Commit 614fb9d1 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: Assert that slots_lock is held when resetting per-vCPU dirty rings 

Assert that slots_lock is held in kvm_dirty_ring_reset() and add a comment
to explain _why_ slots needs to be held for the duration of the reset.

Link: https://lore.kernel.org/all/aCSns6Q5oTkdXUEe@google.com


Suggested-by: default avatarJames Houghton <jthoughton@google.com>
Reviewed-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20250516213540.2546077-7-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e46ad851

virt/kvm/dirty_ring.c

+8 −0
Original line number Diff line number Diff line
@@ -122,6 +122,14 @@ int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring, 
	unsigned long mask = 0;

	struct kvm_dirty_gfn *entry;



	/*

	 * Ensure concurrent calls to KVM_RESET_DIRTY_RINGS are serialized,

	 * e.g. so that KVM fully resets all entries processed by a given call

	 * before returning to userspace.  Holding slots_lock also protects

	 * the various memslot accesses.

	 */

	lockdep_assert_held(&kvm->slots_lock);



	while (likely((*nr_entries_reset) < INT_MAX)) {

		if (signal_pending(current))

			return -EINTR;