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authorJason Gunthorpe <jgg@nvidia.com>2020-11-01 17:08:00 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-11-02 12:14:19 -0800
commitf8f6ae5d077a9bdaf5cbf2ac960a5d1a04b47482 (patch)
tree888155ece3e6e439699ec2d50c09ea5c99092ee9
parent66606567dedf395e0857f531976efad4cbbd39ea (diff)
downloadlinux-f8f6ae5d077a9bdaf5cbf2ac960a5d1a04b47482.tar.bz2
mm: always have io_remap_pfn_range() set pgprot_decrypted()
The purpose of io_remap_pfn_range() is to map IO memory, such as a memory mapped IO exposed through a PCI BAR. IO devices do not understand encryption, so this memory must always be decrypted. Automatically call pgprot_decrypted() as part of the generic implementation. This fixes a bug where enabling AMD SME causes subsystems, such as RDMA, using io_remap_pfn_range() to expose BAR pages to user space to fail. The CPU will encrypt access to those BAR pages instead of passing unencrypted IO directly to the device. Places not mapping IO should use remap_pfn_range(). Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Dave Young" <dyoung@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/0-v1-025d64bdf6c4+e-amd_sme_fix_jgg@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/mm.h9
-rw-r--r--include/linux/pgtable.h4
2 files changed, 9 insertions, 4 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ef360fe70aaf..db6ae4d3fb4e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2759,6 +2759,15 @@ static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
return VM_FAULT_NOPAGE;
}
+#ifndef io_remap_pfn_range
+static inline int io_remap_pfn_range(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ return remap_pfn_range(vma, addr, pfn, size, pgprot_decrypted(prot));
+}
+#endif
+
static inline vm_fault_t vmf_error(int err)
{
if (err == -ENOMEM)
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 38c33eabea89..71125a4676c4 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1427,10 +1427,6 @@ typedef unsigned int pgtbl_mod_mask;
#endif /* !__ASSEMBLY__ */
-#ifndef io_remap_pfn_range
-#define io_remap_pfn_range remap_pfn_range
-#endif
-
#ifndef has_transparent_hugepage
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define has_transparent_hugepage() 1