From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F0EB747772 for ; Thu, 2 May 2024 08:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714640020; cv=none; b=O9HhrFXC4aH+Dmi1WdTIrLwG1tmxchNst+JeEC3qPG038AQRSGlEYmDQb4BDUacTHcGDPPBC9PcV/EVmAvjhIzt0o82EjzmtJnaR2xZSV7LfSP8BvRRV+xWUQQmbLWJ8GK2bABFCeY1wSSpbcNociccdaMEYz+AYCmxu4a/iJb0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714640020; c=relaxed/simple; bh=kBXFxcRpsGgFL2gsK677E62BQQH6Ff9kxpq2NmgT9ao=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fw4HVCPd8t7lHPqPSNuVjBLiURX06WfDXyx/TP6rEIMlnJa7Jdk2LhfSZQ3grLeONQgsFtGBC68bZCuWFcd7FNV/HzGRKqBFRVLsPZNvLjDn2ztceUNa2PyH+opYCKEgJ9X80aeh0LJZYVl5R2K/NVQP6g4bnpggPvEsDoA6HuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B2A882F4; Thu, 2 May 2024 01:54:03 -0700 (PDT) Received: from raptor (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D5DAC3F71E; Thu, 2 May 2024 01:53:36 -0700 (PDT) Date: Thu, 2 May 2024 09:53:34 +0100 From: Alexandru Elisei To: Thomas Huth Cc: Oliver Upton , Andrew Jones , Eric Auger , kvmarm@lists.linux.dev, kvm@vger.kernel.org, Paolo Bonzini Subject: Re: [kvm-unit-tests PATCH] arm64: Default to 4K translation granule Message-ID: References: <20240502074156.1346049-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi, On Thu, May 02, 2024 at 09:58:39AM +0200, Thomas Huth wrote: > On 02/05/2024 09.41, Oliver Upton wrote: > > Some arm64 implementations in the wild, like the Apple parts, do not > > support the 64K translation granule. This can be a bit annoying when > > running with the defaults on such hardware, as every test fails > > before getting the MMU turned on. > > > > Switch the default page size to 4K with the intention of having the > > default setting be the most widely applicable one. > > What about using "getconf PAGESIZE" to get the page size of the host > environment? Would that work, too? That would definitely make the tests run, but I'm worried about reproducibility. If you want to re-run a failed test on a different machine, this introduces a new variable, the host's page size, which might be different between the machines. Or, if you want to look it another way, another configuration knob that the user has to be aware of and control. Unless there's a system out there that doesn't support 4K pages, I'm in favour of having 4K the default. Thanks, Alex > > Thomas > >