From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794046307; b=sDCN96Hrhiua/tI9hfyckFFCZXiyhEqIb84T9fq3fd9SkP3f0JBLsG0btGd0j3zEARiD YYWpWLikAvfXnUUZGlVUi1ejPhZQu8YLTjVoGVm98cr6ahD4n5GCSv9DNMuFwXwFIfuLf 3gwEOj13f7WhzC2WAnCA8lN4uKgsep0CKMuztn/lClnC09LmBCX84dJyKPVOlI0oai0I9 3NUoYw+hqQciI2+GAhQ6EEJlGzgP6VL9WyYjAL5KBAL35YVy5AbaAFd8QpCU98X7Jodpd c83zi/nMeIySkBmSIQTH603Fjju6lO6tXGXO+/12aSK7SzFettyYTxP0HY19Y1DkEAA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046307; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=CiVt+et9mZrBLp+liacRjmoh8r+y6ZRzwAe+qlqAcPA=; b=4ynF6LBLQYWiObxseTxYN1sLdY7C3cVxPw30z8Ug2+FhOtEBCt34Bxs6NJc6jn9Yh/FG kZ2QiGWhFOvmOH9+MntWw4UKFX+c84JS3vNQKIkIXzxezfXGVL0V4jUNLdL6ghiVNKl9z Uog5DxSImg5vEyH+vGmc3/dvnFk91HQVhybd3ANuxGYgqWH8rOGkcnPHROI3/rO1LTiDi Sy57z5VfnHDvoOI/9Y6Unc1zCjKf4TSXM8X3b5zRBz/EwcaXSqP2B6hzyCcV+AL72qeZD lPJJgB8UGNDQ6f3+1oihV/4IolDRHh3dfc3dEcCZatnhXhSFJMgqC2JBpXkVoKBpbpg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bWbZn6yS; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 284C6606A326 for ; Sat, 7 Nov 2026 10:11:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bWbZn6yS Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84AD81F0089F; Sat, 7 Nov 2026 10:11:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046307; bh=CiVt+et9mZrBLp+liacRjmoh8r+y6ZRzwAe+qlqAcPA=; h=From:To:Cc:Subject:Date; b=bWbZn6yS48cWoKZxrR2uJmGBkR6378+sPtTLLzcucPT30Q/xcHgc+UPvLemWPAg+d j2SQt8xJ/ZQ82h+VHdL2ssDTEOak074H1ZMwkjBnt+8GvvdhPY8WouPyJt9QoFGhf4 Ic5N2eJBIrVTA+Et3KX3n3PHixEy7sSkUewnq062oYDYEQ4NvhmRiDMgibg2COppVC R3d951DcP4LQEy31DIA5P2vSZtiTU20yUFcrr61ee09aiWg7Cxn2zJFpMUtjlQIUzc ZC/BxMTFwKyc8qJ2ICrNV9pOzpEpuHGDS4JAFRMCYzlx3S5KB985VOdyW/4C4RhISA eW6MEtyCUY8QA== From: Sasha Levin To: maz@kernel.org, oupton@kernel.org, fuad.tabba@linux.dev Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] KVM: arm64: vgic: Stop the target vcpu when disabling LPIs" failed to apply to 6.18-stable tree Date: Sat, 7 Nov 2026 05:11:45 -0500 Message-ID: <20261107051145-failed-6.18-a1b4bd2c2c26@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x a1b4bd2c2c262b8094c86afb99364d16ac08cb66 # git commit -s git send-email --to '' --in-reply-to '20261107051145-failed-6.18-a1b4bd2c2c26@kernel.org' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From a1b4bd2c2c262b8094c86afb99364d16ac08cb66 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 15 Oct 2026 11:05:38 +0100 Subject: [PATCH] KVM: arm64: vgic: Stop the target vcpu when disabling LPIs Disabling LPIs is pretty nasty, as it directly messes with the AP list of the affected CPU, which could be running... This has the potential to lead to really bad behaviours, and we should not be doing that. Take example on the way the Active state is handled and simply pause the the vcpu so that we are sure it is in a quiescent state, and the state be safely manipulated. Nobody has any expectation of performance for this anyway. Fixes: 96085b949672d ("KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs") Co-developed-by: Oliver Upton Signed-off-by: Oliver Upton Cc: stable@vger.kernel.org Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20261015100539.1011760-7-maz@kernel.org Signed-off-by: Marc Zyngier --- arch/arm64/kvm/vgic/vgic-mmio-v3.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index 5913a20d83019..f5bd29fbe3a90 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -303,9 +303,19 @@ static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu, if (ctlr != GICR_CTLR_ENABLE_LPIS) return; + /* + * Yes, disabling LPIs is painful, since it can be done from + * a *remote* vcpu! So let's not take any chance, and make + * sure that the target vCPU has written their LRs back to the + * irq structures, and release any reference they would have. + * + * If it hurts, don't do it. + */ + kvm_pause_vcpu(vcpu); vgic_flush_pending_lpis(vcpu); vgic_its_invalidate_all_caches(vcpu->kvm); atomic_set_release(&vgic_cpu->ctlr, 0); + kvm_resume_vcpu(vcpu); } else { ctlr = atomic_cmpxchg_acquire(&vgic_cpu->ctlr, 0, GICR_CTLR_ENABLE_LPIS); -- 2.53.0