From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5A0DE77188 for ; Tue, 14 Jan 2025 14:09:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tXhaj-0002wr-6O; Tue, 14 Jan 2025 09:08:28 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tXhaT-0002un-RL for qemu-devel@nongnu.org; Tue, 14 Jan 2025 09:08:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tXhaQ-0004VE-6g for qemu-devel@nongnu.org; Tue, 14 Jan 2025 09:08:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1736863684; 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=bq4gpVCuWRxilqmmULIZ76664+bjXBB++jnvhJ0jtQI=; b=X2k2fFi0cCaBB3Ylb9jD6fAujgsGZSLs2gjzGX6pUEhsp3HmSLxHVI9P3kHOllIUbZLX5C sqpXEwNlsUbI89U5LZjWcqammGooI+fErQDLqAOV4mdlVZ218u1ZqEbHINaHbGwYnvbLG2 fEN8h92AtFOA5cRzcyjzqSQc69fLKAM= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-587-LaTW-FBjOxKFT4-FeVKuiQ-1; Tue, 14 Jan 2025 09:08:03 -0500 X-MC-Unique: LaTW-FBjOxKFT4-FeVKuiQ-1 X-Mimecast-MFC-AGG-ID: LaTW-FBjOxKFT4-FeVKuiQ Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-385d51ba2f5so2772029f8f.2 for ; Tue, 14 Jan 2025 06:08:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736863682; x=1737468482; h=content-transfer-encoding:in-reply-to:organization: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=bq4gpVCuWRxilqmmULIZ76664+bjXBB++jnvhJ0jtQI=; b=iX28oyfX57FbS6/4XMgqWurZjikiOKdlRAFtVSfXgA2pX44TLq2zFclGqxof/C5uSU vYUPG2OZaaG4w+lFaOZA8/pmDipnboudlj7HXXOvgz3jeWjJ4amO+K9m+xsVLuqt+Zbf BXsUS2gm/694a4diIsV4Zf7f5PWAb1LuS6Ufz3/Fbs3lbAUz84qUwtO7+2MSThCCDSQk qlmxfQ8yrbzwrt7joEdD37zUvL5hQUgnq7a+BIXZts7n4K/5Zav8bHpajB+xYqi0PxVC oBE5VPHQPMQc43XU/YYXAkoegGs6dT6fFFFkJbW73MqFECZHYvfjvZsW8py034cgU9Po c6zQ== X-Forwarded-Encrypted: i=1; AJvYcCXB+0Ofw4S/l4x7kuqjxHurnFJ38Er3vosQ+72EiaN5KtwXsVj7YM1ju88j7OzqlvENPn7loepDzBE9@nongnu.org X-Gm-Message-State: AOJu0YwXm8H7IGG+vchivdW0ek7dRkXioL8EaHGBCkK/vTveu0WkEG5S 6gIuoPZx/RD+JBPhigVQbgOpzNGI+yYgFwDC/9tSnIZyTzN50mxieRqC9wUvX2pycgC8n+qu4O9 o/Z0QXOVWXdrcKk7gx+LO4gPqKskaAgTQeJtdQMVkMhGUJnCl9Mbu X-Gm-Gg: ASbGncsVBFBLLcEY35YXUpZ3gXn8VLn0iJ1UXYUJ6ayudwtBcV3Nmz9ZU4p2xC7oFG8 /il7dzAFOqeh5EDguFnsUfih7oqekm5imtQPmAzNDygwqDZfW/FoiUeV95+gnMm+m5v54Lxpz2B MyPlKgOXzISLCsK7hzWzblO5qWGBsS0QwUTvd+CeJxZPPwDaER3hTLYbQHPw/1NNIRqm2cKsZX9 UycooypEXaCGQC05w4a1t/ZqNvhMBBC+pHC78Wv8llYFIwAfwcCixdfn/VPbV5hnp+d+8VIqW6m CuZbPpOFzAea9FTjXu0EAEIHXpDvB3JeROF0PsdDU59f5Tz/t55aoGw8DzenJrgbs3x6h05iOxx rkJOx+ZA6 X-Received: by 2002:a05:6000:1847:b0:385:f060:b7fc with SMTP id ffacd0b85a97d-38a8730a60cmr23977246f8f.25.1736863681037; Tue, 14 Jan 2025 06:08:01 -0800 (PST) X-Google-Smtp-Source: AGHT+IH9xEqCaeRyof0lCkuoXA1eYcp8T3X9crUx1fpEgL6xbIoMiOieKC/KO01voLoAIbKzCrRj+Q== X-Received: by 2002:a05:6000:1847:b0:385:f060:b7fc with SMTP id ffacd0b85a97d-38a8730a60cmr23977164f8f.25.1736863680366; Tue, 14 Jan 2025 06:08:00 -0800 (PST) Received: from ?IPV6:2003:cb:c738:3100:8133:26cf:7877:94aa? (p200300cbc7383100813326cf787794aa.dip0.t-ipconnect.de. [2003:cb:c738:3100:8133:26cf:7877:94aa]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-38a8e383dedsm15188834f8f.35.2025.01.14.06.07.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Jan 2025 06:07:59 -0800 (PST) Message-ID: <83c251ff-60b9-4a31-b61f-466942bcf34e@redhat.com> Date: Tue, 14 Jan 2025 15:07:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 2/6] system/physmem: poisoned memory discard on reboot To: =?UTF-8?Q?=E2=80=9CWilliam_Roche?= , kvm@vger.kernel.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org Cc: peterx@redhat.com, pbonzini@redhat.com, richard.henderson@linaro.org, philmd@linaro.org, peter.maydell@linaro.org, mtosatti@redhat.com, imammedo@redhat.com, eduardo@habkost.net, marcel.apfelbaum@gmail.com, wangyanan55@huawei.com, zhao1.liu@intel.com, joao.m.martins@oracle.com References: <20250110211405.2284121-1-william.roche@oracle.com> <20250110211405.2284121-3-william.roche@oracle.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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20250110211405.2284121-3-william.roche@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.063, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 10.01.25 22:14, “William Roche wrote: > From: William Roche > > Repair poisoned memory location(s), calling ram_block_discard_range(): > punching a hole in the backend file when necessary and regenerating > a usable memory. > If the kernel doesn't support the madvise calls used by this function > and we are dealing with anonymous memory, fall back to remapping the > location(s). > > Signed-off-by: William Roche > --- > system/physmem.c | 57 ++++++++++++++++++++++++++++++------------------ > 1 file changed, 36 insertions(+), 21 deletions(-) > > diff --git a/system/physmem.c b/system/physmem.c > index 7a87548f99..ae1caa97d8 100644 > --- a/system/physmem.c > +++ b/system/physmem.c > @@ -2180,13 +2180,32 @@ void qemu_ram_free(RAMBlock *block) > } > > #ifndef _WIN32 > +/* Simply remap the given VM memory location from start to start+length */ > +static void qemu_ram_remap_mmap(RAMBlock *block, uint64_t start, size_t length) > +{ > + int flags, prot; > + void *area; > + void *host_startaddr = block->host + start; > + > + assert(block->fd < 0); > + flags = MAP_FIXED | MAP_ANONYMOUS; > + flags |= block->flags & RAM_SHARED ? MAP_SHARED : MAP_PRIVATE; > + flags |= block->flags & RAM_NORESERVE ? MAP_NORESERVE : 0; > + prot = PROT_READ; > + prot |= block->flags & RAM_READONLY ? 0 : PROT_WRITE; > + area = mmap(host_startaddr, length, prot, flags, -1, 0); > + if (area != host_startaddr) { > + error_report("Could not remap addr: " RAM_ADDR_FMT "@" RAM_ADDR_FMT "", > + length, start); > + exit(1); > + } Can we return an error and have a single error printed in the caller? return area != host_startaddr ? -errno : 0; > +} > + > void qemu_ram_remap(ram_addr_t addr) > { > RAMBlock *block; > ram_addr_t offset; > - int flags; > - void *area, *vaddr; > - int prot; > + void *vaddr; > size_t page_size; > > RAMBLOCK_FOREACH(block) { > @@ -2202,24 +2221,20 @@ void qemu_ram_remap(ram_addr_t addr) > } else if (xen_enabled()) { > abort(); > } else { > - flags = MAP_FIXED; > - flags |= block->flags & RAM_SHARED ? > - MAP_SHARED : MAP_PRIVATE; > - flags |= block->flags & RAM_NORESERVE ? MAP_NORESERVE : 0; > - prot = PROT_READ; > - prot |= block->flags & RAM_READONLY ? 0 : PROT_WRITE; > - if (block->fd >= 0) { > - area = mmap(vaddr, page_size, prot, flags, block->fd, > - offset + block->fd_offset); > - } else { > - flags |= MAP_ANONYMOUS; > - area = mmap(vaddr, page_size, prot, flags, -1, 0); > - } > - if (area != vaddr) { > - error_report("Could not remap addr: " > - RAM_ADDR_FMT "@" RAM_ADDR_FMT "", > - page_size, addr); > - exit(1); > + if (ram_block_discard_range(block, offset, page_size) != 0) { > + /* > + * Fall back to using mmap() only for anonymous mapping, > + * as if a backing file is associated we may not be able > + * to recover the memory in all cases. > + * So don't take the risk of using only mmap and fail now. > + */ > + if (block->fd >= 0) { > + error_report("Memory poison recovery failure addr: " > + RAM_ADDR_FMT "@" RAM_ADDR_FMT "", > + page_size, addr); See my error message proposal as reply to v4 patch #1: we should similarly just print rb->idstr, offset and page_size like ram_block_discard_range() does. ram_addr_t is weird and not helpful for users. To have a single error if (ram_block_discard_range(block, offset, page_size) != 0) { /* ... if (block->fd >= 0 || qemu_ram_remap_mmap(block, offset, page_size)) { error_report() ... // use proposal from my reply to v4 patch #1 exit(1); } } -- Cheers, David / dhildenb