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Commit 15f36ebd authored by Jason J. Herne's avatar Jason J. Herne Committed by Christian Borntraeger
Browse files

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: default avatarJason 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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent a0bf4f14

arch/s390/kvm/kvm-s390.c

+50 −1
Original line number Diff line number Diff line
@@ -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 @@ int kvm_dev_ioctl_check_extension(long ext) 
	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_dev_ioctl_check_extension(long ext) 
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)

virt/kvm/kvm_main.c

+0 −2
Original line number Diff line number Diff line
@@ -637,14 +637,12 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) 
 */

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;

}