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-rw-r--r--virt/kvm/arm/arm.c23
1 files changed, 11 insertions, 12 deletions
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 4adcee5fc126..d9273f972828 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -66,7 +66,7 @@ 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_RWLOCK(kvm_vmid_lock);
+static DEFINE_SPINLOCK(kvm_vmid_lock);
static bool vgic_present;
@@ -484,7 +484,9 @@ void force_vm_exit(const cpumask_t *mask)
*/
static bool need_new_vmid_gen(struct kvm *kvm)
{
- return unlikely(kvm->arch.vmid_gen != atomic64_read(&kvm_vmid_gen));
+ u64 current_vmid_gen = atomic64_read(&kvm_vmid_gen);
+ smp_rmb(); /* Orders read of kvm_vmid_gen and kvm->arch.vmid */
+ return unlikely(READ_ONCE(kvm->arch.vmid_gen) != current_vmid_gen);
}
/**
@@ -499,16 +501,11 @@ static void update_vttbr(struct kvm *kvm)
{
phys_addr_t pgd_phys;
u64 vmid, cnp = kvm_cpu_has_cnp() ? VTTBR_CNP_BIT : 0;
- bool new_gen;
- read_lock(&kvm_vmid_lock);
- new_gen = need_new_vmid_gen(kvm);
- read_unlock(&kvm_vmid_lock);
-
- if (!new_gen)
+ if (!need_new_vmid_gen(kvm))
return;
- write_lock(&kvm_vmid_lock);
+ spin_lock(&kvm_vmid_lock);
/*
* We need to re-check the vmid_gen here to ensure that if another vcpu
@@ -516,7 +513,7 @@ static void update_vttbr(struct kvm *kvm)
* use the same vmid.
*/
if (!need_new_vmid_gen(kvm)) {
- write_unlock(&kvm_vmid_lock);
+ spin_unlock(&kvm_vmid_lock);
return;
}
@@ -539,7 +536,6 @@ static void update_vttbr(struct kvm *kvm)
kvm_call_hyp(__kvm_flush_vm_context);
}
- kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);
kvm->arch.vmid = kvm_next_vmid;
kvm_next_vmid++;
kvm_next_vmid &= (1 << kvm_vmid_bits) - 1;
@@ -550,7 +546,10 @@ 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 | cnp;
- write_unlock(&kvm_vmid_lock);
+ smp_wmb();
+ WRITE_ONCE(kvm->arch.vmid_gen, atomic64_read(&kvm_vmid_gen));
+
+ spin_unlock(&kvm_vmid_lock);
}
static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)