On 8/25/21 4:52 PM, Jarkko Sakkinen wrote:
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system. Add SGX_MemTotal field to /proc/meminfo, which shows the total amount of usable SGX memory in the system. E.g. with 32 MB reserved for SGX from BIOS, the printout would be: SGX_MemTotal: 22528 kB It is less than 32 MB because some of the space is reserved for Enclave Page Cache Metadata (EPCM), which contains state variables for all the pages in the Enclave Page Cache (EPC). The latter contains the pages, which applications can use to create enclaves. Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> --- v2: * Move ifdef fix for sgx_set_attribute() to a separate patch. --- Documentation/x86/sgx.rst | 6 ++++++ arch/x86/include/asm/sgx.h | 2 ++ arch/x86/kernel/cpu/sgx/main.c | 7 ++++++- arch/x86/mm/pat/set_memory.c | 5 +++++ 4 files changed, 19 insertions(+), 1 deletion(-) diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst index dd0ac96ff9ef..68ee171e1d8f 100644 --- a/Documentation/x86/sgx.rst +++ b/Documentation/x86/sgx.rst @@ -250,3 +250,9 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Supplemental fields for /proc/meminfo +===================================== + +SGX_MemTotal + The total usable SGX protected memory in kilobytes.
Hi, I would prefer to see this listed in Documentation/filesystems/proc.rst as an optional field, depending on CONFIG_X86_SGX. Or at least put a reference in proc.rst to this doc file and its supplemental fields. thanks. -- ~Randy
