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 C60AD29ACDE; Thu, 10 Jul 2025 23:58:53 +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=1752191933; cv=none; b=NVArzqkhbqyyA+lnS0HFkMeIpG1DD0S2+okKdPyxyyYpa0obWxXQ0AtXOr+2Ntg3c4/8rnPFWfqgVNuqRczIDrFPdJpzekIKPDGpuufRy+9mjzUVBE1R9llUBHaPK1E10EkpEznYGxP34bYKz0MaxpToRe0PVDGaHcfQrERDsnc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752191933; c=relaxed/simple; bh=RZSiQFQ5CJhU/h0mQJuZBqy5Y/7NgeYrUN8qKuNGZaI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VCzSRk1kbeK/4y05Aw0WudUjF0bnujMTlP6oNPHvLcA/gP89I5iKWUkMi1oatf8cuybuupV05abFvUSShqUWNmkNgoqNfPc61xVK2ez/6pz6p989O0fAxw7KCPc0yFbLCR0VCszYSvKtIckF8SAWMXJLNT4XbrFA8lsCLERUt68= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LEY/ZBhs; 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="LEY/ZBhs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B37E5C4CEE3; Thu, 10 Jul 2025 23:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752191933; bh=RZSiQFQ5CJhU/h0mQJuZBqy5Y/7NgeYrUN8qKuNGZaI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LEY/ZBhsaDpXenP21NMpx/v0+GdIHZP9qq9rcGq2t9XFbjm0DCSeVg/OP/j+KFDuu pLeuPg9fW/WQmiVRfAG/xwR0KitIoLbBTC+xJcj7MgQFrAqTQX4Qleugflp04piT0t 9a+1uquoUkghyvYfix+SAtquNSpkwsnS4938SK+Ptg6cMTtMbm46w1mbyRniOsQ+Hr MAbPeSmLgAAATN+WIFgvc/b3phu3mDCF8tEv+babk1Uyg4sV8axpK6cCJQwT8pLDbL pFkzjcxZKkYh1Pk0Qcao5jxlna3CdJovmJlWsRLNHcqZ7DaFQ4AUxXbdZrA2Sp9KkJ nOzF8zO051G3A== Date: Thu, 10 Jul 2025 16:58:51 -0700 From: Jakub Kicinski To: Parav Pandit Cc: Dragos Tatulea , "almasrymina@google.com" , "asml.silence@gmail.com" , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Saeed Mahameed , Tariq Toukan , Cosmin Ratiu , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC net-next 1/4] net: Allow non parent devices to be used for ZC DMA Message-ID: <20250710165851.7c86ba84@kernel.org> In-Reply-To: References: <20250702172433.1738947-1-dtatulea@nvidia.com> <20250702172433.1738947-2-dtatulea@nvidia.com> <20250702113208.5adafe79@kernel.org> <20250702135329.76dbd878@kernel.org> 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-Transfer-Encoding: 7bit On Thu, 3 Jul 2025 11:58:50 +0000 Parav Pandit wrote: > > In my head subfunctions are a way of configuring a PCIe PASID ergo they > > _only_ make sense in context of DMA. > SF DMA is on the parent PCI device. > > SIOV_R2 will have its own PCI RID which is ratified or getting ratified. > When its done, SF (as SIOV_R2 device) instantiation can be extended > with its own PCI RID. At that point they can be mapped to a VM. AFAIU every PCIe transaction for a queue with a PASID assigned should have a PASID prefix. Why is a different RID necessary? CPUs can't select IOMMU context based on RID+PASID?