linux/arch
Dexuan Cui 019b383d11 x86/tdx: Retry partially-completed page conversion hypercalls
TDX guest memory is private by default and the VMM may not access it.
However, in cases where the guest needs to share data with the VMM,
the guest and the VMM can coordinate to make memory shared between
them.

The guest side of this protocol includes the "MapGPA" hypercall.  This
call takes a guest physical address range.  The hypercall spec (aka.
the GHCI) says that the MapGPA call is allowed to return partial
progress in mapping this range and indicate that fact with a special
error code.  A guest that sees such partial progress is expected to
retry the operation for the portion of the address range that was not
completed.

Hyper-V does this partial completion dance when set_memory_decrypted()
is called to "decrypt" swiotlb bounce buffers that can be up to 1GB
in size.  It is evidently the only VMM that does this, which is why
nobody noticed this until now.

[ dhansen: rewrite changelog ]

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20230811021246.821-2-decui%40microsoft.com
2023-09-11 16:19:33 -07:00
..
alpha Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
arc ARC updates for v6.6 2023-09-04 15:38:24 -07:00
arm ARM: 2023-09-07 13:52:20 -07:00
arm64 RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
csky arch/csky 2nd patches for 6.6 2023-09-01 08:02:45 -07:00
hexagon Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
ia64 Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
loongarch LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
m68k ata changes for 6.6 2023-09-05 12:37:28 -07:00
microblaze Microblaze patches for 6.6-rc1 2023-09-05 10:15:22 -07:00
mips ARM: 2023-09-07 13:52:20 -07:00
nios2 Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
openrisc OpenRISC updates for 6.6 2023-09-05 10:09:31 -07:00
parisc ata changes for 6.6 2023-09-05 12:37:28 -07:00
powerpc ata changes for 6.6 2023-09-05 12:37:28 -07:00
riscv RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
s390 Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
sh sh updates for v6.6 2023-09-09 14:46:57 -07:00
sparc ata changes for 6.6 2023-09-05 12:37:28 -07:00
um This pull request contains the following changes for UML: 2023-09-04 11:32:21 -07:00
x86 x86/tdx: Retry partially-completed page conversion hypercalls 2023-09-11 16:19:33 -07:00
xtensa Xtensa updates for v6.6 2023-09-07 10:30:17 -07:00
.gitignore
Kconfig Add x86 shadow stack support 2023-08-31 12:20:12 -07:00