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 ED5F0C3601A for ; Thu, 3 Apr 2025 16:20:57 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.936932.1338046 (Exim 4.92) (envelope-from ) id 1u0NJ4-0000tM-KW; Thu, 03 Apr 2025 16:20:42 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 936932.1338046; Thu, 03 Apr 2025 16:20:42 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u0NJ4-0000tF-HF; Thu, 03 Apr 2025 16:20:42 +0000 Received: by outflank-mailman (input) for mailman id 936932; Thu, 03 Apr 2025 16:20:41 +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 1u0NJ3-0000mp-7U for xen-devel@lists.xenproject.org; Thu, 03 Apr 2025 16:20:41 +0000 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [2a00:1450:4864:20::52d]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 92fb40ca-10a7-11f0-9ffb-bf95429c2676; Thu, 03 Apr 2025 18:20:36 +0200 (CEST) Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-5ec9d24acfbso4055952a12.0 for ; Thu, 03 Apr 2025 09:20:36 -0700 (PDT) Received: from [192.168.1.5] (user-109-243-64-225.play-internet.pl. [109.243.64.225]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ac7c01c20f1sm116318266b.177.2025.04.03.09.20.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Apr 2025 09:20:34 -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: 92fb40ca-10a7-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1743697235; x=1744302035; darn=lists.xenproject.org; h=in-reply-to:from:content-language:references:cc:to:subject :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=+z11WJnJOatLnkEUyyYOo4mxIOabotJnqQF68ndEaj0=; b=KMwJXBnF6+opZ2NYzTu4ZOTHAQhzmhfvA8DqvwFh5IsYnzbSdKN/7pCumkkS27F7i9 lbyOeif7hUIi//a3Hk6EpoBb8H0lViORxJNnXtX6J5dmT2xA4CviZiY3dx0EoY7+AcPz gWCbhINEtkKYexnRi0qy62ZCrwr+QJXFvfZsBsi2hvwi5S4vZU129oki0AksypIlbIsP GagQCHkTUSOeJB9hFTk2fV0o6zt9XbjxxrdDMY4M0lj2yppyH+xGI2lS/YmjTdVJH81/ 54UnqgGi/Ufe9xPizgw8b07M8FO0MfMky5W1f3qinT4irsVf65qKaDiVJSCuAV/STt3L ueog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743697235; x=1744302035; h=in-reply-to: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=+z11WJnJOatLnkEUyyYOo4mxIOabotJnqQF68ndEaj0=; b=fs7vgIR6L/i7ZqHqN5uYFrXyLOaXwJDtF35e/DuVVRHrdXbSu1aHNLqIDn5EFz6UFG i1mVIl9Ojt37vl0HOqZHTmvdj4LKxq5XesLqAkmQGA1+/NqsYuZXfE3wCM3KznbrDFJW +wczY7KoqeiFwxDIkwv3pAoIpfqkqlXOFW6c2xdtqVLi9GJrbj0T5NnK53ubpFJd/l21 ZkxKJ6xA0jSgaGW7/dj255DGhbVCnkJrcA3glu9b6/9Ea/KbsAdeVQWiATE2yJW3OrcL bu/ictJet+h7kZ2UrA5FfdW+oM2sQQQqYhIgqTJRfLHYcc02QgTEnsfw+KDZTcv/khA4 7bWg== X-Forwarded-Encrypted: i=1; AJvYcCVdLSu1Vj3JxBoPjkYzLKKYgI8mzFZNH8ROEDbl22EzwI0+A4NdDMbRSqsDFpCbinH1jKx6uepiJXQ=@lists.xenproject.org X-Gm-Message-State: AOJu0YydEZGC0TuA0ugFJlcvAdAS0FmdiLaA2n1oGl8wWr9038LYLWHe tlkxkxpvuxPbb6s7OwrwEyG3nBAzIPu/g/KMC55PRTXCVBySdB7B X-Gm-Gg: ASbGncuT2mpCzqFJW7yZoEyj/Q/rZ4PC+Q7i3mZ+gbKuCeCttCl4OuLYoS6k+O5iCeX YwN7Wsl1VTFx+BMhdiofHMosEuQsxUmrgm2jf1FDGFv6YGslSONpCeNVdd/dv0u556EK7DXifEn qv2ED6dSWe44+SdZtFBdQEhqBfAVMjU4zSIfbbnB7otyDlXKPYJbeMAOFbpPCFtM0XKc1G+03fz WS+x38JrtDFQaanKKTsK8NO3Qm2QDjtGe/m1Q039r+a/nFQPaFa/eu0kEMrra9kVO2RV8t8nk59 zRh4X6sUoTDh0Xf2zVmR2nUwe+ZfusnfGNveqGxVZF4N9YCrmBRcrG6DLfaM7XnP0FmwyzK9RoU tyyRL/tZfFBUeI+ew5zsW X-Google-Smtp-Source: AGHT+IF7xGhlOmChENg1Hao6eTILkSUrWK5mMyvMTJTgCdRq0Jg3AznDwMETJms8aIjKRDlD006R9w== X-Received: by 2002:a17:907:3f1a:b0:ac3:ef17:f6f0 with SMTP id a640c23a62f3a-ac7b6b49876mr352169066b.5.1743697235248; Thu, 03 Apr 2025 09:20:35 -0700 (PDT) Content-Type: multipart/alternative; boundary="------------UokBImlYq4ZEzn8WCJSlYpx7" Message-ID: <30d8e316-aff5-498a-b2bd-448e0b2518ae@gmail.com> Date: Thu, 3 Apr 2025 18:20:33 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] xen/riscv: Increase XEN_VIRT_SIZE To: Jan Beulich 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> Content-Language: en-US From: Oleksii Kurochko In-Reply-To: <9d7e1553-3af8-4fc3-a400-8714d9b68411@suse.com> This is a multi-part message in MIME format. --------------UokBImlYq4ZEzn8WCJSlYpx7 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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). So it seems like we have to check for XEN_VIRT_SIZE != MB(16) and change each time when XEN_VIRT_SIZE is increased. ~ Oleksii --------------UokBImlYq4ZEzn8WCJSlYpx7 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit


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).

So it seems like we have to check for XEN_VIRT_SIZE != MB(16) and change each time when XEN_VIRT_SIZE
is increased.

~ Oleksii
--------------UokBImlYq4ZEzn8WCJSlYpx7--