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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 AAE68C36010 for ; Fri, 4 Apr 2025 07:52:55 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.937915.1338769 (Exim 4.92) (envelope-from ) id 1u0br5-0005Eu-7j; Fri, 04 Apr 2025 07:52:47 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 937915.1338769; Fri, 04 Apr 2025 07:52:47 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u0br5-0005En-2p; Fri, 04 Apr 2025 07:52:47 +0000 Received: by outflank-mailman (input) for mailman id 937915; Fri, 04 Apr 2025 07:52:46 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u0br4-0005Eg-HT for xen-devel@lists.xenproject.org; Fri, 04 Apr 2025 07:52:46 +0000 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [2a00:1450:4864:20::32d]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id cac06101-1129-11f0-9ffb-bf95429c2676; Fri, 04 Apr 2025 09:52:44 +0200 (CEST) Received: by mail-wm1-x32d.google.com with SMTP id 5b1f17b1804b1-43cf034d4abso18325235e9.3 for ; Fri, 04 Apr 2025 00:52:44 -0700 (PDT) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43ec34ae0c5sm38675885e9.15.2025.04.04.00.52.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 04 Apr 2025 00:52:43 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: cac06101-1129-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1743753164; x=1744357964; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=QcY3//PJ1WPeXM90v4eyQhxXTyvAF1pYYiS2pveoGuI=; b=JQykXNeLa8KP3da7Feeu4AipzJook0AAgDEBDRZUfZq/p1BHPKfouW1XpZhhXVBU6A EFBTjTRFAE7SiLnS+zWL+nMOKXHdo5+n7sVUHf5S9cbtzesfbr20SVmezKZddGaCcdTQ VMiEmkbI2Jca84t1ZBXkOPHG9IhZxb980nT2FBE/lhV1dVh49lWPp/LBsV/lkrq+Sp4G VQDZEzCTre0nHRWx0SO0gwns1htu187qAve3cb+SwvsZuT+jvajvP6AqKZVv1FBfyp8P W1fBN3w38vFCjRYa1iHNUXDDyYXU+1lfKoIGDHSbAUh+yjo0UZ+O55RuvQmso4h8FeZ0 G77w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743753164; x=1744357964; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language: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=QcY3//PJ1WPeXM90v4eyQhxXTyvAF1pYYiS2pveoGuI=; b=DKXi6jD5JQMhzlHxgMqz6pbD3myP3CfyczIP10Gd5/kXT5sGsZTb7ytWSlUJdMVUst PQSz6X0lVfdStnnsOUX7872iUV0RkCAZQHwuBJ//GTY1YRtHzu5a0PUeMKDOdBLl64Bk 2QunzAnsJkNRcJv3qrUnYsbWQWvK5yx7+FC0b6eZt8LJOMtNmIA+IX5Go6k8aEs8ofpd gcyvsTCtOrtU3RUjQo7CFK/qErm3KCcYNmLD61McnCwM4dnDdUVyUfRM1DPNMGPZt4+M +WhpY/E6/ZEkE4IVGF3eROIqkL3Iwc8wQE9ewWxrbSR5jI6jd9BGcaJ9IeTqhbuF9/ZG y3gQ== X-Forwarded-Encrypted: i=1; AJvYcCVJtVLgVLLEFkQrDnGVMcg+cIdfQSoo/sRTKzlMMgWtPWo69EF98JPQuD7XvwZzb42PTjv4Pr4dHAE=@lists.xenproject.org X-Gm-Message-State: AOJu0Yy/8TNIzkaA3RrI8vRA3wXuJFdRyVWrcMzaMk7wStss6EDPo1eP D/R8Yy1SlgWmjKySkWonihCeW2j5hUegZn7NZeUGi8jhzpuxEQvYiFzett1xng== X-Gm-Gg: ASbGncullTTnW2+UfQNKiFYm7Sk2IwBiLPHFySNuJrwF3EfapMX8de6nIBjgotBYz/O PQXANzrBsUq1xw43wwzGZE5JzNrCaxYXGM/8o4Md0JAreFEjOFqxpenwEOVzzZQtLxNzbrrQ4BI NkZLELxuhHs3PHexwfBGNOe2dsBPVP9RKtYbwQO0NNbZ7oW2FNubaCZ+nZaKZ0+Z/kHV20sgOA0 M/m9+OUtA1+nebE9jCyR1xQKLXLXD6entlsgU5k9paqTvCumcSOP6XKrJoSG8Xr7FRGKt0O6hc1 3JOqwlVGz/KukObvo4CVnqK/qoZyKf0mnBYx/IF/PuJYr/O3SzW+WpR4bjjhAeChtSSQClqHqmj o+WNvKkrLkMw7Vtj9fXzILWFiRFg58Q== X-Google-Smtp-Source: AGHT+IHTpaJG5j78XKVkstL5sycTbjF6h8kOA9ndCtqnv5LEs0Ckwg6fosWe1MWeqtW05BZxV/+aQw== X-Received: by 2002:a05:600c:1d88:b0:43d:7a:471f with SMTP id 5b1f17b1804b1-43ecf8ece15mr21202555e9.18.1743753163675; Fri, 04 Apr 2025 00:52:43 -0700 (PDT) Message-ID: <14ac3e72-d21d-4b45-a434-d123152c0113@suse.com> Date: Fri, 4 Apr 2025 09:52:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] xen/riscv: Increase XEN_VIRT_SIZE To: Oleksii Kurochko Cc: Alistair Francis , Bob Eshleman , Connor Davis , Andrew Cooper , Anthony PERARD , Michal Orzel , Julien Grall , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Stefano Stabellini , xen-devel@lists.xenproject.org References: <54ebdcb7-071f-411f-803a-930dc330a497@suse.com> <32264ccb-e566-41e0-973f-5bc7d874f970@gmail.com> <9d7e1553-3af8-4fc3-a400-8714d9b68411@suse.com> <30d8e316-aff5-498a-b2bd-448e0b2518ae@gmail.com> <3c2127ec-63fb-457b-8229-fc8a2b9fbf00@suse.com> Content-Language: en-US From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 04.04.2025 09:31, Oleksii Kurochko wrote: > > On 4/4/25 8:56 AM, Jan Beulich wrote: >> On 03.04.2025 18:20, Oleksii Kurochko wrote: >>> On 4/1/25 6:04 PM, Jan Beulich wrote: >>>> On 01.04.2025 17:58, Oleksii Kurochko wrote: >>>>> On 3/31/25 6:14 PM, Jan Beulich wrote: >>>>>> On 31.03.2025 17:20, Oleksii Kurochko wrote: >>>>>>> + _AC(XEN_VIRT_START, UL) >> vpn1_shift; >>>>>>> + const unsigned long xen_virt_end_vpn = >>>>>>> + xen_virt_starn_vpn + ((XEN_VIRT_SIZE >> vpn1_shift) - 1); >>>>>>> + >>>>>>> if ((va >= DIRECTMAP_VIRT_START) && >>>>>>> (va <= DIRECTMAP_VIRT_END)) >>>>>>> return directmapoff_to_maddr(va - directmap_virt_start); >>>>>>> >>>>>>> - BUILD_BUG_ON(XEN_VIRT_SIZE != MB(2)); >>>>>>> - ASSERT((va >> (PAGETABLE_ORDER + PAGE_SHIFT)) == >>>>>>> - (_AC(XEN_VIRT_START, UL) >> (PAGETABLE_ORDER + PAGE_SHIFT))); >>>>>>> + BUILD_BUG_ON(XEN_VIRT_SIZE != MB(8)); >>>>>> Is it necessary to be != ? Won't > suffice? >>>>> It could be just > MB(2). Or perphaps >=. >>>>> = would make the build fail, wouldn't it? >>> I just realized that BUILD_BUG_ON() condition is compared to zero so actually everything what >>> will make the condition true will cause a build fail as inside it used !(condition). >> ??? > > |BUILD_BUG_ON()| forces a compilation error if the given condition is true. Therefore, if the condition > |XEN_VIRT_SIZE != MB(2)| is changed to|XEN_VIRT_SIZE > MB(2)|, the condition will always evaluate to true > (assuming|XEN_VIRT_SIZE| is greater than 2 MB), which will result in a compilation error. Well, it was you who used MB(2) in a reply, when previously talk was of MB(8), and that to grow to MB(16). The BUILD_BUG_ON() is - aiui - about you having set aside enough page table space. Quite possibly the need for this BUILD_BUG_ON() then disappears altogether when XEN_VIRT_SIZE is properly taken into account for the number-of-page-tables calculation. In no event do I see why the MB(2) boundary would be relevant for anything going forward. Jan