[SM] Multicore Security Monitor (keystone-enclave#4)

The security monitor supports SMP up to 8 cores * SMM is protected over all the cores * Enclave Creation/Destruction: PMP registers are globally synchronized using an IPI * Enclave Run/Exit: only the local PMP register is set or unset * Removed unused SBI functions (`copy_to_enclave` and `copy_from_enclave`) * [BUG] Sanctum bootloader does not work with SMP yet; must debug later
dkohlbre · Oct 8, 2018 · cf355ee · cf355ee
1 parent eddf486
commit cf355ee
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Showing 11 changed files with 494 additions and 272 deletions.
diff --git a/machine/mcall.h b/machine/mcall.h
@@ -13,8 +13,6 @@
 
 #define SBI_SM_CREATE_ENCLAVE   101
 #define SBI_SM_DESTROY_ENCLAVE  102
-#define SBI_SM_COPY_TO_ENCLAVE  103
-#define SBI_SM_COPY_FROM_ENCLAVE  104
 #define SBI_SM_RUN_ENCLAVE      105
 #define SBI_SM_EXIT_ENCLAVE     1101
 #define SBI_SM_NOT_IMPLEMENTED  1111

diff --git a/machine/mentry.S b/machine/mentry.S
@@ -15,7 +15,7 @@ trap_table:
   .word pmp_trap
   .word misaligned_store_trap
   .word pmp_trap
-  .word u_ecall_trap // 8 --> ECALL from U-mode
+  .word bad_trap
   .word mcall_trap // 9 --> ECALL from S-mode
   .word bad_trap
   .word bad_trap
@@ -24,6 +24,10 @@ trap_table:
   .word __trap_from_machine_mode
   .word bad_trap
   .word bad_trap
+#ifdef SM_ENABLED
+# define HANDLE_IPI_PMP_VECTOR 16
+  .word handle_pmp_ipi
+#endif
 
   .option norvc
   .section .text.init,"ax",@progbits
@@ -80,6 +84,7 @@ trap_vector:
   lw a0, MENTRY_IPI_PENDING_OFFSET(a0)
   sw x0, MENTRY_IPI_PENDING_OFFSET(a0)
 #endif
+
   and a1, a0, IPI_SOFT
   beqz a1, 1f
   csrs mip, MIP_SSIP
@@ -96,6 +101,11 @@ trap_vector:
   beqz a1, 1f
   wfi
   j 1b
+#ifdef SM_ENABLED
+1:
+  andi a1, a0, IPI_PMP
+  bnez a1, .Lipi_pmp
+#endif
 1:
   j .Lmret
 
@@ -190,6 +200,12 @@ restore_regs:
   LOAD sp, 2*REGBYTES(sp)
   mret
 
+#ifdef SM_ENABLED
+.Lipi_pmp:
+  li a1, HANDLE_IPI_PMP_VECTOR
+  j .Lhandle_trap_in_machine_mode
+#endif
+
 .Ltrap_from_machine_mode:
   csrr sp, mscratch
   addi sp, sp, -INTEGER_CONTEXT_SIZE

diff --git a/machine/mtrap.c b/machine/mtrap.c
@@ -94,8 +94,10 @@ static uintptr_t mcall_set_timer(uint64_t when)
   set_csr(mie, MIP_MTIP);
   return 0;
 }
-
-static void send_ipi_many(uintptr_t* pmask, int event)
+#ifndef SM_ENABLED
+static 
+#endif
+void send_ipi_many(uintptr_t* pmask, int event)
 {
   _Static_assert(MAX_HARTS <= 8 * sizeof(*pmask), "# harts > uintptr_t bits");
   uintptr_t mask = hart_mask;
@@ -109,7 +111,7 @@ static void send_ipi_many(uintptr_t* pmask, int event)
 
   if (event == IPI_SOFT)
     return;
-
+  
   // wait until all events have been handled.
   // prevent deadlock by consuming incoming IPIs.
   uint32_t incoming_ipi = 0;
@@ -172,12 +174,6 @@ void mcall_trap(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc)
     case SBI_SM_DESTROY_ENCLAVE:
       retval = mcall_sm_destroy_enclave(arg0);
       break;
-    case SBI_SM_COPY_TO_ENCLAVE:
-      retval = mcall_sm_copy_to_enclave(arg0, arg1, arg2, arg3);
-      break;
-    case SBI_SM_COPY_FROM_ENCLAVE:
-      retval = mcall_sm_copy_from_enclave(arg0, arg1, arg2);
-      break;
     case SBI_SM_RUN_ENCLAVE:
       retval = mcall_sm_run_enclave(arg0, arg1);
       break;

diff --git a/machine/mtrap.h b/machine/mtrap.h
@@ -79,6 +79,7 @@ static inline void wfi()
 #define IPI_FENCE_I    0x2
 #define IPI_SFENCE_VMA 0x4
 #define IPI_HALT       0x8
+#define IPI_PMP       0x10
 
 #define MACHINE_STACK_SIZE RISCV_PGSIZE
 #define MENTRY_HLS_OFFSET (INTEGER_CONTEXT_SIZE + SOFT_FLOAT_CONTEXT_SIZE)