diff options
| author | Jarkko Sakkinen <jarkko@kernel.org> | 2021-03-18 02:53:31 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-03-19 21:16:51 +0300 |
| commit | 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 (patch) | |
| tree | 3923db74643a5d70124608d73219484b58044ca7 /arch/x86/Kconfig | |
| parent | 51ab30eb2ad4c4a61f827dc18863cd70dc46dc32 (diff) | |
| download | linux-901ddbb9ecf5425183ea0c09d10c2fd7868dce54.tar.xz | |
x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()
Background
==========
SGX enclave memory is enumerated by the processor in contiguous physical
ranges called Enclave Page Cache (EPC) sections. Currently, there is a
free list per section, but allocations simply target the lowest-numbered
sections. This is functional, but has no NUMA awareness.
Fortunately, EPC sections are covered by entries in the ACPI SRAT table.
These entries allow each EPC section to be associated with a NUMA node,
just like normal RAM.
Solution
========
Implement a NUMA-aware enclave page allocator. Mirror the buddy allocator
and maintain a list of enclave pages for each NUMA node. Attempt to
allocate enclave memory first from local nodes, then fall back to other
nodes.
Note that the fallback is not as sophisticated as the buddy allocator
and is itself not aware of NUMA distances. When a node's free list is
empty, it searches for the next-highest node with enclave pages (and
will wrap if necessary). This could be improved in the future.
Other
=====
NUMA_KEEP_MEMINFO dependency is required for phys_to_target_node().
[ Kai Huang: Do not return NULL from __sgx_alloc_epc_page() because
callers do not expect that and that leads to a NULL ptr deref. ]
[ dhansen: Fix an uninitialized 'nid' variable in
__sgx_alloc_epc_page() as
Reported-by: kernel test robot <lkp@intel.com>
to avoid any potential allocations from the wrong NUMA node or even
premature allocation failures. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/lkml/158188326978.894464.217282995221175417.stgit@dwillia2-desk3.amr.corp.intel.com/
Link: https://lkml.kernel.org/r/20210319040602.178558-1-kai.huang@intel.com
Link: https://lkml.kernel.org/r/20210318214933.29341-1-dave.hansen@intel.com
Link: https://lkml.kernel.org/r/20210317235332.362001-2-jarkko.sakkinen@intel.com
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2792879d398e..35391e94bd22 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1931,6 +1931,7 @@ config X86_SGX depends on CRYPTO_SHA256=y select SRCU select MMU_NOTIFIER + select NUMA_KEEP_MEMINFO if NUMA help Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions that can be used by applications to set aside private regions of code |