KVM: s390: Add proper dirty bitmap support to S390 kvm.
Replace the kvm_s390_sync_dirty_log() stub with code to construct the KVM
dirty_bitmap from S390 memory change bits. Also add code to properly clear
the dirty_bitmap size when clearing the bitmap.
Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
CC: Dominik Dingel <dingel@linux.vnet.ibm.com>
[Dominik Dingel: use gmap_test_and_clear_dirty, locking fixes]
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 b767ec9..346a347 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -11,6 +11,7 @@
* Christian Borntraeger <borntraeger@de.ibm.com>
* Heiko Carstens <heiko.carstens@de.ibm.com>
* Christian Ehrhardt <ehrhardt@de.ibm.com>
+ * Jason J. Herne <jjherne@us.ibm.com>
*/
#include <linux/compiler.h>
@@ -179,6 +180,25 @@
return r;
}
+static void kvm_s390_sync_dirty_log(struct kvm *kvm,
+ struct kvm_memory_slot *memslot)
+{
+ gfn_t cur_gfn, last_gfn;
+ unsigned long address;
+ struct gmap *gmap = kvm->arch.gmap;
+
+ down_read(&gmap->mm->mmap_sem);
+ /* Loop over all guest pages */
+ last_gfn = memslot->base_gfn + memslot->npages;
+ for (cur_gfn = memslot->base_gfn; cur_gfn <= last_gfn; cur_gfn++) {
+ address = gfn_to_hva_memslot(memslot, cur_gfn);
+
+ if (gmap_test_and_clear_dirty(address, gmap))
+ mark_page_dirty(kvm, cur_gfn);
+ }
+ up_read(&gmap->mm->mmap_sem);
+}
+
/* Section: vm related */
/*
* Get (and clear) the dirty memory log for a memory slot.
@@ -186,7 +206,36 @@
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log)
{
- return 0;
+ int r;
+ unsigned long n;
+ struct kvm_memory_slot *memslot;
+ int is_dirty = 0;
+
+ mutex_lock(&kvm->slots_lock);
+
+ r = -EINVAL;
+ if (log->slot >= KVM_USER_MEM_SLOTS)
+ goto out;
+
+ memslot = id_to_memslot(kvm->memslots, log->slot);
+ r = -ENOENT;
+ if (!memslot->dirty_bitmap)
+ goto out;
+
+ kvm_s390_sync_dirty_log(kvm, memslot);
+ r = kvm_get_dirty_log(kvm, log, &is_dirty);
+ if (r)
+ goto out;
+
+ /* Clear the dirty log */
+ if (is_dirty) {
+ n = kvm_dirty_bitmap_bytes(memslot);
+ memset(memslot->dirty_bitmap, 0, n);
+ }
+ r = 0;
+out:
+ mutex_unlock(&kvm->slots_lock);
+ return r;
}
static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 56baae8..7facdb1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -637,14 +637,12 @@
*/
static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
{
-#ifndef CONFIG_S390
unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
if (!memslot->dirty_bitmap)
return -ENOMEM;
-#endif /* !CONFIG_S390 */
return 0;
}
