xen/arm64: Print a per-CPU message with the BP hardening method used

This will make easier to know whether BP hardening has been enabled for
a CPU and which method is used.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Volodymyr Babcuk <volodymyr_babchuk@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
index c243521ed40dadc96729d8b1bf7048b156ee1183..8d5f8d372a2fef83963004797568b0e9d60469a8 100644 (file)
--- a/xen/arch/arm/cpuerrata.c
+++ b/xen/arch/arm/cpuerrata.c
@@ -79,7 +79,8 @@ static bool copy_hyp_vect_bpi(unsigned int slot, const char *hyp_vec_start,
 static bool __maybe_unused
 install_bp_hardening_vec(const struct arm_cpu_capabilities *entry,
                          const char *hyp_vec_start,
-                         const char *hyp_vec_end)
+                         const char *hyp_vec_end,
+                         const char *desc)
 {
     static int last_slot = -1;
     static DEFINE_SPINLOCK(bp_lock);
@@ -94,6 +95,9 @@ install_bp_hardening_vec(const struct arm_cpu_capabilities *entry,
     if ( !entry->matches(entry) )
         return true;
 
+    printk(XENLOG_INFO "CPU%u will %s on exception entry\n",
+           smp_processor_id(), desc);
+
     /*
      * No need to install hardened vector when the processor has
      * ID_AA64PRF0_EL1.CSV2 set.
@@ -157,7 +161,8 @@ static int enable_psci_bp_hardening(void *data)
      */
     if ( psci_ver >= PSCI_VERSION(0, 2) )
         ret = install_bp_hardening_vec(data, __psci_hyp_bp_inval_start,
-                                       __psci_hyp_bp_inval_end);
+                                       __psci_hyp_bp_inval_end,
+                                       "call PSCI get version");
     else if ( !warned )
     {
         ASSERT(system_state < SYS_STATE_active);