The kernel manages the MKTME (Multi-Key Total Memory Encryption) Keys
as a system wide single pool of keys. The hardware, however, manages
the keys on a per physical package basis. Each physical package
maintains a Key Table that all CPU's in that package share.
In order to maintain the consistent, system wide view that the kernel
requires, program all physical packages during a key program request.
Change-Id: I0ff46f37fde47a0305842baeb8ea600b6c568639
Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
---
security/keys/mktme_keys.c | 61 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 60 insertions(+), 1 deletion(-)
diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index e615eb58e600..7f113146acf2 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -21,6 +21,7 @@
#include "internal.h"
struct kmem_cache *mktme_prog_cache; /* Hardware programming cache */
+cpumask_var_t mktme_leadcpus; /* one cpu per pkg to program keys */
static const char * const mktme_program_err[] = {
"KeyID was successfully programmed", /* 0 */
@@ -59,6 +60,37 @@ static void mktme_destroy_key(struct key *key)
key_put_encrypt_ref(mktme_map_keyid_from_key(key));
}
+struct mktme_hw_program_info {
+ struct mktme_key_program *key_program;
+ unsigned long status;
+};
+
+/* Program a KeyID on a single package. */
+static void mktme_program_package(void *hw_program_info)
+{
+ struct mktme_hw_program_info *info = hw_program_info;
+ int ret;
+
+ ret = mktme_key_program(info->key_program);
+ if (ret != MKTME_PROG_SUCCESS)
+ WRITE_ONCE(info->status, ret);
+}
+
+/* Program a KeyID across the entire system. */
+static int mktme_program_system(struct mktme_key_program *key_program,
+ cpumask_var_t mktme_cpumask)
+{
+ struct mktme_hw_program_info info = {
+ .key_program = key_program,
+ .status = MKTME_PROG_SUCCESS,
+ };
+ get_online_cpus();
+ on_each_cpu_mask(mktme_cpumask, mktme_program_package, &info, 1);
+ put_online_cpus();
+
+ return info.status;
+}
+
/* Copy the payload to the HW programming structure and program this KeyID */
static int mktme_program_keyid(int keyid, struct mktme_payload *payload)
{
@@ -84,7 +116,7 @@ static int mktme_program_keyid(int keyid, struct mktme_payload *payload)
kprog->key_field_2[i] ^= kern_entropy[i];
}
}
- ret = mktme_key_program(kprog);
+ ret = mktme_program_system(kprog, mktme_leadcpus);
kmem_cache_free(mktme_prog_cache, kprog);
return ret;
}
@@ -299,6 +331,28 @@ struct key_type key_type_mktme = {
.destroy = mktme_destroy_key,
};
+static int mktme_build_leadcpus_mask(void)
+{
+ int online_cpu, mktme_cpu;
+ int online_pkgid, mktme_pkgid = -1;
+
+ if (!zalloc_cpumask_var(&mktme_leadcpus, GFP_KERNEL))
+ return -ENOMEM;
+
+ for_each_online_cpu(online_cpu) {
+ online_pkgid = topology_physical_package_id(online_cpu);
+
+ for_each_cpu(mktme_cpu, mktme_leadcpus) {
+ mktme_pkgid = topology_physical_package_id(mktme_cpu);
+ if (mktme_pkgid == online_pkgid)
+ break;
+ }
+ if (mktme_pkgid != online_pkgid)
+ cpumask_set_cpu(online_cpu, mktme_leadcpus);
+ }
+ return 0;
+}
+
/*
* Allocate the global mktme_map structure based on the available keyids.
* Create a cache for the hardware structure. Initialize the encrypt_count
@@ -323,10 +377,15 @@ static int __init init_mktme(void)
if (mktme_alloc_encrypt_array() < 0)
goto free_cache;
+ if (mktme_build_leadcpus_mask() < 0)
+ goto free_array;
+
ret = register_key_type(&key_type_mktme);
if (!ret)
return ret; /* SUCCESS */
+ free_cpumask_var(mktme_leadcpus);
+free_array:
mktme_free_encrypt_array();
free_cache:
kmem_cache_destroy(mktme_prog_cache);
--
2.14.1
