allow kernel to tell VM extra physical addresses it wants mapped in.

used in the future for mapping in local APIC memory.

include/minix/com.h

@@ -608,6 +608,14 @@
 #define SVMCTL_MRG_WRITE	m1_i2	/* MEMREQ_GET reply: writeflag */
 #define SVMCTL_MRG_EP		m1_i3	/* MEMREQ_GET reply: process */
 #define SVMCTL_MRG_REQUESTOR	m1_p2	/* MEMREQ_GET reply: requestor */
+#define SVMCTL_MAP_VIR_ADDR	m1_p1
+
+/* Reply message for VMCTL_KERN_PHYSMAP */
+#define SVMCTL_MAP_FLAGS	m2_i1	/* VMMF_* */
+#define SVMCTL_MAP_PHYS_ADDR	m2_l1
+#define SVMCTL_MAP_PHYS_LEN	m2_l2
+
+#define VMMF_UNCACHED		(1L << 0)
 
 /* Codes and field names for SYS_SYSCTL. */
 #define SYSCTL_CODE		m1_i1	/* SYSCTL_CODE_* below */
@@ -632,6 +640,8 @@
 #define VMCTL_ENABLE_PAGING	24
 #define VMCTL_I386_INVLPG	25
 #define VMCTL_FLUSHTLB		26
+#define VMCTL_KERN_PHYSMAP	27
+#define VMCTL_KERN_MAP_REPLY	28
 
 /* Field names for SYS_VTIMER. */
 #define VT_WHICH	m2_i1	/* which timer to set/retrieve */

include/minix/syslib.h

@@ -68,6 +68,9 @@ _PROTOTYPE( int sys_readbios, (phys_bytes address, void *buf, size_t size));
 _PROTOTYPE( int sys_stime, (time_t boottime));
 _PROTOTYPE( int sys_sysctl, (int ctl, char *arg1, int arg2));
 _PROTOTYPE( int sys_sysctl_stacktrace, (endpoint_t who));
+_PROTOTYPE( int sys_vmctl_get_mapping, (int index, phys_bytes *addr,
+	phys_bytes *len, int *flags));
+_PROTOTYPE( int sys_vmctl_reply_mapping, (int index, vir_bytes addr));
 
 /* Shorthands for sys_sdevio() system call. */
 #define sys_insb(port, proc_ep, buffer, count) \

kernel/arch/i386/memory.c

@@ -715,7 +715,7 @@ void vm_print(u32_t *root)
 
 	printf("page table 0x%lx:\n", root);
 
-	for(pde = 10; pde < I386_VM_DIR_ENTRIES; pde++) {
+	for(pde = 0; pde < I386_VM_DIR_ENTRIES; pde++) {
 		u32_t pde_v;
 		u32_t *pte_a;
 		pde_v = phys_get32((u32_t) (root + pde));
@@ -1028,3 +1028,19 @@ void i386_freepde(int pde)
 		return;
 	freepdes[nfreepdes++] = pde;
 }
+
+PUBLIC arch_phys_map(int index, phys_bytes *addr, phys_bytes *len, int *flags)
+{
+	/* we don't want anything */
+	return EINVAL;
+}
+
+PUBLIC arch_phys_map_reply(int index, vir_bytes addr)
+{
+	return OK;
+}
+
+PUBLIC int arch_enable_paging(void)
+{
+	return OK;
+}

kernel/proto.h

@@ -161,5 +161,9 @@ _PROTOTYPE( int vm_suspend, (struct proc *caller, struct proc *target,
 	phys_bytes lin, phys_bytes size, int wrflag, int type));
 _PROTOTYPE( int delivermsg, (struct proc *target));
 _PROTOTYPE( void arch_do_syscall, (struct proc *proc)			);
+_PROTOTYPE( int arch_phys_map, (int index, phys_bytes *addr,
+	phys_bytes *len, int *flags));
+_PROTOTYPE( int arch_phys_map_reply, (int index, vir_bytes addr));
+_PROTOTYPE( int arch_enable_paging, (void));
 
 #endif /* PROTO_H */

kernel/system/do_vmctl.c

@@ -22,6 +22,7 @@ register message *m_ptr;	/* pointer to request message */
   int proc_nr, i;
   endpoint_t ep = m_ptr->SVMCTL_WHO;
   struct proc *p, *rp, *target;
+  int err;
 
   if(ep == SELF) { ep = m_ptr->m_source; }
 
@@ -119,6 +120,11 @@ register message *m_ptr;	/* pointer to request message */
 
 		return OK;
 	case VMCTL_ENABLE_PAGING:
+		/*
+		 * system task must not get preempted while switching to paging,
+		 * interrupt handling is not safe
+		 */
+		lock;
 		if(vm_running) 
 			minix_panic("do_vmctl: paging already enabled", NO_NUM);
 		vm_init(p);
@@ -126,11 +132,29 @@ register message *m_ptr;	/* pointer to request message */
 			minix_panic("do_vmctl: paging enabling failed", NO_NUM);
 		vmassert(p->p_delivermsg_lin ==
 		  umap_local(p, D, p->p_delivermsg_vir, sizeof(message)));
+		if ((err = arch_enable_paging()) != OK) {
+			unlock;
+			return err;
+		}
 		if(newmap(p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
 			minix_panic("do_vmctl: newmap failed", NO_NUM);
 		FIXLINMSG(p);
 		vmassert(p->p_delivermsg_lin);
+		unlock;
 		return OK;
+	case VMCTL_KERN_PHYSMAP:
+	{
+		int i = m_ptr->SVMCTL_VALUE;
+		return arch_phys_map(i,
+			(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_ADDR,
+			(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_LEN,
+			&m_ptr->SVMCTL_MAP_FLAGS);
+	}
+	case VMCTL_KERN_MAP_REPLY:
+	{
+		return arch_phys_map_reply(m_ptr->SVMCTL_VALUE,
+			(vir_bytes) m_ptr->SVMCTL_MAP_VIR_ADDR);
+	}
   }
 
   /* Try architecture-specific vmctls. */

lib/syslib/sys_vmctl.c

@@ -69,3 +69,38 @@ PUBLIC int sys_vmctl_enable_paging(struct mem_map *map)
 	m.SVMCTL_VALUE = (int) map;
 	return _taskcall(SYSTASK, SYS_VMCTL, &m);
 }
+
+PUBLIC int sys_vmctl_get_mapping(int index,
+	phys_bytes *addr, phys_bytes *len, int *flags)
+{
+	int r;
+	message m;
+
+	m.SVMCTL_WHO = SELF;
+	m.SVMCTL_PARAM = VMCTL_KERN_PHYSMAP;
+	m.SVMCTL_VALUE = (int) index;
+
+	r = _taskcall(SYSTASK, SYS_VMCTL, &m);
+
+	if(r != OK)
+		return r;
+
+	*addr = m.SVMCTL_MAP_PHYS_ADDR;
+	*len = m.SVMCTL_MAP_PHYS_LEN;
+	*flags = m.SVMCTL_MAP_FLAGS;
+
+	return OK;
+}
+
+PUBLIC int sys_vmctl_reply_mapping(int index, vir_bytes addr)
+{
+	int r;
+	message m;
+
+	m.SVMCTL_WHO = SELF;
+	m.SVMCTL_PARAM = VMCTL_KERN_MAP_REPLY;
+	m.SVMCTL_VALUE = index;
+	m.SVMCTL_MAP_VIR_ADDR = (char *) addr;
+
+	return _taskcall(SYSTASK, SYS_VMCTL, &m);
+}