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Mon, 23 Mar 2026 10:46:52 +0000 (GMT) Date: Mon, 23 Mar 2026 11:46:51 +0100 From: Steffen Eiden To: Claudio Imbrenda Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, nrb@linux.ibm.com, gra@linux.ibm.com, schlameuss@linux.ibm.com, hca@linux.ibm.com, david@kernel.org Subject: Re: [PATCH v2 2/8] KVM: s390: Remove non-atomic dat_crstep_xchg() Message-ID: <20260323104651.66303-B-seiden@linux.ibm.com> References: <20260320161542.202913-1-imbrenda@linux.ibm.com> <20260320161542.202913-3-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260320161542.202913-3-imbrenda@linux.ibm.com> X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=IqITsb/g c=1 sm=1 tr=0 ts=69c11a22 cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=kj9zAlcOel0A:10 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VnNF1IyMAAAA:8 a=4MpGQi6Peogm6hhcHeQA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzIzMDA4MCBTYWx0ZWRfX2swM5kjf35zM /xH+Iu6Fa7QmaedHAA6bw+U0OlhO8mea5yo4nXY3F0eIJvedxFC4Xs6kmMrWqdOSp5rA+Kf4gPt r/rvSI/jTwSnlvJFWF3B5xrIaD61LjC9vYVXsEKKVow5JI9R/3wpqg2Ir5zc5Nd/Dfod+gBvGEX tOs9D+ZDkb3MTn9f223bddSsmHrYQRoD90M4CPCROXXz7XlhqvEe5aR7prdboGD3TaO25oWIwjm Yus4J3rnMX8j7vRLmzpJJnD39PTy1zZes3QVp6dt1UOoP/dFybWJuE2XwYcRTzvYuuPVfTuHRYK avZhSHLbERKMp+kmr4eJ7ZxnlNvdi5rv1hP5nW4HJYYggyBlbVCrmCgfSzrIjw6YnUX2LL2uXNG Vry+kY91wmGcDDFVRywBg2c0ZLTkGnlgnTDbaTHepsiheqYST9Kl09FlDUvPUlKhU7SQO7PJ+QS Gh9KK0Wk+TD3Q8tWVUQ== X-Proofpoint-GUID: sDTGbwmDFKcdlS8FPjoHsLTUCi15508D X-Proofpoint-ORIG-GUID: sDTGbwmDFKcdlS8FPjoHsLTUCi15508D X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-23_03,2026-03-20_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 clxscore=1015 spamscore=0 impostorscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 priorityscore=1501 lowpriorityscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603230080 On Fri, Mar 20, 2026 at 05:15:36PM +0100, Claudio Imbrenda wrote: > In practice dat_crstep_xchg() is racy and hard to use correctly. Simply > remove it and replace its uses with dat_crstep_xchg_atomic(). > > This solves some actual races that lead to system hangs / crashes. > > Signed-off-by: Claudio Imbrenda > Fixes: 589071eaaa8f ("KVM: s390: KVM page table management functions: clear and replace") > Fixes: 94fd9b16cc67 ("KVM: s390: KVM page table management functions: lifecycle management") Reviewed-by: Steffen Eiden