From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D42B453A7 for ; Fri, 10 Oct 2025 13:12:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760101953; cv=none; b=TNIuguQZ3xX+A76ecW0MHA7ocTA3IYIyxwSZeWJKMITNa1Oab2VuAT/uIG7cCSx9iE6k/zGDVWrznuJH3KQ9XeAilheK6/6MdrXcbw2uXhuLcpU+53lHl8yupCNQo04VGwVQbd7ohmEYHywLkpNVTGxEj7iL9EIwBIxvmld4MnM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760101953; c=relaxed/simple; bh=sBPVB7GNeg2kM1qt8bUyv5xSPcV437VxM3fppo3k470=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=ruIUEXdB7zVIYnIX3uAvRNA+Z+5JYJ4FpbS6zdmUM5iNTFRjhu93sCFUeeph17yE3iYC/vtOrnfMi4NZdDLwZzht9aPYqGjwqsUfbx3f1rN87eYIcDBXUFhxmSR7lxex4SkQ0imAVMR6eQuf4AQxW2P7W4uPVLWDOaEysGVcy0s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aVvkvMXa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aVvkvMXa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 532DFC4CEF1; Fri, 10 Oct 2025 13:12:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760101953; bh=sBPVB7GNeg2kM1qt8bUyv5xSPcV437VxM3fppo3k470=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=aVvkvMXaXm00aa7Ulqyc5Q0nih1b8l3bsLSviCppnSsac1p0tcbWclNQSiNjcmh13 izDdbzD6WmlhArOL0P/SFQrz86eqXAj2kvNIC+NW40GP+8WxTNNliQer6BsNa8MQiK 1olnKuelDkKvRHRtQ9ii1a0bFh4iTw1HT2edIPez1Or0S4Mx0lkjemC+bBey6oxWoF iFEQ3EmduRX9bfXJ81uN0ZCTzYmkb+wzyJxFpqXaAz6XSOSQSAL4dCJ3dsax3XdH70 r8nGfy6B3CbO6+F2XnhvLg948Q3UXWnEKgEU3oRVDhAP5yjRsEReOEY60xCuet4ZV7 0z67uL5pMspVQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1v7Cv8-0000000Cv69-423f; Fri, 10 Oct 2025 13:12:31 +0000 Date: Fri, 10 Oct 2025 14:12:30 +0100 Message-ID: <86cy6uyk75.wl-maz@kernel.org> From: Marc Zyngier To: Jan Kotas Cc: Oliver Upton , "kvmarm@lists.linux.dev" Subject: Re: HCR_EL2 GET_ONE_REG value difference In-Reply-To: <7867DE4D-41A2-4195-AF98-0055987D4D93@global.cadence.com> References: <47FBDCE7-F8D8-4071-93D8-E4E494D41F34@global.cadence.com> <86ikgnxfl0.wl-maz@kernel.org> <2268E166-0EA0-4C9D-B1AF-EEECB48B926B@global.cadence.com> <86frbrxd2m.wl-maz@kernel.org> <3E1DF662-DD3A-49B4-A67E-55E9658BAF52@global.cadence.com> <86ecrbx90j.wl-maz@kernel.org> <7867DE4D-41A2-4195-AF98-0055987D4D93@global.cadence.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: jank@cadence.com, oliver.upton@linux.dev, kvmarm@lists.linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Fri, 10 Oct 2025 13:49:43 +0100, Jan Kotas wrote: > > > On 10 Oct 2025, at 13:59, Marc Zyngier wrote: > > > > Given that, my take is that what we have today is not only correct, > > but actually the desirable behaviour. > > From this point of view, I agree as well. > > And as you said, it allows us to compare what the HW actually does, > and what the Guest may try to do. It could be a neat debug feature. > Maybe it would be worth adding a note about sanitization to kernel docs? We take patches! ;-) > Thanks for taking the time to respond. > It also helped me to rule out bugs in our VMM implementation. Oh gawd... good luck with that! ;-) M. -- Without deviation from the norm, progress is not possible.