s390/mm: extended gmap pte notifier
The current gmap pte notifier forces a pte into to a read-write state.
If the pte is invalidated the gmap notifier is called to inform KVM
that the mapping will go away.
Extend this approach to allow read-write, read-only and no-access
as possible target states and call the pte notifier for any change
to the pte.
This mechanism is used to temporarily set specific access rights for
a pte without doing the heavy work of a true mprotect call.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 67f1b6b..b6e7f66 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/mman.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/slab.h>
@@ -185,7 +186,7 @@
int kvm_arch_hardware_setup(void)
{
gmap_notifier.notifier_call = kvm_gmap_notifier;
- gmap_register_ipte_notifier(&gmap_notifier);
+ gmap_register_pte_notifier(&gmap_notifier);
atomic_notifier_chain_register(&s390_epoch_delta_notifier,
&kvm_clock_notifier);
return 0;
@@ -193,7 +194,7 @@
void kvm_arch_hardware_unsetup(void)
{
- gmap_unregister_ipte_notifier(&gmap_notifier);
+ gmap_unregister_pte_notifier(&gmap_notifier);
atomic_notifier_chain_unregister(&s390_epoch_delta_notifier,
&kvm_clock_notifier);
}
@@ -2272,16 +2273,16 @@
return 0;
/*
* We use MMU_RELOAD just to re-arm the ipte notifier for the
- * guest prefix page. gmap_ipte_notify will wait on the ptl lock.
+ * guest prefix page. gmap_mprotect_notify will wait on the ptl lock.
* This ensures that the ipte instruction for this request has
* already finished. We might race against a second unmapper that
* wants to set the blocking bit. Lets just retry the request loop.
*/
if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) {
int rc;
- rc = gmap_ipte_notify(vcpu->arch.gmap,
- kvm_s390_get_prefix(vcpu),
- PAGE_SIZE * 2);
+ rc = gmap_mprotect_notify(vcpu->arch.gmap,
+ kvm_s390_get_prefix(vcpu),
+ PAGE_SIZE * 2, PROT_WRITE);
if (rc)
return rc;
goto retry;