From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f44.google.com (mail-oa1-f44.google.com [209.85.160.44]) (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 F21DD1DA38 for ; Fri, 26 Jan 2024 15:44:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706283871; cv=none; b=MRDJkTolCxblYIqcdVUckfrAaIgivioy2ubFSL0BOVg80mKzsGfsz5ccc5qupczofbuGJ1t+YC5J+WDTDGn1mlTIHLHlKz+/DcHm3snQN3mXAS8doU7qF0Laxqa3jKiQ9MOEhB0LxRR3oP6lIBJ1hUiydZ6Ts/AVLU+G67CR0uo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706283871; c=relaxed/simple; bh=UiLdiIVvMb83SWw7AGXvISH8OI0rahijuASgroB/Hlk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cFCRr3jWYBrrZUFc2pqRnXIjotSqRdomAdwtfRUSwCqScOLIhOXBXyf0G30QSS4bFNgvtMgf+Xy492mIldp+yBO7UTMxGeuQy1ruep9abT55EkGpE8Y3/IfrtOvojjYY2YOQwIL5C6xKzykD2fVP8pnNUg1o/FfVcCVVRrbJsk4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=XPmKa4ht; arc=none smtp.client-ip=209.85.160.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="XPmKa4ht" Received: by mail-oa1-f44.google.com with SMTP id 586e51a60fabf-206689895bfso328275fac.1 for ; Fri, 26 Jan 2024 07:44:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1706283869; x=1706888669; darn=vger.kernel.org; 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=ifj3vKt8QC0k+Lvrl/eE4vaSsPq+S4SksoQKXsBRSXc=; b=XPmKa4htdyIFQN5nkahRKFHwjBIj2w5nnjnY1CyS6eVuLv3IrPCwmLUgoyVIAkXD4U P1jun110v+iDL6vurH48iPpOv8S1BmzzTMcimFbXtQCsXtQlviUT2tQMSKmyK+4XCXFe n39GTlT4ZJyrynW6hqgC/kXgsU2hJlTH0dKRJsHzuRomi6ncG1mOu61Fd9roa6dwduUq m8qJkDNwKT8M8M2KvISQ+ovcf4bY7EgZqz//rM9qPeJzVOx+t4W6XM16TiiOZiRRITMz O5s22W3MQ/r6vJdV6wFmhQbFKMlzpxLGW/lfwvUrkFpPolQPZt4mVU3XDM44WmTHZEEM lI/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706283869; x=1706888669; 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=ifj3vKt8QC0k+Lvrl/eE4vaSsPq+S4SksoQKXsBRSXc=; b=O3URtzSupLvobWWCLTHJyFS41thRp2es9UFUNj/a59Aa6RkjG8+RWw1VhDzgOvVq5U yRerslJCrVEaLip8xeXU61C8PmEEaaZf+tbhkEwegTmKpt/N+MzZt63lILcXW+BkWcxl qNlNWkewLlXrrEJ7nOWlR1plKy9i/UaWjIFG0+GUL/h8D9XQF95JJ71ZeitCB/0YmPc7 lMu66OaxM+5SBqctHQ3rxEVqC5CG7ci2h9BOG/4uDtbztd18myun9b5ZM78Ub7M5XxCZ De3G362jREoYDLwwPwg1iuQSM2cMXXeccRdTkiMSNhf23nLDnquNGIr6+6UUTFPhYxEe HM/A== X-Gm-Message-State: AOJu0Yz6V3i8r3mv4sFghjaV8UO1VYVF970eO0/Ur1xwvF4A8rO/78f2 nbYCrxZpX8B1kcJdXBt/1MziZ1kmT5SZrBrYtpLDftCfS3AWr87WLNsM7XjbF00= X-Google-Smtp-Source: AGHT+IHvXs9zt8rzQimULCxVKWRw2gBSkFT+WcT7r0xChxJT011B7UN6s63xs55ItZMqKHL08VvUaA== X-Received: by 2002:a05:6871:2787:b0:214:2544:bfd9 with SMTP id zd7-20020a056871278700b002142544bfd9mr955769oab.43.1706283869008; Fri, 26 Jan 2024 07:44:29 -0800 (PST) Received: from ziepe.ca (hlfxns017vw-142-68-80-239.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.68.80.239]) by smtp.gmail.com with ESMTPSA id pl10-20020a0568704e0a00b0021837cadf53sm200549oab.39.2024.01.26.07.44.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Jan 2024 07:44:28 -0800 (PST) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1rTONX-009SCu-NX; Fri, 26 Jan 2024 11:44:27 -0400 Date: Fri, 26 Jan 2024 11:44:27 -0400 From: Jason Gunthorpe To: Timothy Pearson Cc: Shivaprasad G Bhat , iommu , linuxppc-dev , linux-kernel , Michael Ellerman , npiggin , christophe leroy , aneesh kumar , naveen n rao , jroedel , aik , bgray , Greg Kroah-Hartman , gbatra , vaibhav Subject: Re: [PATCH 1/2] powerpc: iommu: Bring back table group release_ownership() call Message-ID: <20240126154427.GB50608@ziepe.ca> References: <170618450592.3805.8216395093813382208.stgit@ltcd48-lp2.aus.stglab.ibm.com> <170618451433.3805.9015493852395837391.stgit@ltcd48-lp2.aus.stglab.ibm.com> <20240125155017.GW50608@ziepe.ca> <20240126151701.GZ50608@ziepe.ca> <392247278.10124607.1706282995795.JavaMail.zimbra@raptorengineeringinc.com> <20240126153806.GA50608@ziepe.ca> <1453449220.10126352.1706283596477.JavaMail.zimbra@raptorengineeringinc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1453449220.10126352.1706283596477.JavaMail.zimbra@raptorengineeringinc.com> On Fri, Jan 26, 2024 at 09:39:56AM -0600, Timothy Pearson wrote: > > Just forget about the weird KVM and SPAPR stuff, leave it under the > > kconfig of the old code and nobody will run it. Almost nobody already > > runs it, apparently. > > We actually use QEMU/KVM/VFIO extensively at Raptor, so need the > support and need it to be performant... I wonder if you alone are the "almost" :) The KVM entanglement was hairy and scary. I never did figure out what was really going on there. Maybe you don't need all of it and can be successful with a more typical iommu working model? Suggest to tackle it after getting the first parts done. Jason