From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2492043B3CC; Tue, 11 Aug 2026 17:26:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786469216; cv=none; b=o+PtcWL/M4CbeM6swbrqBM8hk3xmQ/zaEaZlYzvomXBjQFeM+muiIDAB2CsXcLvyr1yvA22ML3YFyWrguW63xfUII5wHj+ChUbqM9nG2pvboDe+mXfQP+3w9Yqxzf7CevmXqqjTlrD59ka19HbdpuASg09Y2Kte+Po9XA2XX2+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786469216; c=relaxed/simple; bh=OXs8A6IEUdh5f1zdVIJ2OZ/6mklZnyy4NoWKugnXkWY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hYhbsuX++qfuwtQTku2Z32eBk5OZDm1jGfmUyfOdaZzK2+HwllsNfrsoQyC3RK590CQHFNpWkQgPBnpRybbUca9jkDzpFJNNVnE7bLJf1si3E6rY7VZ0ODyET/b1oV7T3GzEAiGpqCPzWIK/IonnIl69QRsjaS0eAZxi3AtX0DA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=de.ibm.com; spf=pass smtp.mailfrom=de.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=Vj+zN1Wl; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=de.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=de.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="Vj+zN1Wl" Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67BGVdd3964205; Tue, 11 Aug 2026 17:26:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=H4f/fg ixoM2QbL6oxJwzSa0M9zyxDv6IgZti4/G6ETg=; b=Vj+zN1WllyYvO+Io2FJvnT U2dvrvsSGDqfePdEuICE7YXM6BH0aFGTSNEH+PahkTi3Vmr1S/MnM0qjWAXQcIWx uRjx37Lb4Id/K6Zq7fTBm8o42MN7DQlzZOEXpK3Gf7Mt+j/kg9ZEYL+9UY/Bdlep Tf3GVtyM7VK2LNHifaKGQPNBQASZpwVgVsEXoE9CCo2SadaqNE5vT4y1i9QZ3Ib+ R/Jpila8ACqt9fhCeg5z55YhhQwMiilmS8W/x0NmyOmD6RpwU0dUZv5UAgPxKy/U x6vdjU4aWZVfp6IcnAcs63vwDASXMjyMrggMYIVZ0oO2qiiG9EnTo4Y87wJNVOtg == Received: from ppma11.dal12v.mail.ibm.com (db.9e.1632.ip4.static.sl-reverse.com [50.22.158.219]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4fwvnw5h0g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 Aug 2026 17:26:48 +0000 (GMT) Received: from pps.filterd (ppma11.dal12v.mail.ibm.com [127.0.0.1]) by ppma11.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 67BHQFo9000639; Tue, 11 Aug 2026 17:26:47 GMT Received: from smtprelay07.fra02v.mail.ibm.com ([9.218.2.229]) by ppma11.dal12v.mail.ibm.com (PPS) with ESMTPS id 4fxhfy1ru3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 Aug 2026 17:26:47 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (smtpav07.fra02v.mail.ibm.com [10.20.54.106]) by smtprelay07.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 67BHQh1V43778338 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 11 Aug 2026 17:26:44 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D511E2004D; Tue, 11 Aug 2026 17:26:43 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6A00620040; Tue, 11 Aug 2026 17:26:43 +0000 (GMT) Received: from [9.111.66.26] (unknown [9.111.66.26]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 11 Aug 2026 17:26:43 +0000 (GMT) Message-ID: Date: Tue, 11 Aug 2026 19:26:42 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 02/11] KVM: s390: Use srcu in kvm_arch_vcpu_unlocked_ioctl() To: Claudio Imbrenda , linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@kernel.org, seiden@linux.ibm.com, nrb@linux.ibm.com, schlameuss@linux.ibm.com, gra@linux.ibm.com References: <20260811155641.219777-1-imbrenda@linux.ibm.com> <20260811155641.219777-3-imbrenda@linux.ibm.com> Content-Language: en-US From: Christian Borntraeger In-Reply-To: <20260811155641.219777-3-imbrenda@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=RsP16imK c=1 sm=1 tr=0 ts=6a7b5b58 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VnNF1IyMAAAA:8 a=pG9oRMbJIAFsXvPiO7gA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: T-1EEVw0mK3I5Q9Wfg_ILvrBf4Naq0wb X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODExMDE0MiBTYWx0ZWRfXxG1YNmbiaOlc 3h7QunlA9Cx/iCw7jYKpSy9BKdxAkALYFOS/cN11OCEzmA61ujVwCyKWjZGM7w4w+tDJcG8Zpdn lXBqW8jOhxPTBEdU6b1H5NN1iwsOVCSYE9lD1046XUxZlUp4A+fe6AQFV00DScMIjgDK3nRpIlH 8Q8FQfd0Sx3BtGgN1rQVzfillQ8SUcsU0znl5beV7t68cY3M4mocL7tNyMh/YMZVSQjIfCgVhck CS+hwPvyz1G8DRVt8wkIhjgIY3h3K3tKMJyCfbp+vIKnewIlEZqIi7WAqs6EjjMJADMQZckWnew gx+/YkMIcpsR0Ko5CChUeyoa+BRcD7Rn93slMKjDH02QwCTGgiX0/lT3+xi9+34rkQaWttPrxcB CTWm/6qXS05x8Hxv5uWMNuFdU94hxJjmITOl9B3WMA51xbdL2lkHOT/3bcZrHzl9trzATXWhlKt KXoXECbNYr+8SKtadVg== X-Proofpoint-ORIG-GUID: T-1EEVw0mK3I5Q9Wfg_ILvrBf4Naq0wb X-Proofpoint-Spam-Info: AW1haW4tMjYwODExMDE0MiBTYWx0ZWRfX57mcyzfpMFaN J746tUAv+cEfPlnepSoePD31NAxP1GY2rQGtIFjM/cw6n9FZrGxos1mRnqCoq9ESrjumWzseZuN ryxd2HbAhSCSACZli4OvfjYTbIrQTcU= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-11_04,2026-08-10_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 suspectscore=0 clxscore=1015 malwarescore=0 phishscore=0 adultscore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608110142 Am 11.08.26 um 17:56 schrieb Claudio Imbrenda: > kvm_arch_vcpu_unlocked_ioctl() is called without further locks held, but > kvm_s390_inject_vcpu(), which is called from there, needs either the > kvm->srcu or the slots lock. > > Fix by taking the kvm->srcu in kvm_arch_vcpu_unlocked_ioctl(). > > Fixes: ba5c1e9b6cee ("KVM: s390: interrupt subsystem, cpu timer, waitpsw") > Signed-off-by: Claudio Imbrenda > --- > arch/s390/kvm/kvm-s390.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 518a69c55e85..02c5428ba239 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -5444,6 +5444,8 @@ long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl, > void __user *argp = (void __user *)arg; > int rc; > > + guard(srcu)(&vcpu->kvm->srcu); > + not a bug, but just having srcu around both inject would avoid having holding srcu on the argument usercopy. This is not forbidden but might just take a while when paging. scoped_guard(srcu)(&vcpu->kvm->srcu) rc = kvm_s390_inject_vcpu(vcpu, &s390irq); in any way, no objection to your variant and a real fix. Reviewed-by: Christian Borntraeger > switch (ioctl) { > case KVM_S390_IRQ: { > struct kvm_s390_irq s390irq;