[RFC][PATCH 11/34] x86/cpu/intel: Prepare MKTME for "address configuration" infrastructure

Dave Hansen
2024-02-22T18:39:41Z

Intel also does memory encryption and also fiddles with the physical
address bits. This is currently called for *each* CPU, but practically
only done on the boot CPU because of 'mktme_status'.

Move it from the "each CPU" ->c_init() function to ->c_bsp_init() where
the whole thing only gets called once ever. This also necessitates moving
detect_tme() and its entourage around in the file.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
---

b/arch/x86/kernel/cpu/intel.c | 174 +++++++++++++++++++++---------------------
1 file changed, 87 insertions(+), 87 deletions(-)

diff -puN arch/x86/kernel/cpu/intel.c~intel-move-TME-detection arch/x86/kernel/cpu/intel.c
--- a/arch/x86/kernel/cpu/intel.c~intel-move-TME-detection 2024-02-22 10:08:53.820663775 -0800
+++ b/arch/x86/kernel/cpu/intel.c 2024-02-22 10:08:53.824663932 -0800
@@ -324,9 +324,96 @@ static void early_init_intel(struct cpui
detect_ht_early(c);
}

+#define MSR_IA32_TME_ACTIVATE 0x982
+
+/* Helpers to access TME_ACTIVATE MSR */
+#define TME_ACTIVATE_LOCKED(x) (x & 0x1)
+#define TME_ACTIVATE_ENABLED(x) (x & 0x2)
+
+#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */
+#define TME_ACTIVATE_POLICY_AES_XTS_128 0
+
+#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */
+
+#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */
+#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1
+
+/* Values for mktme_status (SW only construct) */
+#define MKTME_ENABLED 0
+#define MKTME_DISABLED 1
+#define MKTME_UNINITIALIZED 2
+static int mktme_status = MKTME_UNINITIALIZED;
+
+static void detect_tme(struct cpuinfo_x86 *c)
+{
+ u64 tme_activate, tme_policy, tme_crypto_algs;
+ int keyid_bits = 0, nr_keyids = 0;
+ static u64 tme_activate_cpu0 = 0;
+
+ rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
+
+ if (mktme_status != MKTME_UNINITIALIZED) {
+ if (tme_activate != tme_activate_cpu0) {
+ /* Broken BIOS? */
+ pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
+ pr_err_once("x86/tme: MKTME is not usable\n");
+ mktme_status = MKTME_DISABLED;
+
+ /* Proceed. We may need to exclude bits from x86_phys_bits. */
+ }
+ } else {
+ tme_activate_cpu0 = tme_activate;
+ }
+
+ if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
+ pr_info_once("x86/tme: not enabled by BIOS\n");
+ mktme_status = MKTME_DISABLED;
+ return;
+ }
+
+ if (mktme_status != MKTME_UNINITIALIZED)
+ goto detect_keyid_bits;
+
+ pr_info("x86/tme: enabled by BIOS\n");
+
+ tme_policy = TME_ACTIVATE_POLICY(tme_activate);
+ if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
+ pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
+
+ tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
+ if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
+ pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
+ tme_crypto_algs);
+ mktme_status = MKTME_DISABLED;
+ }
+detect_keyid_bits:
+ keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
+ nr_keyids = (1UL << keyid_bits) - 1;
+ if (nr_keyids) {
+ pr_info_once("x86/mktme: enabled by BIOS\n");
+ pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
+ } else {
+ pr_info_once("x86/mktme: disabled by BIOS\n");
+ }
+
+ if (mktme_status == MKTME_UNINITIALIZED) {
+ /* MKTME is usable */
+ mktme_status = MKTME_ENABLED;
+ }
+
+ /*
+ * KeyID bits effectively lower the number of physical address
+ * bits. Update cpuinfo_x86::x86_phys_bits accordingly.
+ */
+ c->x86_phys_bits -= keyid_bits;
+}
+
static void bsp_init_intel(struct cpuinfo_x86 *c)
{
resctrl_cpu_detect(c);
+
+ if (cpu_has(c, X86_FEATURE_TME))
+ detect_tme(c);
}

#ifdef CONFIG_X86_32
@@ -482,90 +569,6 @@ static void srat_detect_node(struct cpui
#endif
}

-#define MSR_IA32_TME_ACTIVATE 0x982
-
-/* Helpers to access TME_ACTIVATE MSR */
-#define TME_ACTIVATE_LOCKED(x) (x & 0x1)
-#define TME_ACTIVATE_ENABLED(x) (x & 0x2)
-
-#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */
-#define TME_ACTIVATE_POLICY_AES_XTS_128 0
-
-#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */
-
-#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */
-#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1
-
-/* Values for mktme_status (SW only construct) */
-#define MKTME_ENABLED 0
-#define MKTME_DISABLED 1
-#define MKTME_UNINITIALIZED 2
-static int mktme_status = MKTME_UNINITIALIZED;
-
-static void detect_tme(struct cpuinfo_x86 *c)
-{
- u64 tme_activate, tme_policy, tme_crypto_algs;
- int keyid_bits = 0, nr_keyids = 0;
- static u64 tme_activate_cpu0 = 0;
-
- rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
-
- if (mktme_status != MKTME_UNINITIALIZED) {
- if (tme_activate != tme_activate_cpu0) {
- /* Broken BIOS? */
- pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
- pr_err_once("x86/tme: MKTME is not usable\n");
- mktme_status = MKTME_DISABLED;
-
- /* Proceed. We may need to exclude bits from x86_phys_bits. */
- }
- } else {
- tme_activate_cpu0 = tme_activate;
- }
-
- if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
- pr_info_once("x86/tme: not enabled by BIOS\n");
- mktme_status = MKTME_DISABLED;
- return;
- }
-
- if (mktme_status != MKTME_UNINITIALIZED)
- goto detect_keyid_bits;
-
- pr_info("x86/tme: enabled by BIOS\n");
-
- tme_policy = TME_ACTIVATE_POLICY(tme_activate);
- if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
- pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
-
- tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
- if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
- pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
- tme_crypto_algs);
- mktme_status = MKTME_DISABLED;
- }
-detect_keyid_bits:
- keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
- nr_keyids = (1UL << keyid_bits) - 1;
- if (nr_keyids) {
- pr_info_once("x86/mktme: enabled by BIOS\n");
- pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
- } else {
- pr_info_once("x86/mktme: disabled by BIOS\n");
- }
-
- if (mktme_status == MKTME_UNINITIALIZED) {
- /* MKTME is usable */
- mktme_status = MKTME_ENABLED;
- }
-
- /*
- * KeyID bits effectively lower the number of physical address
- * bits. Update cpuinfo_x86::x86_phys_bits accordingly.
- */
- c->x86_phys_bits -= keyid_bits;
-}
-
static void init_cpuid_fault(struct cpuinfo_x86 *c)
{
u64 msr;
@@ -702,9 +705,6 @@ static void init_intel(struct cpuinfo_x8

init_ia32_feat_ctl(c);

- if (cpu_has(c, X86_FEATURE_TME))
- detect_tme(c);
-
init_intel_misc_features(c);

split_lock_init();
_