bug fixes

am/include/x86.h

@@ -322,6 +322,12 @@ static inline uintptr_t get_cr2() {
   return val;
 }
 
+static inline uintptr_t get_cr3() {
+  volatile uintptr_t val;
+  asm volatile ("mov %%cr3, %0" : "=r"(val));
+  return val;
+}
+
 static inline void set_cr3(void *pdir) {
   asm volatile ("mov %0, %%cr3" : : "r"(pdir));
 }

am/src/x86_64/qemu/cte.c

@@ -14,7 +14,7 @@ static void __am_irq_handle_internal(struct trap_frame *tf) {
     .msg = "(no message)",
   };
  
-//  printf("[%d/%d] ", tf->irq, _cpu());
+  printf("[%d/%d] ", tf->irq, _cpu());
 
 #define dump(ctx, name) printf("%s = %08x (%d) %p\n", #name, (ctx).name, (ctx).name, (ctx).name);
 
@@ -25,6 +25,8 @@ static void __am_irq_handle_internal(struct trap_frame *tf) {
   saved_ctx.rflags = tf->rflags;
   saved_ctx.rsp    = tf->rsp;
   saved_ctx.ss     = tf->ss;
+  saved_ctx.uvm    = (void *)get_cr3();
+
 
 #define DUMP(ctx) \
   dump((ctx),rax); dump((ctx),rbx); dump((ctx),rcx); dump((ctx),rdx); dump((ctx),rbp); dump((ctx),rsi); dump((ctx),rdi); \
@@ -33,11 +35,14 @@ static void __am_irq_handle_internal(struct trap_frame *tf) {
   dump((ctx),rsp); dump((ctx),rsp0); dump((ctx),uvm);
 
 #else
-  saved_ctx     = tf->saved_context;
-  saved_ctx.eip = tf->eip;
-  saved_ctx.cs  = tf->cs;
+  saved_ctx        = tf->saved_context;
+  saved_ctx.eip    = tf->eip;
+  saved_ctx.cs     = tf->cs;
   saved_ctx.eflags = tf->eflags;
+  saved_ctx.esp0   = CPU->tss.esp0;
+  saved_ctx.uvm    = (void *)get_cr3();
   if (tf->cs & DPL_USER) {
+    saved_ctx.ss3 = USEL(SEG_UDATA);
   } else {
     saved_ctx.esp = (uint32_t)(tf + 1) - 8; // no ss/esp saved
   }
@@ -49,6 +54,8 @@ static void __am_irq_handle_internal(struct trap_frame *tf) {
   dump((ctx),esp);  dump((ctx),esp0);  dump((ctx),uvm);  
 #endif
 
+//  DUMP(saved_ctx);
+
   #define IRQ    T_IRQ0 + 
   #define MSG(m) ev.msg = m;
 
@@ -99,13 +106,16 @@ static void __am_irq_handle_internal(struct trap_frame *tf) {
 
   _Context *ret_ctx = user_handler(ev, &saved_ctx);
 
+//  printf("====== return ========\n");
+//  DUMP(*ret_ctx);
+
   if (ret_ctx->uvm) {
     bug_on(ret_ctx->cs != USEL(SEG_UCODE));
     set_cr3(ret_ctx->uvm);
 #if __x86_64__
     __am_thiscpu_setstk0(0, ret_ctx->rsp0);
 #else
-    __am_thiscpu_setstk0(ret_ctx->ds, ret_ctx->esp0);
+    __am_thiscpu_setstk0(KSEL(SEG_KDATA), ret_ctx->esp0);
 #endif
   }
   __am_iret(ret_ctx ? ret_ctx : &saved_ctx);

am/src/x86_64/qemu/vme.c

@@ -43,7 +43,7 @@ static const struct vm_area vm_areas[] = {
 #else
   { RANGE(    0x40000000,     0x80000000), 0 }, // 1 GiB user space
   { RANGE(    0x00000000,     0x40000000), 1 }, // 1 GiB kernel
-  { RANGE(    0xf0000000,     0x00000000), 1 }, // memory-mapped I/O
+  { RANGE(    0xfd000000,     0x00000000), 1 }, // memory-mapped I/O
 #endif
 };
 #define uvm_area (vm_areas[0].area)
@@ -195,14 +195,16 @@ _Context *_ucontext(_AddressSpace *as, _Area ustack, _Area kstack, void *entry,
 
 #if __x86_64__
   ctx->cs = USEL(SEG_UCODE);
+  ctx->rip = (uintptr_t)entry;
+  ctx->rflags = FL_IF;
   ctx->ss = USEL(SEG_UDATA);
   ctx->rsp = ROUNDDOWN(ustack.end, 16);
-  ctx->rip = (uintptr_t)entry;
   ctx->rsp0 = stk_top;
 #else
   ctx->cs = USEL(SEG_UCODE);
-  ctx->ds = ctx->ss3 = USEL(SEG_UDATA);
   ctx->eip = (uint32_t)entry;
+  ctx->eflags = FL_IF;
+  ctx->ds = ctx->ss3 = USEL(SEG_UDATA);
   ctx->esp0 = stk_top;
   ctx->esp = ROUNDDOWN(ustack.end, 16);
 #endif

am/src/x86_64/qemu/x86.c

@@ -63,7 +63,7 @@ void __am_percpu_initgdt() {
   gdt[SEG_TSS+0] = (sizeof(CPU->tss) - 1) | ((tss & 0xffffff) << 16) |
                    (0x00e9LL << 40) | (((tss >> 24) & 0xff) << 56);
   gdt[SEG_TSS+1] = (tss >> 32);
-  set_gdt(gdt, sizeof(SegDesc64) * (NR_SEG + 1));
+  set_gdt(gdt, sizeof(gdt[0]) * (NR_SEG + 1));
   set_tr(KSEL(SEG_TSS));
 #else
   SegDesc32 *gdt = CPU->gdt;
@@ -73,7 +73,8 @@ void __am_percpu_initgdt() {
   gdt[SEG_UCODE] = SEG32(STA_X | STA_R,   0,     0xffffffff, DPL_USER);
   gdt[SEG_UDATA] = SEG32(STA_W,           0,     0xffffffff, DPL_USER);
   gdt[SEG_TSS]   = SEG16(STS_T32A,      tss, sizeof(*tss)-1, DPL_KERN);
-  set_gdt(gdt, sizeof(SegDesc32) * NR_SEG);
+
+  set_gdt(gdt, sizeof(gdt[0]) * NR_SEG);
   set_tr(KSEL(SEG_TSS));
 #endif
 }

tests/amtest/src/tests/vm.c

@@ -31,7 +31,7 @@ _Context* vm_handler(_Event ev, _Context *ctx) {
         (ev.cause & _PROT_WRITE) ? "[write fail]" : "");
       break;
     case _EVENT_SYSCALL:
-      // printf("%d ", ctx->GPRx);
+      printf("%d ", ctx->GPRx);
       break;
     default:
       assert(0);