/*===========================================================================*
* do_rs_update *
*===========================================================================*/
int do_rs_update(message *m_ptr)
{
endpoint_t src_e, dst_e, reply_e;
int src_p, dst_p;
struct vmproc *src_vmp, *dst_vmp;
int r, sys_upd_flags;
src_e = m_ptr->m_lsys_vm_update.src;
dst_e = m_ptr->m_lsys_vm_update.dst;
sys_upd_flags = m_ptr->m_lsys_vm_update.flags;
reply_e = m_ptr->m_source;
/* Lookup slots for source and destination process. */
if(vm_isokendpt(src_e, &src_p) != OK) {
printf("do_rs_update: bad src endpoint %d\n", src_e);
return EINVAL;
}
src_vmp = &vmproc[src_p];
if(vm_isokendpt(dst_e, &dst_p) != OK) {
printf("do_rs_update: bad dst endpoint %d\n", dst_e);
return EINVAL;
}
dst_vmp = &vmproc[dst_p];
/* Check flags. */
if((sys_upd_flags & (SF_VM_ROLLBACK|SF_VM_NOMMAP)) == 0) {
/* Can't preallocate when transfering mmapped regions. */
if(map_region_lookup_type(dst_vmp, VR_PREALLOC_MAP)) {
return ENOSYS;
}
}
/* Let the kernel do the update first. */
r = sys_update(src_e, dst_e,
sys_upd_flags & SF_VM_ROLLBACK ? SYS_UPD_ROLLBACK : 0);
if(r != OK) {
return r;
}
/* Do the update in VM now. */
r = swap_proc_slot(src_vmp, dst_vmp);
if(r != OK) {
return r;
}
r = swap_proc_dyn_data(src_vmp, dst_vmp, sys_upd_flags);
if(r != OK) {
return r;
}
pt_bind(&src_vmp->vm_pt, src_vmp);
pt_bind(&dst_vmp->vm_pt, dst_vmp);
/* Reply in case of external request, update-aware. */
if(reply_e != VM_PROC_NR) {
if(reply_e == src_e) reply_e = dst_e;
else if(reply_e == dst_e) reply_e = src_e;
m_ptr->m_type = OK;
r = ipc_send(reply_e, m_ptr);
if(r != OK) {
panic("ipc_send() error");
}
}
return SUSPEND;
}
/*===========================================================================*
* pt_init_mem *
*===========================================================================*/
PUBLIC void pt_init_mem()
{
/* Architecture-specific memory initialization. Make sure all the pages
* shared with the kernel and VM's page tables are mapped above the stack,
* so that we can easily transfer existing mappings for new VM instances.
*/
phys_bytes new_page_directories_phys;
u32_t *new_page_directories;
phys_bytes new_pt_dir_phys;
u32_t *new_pt_dir;
phys_bytes new_pt_phys;
u32_t *new_pt;
pt_t *vmpt;
int i;
vmpt = &vmprocess->vm_pt;
/* We should be running this when VM has been assigned a page
* table and memory initialization has already been performed.
*/
assert(vmprocess->vm_flags & VMF_HASPT);
assert(meminit_done);
/* Throw away static spare pages. */
vm_checkspares();
for(i = 0; i < SPAREPAGES; i++) {
if(sparepages[i].page && (vir_bytes) sparepages[i].page
< vmprocess->vm_stacktop) {
sparepages[i].page = NULL;
missing_spares++;
}
}
vm_checkspares();
/* Rellocate page for page directories pointers. */
if(!(new_page_directories = vm_allocpage(&new_page_directories_phys,
VMP_PAGETABLE)))
panic("unable to reallocated page for page dir ptrs");
assert((vir_bytes) new_page_directories >= vmprocess->vm_stacktop);
memcpy(new_page_directories, page_directories, I386_PAGE_SIZE);
page_directories = new_page_directories;
pagedir_pde_val = (new_page_directories_phys & I386_VM_ADDR_MASK) |
(pagedir_pde_val & ~I386_VM_ADDR_MASK);
/* Remap in kernel. */
pt_mapkernel(vmpt);
/* Reallocate VM's page directory. */
if((vir_bytes) vmpt->pt_dir < vmprocess->vm_stacktop) {
if(!(new_pt_dir= vm_allocpage(&new_pt_dir_phys, VMP_PAGEDIR))) {
panic("unable to reallocate VM's page directory");
}
assert((vir_bytes) new_pt_dir >= vmprocess->vm_stacktop);
memcpy(new_pt_dir, vmpt->pt_dir, I386_PAGE_SIZE);
vmpt->pt_dir = new_pt_dir;
vmpt->pt_dir_phys = new_pt_dir_phys;
pt_bind(vmpt, vmprocess);
}
/* Reallocate VM's page tables. */
for(i = proc_pde; i < I386_VM_DIR_ENTRIES; i++) {
if(!(vmpt->pt_dir[i] & I386_VM_PRESENT)) {
continue;
}
assert(vmpt->pt_pt[i]);
if((vir_bytes) vmpt->pt_pt[i] >= vmprocess->vm_stacktop) {
continue;
}
vm_checkspares();
if(!(new_pt = vm_allocpage(&new_pt_phys, VMP_PAGETABLE)))
panic("unable to reallocate VM's page table");
assert((vir_bytes) new_pt >= vmprocess->vm_stacktop);
memcpy(new_pt, vmpt->pt_pt[i], I386_PAGE_SIZE);
vmpt->pt_pt[i] = new_pt;
vmpt->pt_dir[i] = (new_pt_phys & I386_VM_ADDR_MASK) |
(vmpt->pt_dir[i] & ~I386_VM_ADDR_MASK);
}
}
/*===========================================================================*
* pt_init *
*===========================================================================*/
PUBLIC void pt_init(phys_bytes usedlimit)
{
/* By default, the kernel gives us a data segment with pre-allocated
* memory that then can't grow. We want to be able to allocate memory
* dynamically, however. So here we copy the part of the page table
* that's ours, so we get a private page table. Then we increase the
* hardware segment size so we can allocate memory above our stack.
*/
pt_t *newpt;
int s, r;
vir_bytes v;
phys_bytes lo, hi;
vir_bytes extra_clicks;
u32_t moveup = 0;
int global_bit_ok = 0;
int free_pde;
struct vm_ep_data ep_data;
vir_bytes sparepages_mem;
phys_bytes sparepages_ph;
vir_bytes ptr;
int f = 0;
/* Shorthand. */
newpt = &vmprocess->vm_pt;
/* Get ourselves spare pages. */
ptr = (vir_bytes) static_sparepages;
ptr += I386_PAGE_SIZE - (ptr % I386_PAGE_SIZE);
if(!(sparepages_mem = ptr))
panic("pt_init: aalloc for spare failed");
if((r=sys_umap(SELF, VM_D, (vir_bytes) sparepages_mem,
I386_PAGE_SIZE*SPAREPAGES, &sparepages_ph)) != OK)
panic("pt_init: sys_umap failed: %d", r);
missing_spares = 0;
assert(STATIC_SPAREPAGES < SPAREPAGES);
for(s = 0; s < SPAREPAGES; s++) {
if(s >= STATIC_SPAREPAGES) {
sparepages[s].page = NULL;
missing_spares++;
continue;
}
sparepages[s].page = (void *) (sparepages_mem + s*I386_PAGE_SIZE);
sparepages[s].phys = sparepages_ph + s*I386_PAGE_SIZE;
}
/* global bit and 4MB pages available? */
global_bit_ok = _cpufeature(_CPUF_I386_PGE);
bigpage_ok = _cpufeature(_CPUF_I386_PSE);
/* Set bit for PTE's and PDE's if available. */
if(global_bit_ok)
global_bit = I386_VM_GLOBAL;
/* The kernel and boot time processes need an identity mapping.
* We use full PDE's for this without separate page tables.
* Figure out which pde we can start using for other purposes.
*/
id_map_high_pde = usedlimit / I386_BIG_PAGE_SIZE;
/* We have to make mappings up till here. */
free_pde = id_map_high_pde+1;
/* Initial (current) range of our virtual address space. */
lo = CLICK2ABS(vmprocess->vm_arch.vm_seg[T].mem_phys);
hi = CLICK2ABS(vmprocess->vm_arch.vm_seg[S].mem_phys +
vmprocess->vm_arch.vm_seg[S].mem_len);
assert(!(lo % I386_PAGE_SIZE));
assert(!(hi % I386_PAGE_SIZE));
if(lo < VM_PROCSTART) {
moveup = VM_PROCSTART - lo;
assert(!(VM_PROCSTART % I386_PAGE_SIZE));
assert(!(lo % I386_PAGE_SIZE));
assert(!(moveup % I386_PAGE_SIZE));
}
/* Make new page table for ourselves, partly copied
* from the current one.
*/
if(pt_new(newpt) != OK)
panic("pt_init: pt_new failed");
/* Set up mappings for VM process. */
for(v = lo; v < hi; v += I386_PAGE_SIZE) {
/* We have to write the new position in the PT,
* so we can move our segments.
*/
if(pt_writemap(vmprocess, newpt, v+moveup, v, I386_PAGE_SIZE,
I386_VM_PRESENT|I386_VM_WRITE|I386_VM_USER, 0) != OK)
panic("pt_init: pt_writemap failed");
}
/* Move segments up too. */
vmprocess->vm_arch.vm_seg[T].mem_phys += ABS2CLICK(moveup);
vmprocess->vm_arch.vm_seg[D].mem_phys += ABS2CLICK(moveup);
vmprocess->vm_arch.vm_seg[S].mem_phys += ABS2CLICK(moveup);
/* Allocate us a page table in which to remember page directory
* pointers.
*/
if(!(page_directories = vm_allocpage(&page_directories_phys,
VMP_PAGETABLE)))
panic("no virt addr for vm mappings");
memset(page_directories, 0, I386_PAGE_SIZE);
/* Increase our hardware data segment to create virtual address
* space above our stack. We want to increase it to VM_DATATOP,
* like regular processes have.
*/
extra_clicks = ABS2CLICK(VM_DATATOP - hi);
vmprocess->vm_arch.vm_seg[S].mem_len += extra_clicks;
/* We pretend to the kernel we have a huge stack segment to
* increase our data segment.
*/
vmprocess->vm_arch.vm_data_top =
(vmprocess->vm_arch.vm_seg[S].mem_vir +
vmprocess->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
/* Where our free virtual address space starts.
* This is only a hint to the VM system.
*/
newpt->pt_virtop = 0;
/* Let other functions know VM now has a private page table. */
vmprocess->vm_flags |= VMF_HASPT;
/* Now reserve another pde for kernel's own mappings. */
{
int kernmap_pde;
phys_bytes addr, len;
int flags, index = 0;
u32_t offset = 0;
kernmap_pde = free_pde++;
offset = kernmap_pde * I386_BIG_PAGE_SIZE;
while(sys_vmctl_get_mapping(index, &addr, &len,
&flags) == OK) {
vir_bytes vir;
if(index >= MAX_KERNMAPPINGS)
panic("VM: too many kernel mappings: %d", index);
kern_mappings[index].phys_addr = addr;
kern_mappings[index].len = len;
kern_mappings[index].flags = flags;
kern_mappings[index].lin_addr = offset;
kern_mappings[index].flags =
I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE |
global_bit;
if(flags & VMMF_UNCACHED)
kern_mappings[index].flags |= PTF_NOCACHE;
if(addr % I386_PAGE_SIZE)
panic("VM: addr unaligned: %d", addr);
if(len % I386_PAGE_SIZE)
panic("VM: len unaligned: %d", len);
vir = arch_map2vir(&vmproc[VMP_SYSTEM], offset);
if(sys_vmctl_reply_mapping(index, vir) != OK)
panic("VM: reply failed");
offset += len;
index++;
kernmappings++;
}
}
/* Find a PDE below processes available for mapping in the
* page directories (readonly).
*/
pagedir_pde = free_pde++;
pagedir_pde_val = (page_directories_phys & I386_VM_ADDR_MASK) |
I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE;
/* Tell kernel about free pde's. */
first_free_pde = free_pde;
while(free_pde*I386_BIG_PAGE_SIZE < VM_PROCSTART && f < FREE_PDES) {
if((r=sys_vmctl(SELF, VMCTL_I386_FREEPDE, free_pde++)) != OK) {
panic("VMCTL_I386_FREEPDE failed: %d", r);
}
f++;
}
/* first pde in use by process. */
proc_pde = free_pde;
/* Give our process the new, copied, private page table. */
pt_mapkernel(newpt); /* didn't know about vm_dir pages earlier */
pt_bind(newpt, vmprocess);
/* new segment limit for the kernel after paging is enabled */
ep_data.data_seg_limit = free_pde*I386_BIG_PAGE_SIZE;
/* the memory map which must be installed after paging is enabled */
ep_data.mem_map = vmprocess->vm_arch.vm_seg;
/* Now actually enable paging. */
if(sys_vmctl_enable_paging(&ep_data) != OK)
panic("pt_init: enable paging failed");
/* Back to reality - this is where the stack actually is. */
vmprocess->vm_arch.vm_seg[S].mem_len -= extra_clicks;
/* Pretend VM stack top is the same as any regular process, not to
* have discrepancies with new VM instances later on.
*/
vmprocess->vm_stacktop = VM_STACKTOP;
/* All OK. */
return;
}
/*===========================================================================*
* do_fork *
*===========================================================================*/
int do_fork(message *msg)
{
int r, proc, childproc;
struct vmproc *vmp, *vmc;
pt_t origpt;
vir_bytes msgaddr;
SANITYCHECK(SCL_FUNCTIONS);
if(vm_isokendpt(msg->VMF_ENDPOINT, &proc) != OK) {
printf("VM: bogus endpoint VM_FORK %d\n", msg->VMF_ENDPOINT);
SANITYCHECK(SCL_FUNCTIONS);
return EINVAL;
}
childproc = msg->VMF_SLOTNO;
if(childproc < 0 || childproc >= NR_PROCS) {
printf("VM: bogus slotno VM_FORK %d\n", msg->VMF_SLOTNO);
SANITYCHECK(SCL_FUNCTIONS);
return EINVAL;
}
vmp = &vmproc[proc]; /* parent */
vmc = &vmproc[childproc]; /* child */
assert(vmc->vm_slot == childproc);
/* The child is basically a copy of the parent. */
origpt = vmc->vm_pt;
*vmc = *vmp;
vmc->vm_slot = childproc;
region_init(&vmc->vm_regions_avl);
vmc->vm_endpoint = NONE; /* In case someone tries to use it. */
vmc->vm_pt = origpt;
#if VMSTATS
vmc->vm_bytecopies = 0;
#endif
if(pt_new(&vmc->vm_pt) != OK) {
return ENOMEM;
}
SANITYCHECK(SCL_DETAIL);
if(map_proc_copy(vmc, vmp) != OK) {
printf("VM: fork: map_proc_copy failed\n");
pt_free(&vmc->vm_pt);
return(ENOMEM);
}
/* Only inherit these flags. */
vmc->vm_flags &= VMF_INUSE;
/* inherit the priv call bitmaps */
memcpy(&vmc->vm_call_mask, &vmp->vm_call_mask, sizeof(vmc->vm_call_mask));
/* Tell kernel about the (now successful) FORK. */
if((r=sys_fork(vmp->vm_endpoint, childproc,
&vmc->vm_endpoint, PFF_VMINHIBIT, &msgaddr)) != OK) {
panic("do_fork can't sys_fork: %d", r);
}
if((r=pt_bind(&vmc->vm_pt, vmc)) != OK)
panic("fork can't pt_bind: %d", r);
{
vir_bytes vir;
/* making these messages writable is an optimisation
* and its return value needn't be checked.
*/
vir = msgaddr;
if (handle_memory(vmc, vir, sizeof(message), 1, NULL, 0, 0) != OK)
panic("do_fork: handle_memory for child failed\n");
vir = msgaddr;
if (handle_memory(vmp, vir, sizeof(message), 1, NULL, 0, 0) != OK)
panic("do_fork: handle_memory for parent failed\n");
}
/* Inform caller of new child endpoint. */
msg->VMF_CHILD_ENDPOINT = vmc->vm_endpoint;
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
