linux-kernel - [PATCH 5.4 213/215] iommu/vt-d: Make Intel SVM code 64-bit only

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 20 Jul 2020 17:38:15 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Joerg Roedel <jroedel@...e.de>,
        Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 5.4 213/215] iommu/vt-d: Make Intel SVM code 64-bit only

From: Lu Baolu <baolu.lu@...ux.intel.com>

commit 9486727f5981a5ec5c0b699fb1777451bd6786e4 upstream.

Current Intel SVM is designed by setting the pgd_t of the processor page
table to FLPTR field of the PASID entry. The first level translation only
supports 4 and 5 level paging structures, hence it's infeasible for the
IOMMU to share a processor's page table when it's running in 32-bit mode.
Let's disable 32bit support for now and claim support only when all the
missing pieces are ready in the future.

Fixes: 1c4f88b7f1f92 ("iommu/vt-d: Shared virtual address in scalable mode")
Suggested-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
Link: https://lore.kernel.org/r/20200622231345.29722-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/iommu/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -205,7 +205,7 @@ config INTEL_IOMMU_DEBUGFS
 
 config INTEL_IOMMU_SVM
 	bool "Support for Shared Virtual Memory with Intel IOMMU"
-	depends on INTEL_IOMMU && X86
+	depends on INTEL_IOMMU && X86_64
 	select PCI_PASID
 	select MMU_NOTIFIER
 	help