From: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx>
The ipte-locking should be done for each VM seperately, not globally.
This way we avoid possible congestions when the simple ipte-lock is used
and multiple VMs are running.
Suggested-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx>
Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/asm/kvm_host.h | 2 ++
arch/s390/kvm/gaccess.c | 20 +++++++++-----------
arch/s390/kvm/kvm-s390.c | 1 +
3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 2175f911..584b820 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -434,6 +434,8 @@ struct kvm_arch{
int user_cpu_state_ctrl;
struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
wait_queue_head_t ipte_wq;
+ int ipte_lock_count;
+ struct mutex ipte_mutex;
spinlock_t start_stop_lock;
struct kvm_s390_crypto crypto;
};
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 0f961a1..c1424e8 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -207,8 +207,6 @@ union raddress {
unsigned long pfra : 52; /* Page-Frame Real Address */
};
-static int ipte_lock_count;
-static DEFINE_MUTEX(ipte_mutex);
int ipte_lock_held(struct kvm_vcpu *vcpu)
{
@@ -216,16 +214,16 @@ int ipte_lock_held(struct kvm_vcpu *vcpu)
if (vcpu->arch.sie_block->eca & 1)
return ic->kh != 0;
- return ipte_lock_count != 0;
+ return vcpu->kvm->arch.ipte_lock_count != 0;
}
static void ipte_lock_simple(struct kvm_vcpu *vcpu)
{
union ipte_control old, new, *ic;
- mutex_lock(&ipte_mutex);
- ipte_lock_count++;
- if (ipte_lock_count > 1)
+ mutex_lock(&vcpu->kvm->arch.ipte_mutex);
+ vcpu->kvm->arch.ipte_lock_count++;
+ if (vcpu->kvm->arch.ipte_lock_count > 1)
goto out;
ic = &vcpu->kvm->arch.sca->ipte_control;
do {
@@ -238,16 +236,16 @@ static void ipte_lock_simple(struct kvm_vcpu *vcpu)
new.k = 1;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
out:
- mutex_unlock(&ipte_mutex);
+ mutex_unlock(&vcpu->kvm->arch.ipte_mutex);
}
static void ipte_unlock_simple(struct kvm_vcpu *vcpu)
{
union ipte_control old, new, *ic;
- mutex_lock(&ipte_mutex);
- ipte_lock_count--;
- if (ipte_lock_count)
+ mutex_lock(&vcpu->kvm->arch.ipte_mutex);
+ vcpu->kvm->arch.ipte_lock_count--;
+ if (vcpu->kvm->arch.ipte_lock_count)
goto out;
ic = &vcpu->kvm->arch.sca->ipte_control;
do {
@@ -256,7 +254,7 @@ static void ipte_unlock_simple(struct kvm_vcpu *vcpu)
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
wake_up(&vcpu->kvm->arch.ipte_wq);
out:
- mutex_unlock(&ipte_mutex);
+ mutex_unlock(&vcpu->kvm->arch.ipte_mutex);
}
static void ipte_lock_siif(struct kvm_vcpu *vcpu)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 55aade4..3e83d4b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -453,6 +453,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
spin_lock_init(&kvm->arch.float_int.lock);
INIT_LIST_HEAD(&kvm->arch.float_int.list);
init_waitqueue_head(&kvm->arch.ipte_wq);
+ mutex_init(&kvm->arch.ipte_mutex);
debug_register_view(kvm->arch.dbf, &debug_sprintf_view);
VM_EVENT(kvm, 3, "%s", "vm created");
--
1.9.3
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