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=1794047738; b=AI9s2lR4nAf0PsSjjHgF3ggA47ZdZGiEZ20TN/YKymGN1MvJR3yUdrBZI2Ca/PFsrYKl spKrdDEhNYwYjakdd8v/H1rYf39LRsFIxOnmtyLrqwSNlXpDYy/EfHqDtsNrEyMO0A3ir eQryc/MEJxwEC7dbjTyqB2D6upRfRY3+WFg1VkG6VnDVtjL+UvEGfx/YHEKcQYmpwJ/68 OqEk6GgGWmH43DzTl3qyhvxNZBeS6eDZBa/unaI2IxCi0/IWpAKyRf8NjKfDLIa85/+Og peO+ebLoSqo+tZmeDfcsJgUO2e3PiI8rlnC2vcrXc46QiXUHVq/av7i3iEyImLP1E+w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047738; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=144crMHZKZO09oAFTS5DYg5GwQGCvKKSOgnwQ/KUXI4=; b=YhW/bxKCJZPIW6r4iioy5IhSpAUWBEwLKLl+5ZLeJfRd6zL8aIigs4eF8ot+NuSu4eOy oGvHrs9S7aWx93w+GC3ba5rFIN9gZiUEaT+YTRRidI4nfyxMJE0rIG6deZvs/ECzPYvoR nziZKAJjOy6Y5eKBQyDhVz4HYPkUh48v7WDrDWOnUyvCcVxsvNoGfUxXQfxbDm2pxhMR3 zCnHTBqhgejgC38VJS4gPkRJ68JD/Gq74Sz2QubtWhrAT7g65WQuQnb2nNA8jDbwj3RvD JD3aFNkJKUY/knvKv1Ss8T7IM0YgxDHBagkkGKK2HfwCb06NLgmo4zrBc3yTP3x5OPQ== 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=PYTB4+Nz; 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 91B10606A326 for ; Sat, 7 Nov 2026 10:35:38 +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=PYTB4+Nz Received: by smtp.kernel.org (Postfix) with ESMTPSA id A60201F0089F; Sat, 7 Nov 2026 10:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047738; bh=144crMHZKZO09oAFTS5DYg5GwQGCvKKSOgnwQ/KUXI4=; h=From:To:Cc:Subject:Date; b=PYTB4+Nz1gc44Eg9hgIGhRlhTlKZLf/PPSDtaxyDFD3K0noZ92Pn0aN13r2McxMC2 CJjlXXyVDfhYz2Hr7v1Otpven5/BJUCzyey8fbb8QiXDA4E9ju8yNZLpHWy2YGhul4 TEgFzCDXFSVz5ooqooj7CvDnmXzbIQsUuVmGRU+oO4FI83XMc+QBJ32MSX1pPV3jEC jCax26or4ttRJkip9qxa4tbXAjQul8wWzt2XDJcRengPIc1ih+NyBEsP9LpvYcnGur K80VFV0PRys4ukeCcJNfGChh/4OhiqQgajnok+o4m4DOxGynW/gN+D1OsehL2AqNhO GNjpCmXZHlPkA== 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 6.6-stable tree Date: Sat, 7 Nov 2026 05:35:36 -0500 Message-ID: <20261107053536-failed-6.6-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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x a1b4bd2c2c262b8094c86afb99364d16ac08cb66 # git commit -s git send-email --to '' --in-reply-to '20261107053536-failed-6.6-a1b4bd2c2c26@kernel.org' --subject-prefix 'PATCH 6.6.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