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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2017-07-17 16:10:22 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-07-18 11:38:03 +0200 |
| commit | 648babb7078c6310d2af5b8aa01f086030916968 (patch) | |
| tree | c386725f2a5dbd748b5918e638a67e45e4d3e59b /lib/swiotlb.c | |
| parent | c7753208a94c73d5beb1e4bd843081d6dc7d4678 (diff) | |
| download | linux-0-day-648babb7078c6310d2af5b8aa01f086030916968.tar.gz linux-0-day-648babb7078c6310d2af5b8aa01f086030916968.tar.xz | |
swiotlb: Add warnings for use of bounce buffers with SME
Add warnings to let the user know when bounce buffers are being used for
DMA when SME is active. Since the bounce buffers are not in encrypted
memory, these notifications are to allow the user to determine some
appropriate action - if necessary. Actions can range from utilizing an
IOMMU, replacing the device with another device that can support 64-bit
DMA, ignoring the message if the device isn't used much, etc.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/d112564053c3f2e86ca634a8d4fa4abc0eb53a6a.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/swiotlb.c')
| -rw-r--r-- | lib/swiotlb.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 04ac91acf1930..8c6c83ef57a43 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -507,6 +507,9 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); + if (sme_active()) + pr_warn_once("SME is active and system is using DMA bounce buffers\n"); + mask = dma_get_seg_boundary(hwdev); tbl_dma_addr &= mask; |