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=1794046985; b=pUEL+6m68WAoYOuVYd4/cOjhZQBLXHupRQ4/Sycl4TXCqP4oDPOq1cpnj8resICxzJ0J mcz4MpyknHB2TmQaI1jeKe38DCl4KkZwMzkdZU9a3IBA4dtxXzaDHxtctYNACYbpq6X8U jTFhbeTJkZnAM410UZ8gRZfZMZIKpuW7H5qKPZc/F39xZjpGsvX2CvvvJSWURqibSstlA vIDXENEsMXo+hpkP2/Azufh4xvGrdtv6JsKKkXK6XsaZYvwN+0CPBUgsTl9/7c1HTBw9t 2P7NKMCn6KWRZz+StWEKZzIKb23L40wNz+4/R3LgXy8BLNrFQNosi5y7AAzm++qXhlQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046985; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=rwTt/XAb0VdHtUVyw78tnZbuh23LYbtlsA59GuX/E1I=; b=T0i2QU6ZWg0SS5uKMGXoj6iyfN79YKfdSwu/ognTF3VGlrXdlhWvxlMhSdk7+LSdrTSl 88JUejZiBbJiEsgb62OmAPaDnqSYVbvQZzpw8XRgzqBRJy+1X9rx5MT0xh4oaxujbHfwY iBE7fFHCpn5zXl/wO70muDNrU4Dq85vyhc6Qouy+YrEWjlire6dHHs6Zx80Hgd3LI2/F7 1IAazi+wfAGbTkwVFxOOVGNxhC3zMN1KcujjcE1vd9brl+LEzBIly7nqEcpASSm/0+1YP gMOU0SIbMMygPb8xbNZ3lScJcjhksyIn9pOEowkrbOPED9b9BrzFW/Bqx1Nzqe8P0Fg== 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=mBMVeri8; 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 007EB606A32F for ; Sat, 7 Nov 2026 10:23:04 +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=mBMVeri8 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AF2C1F0089F; Sat, 7 Nov 2026 10:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046984; bh=rwTt/XAb0VdHtUVyw78tnZbuh23LYbtlsA59GuX/E1I=; h=From:To:Cc:Subject:Date; b=mBMVeri8inFPtIABtnI7fGDEfNbXXlhLP4f/c9cSw6aDXMjfCJTdKh0yjVQ3fgJ4g 4EnM+xqS7tZTAAKPMYdq89y0ohb+VwMSaD7l4rM7YMBBDFnUjFZGMTlroxnGGDQGe3 szaq0ElD+CjrqPxPrjHu17vnwdy0gIx655GCwVVt0FMLGZgpKH3+PJx6HFklkPBGgF 1GFzIdHkUqVJIo8V7+7SIz/CSQTNs372uPkPTd64AjCBxlfIdgzBIP7ovJ0ZxOXuBH TUUyyeECyH4vGeTRYP0RKL2/REJ34xOAWIFnOpyLOj4Ul2KNDHrKE6tNXBaYFfRk7n FCunUvR7/h79g== 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 6.12-stable tree Date: Sat, 7 Nov 2026 05:23:03 -0500 Message-ID: <20261107052303-failed-6.12-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 6.12-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-6.12.y git checkout FETCH_HEAD git cherry-pick -x a1b4bd2c2c262b8094c86afb99364d16ac08cb66 # git commit -s git send-email --to '' --in-reply-to '20261107052303-failed-6.12-a1b4bd2c2c26@kernel.org' --subject-prefix 'PATCH 6.12.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