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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2022-04-06 01:29:34 +0200 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-04-07 17:27:53 +0200 |
| commit | 9aa6ea69852c46e551f4180dce4208bd53df418c (patch) | |
| tree | 5cdd8678e9e9376c1a04169d7670b073e333eee9 /arch/x86/mm/ioremap.c | |
| parent | x86/topology: Disable CPU online/offline control for TDX guests (diff) | |
| download | linux-9aa6ea69852c46e551f4180dce4208bd53df418c.tar.xz linux-9aa6ea69852c46e551f4180dce4208bd53df418c.zip | |
x86/tdx: Make pages shared in ioremap()
In TDX guests, guest memory is protected from host access. If a guest
performs I/O, it needs to explicitly share the I/O memory with the host.
Make all ioremap()ed pages that are not backed by normal memory
(IORES_DESC_NONE or IORES_DESC_RESERVED) mapped as shared.
The permissions in PAGE_KERNEL_IO already work for "decrypted" memory
on AMD SEV/SME systems. That means that they have no need to make a
pgprot_decrypted() call.
TDX guests, on the other hand, _need_ change to PAGE_KERNEL_IO for
"decrypted" mappings. Add a pgprot_decrypted() for TDX.
Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20220405232939.73860-26-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/mm/ioremap.c')
| -rw-r--r-- | arch/x86/mm/ioremap.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 17a492c27306..1ad0228f8ceb 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -242,10 +242,15 @@ __ioremap_caller(resource_size_t phys_addr, unsigned long size, * If the page being mapped is in memory and SEV is active then * make sure the memory encryption attribute is enabled in the * resulting mapping. + * In TDX guests, memory is marked private by default. If encryption + * is not requested (using encrypted), explicitly set decrypt + * attribute in all IOREMAPPED memory. */ prot = PAGE_KERNEL_IO; if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted) prot = pgprot_encrypted(prot); + else + prot = pgprot_decrypted(prot); switch (pcm) { case _PAGE_CACHE_MODE_UC: |