From: Thomas Hellstrom <[email protected]> When force_dma_unencrypted() returns true, the linear kernel map of the coherent pages have had the encryption bit explicitly cleared and the page content is unencrypted. Make sure that any additional PTEs we set up to these pages also have the encryption bit cleared by having dma_pgprot() return a protection with the encryption bit cleared in this case.
Cc: Dave Hansen <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Christian König <[email protected]> Cc: Marek Szyprowski <[email protected]> Cc: Tom Lendacky <[email protected]> Signed-off-by: Thomas Hellstrom <[email protected]> --- kernel/dma/mapping.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b0038ca3aa92..2b499dcae74f 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -157,6 +157,8 @@ EXPORT_SYMBOL(dma_get_sgtable_attrs); */ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) { + if (force_dma_unencrypted(dev)) + prot = pgprot_decrypted(prot); if (dev_is_dma_coherent(dev) || (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) && (attrs & DMA_ATTR_NON_CONSISTENT))) -- 2.20.1
