From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D0E3D14286; Fri, 23 May 2025 15:42:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748014964; cv=none; b=N5FlSlgZSs5XEBOudD55UHz/BpCwqRgUGyXVT/fAXWR2mP4HsENJbhW2yJaPzxu+Lg7K8us1vu9G6H6l8AcWsVj93DZrGkHSW+6PnsN8AAiy8F8/evqYzq9OAtnpo4TUPe+oEM7Wkp5doTQsJEpecGE93tlTzBs+Nh8zUf12pB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748014964; c=relaxed/simple; bh=KVwP6ZaTXIHoBZVmEEJrV8NQeE4NX4pX/91S5eZzI1M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dYBsZMBw83ntgkFtFCgB7qwE2KzcWz1pu9HnSTZUTiOwIcgeeFKZooh0nn6O5o0dMLvYEeN0U2jiSB+/zkxrsTqGzfhZjT3+2kKoSjmmoB1lg3nHIvfzQ/PJxUy4jxAYWa7xr1MgHo4uOgVviuSAnWb0Jsgpv7ejGZAqi+rpVhM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=EhZXxL0G; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EhZXxL0G" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=cWvExEmX2CXey0nsq/xA9W7LqAPoEJF71YAIT7PxRDc=; b=EhZXxL0GrKtd3iSJ+wPvrbA+m5 PpjOO7lePi0JrCwZhX78wxsMvPt/LHuIREgspeBc5Qc+DXhrkEbkGpNvTwrh7u8pb1D8K8sJWiKZX OBfQXsavrfpWm3ai2iDsAgzOyzdrxcD2WtwhZG8tI/hplK+t/jUVOzTfi/Z2P/R0zTe8fyg5BDkJc SPYu1BIBZA0GuQ+/BjZL/J2Z25LiMrKmF493AnlgWmT1aWoNbSD1orK84KSwGUKX5COCj9/LMW8rr cKfL6Kc9kL+0kdRXh4qZHOP5blhDmaFRfwb2EM1j1+Efq0XX5EwCzivzAJ7UyJN/4U2m3zNSnO2nf QzX76JNg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uIUXh-00000004HKU-1vig; Fri, 23 May 2025 15:42:41 +0000 Date: Fri, 23 May 2025 08:42:41 -0700 From: Christoph Hellwig To: Daisuke Matsuda Cc: Christoph Hellwig , linux-rdma@vger.kernel.org, linux-mm@kvack.org, leon@kernel.org, jgg@ziepe.ca, akpm@linux-foundation.org, jglisse@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, zyjzyj2000@gmail.com Subject: Re: [PATCH] mm/hmm: Allow hmm_dma_map_alloc() to tolerate NULL device Message-ID: References: <20250523143537.10362-1-dskmtsd@gmail.com> <63702a66-4cc6-4562-89f4-857fe3f044e8@gmail.com> Precedence: bulk X-Mailing-List: linux-rdma@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: <63702a66-4cc6-4562-89f4-857fe3f044e8@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Thank you very much, but I know rxe very well. And given your apparent knowledge of the rdma subsystem you should also know pretty well that it does not otherwise call into the dma mapping core for virtual devices because calling into the dma mapping code is not valid for the virtual devices. Please fix the rdma core to not call into the hmm dma mapping helpers for the ib_uses_virt_dma() case.