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Patch "iommu/dma: Don't reserve PCI I/O windows" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jul 3, 2017

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This is a note to let you know that I've just added the patch titled

iommu/dma: Don't reserve PCI I/O windows

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iommu-dma-don-t-reserve-pci-i-o-windows.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 938f1bbe35e3a7cb07e1fa7c512e2ef8bb866bdf Mon Sep 17 00:00:00 2001

From: Robin Murphy <[email protected]>
Date: Thu, 16 Mar 2017 17:00:17 +0000
Subject: iommu/dma: Don't reserve PCI I/O windows

From: Robin Murphy <[email protected]>

commit 938f1bbe35e3a7cb07e1fa7c512e2ef8bb866bdf upstream.

Even if a host controller's CPU-side MMIO windows into PCI I/O space do happen to leak into PCI memory space such that it might treat them as peer addresses, trying to reserve the corresponding I/O space addresses doesn't do anything to help solve that problem. Stop doing a silly thing.

Fixes fade1ec055dc ("iommu/dma: Avoid PCI host bridge windows")
---
 drivers/iommu/dma-iommu.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
drivers/iommu/dma-iommu.c +1 -2
@@ -112,8 +112,7 @@ static void iova_reserve_pci_windows(str
 	unsigned long lo, hi;
 
 	resource_list_for_each_entry(window, &bridge->windows) {
-		if (resource_type(window->res) != IORESOURCE_MEM &&
-		    resource_type(window->res) != IORESOURCE_IO)
+		if (resource_type(window->res) != IORESOURCE_MEM)
 			continue;
 
 		lo = iova_pfn(iovad, window->res->start - window->offset);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/iommu-handle-default-domain-attach-failure.patch queue-4.9/iommu-dma-don-t-reserve-pci-i-o-windows.patch