From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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.lore.kernel.org (Postfix) with ESMTPS id CED62CA0EFF for ; Thu, 21 Aug 2025 03:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=D4SM6zHJ9Q6ObBfi9kz8op3wvjKvHEZA6J8C6N7vBkM=; b=mvELbPBghB0KbGbbNwfi/jdVEB VeME/i7p0CGB0UbcFdny4RCsL8PhnttxNX7kTcTbiVhFjeEsGrjiYo3IDvWjqt9wcgsk1K8885yIB D0DCo3M2KaskwNxk5JCke2yCUS7EfjEAxwGNXUIX6NywGH7Du9RvTN+YsLzpI4zbkLLBCqiqj33Rh oqKwck0MWbruOZ5ti9FTmYy9rM6qssfaiE9mjhfrsBc3FDQDd8TXgJazIocmhW+DuzC3pTGU0w9pa iHqIVdVnXsOhfGxJLlpF/3UTdTLA3TN7N+1wdY/KiA6q4ICMZ9xV1eXQxUs0jfGTv6oRidaYIriQP HHCGmfMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uowDz-0000000FhOQ-12Ei; Thu, 21 Aug 2025 03:44:27 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uoQIL-0000000B81U-36rD for linux-nvme@lists.infradead.org; Tue, 19 Aug 2025 17:38:49 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 1387861430; Tue, 19 Aug 2025 17:38:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B8E5C4CEF4; Tue, 19 Aug 2025 17:38:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755625128; bh=5GnXky7X8jRP4E4M761xyU7kxSqR5w3y9HvcAnisW/0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bp6IjwCK6iikZBNKRNzlwQSTkIdVOg07zMkHxMwHx2bN8ViJPSPzqSH/QAyq4vh06 wQO6Ewlb0QQbKPmgYqrA9uKQ5ZlVlzrl395y0zlmmQVZo3cmxr2dce8aTWrEgEuVvU PK81BrhFBj0Sb03L1mOYr5A5QlqVfAMBpJE1psdYb9zwXYegwG/tfmrm5FOWTNfeE8 iY+rPNAKXFYUB6cprmGsa0u1KrjeSM4hl6Yb32H9zVNhuHEbrWVA9oc/K4UQWl86vA 0GIK4Y52fniR/iFJCHHd5h1oBGaE5KSvHvvy9rnqAMrstqGlP8VTJe6ApXPe+l+dK9 yBb54yNAL7EtQ== From: Leon Romanovsky To: Marek Szyprowski Cc: Leon Romanovsky , Jason Gunthorpe , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , iommu@lists.linux.dev, Jason Wang , Jens Axboe , Joerg Roedel , Jonathan Corbet , Juergen Gross , kasan-dev@googlegroups.com, Keith Busch , linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvme@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, Madhavan Srinivasan , Masami Hiramatsu , Michael Ellerman , "Michael S. Tsirkin" , Miguel Ojeda , Robin Murphy , rust-for-linux@vger.kernel.org, Sagi Grimberg , Stefano Stabellini , Steven Rostedt , virtualization@lists.linux.dev, Will Deacon , xen-devel@lists.xenproject.org Subject: [PATCH v4 13/16] mm/hmm: properly take MMIO path Date: Tue, 19 Aug 2025 20:36:57 +0300 Message-ID: <4b929da0b2dec4bccf489f35ee06098b437053b2.1755624249.git.leon@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Wed, 20 Aug 2025 20:44:16 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org From: Leon Romanovsky In case peer-to-peer transaction traverses through host bridge, the IOMMU needs to have IOMMU_MMIO flag, together with skip of CPU sync. The latter was handled by provided DMA_ATTR_SKIP_CPU_SYNC flag, but IOMMU flag was missed, due to assumption that such memory can be treated as regular one. Reuse newly introduced DMA attribute to properly take MMIO path. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky --- mm/hmm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index 015ab243f081..6556c0e074ba 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -746,7 +746,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, case PCI_P2PDMA_MAP_NONE: break; case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + attrs |= DMA_ATTR_MMIO; pfns[idx] |= HMM_PFN_P2PDMA; break; case PCI_P2PDMA_MAP_BUS_ADDR: @@ -776,7 +776,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, goto error; dma_addr = dma_map_phys(dev, paddr, map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); if (dma_mapping_error(dev, dma_addr)) goto error; @@ -811,16 +811,17 @@ bool hmm_dma_unmap_pfn(struct device *dev, struct hmm_dma_map *map, size_t idx) if ((pfns[idx] & valid_dma) != valid_dma) return false; + if (pfns[idx] & HMM_PFN_P2PDMA) + attrs |= DMA_ATTR_MMIO; + if (pfns[idx] & HMM_PFN_P2PDMA_BUS) ; /* no need to unmap bus address P2P mappings */ - else if (dma_use_iova(state)) { - if (pfns[idx] & HMM_PFN_P2PDMA) - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + else if (dma_use_iova(state)) dma_iova_unlink(dev, state, idx * map->dma_entry_size, map->dma_entry_size, DMA_BIDIRECTIONAL, attrs); - } else if (dma_need_unmap(dev)) + else if (dma_need_unmap(dev)) dma_unmap_phys(dev, dma_addrs[idx], map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); pfns[idx] &= ~(HMM_PFN_DMA_MAPPED | HMM_PFN_P2PDMA | HMM_PFN_P2PDMA_BUS); -- 2.50.1