Hi Jarkko,
On 9/13/2021 8:04 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 an attribute for the amount of SGX memory in bytes to each NUMA
node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size.
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
v5: A new patch based on the discussion at
https://lore.kernel.org/linux-sgx/3a7cab4115b4f902f3509ad8652e616b91703e1d.camel@xxxxxxxxxx/T/#t
---
Documentation/x86/sgx.rst | 14 ++++++
arch/x86/kernel/cpu/sgx/main.c | 90 ++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/sgx/sgx.h | 2 +
3 files changed, 106 insertions(+)
...
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index a6e313f1a82d..c43b5a0120c1 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -717,6 +717,7 @@ static bool __init sgx_page_cache_init(void)
}
sgx_epc_sections[i].node = &sgx_numa_nodes[nid];
+ sgx_numa_nodes[nid].size += size;
sgx_nr_epc_sections++;
}
The above memory seems to be uninitialized at the time it is incremented.
I tried this out on a system that reports the following:
$ dmesg | grep EPC
[ 7.252838] sgx: EPC section 0x1000c00000-0x107f7fffff
[ 7.256921] sgx: EPC section 0x2000c00000-0x207fffffff
It shows unexpectedly large values:
$ cat /sys/devices/system/node/node*/sgx/memory_size
12421486739271732874
16308428754864105707
System reported sane values after adding this fixup:
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 3380390cc052..d73bbfbfc05d 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -621,7 +621,7 @@ static bool __init sgx_page_cache_init(void)
int nid;
int i;
- sgx_numa_nodes = kmalloc_array(num_possible_nodes(),
sizeof(*sgx_numa_nodes), GFP_KERNEL);
+ sgx_numa_nodes = kcalloc(num_possible_nodes(),
sizeof(*sgx_numa_nodes), GFP_KERNEL);
if (!sgx_numa_nodes)
return false;
After fixup:
$ cat /sys/devices/system/node/node*/sgx/memory_size
2126512128
2134900736
Reinette
