From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 44FD1335068 for ; Fri, 17 Oct 2025 15:08:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760713683; cv=none; b=eACznhie1dTUxmUmuxx1sZMbBusAagx8VFH3YNkSwmDztNYh8p7mYZAqrPJIECJhV5PdXNmCMqGcLhll3qvXbBWz8qnvvzu7Wd53BI5HD9F7EqkgIypWAWPiiWU+i7HKlFbZkZTtqYkZ3/+NEr/Ge5x32jQn26FNJzuQ4ZBlhfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760713683; c=relaxed/simple; bh=8FnhvHU+cZJ6d29TK17dqd2oLil9K+bBITH2vkfujHU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QJoC8Aj7F8NaFaWX3ALhzDCT2OLuZGXZnp7LLlxJPvHPhN900N16U3+K3mI79Ke0RjMDSbeVr2doQrOoTY1XJV6zIlOQVY+UBtMa9YSo6QucZgejIBCykLm9BE/r5Kp25ef6bEdo4r4VzEycMLsmZGRawWQFhPnikzYo3ffRBSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=BCJS0RwE; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BCJS0RwE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1760713680; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=J9X1BIc43NGsZkRZORFu1zjHPZ7Rg9eKPpWeWjUt83E=; b=BCJS0RwERZqTTxp6td9O4MooXheoFNotNxISPNUJMFphzaxmr3wTNjIt0GeRuntyK9wpLC vcg5/LQjbissnh15ziue/r5U84xFd5MTkKvvonYt1bS8QVNaOQonI7AgmSK9kx7KYu06Pz 7rqz1XtuqwKQLim/mUSS+atHSzXzHu4= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-631-5cvVZ8SzPI-6dJ4QbSwIQw-1; Fri, 17 Oct 2025 11:07:58 -0400 X-MC-Unique: 5cvVZ8SzPI-6dJ4QbSwIQw-1 X-Mimecast-MFC-AGG-ID: 5cvVZ8SzPI-6dJ4QbSwIQw_1760713676 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-471193dacffso5946605e9.2 for ; Fri, 17 Oct 2025 08:07:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760713676; x=1761318476; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=J9X1BIc43NGsZkRZORFu1zjHPZ7Rg9eKPpWeWjUt83E=; b=gYXAO7R4vL79XFRtYD3JnuZPuIuU/3eoPHOLqCs6cDvIofMGCbzfh+8M+o4BLDnrI3 zgMrkJAfcyb0Ip4R30IQvKwkQzCuPH4xAdrRrZHEPjvZAzIzEjxkU+NgP/48zUN+D4l8 hBpd62ks798+OzT77bVBearS50Cf8AL0yYbm3gE/Y3BufhDhtP8A84TxBqf7CMCQsR+c lZ28Q0qrKI349ZHQG+Z5I7VJySqUm0AnXEkcKNd6WmXEKiNY/WNvaqwDs7O1IVdHJScF Nt2WlPLb4MogxC6yytm6bLKgMWVdFuz0lR4/NeyVoE3dTaAF9z2X+2J0KYW4ASLVaGaE hTSw== X-Forwarded-Encrypted: i=1; AJvYcCVE54R63dB2gkrk7TIesaXUFdBCGWK6HWDYLP/yaK2AOUkuPN4JNL+OnBxGNhH/CHfN248IuwAzJCSn@vger.kernel.org X-Gm-Message-State: AOJu0YwsdhVwhWKt+J9UiQQS2U25EoM8wbXFvV+D7YqI7y3/hx1cM1QX x99lyVX4C92QBwuVkjwfG4FsCgdr65ys47e3qWb+OnOpm/pMB8nr+FXYJ5ghL0dT5Xu0is4bX/F AgsujLT51/fqYfEL412YQm6knVtHZSNfiDvNsfzwWPAS5RvG0R89X6IxEK6SCFL0= X-Gm-Gg: ASbGncsQXf9WWOttZBk27WbVybHgNHrs9O3l1+PkXCfh5ISfBOuoyNkw1NytRnNQsHx lr5H+ba4pK/S9cK76uFIy2Pk+ydC8UZXYD5khm7cJyid6JL2fGalvC5wpF0CxdMkN2IKtOrgfKq /cvXAc2OlFmdmRnn+L2DTwRQQwwoPT0CSrqlArgfv96oaBxEIqRRSMPFsD+MM9aXea3m4z8p3o7 VlQeBfHO6YUTXYm/4oUDWJoZbM/1s1EpuZELfINfukQ7ewPMUhYQnWiLio0JCXl99IIHpzLC2hK erjruGFlcCMfF+EswG7Dc4bIpAVzLqNHdnvz3X4mEQeTDcTE3HkC2DagahrE8XwXs1P6rAmydYp rOW/g0j92GWulIQRKP5gI5qF+BlYxxkrAGNjedwpk2BYP784GB9ofFYc+vw18Yxt6Yku4xGH5td ADLO9nrghsZNAgP4S4+CB4uJod/MI= X-Received: by 2002:a05:600c:818f:b0:46f:b42e:e361 with SMTP id 5b1f17b1804b1-47117931c89mr25044715e9.41.1760713675696; Fri, 17 Oct 2025 08:07:55 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEeV20qcvkEmPA1bp02PI7vEzOGbT0hRxWJer5oIgjdZd36IQslHVl6fowxmxv1EbzRsULEwQ== X-Received: by 2002:a05:600c:818f:b0:46f:b42e:e361 with SMTP id 5b1f17b1804b1-47117931c89mr25044545e9.41.1760713675293; Fri, 17 Oct 2025 08:07:55 -0700 (PDT) Received: from ?IPV6:2003:d8:2f0c:c200:fa4a:c4ff:1b32:21ce? (p200300d82f0cc200fa4ac4ff1b3221ce.dip0.t-ipconnect.de. [2003:d8:2f0c:c200:fa4a:c4ff:1b32:21ce]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47114428dbfsm85439735e9.5.2025.10.17.08.07.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 17 Oct 2025 08:07:54 -0700 (PDT) Message-ID: <8c778cd0-5608-4852-9840-4d98828d7b33@redhat.com> Date: Fri, 17 Oct 2025 17:07:53 +0200 Precedence: bulk X-Mailing-List: linux-next@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: linux-next: KVM/s390x regression To: Christian Borntraeger , balbirs@nvidia.com Cc: Liam.Howlett@oracle.com, airlied@gmail.com, akpm@linux-foundation.org, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, dakr@kernel.org, dev.jain@arm.com, dri-devel@lists.freedesktop.org, francois.dugast@intel.com, gourry@gourry.net, joshua.hahnjy@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, lyude@redhat.com, matthew.brost@intel.com, mpenttil@redhat.com, npache@redhat.com, osalvador@suse.de, rakie.kim@sk.com, rcampbell@nvidia.com, ryan.roberts@arm.com, simona@ffwll.ch, ying.huang@linux.alibaba.com, ziy@nvidia.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-next@vger.kernel.org References: <20251001065707.920170-4-balbirs@nvidia.com> <20251017144924.10034-1-borntraeger@linux.ibm.com> <9beff9d6-47c7-4a65-b320-43efd1e12687@redhat.com> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 17.10.25 17:01, Christian Borntraeger wrote: > Am 17.10.25 um 16:54 schrieb David Hildenbrand: >> On 17.10.25 16:49, Christian Borntraeger wrote: >>> This patch triggers a regression for s390x kvm as qemu guests can no longer start >>> >>> error: kvm run failed Cannot allocate memory >>> PSW=mask 0000000180000000 addr 000000007fd00600 >>> R00=0000000000000000 R01=0000000000000000 R02=0000000000000000 R03=0000000000000000 >>> R04=0000000000000000 R05=0000000000000000 R06=0000000000000000 R07=0000000000000000 >>> R08=0000000000000000 R09=0000000000000000 R10=0000000000000000 R11=0000000000000000 >>> R12=0000000000000000 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000 >>> C00=00000000000000e0 C01=0000000000000000 C02=0000000000000000 C03=0000000000000000 >>> C04=0000000000000000 C05=0000000000000000 C06=0000000000000000 C07=0000000000000000 >>> C08=0000000000000000 C09=0000000000000000 C10=0000000000000000 C11=0000000000000000 >>> C12=0000000000000000 C13=0000000000000000 C14=00000000c2000000 C15=0000000000000000 >>> >>> KVM on s390x does not use THP so far, will investigate. Does anyone have a quick idea? >> >> Only when running KVM guests and apart from that everything else seems to be fine? > > We have other weirdness in linux-next but in different areas. Could that somehow be > related to use disabling THP for the kvm address space? Not sure ... it's a bit weird. I mean, when KVM disables THPs we essentially just remap everything to be mapped by PTEs. So there shouldn't be any PMDs in that whole process. Remapping a file THP (shmem) implies zapping the THP completely. I assume in your kernel config has CONFIG_ZONE_DEVICE and CONFIG_ARCH_ENABLE_THP_MIGRATION set, right? I'd rule out copy_huge_pmd(), zap_huge_pmd() a well. What happens if you revert the change in mm/pgtable-generic.c? But the whole -ENOMEM error is a weird symptom. -- Cheers David / dhildenb