From nobody Mon Jun 8 21:59:13 2026 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 46D98223702 for ; Tue, 26 May 2026 12:53:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779800011; cv=none; b=obAWGF90d3kFDp/gk1w72/6xNvjWBK+Aoj8cfGhxw28CZldO+nPorLCZhOXeGMupcNPF7n9KJ0NO8cKPYEe5KwhcKiPz1YJf9F5lqf0BPaf/kNiARE12pbnOKc67vcZIy57cGN88nFbDh2/ryF43GwHS6nuhBlE3CB9J+gRtXuM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779800011; c=relaxed/simple; bh=IRF0PckoUSZFfNTXiC5JqKlU1FPgl6hVje7/9dOcAc4=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=LQvdkkv0F43Ct0kkUxaELo1nNgeMJpGoSqqZI4cJNM0bV9zXuI0rtKbJ4dxVkFOrr228xyIRxnroveWd+03x31HYLFah2onpoq1BXUSpuoCqjTX08E5olT8h7x5+UgwVJn1Cx5AwZmjd+dOHqEaux4ftHLtLgL139XcttOi7TPs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=JengKdbX; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="JengKdbX" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-43ff19e54beso6799078f8f.2 for ; Tue, 26 May 2026 05:53:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779800009; x=1780404809; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=acvmgNPS7kuyE45pt1syfWlXH/w85mKYitCTw47nvPc=; b=JengKdbXu9Z08NQuG7j+4Im2d+CFg4KgUCxtNL3bQUK3f4yz0pY9PGujXRdGI0DcPU FdKR5Tv7AGmC4t5xStfmAs292cSWQCKjBu2iSn/1L2AxnFn8R7MzJ6tCXpsjkimsRYUf jar9nx/GAgxAJNvEgPiymRwB/6TCHe09UA0b2Ckr0IzK4R4B4+4AXz8CFCHnYGEoV9vc FTbCxhJ5Jm7E16639Zl4aYe3mVYU8i4Wu6qFnX1VqD96O34SlY8RHVo3zvzww7pelTPH h1USGKQ3F4IkbB6lCuT9VbndX+Sxy39OGwdRrVi60O5Q9tdZG5s+ItIrTYHSG8aATdMv dvZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779800009; x=1780404809; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=acvmgNPS7kuyE45pt1syfWlXH/w85mKYitCTw47nvPc=; b=b9BjXptzHsxY9yj6BKfWFKavxWPkh7aSWTIQZqtBG/8A/BbkliIndsSEofxhzGfgeJ XbzmSIDk+B9D7rsHc3DukF+MqjCYtDQgyNCwDcJurZtriV/cUiKbajGnIsFg1QeBTN9i Rya1U/VH4ypnC5soIwL00MDT0JQzh+BuZ0XnxUNW8teG7Xvl5r3HmT08CB2U9NupdGOv 386KleUlrpQYSXWOnnF+9jL/AUz/qm6nLT21pS5KSbBQjn2pKtiVP8PD3cSsYDCDmvz4 +3GqyWM161Rp/tzpd0+DUqu73LjyDJl0A1/ukPVonN7i9x9BfgKSHVic1Ho0E5AfDPb1 /LDQ== X-Forwarded-Encrypted: i=1; AFNElJ+vwfxP/rypdr3PfRlUgVSfkwZUB7R9irtfJ3gX+BXo1WWniHlpyeWpmch6cOmtMjm6PAuE2Aq5YWJrhRk=@vger.kernel.org X-Gm-Message-State: AOJu0Ywx9x3wMsDa1QQHoaVffJELvlk0LPfL11vKzZ3cTc5wNf3fSgwr IEKrQIKS4f6TFM2nVMCKc14dyC1nNSzcY+TF9WIToW2nrqcNc/xOgw3GUBYyKXjAM6owqUksiyY JfLgzjQR1vCOuiA== X-Received: from wrme2.prod.google.com ([2002:adf:e382:0:b0:44e:14c6:8605]) (user=smostafa job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2411:b0:43d:775b:c9bd with SMTP id ffacd0b85a97d-45eb38a167amr31151264f8f.10.1779800008357; Tue, 26 May 2026 05:53:28 -0700 (PDT) Date: Tue, 26 May 2026 12:53:17 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260526125317.3672297-1-smostafa@google.com> Subject: [PATCH v3] irqchip/gic-v4: Don't advertise VLPIs if no ITS is probed From: Mostafa Saleh To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: maz@kernel.org, tglx@kernel.org, Mostafa Saleh Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When accidentally setting =E2=80=9Ckvm-arm.vgic_v4_enable=3D1=E2=80=9D on t= he wrong setup that has no MSI controller device tree node (it exists but not used) and GICv4, it caused a panic as =E2=80=9Cgic_domain=E2=80=9D is N= ULL and the kernel attempted to access its ops. Originally, I hit this on an older kernel, but was able to reproduce it on upstream with Qemu by hacking this unreasonable setup. [ 33.145536] Unable to handle kernel NULL pointer dereference at virtual = address 0000000000000028 [ 33.145658] Mem abort info: [ 33.145751] ESR =3D 0x0000000096000006 ... [ 33.154057] CPU: 1 UID: 0 PID: 295 Comm: lkvm-static Not tainted 7.1.0-r= c4-ge3f15ad3970e #5 PREEMPT [ 33.156922] Hardware name: linux,dummy-virt (DT) [ 33.158780] pstate: 81402005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE= =3D--) [ 33.160340] pc : __irq_domain_instantiate+0x1d4/0x578 [ 33.162602] lr : __irq_domain_instantiate+0x1cc/0x578 Set vLPI support to false at init time if the host has no ITS, so it propagates properly to kvm_vgic_global_state.has_gicv4. Suggested-by: Marc Zyngier Acked-by: Marc Zyngier Signed-off-by: Mostafa Saleh --- v3: Reword subject based on Marc feedback. v2: Fix the issue at construction as Marc suggested. --- drivers/irqchip/irq-gic-v3-its.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-= its.c index 291d7668cc8d..d02cb9c17c0b 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -5837,6 +5837,7 @@ int __init its_init(struct fwnode_handle *handle, str= uct rdists *rdists, its_acpi_probe(); =20 if (list_empty(&its_nodes)) { + rdists->has_vlpis =3D false; pr_warn("ITS: No ITS available, not enabling LPIs\n"); return -ENXIO; } --=20 2.54.0.746.g67dd491aae-goog