From: Sean Christopherson <seanjc@google.com>
Date: Fri, 16 May 2025 21:35:36 +0000 (-0700)
Subject: KVM: Bail from the dirty ring reset flow if a signal is pending
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=49005a2a3d2a2974db486e330dfb7c8bc85df17f;p=thirdparty%2Flinux.git

KVM: Bail from the dirty ring reset flow if a signal is pending

Abort a dirty ring reset if the current task has a pending signal, as the
hard limit of INT_MAX entries doesn't ensure KVM will respond to a signal
in a timely fashion.

Fixes: fb04a1eddb1a ("KVM: X86: Implement ring-based dirty memory tracking")
Reviewed-by: James Houghton <jthoughton@google.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20250516213540.2546077-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
---

diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index 77986f34eff84..e844e869e8c7f 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c
@@ -118,6 +118,9 @@ int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring,
 	cur_slot = cur_offset = mask = 0;
 
 	while (likely((*nr_entries_reset) < INT_MAX)) {
+		if (signal_pending(current))
+			return -EINTR;
+
 		entry = &ring->dirty_gfns[ring->reset_index & (ring->size - 1)];
 
 		if (!kvm_dirty_gfn_harvested(entry))