From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from va-1-115.ptr.blmpb.com (va-1-115.ptr.blmpb.com [209.127.230.115]) (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 E90CC3932CC for ; Mon, 13 Apr 2026 07:23:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.127.230.115 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776065032; cv=none; b=jsmno3Obiu6b2RWaFuKS2I2pkGlF0Wrw+jObNMlttit7ZYYMzgjTeNKGdT6m1ux6SxnN6djgMX2nDKvPnBr/BqFz3yKC5bxKiuSRudtUhbyyysHjQMXtZfRtqed7yWN/H4d38/LCJSDH4JGLWdi2MtCrM3NB4pfsdV5X5r2JK7w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776065032; c=relaxed/simple; bh=0zZfHOOWFWw4+HC5cgC+7XSH/R0wjD1a138VWny+jHA=; h=To:Subject:Date:Message-Id:Cc:From:Mime-Version:Content-Type; b=i3ePAETychAXV4GaJHzpB/iAM5Y59iWvoIIQpzprpo2eLV+1cX47RtkCI57aKM7YmVJnLvzAt7Wr8YpXIMF5PsFOmxhr0s57f4nm6KtJtZlrkSsouFZahGpCunoHvIFWpzCpFSNk1lJ+NEmkpyv3ufYtg1yqYaRr4vIcIOg0ksI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=ULGSXsZe; arc=none smtp.client-ip=209.127.230.115 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="ULGSXsZe" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1776065019; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=jP3ET5/NQK/iIZIBTGcvS9TsKHd5N6bf39hH0vZuuvw=; b=ULGSXsZeW6xQzUEpP1k8aHAryB5PWPQ6p4GKAaCNNrruM5qNpvWkFPfUN6CXUyRx89mU/R MCD0nNXzCgv8ejMYtcVv5TiLE+wYLTVmneMZgytg2Qhz/B7T/SEcXX0xNWln+SGe5I3Abx 3UTRv1Fv+Wn7AFYT9uKk9lb9jeEeeaiM9MnqMOS2twn4Uzbu+RhUN43QiqXpR/azdKOuff 9C82I28t0D0WB07YCyWpjoS9d9EfBFitRgLBqZyW4xiqaU4FMViRtW4BiJFBIs8G6l0xGr IQE2Kct7dkt1WgqQYkK1sqkV55mS4oAW6KvTLGxNUJV9CRAwlxX/t/cbRpEsEg== X-Original-From: Jinhui Guo Content-Transfer-Encoding: 7bit To: "Michael S. Tsirkin" , "Jason Wang" , "Xuan Zhuo" , =?utf-8?q?Eugenio_P=C3=A9rez?= , "Jiri Pirko" Subject: [PATCH] virtio_pci_modern: Use GFP_ATOMIC with spin_lock_irqsave held in virtqueue_exec_admin_cmd() Date: Mon, 13 Apr 2026 15:22:49 +0800 Message-Id: <20260413072249.30433-1-guojinhui.liam@bytedance.com> X-Mailer: git-send-email 2.17.1 X-Lms-Return-Path: Cc: , , "Jinhui Guo" , From: "Jinhui Guo" Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 virtqueue_exec_admin_cmd() holds admin_vq->lock with spin_lock_irqsave(), which disables interrupts. Using GFP_KERNEL inside this critical section is unsafe because kmalloc() may sleep, leading to potential deadlocks or scheduling violations. Switch to GFP_ATOMIC to ensure the allocation is non-blocking. Fixes: 4c3b54af907e ("virtio_pci_modern: use completion instead of busy loop to wait on admin cmd result") Cc: stable@vger.kernel.org Signed-off-by: Jinhui Guo --- drivers/virtio/virtio_pci_modern.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index 6d8ae2a6a8ca..db8e4f88b749 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -101,7 +101,7 @@ static int virtqueue_exec_admin_cmd(struct virtio_pci_admin_vq *admin_vq, return -EIO; spin_lock_irqsave(&admin_vq->lock, flags); - ret = virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_KERNEL); + ret = virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); if (ret < 0) { if (ret == -ENOSPC) { spin_unlock_irqrestore(&admin_vq->lock, flags); -- 2.20.1