linux-kernel - [PATCH 2/5] KVM: Bail from the dirty ring reset flow if a signal is pending

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Message-ID: <20250111010409.1252942-3-seanjc@google.com>
Date: Fri, 10 Jan 2025 17:04:06 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Peter Xu <peterx@...hat.com>, Yan Zhao <yan.y.zhao@...el.com>, 
	Maxim Levitsky <mlevitsk@...hat.com>, Sean Christopherson <seanjc@...gle.com>
Subject: [PATCH 2/5] 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")
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 virt/kvm/dirty_ring.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index 2faf894dec5a..a81ad17d5eef 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c
@@ -117,6 +117,9 @@ 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))
-- 
2.47.1.613.gc27f4b7a9f-goog