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 94F13C46CD2 for ; Tue, 9 Jan 2024 15:04:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rNDdK-0006Oc-8I; Tue, 09 Jan 2024 10:03:14 -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 1rNDdH-0006NC-Lp for qemu-devel@nongnu.org; Tue, 09 Jan 2024 10:03:13 -0500 Received: from mail-wm1-x334.google.com ([2a00:1450:4864:20::334]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rNDdF-0000nh-31 for qemu-devel@nongnu.org; Tue, 09 Jan 2024 10:03:10 -0500 Received: by mail-wm1-x334.google.com with SMTP id 5b1f17b1804b1-40e4f692d06so4515945e9.1 for ; Tue, 09 Jan 2024 07:03:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1704812587; x=1705417387; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:user-agent :references:in-reply-to:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=bMCIZkhJJvpb7DyTODzhTGE3JWll8OFtAiYyBvwGmik=; b=b+Aes26zrtE8ilgFD4/Jeor5fulinVwt0HffC7712j7VWHV1Uw+qJjCqpKsFDKkZ2r IO4/BlbqQEzIUUNr5C8/cjj1L9W27NdQjWI+mtyA0XbgN+Uqr3t9NMMlCY9DvKdtzL3l iMEqwWFpvcV/WuzFS5/V16PKCAAjZvA6XaW5HGFojqaJpZpQR84KwBWlyWomXYI4x2hb cXb/Wm+8EgHvnp4mWQUN2mQvry9hnuAxVTV0wPAUTPHWpNqOLNmPDx1rU7zOia4CfaYL i7W4Mmfsq8v790mhddY6HEf/ioebYVGnTGGCniA44lwkWamPst3yIIW87h/air+c5X+K LJvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704812587; x=1705417387; h=content-transfer-encoding:mime-version:message-id:date:user-agent :references:in-reply-to:subject:cc:to:from:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=bMCIZkhJJvpb7DyTODzhTGE3JWll8OFtAiYyBvwGmik=; b=CjgDtTMtzbLYQsFE0BLZ4kAf8g0Aimd/aBGHhYZUTzQaSh4VfTRI9DOnD7p+2vnoyn /SgRroCUy3HSXa9UAQPNAZCwllafiHFKbsMSXjsG0tuOsTipZI0eqOU1LZTNzebkGI49 FrcxeH7+2+nS/gk9Zl8lZjQM/pICa91BNqWn3Ea/YKJdRQ7h+elJIH5uI3vpStUbtNer cV5TAW5gsQKVqz5JhTkt9xN/uPNi3VhYgizFMCDOiDzrffyvCGHh5ejwSzgj7xv52m14 j9RRnM64mqRIUQ/hHI0E+4DjGdjPTX2AQ+wVaAJ0CKwWuf9apbbMLJDJr7axfOi3udps tAZA== X-Gm-Message-State: AOJu0Yy1CodjE1tg+2BRBCw4belksYwigWL+Ws9NrRc2+G7pc1EeUzAa FtELB2Ih8XtU6dRUzkDknx4zpN5J3GWtUA== X-Google-Smtp-Source: AGHT+IGLsy7eKNgCuG4w7hafs0T2A1r/89JKgtzIFTDqXG9YXodo/+FY1pz3y/RmNSPdA2A7hy/b5Q== X-Received: by 2002:a7b:cc0d:0:b0:40d:785e:34a8 with SMTP id f13-20020a7bcc0d000000b0040d785e34a8mr498924wmh.65.1704812586952; Tue, 09 Jan 2024 07:03:06 -0800 (PST) Received: from draig.lan ([85.9.250.243]) by smtp.gmail.com with ESMTPSA id f9-20020a05600c154900b0040e4ca7fcb4sm3795922wmg.37.2024.01.09.07.03.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jan 2024 07:03:06 -0800 (PST) Received: from draig (localhost [IPv6:::1]) by draig.lan (Postfix) with ESMTP id 2A0C45F785; Tue, 9 Jan 2024 15:03:06 +0000 (GMT) From: =?utf-8?Q?Alex_Benn=C3=A9e?= To: Peter Maydell Cc: Michael Tokarev , QEMU Developers Subject: Re: virtio-pci in qemu-system-arm is broken in 8.2 In-Reply-To: (Peter Maydell's message of "Tue, 9 Jan 2024 14:31:45 +0000") References: <90d7351c-2680-4ab6-95ee-5dac4e3f21c5@tls.msk.ru> <560c9f56-f0d8-4def-863a-63ba4226209e@tls.msk.ru> <87bk9uh9jd.fsf@draig.linaro.org> User-Agent: mu4e 1.11.27; emacs 29.1 Date: Tue, 09 Jan 2024 15:03:06 +0000 Message-ID: <875y02h7md.fsf@draig.linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::334; envelope-from=alex.bennee@linaro.org; helo=mail-wm1-x334.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 Peter Maydell writes: > On Tue, 9 Jan 2024 at 14:21, Alex Benn=C3=A9e wr= ote: >> >> Peter Maydell writes: >> >> > On Tue, 9 Jan 2024 at 11:33, Peter Maydell = wrote: >> >> On Mon, 8 Jan 2024 at 17:38, Michael Tokarev wrote: >> >> > Speaking of config. This is standard debian config, I'm attaching o= ne >> >> > to this email. It can be found in the package, eg >> >> > http://deb.debian.org/debian/pool/main/l/linux/linux-image-6.6.9-ar= mmp_6.6.9-1_armhf.deb >> >> > in /boot/config-$(uname -r). >> >> >> >> It does seem to be a config thing -- on a plain upstream >> >> v6.6.9 my config works and that debian default one does >> >> not. Now to try to identify which particular config >> >> difference is at fault. (It's not the CONFIG_VMSPLIT one, >> >> I just tried that.) >> > >> > Oh, your kernel isn't an LPAE one (i.e. CONFIG_LPAE is not >> > set). That will obviously never be able to access registers >> > above the 4GB mark (though the kernel's error message in this >> > situation is a bit unhelpful and could perhaps be improved). >> > If I set CONFIG_LPAE on the non-working config it starts working. >> > >> > I think then the answer is: >> > * if you want to use the (default) highmem setup, use an LPAE kernel >> > * if you want to use a non-LPAE kernel, tell QEMU to avoid >> > highmem using '-machine virt,highmem=3Doff' >> >> Could we expand the "highmem" description in >> https://www.qemu.org/docs/master/system/arm/virt.html to make it >> clearer. I'm sure this isn't the first time there have been 32bit >> difficulties with non-LPAE kernels? > > Sure. We could make the highmem property description read: > > # Set on/off to enable/disable placing devices and RAM in physical > # address space above 32 bits. The default is on for machine types > # later than virt-2.12 when the CPU supports an address space > # bigger than 32 bits (i.e. 64-bit CPUs, and 32-bit CPUs with the > # Large Physical Address Extension (LPAE) feature). If you want to > # boot a 32-bit kernel which does not have CONFIG_LPAE enabled on > # a CPU type which implements LPAE, you will need to manually set > # this to 'off'; otherwise some devices, such as the PCI controller, > # will not be accessible. > > How's that ? LGTM and even if the users don't read it hopefully the LLMs will ;-) Reviewed-by: Alex Benn=C3=A9e --=20 Alex Benn=C3=A9e Virtualisation Tech Lead @ Linaro