chore: comment context variants and use running

runtime/include/arch/common.h

@@ -30,10 +30,10 @@ typedef enum
 /* The enum is compared directly in assembly, so maintain integral values! */
 typedef enum
 {
-	arch_context_unused  = 0,
+	arch_context_unused  = 0, /* Has not have saved a context */
-	arch_context_fast    = 1,
+	arch_context_fast    = 1, /* Saved a fastpath context */
-	arch_context_slow    = 2,
+	arch_context_slow    = 2, /* Saved a slowpath context */
-	arch_context_running = 3
+	arch_context_running = 3  /* Context is executing and content is out of date */
 } arch_context_t;
 
 

runtime/include/arch/context.h

@@ -53,6 +53,7 @@ arch_mcontext_restore(mcontext_t *active_context, struct arch_context *sandbox_c
 	/* Restore mcontext */
 	memcpy(active_context, &sandbox_context->mctx, sizeof(mcontext_t));
 	memset(&sandbox_context->mctx, 0, sizeof(mcontext_t));
+	sandbox_context->variant = arch_context_running;
 }
 
 /**
@@ -77,6 +78,7 @@ arch_context_restore(mcontext_t *active_context, struct arch_context *sandbox_co
 	active_context->gregs[REG_RIP]  = sandbox_context->regs[ureg_rip] + ARCH_SIG_JMP_OFF;
 	sandbox_context->regs[ureg_rsp] = 0;
 	sandbox_context->regs[ureg_rip] = 0;
+	sandbox_context->variant        = arch_context_running;
 }
 
 /**