update_vttbr(struct kvm *kvm)
         vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK(kvm_vmid_bits);
         kvm->arch.vttbr = kvm_phys_to_vttbr(pgd_phys) | vmid;
 
-        spin_unlock(&kvm_vmid_lock);
+        write_unlock(&kvm_vmid_lock);
 }
 
 static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)