From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F448194A6D for ; Mon, 17 Jun 2024 11:23:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718623394; cv=none; b=H2hrkNdSGwH4SwMIfN24t0zSS6N1eZ2YNlgy2Ytl2gMeQy/JzgXsdNCjpAm6GS83OuLJiEDtl8VnSaw5/GGO6djCnAwQMsGEh4b5AbtJpYtO4zhs1V0EHxLA8sWNqy6feeFpr5rA8odSL5uyj3W3SfSdTtnLkcxoi/UPficJtnU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718623394; c=relaxed/simple; bh=StZPGP5/i6bU5Xn6N3H5JCPZRkydWn4sCNBBZMzJ8cs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bHXn210wei+Aj0q6QmMkm7P2Qbzs/r6lUwyAwc001ONPataB6gPr7oiqf6XYkmOs398KgYsearWNdwdJNK7HwB08YHjWrmeSmHXgQCh/lPC/l++wNqEnljd6CKXLn4f2ebgakmFd77L9q+rMcOifQm0gjK3m7so+6pMMLm+59b0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=g+WH21i7; arc=none smtp.client-ip=209.85.221.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="g+WH21i7" Received: by mail-wr1-f54.google.com with SMTP id ffacd0b85a97d-36087277246so1403701f8f.3 for ; Mon, 17 Jun 2024 04:23:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1718623391; x=1719228191; darn=lists.linux.dev; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=sM9D3IqfgB50OxP9LSaIkbOJs5yF44MMVnRSPz65e9Q=; b=g+WH21i7gyFr9N0PtL8AM736hM1Iq1TuJi0yysyOORooMt8u16VWHCeExVO/6CtUMP FaVuUYlhBIGVt6lNk/tPglG8pIZyJkYaOySZmBj61kPDq/S/n9QE+H+xNZoUTpWTbqeN FIEW3JH6tpKMANPWzmGKqxN8zhH15znNKaN9eb0hrnYQoT6jK5a6njIQybQU/E0Vo+YO aOojniGcoSrjjSy0oBWDGF97/4TBvLb1o22qkWhn3hsUTLgEcVxYN7Ja5jNySW5ylclH ckk5bN8YPbQcreytmkiWJXmn/ll/0cu0hZnJGhM2uoblPWvLBPsABpYt4//RxRTrW5lq fsdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718623391; x=1719228191; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=sM9D3IqfgB50OxP9LSaIkbOJs5yF44MMVnRSPz65e9Q=; b=W5VuqoSkthUDkz3sxK646iOGwqJ8zDAKZf0mNVuACRDX1ovTxJ+E6WLMtMqEddK0DQ XwgPaw4aNeMAobbYh8uG3VzLNcKH76ZmxSJvQW7WE+rqfDmFP5CEFKABS1kEEfXiaGNn CQXyIJ+y+w7fiVeE5SO08uQEzHCkn8FXb8y/Azsy8Pxz6jQ7mo8NUELUWhjSXF7Z8bxp AM03QDu3sh6/jKwjvjMaFkMyyYc/o8bym3qkeQoU8vOlqLLRBzdiAmQ84fCNRlJa5IiI m1LEcQgMyLQFjYm5itTH6ywZnT1ABsR6Js+iXawIkmAEt/OSAyGunGaMmLcTQpfkBooa 4HeA== X-Forwarded-Encrypted: i=1; AJvYcCVbNE3NID108bDca1KCZ9QAGD6mmZOY4ySRy0axFPUAB57vuGzt30EW+9FCrOWoQJTT2AXQbdX1vv05342fLM4EIeiA+r36r3dLNg== X-Gm-Message-State: AOJu0YwAkm8gcxKRQ6ZKtCjx/Nr0/T+IkKunjln7M9cg+DhOJzichrZe lQjb767GU4PdbL40s1Xa4uDjNNjWJW5ek5H4xR1e5757JLwFff9pJo92mBuHugI= X-Google-Smtp-Source: AGHT+IETE+Maao3JAp1ZfgvsbcmTneajMGOq/KKGP7BvZAyqnGu9qO6mLUlHKQfEume52Ehz/Rt4gQ== X-Received: by 2002:adf:f902:0:b0:360:727b:8b47 with SMTP id ffacd0b85a97d-3607a7e7c15mr8074845f8f.63.1718623390738; Mon, 17 Jun 2024 04:23:10 -0700 (PDT) Received: from myrica ([2.221.137.100]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-360750acf32sm11673653f8f.49.2024.06.17.04.23.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jun 2024 04:23:10 -0700 (PDT) Date: Mon, 17 Jun 2024 12:23:26 +0100 From: Jean-Philippe Brucker To: Peter Maydell Cc: Suzuki K Poulose , Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev, Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , fvogt@suse.de Subject: Re: [PATCH v3 02/14] arm64: Detect if in a realm and set RIPAS RAM Message-ID: <20240617112326.GA1193@myrica> References: <20240605093006.145492-1-steven.price@arm.com> <20240605093006.145492-3-steven.price@arm.com> <20240612104023.GB4602@myrica> <3301ddd8-f088-48e3-bfac-460891698eac@arm.com> <20240613105107.GC417776@myrica> Precedence: bulk X-Mailing-List: linux-coco@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: On Mon, Jun 17, 2024 at 11:27:31AM +0100, Peter Maydell wrote: > On Thu, 13 Jun 2024 at 11:50, Jean-Philippe Brucker > wrote: > > > > On Wed, Jun 12, 2024 at 11:59:22AM +0100, Suzuki K Poulose wrote: > > > On 12/06/2024 11:40, Jean-Philippe Brucker wrote: > > > > On Wed, Jun 05, 2024 at 10:29:54AM +0100, Steven Price wrote: > > > > > From: Suzuki K Poulose > > > > > > > > > > Detect that the VM is a realm guest by the presence of the RSI > > > > > interface. > > > > > > > > > > If in a realm then all memory needs to be marked as RIPAS RAM initially, > > > > > the loader may or may not have done this for us. To be sure iterate over > > > > > all RAM and mark it as such. Any failure is fatal as that implies the > > > > > RAM regions passed to Linux are incorrect - which would mean failing > > > > > later when attempting to access non-existent RAM. > > > > > > > > > > Signed-off-by: Suzuki K Poulose > > > > > Co-developed-by: Steven Price > > > > > Signed-off-by: Steven Price > > > > > > > > > +static bool rsi_version_matches(void) > > > > > +{ > > > > > + unsigned long ver_lower, ver_higher; > > > > > + unsigned long ret = rsi_request_version(RSI_ABI_VERSION, > > > > > + &ver_lower, > > > > > + &ver_higher); > > > > > > > > There is a regression on QEMU TCG (in emulation mode, not running under KVM): > > > > > > > > qemu-system-aarch64 -M virt -cpu max -kernel Image -nographic > > > > > > > > This doesn't implement EL3 or EL2, so SMC is UNDEFINED (DDI0487J.a R_HMXQS), > > > > and we end up with an undef instruction exception. So this patch would > > > > also break hardware that only implements EL1 (I don't know if it exists). > > > > > > Thanks for the report, Could we not check ID_AA64PFR0_EL1.EL3 >= 0 ? I > > > think we do this for kvm-unit-tests, we need the same here. > > > > Good point, it also fixes this case and is simpler. It assumes RMM doesn't > > hide this field, but I can't think of a reason it would. > > > > This command won't work anymore: > > > > qemu-system-aarch64 -M virt,secure=on -cpu max -kernel Image -nographic > > > > implements EL3 and SMC still treated as undef. QEMU has a special case for > > starting at EL2 in this case, but I couldn't find what this is for. > > That's a bit of an odd config, because it says "emulate EL3 but > never use it". QEMU's boot loader starts the kernel at EL2 because > the kernel boot protocol requires that (this is more relevant on > boards other than virt where EL3 is not command-line disableable). > I have a feeling we've occasionally found that somebody's had some > corner case reason to use it, though. (eg > https://gitlab.com/qemu-project/qemu/-/issues/1899 > is from somebody who says they use this when booting Windows 11 because > it asserts at boot time that EL3 is present and won't boot otherwise.) Thanks for the pointer. In this case it looks like Linux was used as reproducer and not the main use-case, though I wonder if some CIs regularly boot this particular configuration. > > Your underlying problem here seems to be that you don't have > a way for the firmware to say "hey, SMC works, you can use it" ? We do: SMCCC recommends to look at the PSCI conduit declared in DT/ACPI. Given that RMM mandates using the SMC conduit for both PSCI and RSI calls, we could use this discovery mechanism here. The problem is that we have to discover it very early at boot, before the DT infrastructure is ready, so the implementation is a little awkward. I did post one earlier in this thread but it doesn't yet account for ACPI-only boot, which will need something similar. Testing ID_AA64PFR0_EL1.EL3 would be much simpler, but it would break this config. Thanks, Jean