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start all processes, including VM, in VM_PROCSTART in linear address space,

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to make space for kernel to be able to map in things below there.
This commit is contained in:
Ben Gras 2009-05-11 19:11:37 +00:00
parent ade4c03b73
commit d2caeb6146
5 changed files with 125 additions and 289 deletions
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2
servers/vm/exec.c
View file

@ -221,7 +221,7 @@ SANITYCHECK(SCL_DETAIL);
SANITYCHECK(SCL_DETAIL);
proc_new(rmp,
kernel_top_bytes, /* where to start the process in the page table */
VM_PROCSTART, /* where to start the process in the page table */
CLICK2ABS(text_clicks),/* how big is the text in bytes, page-aligned */
CLICK2ABS(data_clicks),/* how big is data+bss, page-aligned */
CLICK2ABS(stack_clicks),/* how big is stack, page-aligned */

3
servers/vm/i386/memory.h
View file

@ -14,6 +14,9 @@
#define SLAB_PAGESIZE I386_PAGE_SIZE
#define VM_PAGE_SIZE I386_PAGE_SIZE
/* Where do processes start in linear (i.e. page table) memory? */
#define VM_PROCSTART (I386_BIG_PAGE_SIZE*10)
#define CLICKSPERPAGE (I386_PAGE_SIZE/CLICK_SIZE)
/* Where is the kernel? */

400
servers/vm/i386/pagetable.c
View file

@ -46,7 +46,7 @@ struct vmproc *vmp = &vmproc[VM_PROC_NR];
* circular dependency on allocating memory and writing it into VM's
* page table.
*/
#define SPAREPAGES 3
#define SPAREPAGES 5
static struct {
void *page;
u32_t phys;
@ -485,144 +485,8 @@ PUBLIC int pt_new(pt_t *pt)
return OK;
}
/*===========================================================================*
* pt_allocmap *
*===========================================================================*/
PUBLIC int pt_allocmap(pt_t *pt, vir_bytes v_min, vir_bytes v_max,
size_t bytes, u32_t pageflags, u32_t memflags, vir_bytes *v_final)
{
/* Allocate new memory, and map it into the page table. */
u32_t newpage;
u32_t v;
int r;
/* Input sanity check. */
PT_SANE(pt);
vm_assert(!(pageflags & ~PTF_ALLFLAGS));
/* Valid no-op. */
if(bytes == 0) return OK;
/* Round no. of bytes up to a page. */
if(bytes % I386_PAGE_SIZE) {
bytes += I386_PAGE_SIZE - (bytes % I386_PAGE_SIZE);
}
/* Special case; if v_max is 0, the request is to map the memory
* into v_min at exactly that location. We raise v_max as necessary,
* so the check to see if the virtual space is free does happen.
*/
if(v_max == 0) {
v_max = v_min + bytes;
/* Sanity check. */
if(v_max < v_min) {
printf("pt_allocmap: v_min 0x%lx and bytes 0x%lx\n",
v_min, bytes);
return ENOMEM;
}
}
/* Basic sanity check. */
if(v_max < v_min) {
printf("pt_allocmap: v_min 0x%lx, v_max 0x%lx\n", v_min, v_max);
return ENOMEM;
}
/* v_max itself may not be used. Bytes may be 0. */
if(v_max < v_min + bytes) {
printf("pt_allocmap: v_min 0x%lx, bytes 0x%lx, v_max 0x%lx\n",
v_min, bytes, v_max);
return ENOMEM;
}
/* Find where to fit this into the virtual address space. */
v = findhole(pt, bytes, v_min, v_max);
if(v == NO_MEM) {
printf("pt_allocmap: no hole found to map 0x%lx bytes into\n",
bytes);
return ENOSPC;
}
vm_assert(!(v % I386_PAGE_SIZE));
if(v_final) *v_final = v;
/* Memory is currently always allocated contiguously physically,
* but if that were to change, note the setting of
* PAF_CONTIG in memflags.
*/
newpage = ALLOC_MEM(CLICKSPERPAGE * bytes / I386_PAGE_SIZE, memflags);
if(newpage == NO_MEM) {
printf("pt_allocmap: out of memory\n");
return ENOMEM;
}
/* Write into the page table. */
if((r=pt_writemap(pt, v, CLICK2ABS(newpage), bytes,
pageflags | PTF_MAPALLOC, 0)) != OK) {
FREE_MEM(newpage, CLICKSPERPAGE * bytes / I386_PAGE_SIZE);
return r;
}
/* Sanity check result. */
PT_SANE(pt);
return OK;
}
/*===========================================================================*
* raw_readmap *
*===========================================================================*/
PRIVATE int raw_readmap(phys_bytes root, u32_t v, u32_t *phys, u32_t *flags)
{
u32_t dir[I386_VM_DIR_ENTRIES];
u32_t tab[I386_VM_PT_ENTRIES];
int pde, pte, r;
/* Sanity check. */
vm_assert((root % I386_PAGE_SIZE) == 0);
vm_assert((v % I386_PAGE_SIZE) == 0);
/* Get entry in page directory. */
pde = I386_VM_PDE(v);
if((r=sys_physcopy(SYSTEM, PHYS_SEG, root,
SELF, VM_D, (phys_bytes) dir, sizeof(dir))) != OK) {
printf("VM: raw_readmap: sys_physcopy failed (dir) (%d)\n", r);
return EFAULT;
}
if(!(dir[pde] & I386_VM_PRESENT)) {
printf("raw_readmap: 0x%lx: pde %d not present: 0x%lx\n",
v, pde, dir[pde]);
return EFAULT;
}
/* Get entry in page table. */
if((r=sys_physcopy(SYSTEM, PHYS_SEG, I386_VM_PFA(dir[pde]),
SELF, VM_D, (vir_bytes) tab, sizeof(tab))) != OK) {
printf("VM: raw_readmap: sys_physcopy failed (tab) (r)\n");
return EFAULT;
}
pte = I386_VM_PTE(v);
if(!(tab[pte] & I386_VM_PRESENT)) {
printf("raw_readmap: 0x%lx: pde %d not present: 0x%lx\n",
v, pte, tab[pte]);
return EFAULT;
}
/* Get address and flags. */
*phys = I386_VM_PFA(tab[pte]);
*flags = tab[pte] & PTF_ALLFLAGS;
return OK;
}
/*===========================================================================*
* pt_init *
* pt_init *
*===========================================================================*/
PUBLIC void pt_init(void)
{
@ -632,102 +496,127 @@ PUBLIC void pt_init(void)
* 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.
*/
u32_t my_cr3;
pt_t *newpt;
int s, r;
vir_bytes v;
phys_bytes lo, hi;
vir_bytes extra_clicks;
pt_t *newpt;
int s, r;
vir_bytes v;
phys_bytes lo, hi;
vir_bytes extra_clicks;
u32_t moveup = 0;
/* Shorthand. */
newpt = &vmp->vm_pt;
/* Retrieve current CR3 - shared page table. */
if((r=sys_vmctl_get_cr3_i386(SELF, &my_cr3)) != OK)
vm_panic("pt_init: sys_vmctl_get_cr3_i386 failed", r);
/* Shorthand. */
newpt = &vmp->vm_pt;
/* Get ourselves a spare page. */
for(s = 0; s < SPAREPAGES; s++) {
if(!(sparepages[s].page = aalloc(I386_PAGE_SIZE)))
vm_panic("pt_init: aalloc for spare failed", NO_NUM);
if((r=sys_umap(SELF, VM_D, (vir_bytes) sparepages[s].page,
I386_PAGE_SIZE, &sparepages[s].phys)) != OK)
vm_panic("pt_init: sys_umap failed", r);
}
/* Make new page table for ourselves, partly copied
* from the current one.
*/
if(pt_new(newpt) != OK)
vm_panic("pt_init: pt_new failed", NO_NUM);
/* Initial (current) range of our virtual address space. */
lo = CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_phys);
hi = CLICK2ABS(vmp->vm_arch.vm_seg[S].mem_phys +
vmp->vm_arch.vm_seg[S].mem_len);
/* Copy the mappings from the shared page table to our private one. */
for(v = lo; v < hi; v += I386_PAGE_SIZE) {
phys_bytes addr;
u32_t flags;
if(raw_readmap(my_cr3, v, &addr, &flags) != OK)
vm_panic("pt_init: raw_readmap failed", NO_NUM);
if(pt_writemap(newpt, v, addr, I386_PAGE_SIZE, flags, 0) != OK)
vm_panic("pt_init: pt_writemap failed", NO_NUM);
}
/* Map in kernel. */
if(pt_mapkernel(newpt) != OK)
vm_panic("pt_init: pt_mapkernel failed", NO_NUM);
/* Give our process the new, copied, private page table. */
pt_bind(newpt, vmp);
/* 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);
vmp->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.
*/
/* Get ourselves a spare page. */
for(s = 0; s < SPAREPAGES; s++) {
if(!(sparepages[s].page = aalloc(I386_PAGE_SIZE)))
vm_panic("pt_init: aalloc for spare failed", NO_NUM);
if((r=sys_umap(SELF, VM_D, (vir_bytes) sparepages[s].page,
I386_PAGE_SIZE, &sparepages[s].phys)) != OK)
vm_panic("pt_init: sys_umap failed", r);
}
/* Make new page table for ourselves, partly copied
* from the current one.
*/
if(pt_new(newpt) != OK)
vm_panic("pt_init: pt_new failed", NO_NUM);
/* Initial (current) range of our virtual address space. */
lo = CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_phys);
hi = CLICK2ABS(vmp->vm_arch.vm_seg[S].mem_phys +
vmp->vm_arch.vm_seg[S].mem_len);
vm_assert(!(lo % I386_PAGE_SIZE));
vm_assert(!(hi % I386_PAGE_SIZE));
if(lo < VM_PROCSTART) {
moveup = VM_PROCSTART - lo;
vm_assert(!(VM_PROCSTART % I386_PAGE_SIZE));
vm_assert(!(lo % I386_PAGE_SIZE));
vm_assert(!(moveup % I386_PAGE_SIZE));
}
/* Set up mappings for VM process. */
for(v = lo; v < hi; v += I386_PAGE_SIZE) {
phys_bytes addr;
u32_t flags;
/* We have to write the old and new position in the PT,
* so we can move our segments.
*/
if(pt_writemap(newpt, v+moveup, v, I386_PAGE_SIZE,
I386_VM_PRESENT|I386_VM_WRITE|I386_VM_USER, 0) != OK)
vm_panic("pt_init: pt_writemap failed", NO_NUM);
if(pt_writemap(newpt, v, v, I386_PAGE_SIZE,
I386_VM_PRESENT|I386_VM_WRITE|I386_VM_USER, 0) != OK)
vm_panic("pt_init: pt_writemap failed", NO_NUM);
}
/* Move segments up too. */
vmp->vm_arch.vm_seg[T].mem_phys += ABS2CLICK(moveup);
vmp->vm_arch.vm_seg[D].mem_phys += ABS2CLICK(moveup);
vmp->vm_arch.vm_seg[S].mem_phys += ABS2CLICK(moveup);
/* Map in kernel. */
if(pt_mapkernel(newpt) != OK)
vm_panic("pt_init: pt_mapkernel failed", NO_NUM);
/* Give our process the new, copied, private page table. */
pt_bind(newpt, vmp);
/* 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);
vmp->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.
*/
vmp->vm_arch.vm_data_top =
(vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
(vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
if((s=sys_newmap(VM_PROC_NR, vmp->vm_arch.vm_seg)) != OK)
vm_panic("VM: pt_init: sys_newmap failed", s);
/* Back to reality - this is where the stack actually is. */
vmp->vm_arch.vm_seg[S].mem_len -= extra_clicks;
/* Wipe old mappings from VM. */
for(v = lo; v < hi; v += I386_PAGE_SIZE) {
if(pt_writemap(newpt, v, MAP_NONE, I386_PAGE_SIZE,
0, WMF_OVERWRITE) != OK)
vm_panic("pt_init: pt_writemap failed", NO_NUM);
}
/* Where our free virtual address space starts.
* This is only a hint to the VM system.
*/
newpt->pt_virtop = (vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
if((s=sys_newmap(VM_PROC_NR, vmp->vm_arch.vm_seg)) != OK)
vm_panic("VM: pt_init: sys_newmap failed", s);
/* Let other functions know VM now has a private page table. */
vmp->vm_flags |= VMF_HASPT;
/* Back to reality - this is where the stack actually is. */
vmp->vm_arch.vm_seg[S].mem_len -= extra_clicks;
/* Reserve a page in our virtual address space that we
* can use to map in arbitrary physical pages.
*/
varmap_loc = findhole(newpt, I386_PAGE_SIZE,
CLICK2ABS(vmp->vm_arch.vm_seg[D].mem_phys) + vmp->vm_stacktop,
vmp->vm_arch.vm_data_top);
if(varmap_loc == NO_MEM) {
vm_panic("no virt addr for vm mappings", NO_NUM);
}
varmap = (unsigned char *) (varmap_loc -
CLICK2ABS(vmp->vm_arch.vm_seg[D].mem_phys));
/* Where our free virtual address space starts.
* This is only a hint to the VM system.
*/
newpt->pt_virtop = (vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
/* Let other functions know VM now has a private page table. */
vmp->vm_flags |= VMF_HASPT;
/* Reserve a page in our virtual address space that we
* can use to map in arbitrary physical pages.
*/
varmap_loc = findhole(newpt, I386_PAGE_SIZE,
CLICK2ABS(vmp->vm_arch.vm_seg[D].mem_phys) + vmp->vm_stacktop,
vmp->vm_arch.vm_data_top);
if(varmap_loc == NO_MEM) {
vm_panic("no virt addr for vm mappings", NO_NUM);
}
varmap = (unsigned char *) (varmap_loc -
CLICK2ABS(vmp->vm_arch.vm_seg[D].mem_phys));
/* All OK. */
return;
/* All OK. */
return;
}
/*===========================================================================*
* pt_bind *
*===========================================================================*/
@ -834,63 +723,6 @@ PUBLIC void pt_cycle(void)
vm_checkspares();
}
/*===========================================================================*
* pt_copy *
*===========================================================================*/
PUBLIC int pt_copy(pt_t *src, pt_t *dst)
{
int i, r;
SANITYCHECK(SCL_FUNCTIONS);
PT_SANE(src);
if((r=pt_new(dst)) != OK)
return r;
for(i = 0; i < I386_VM_DIR_ENTRIES; i++) {
int p;
if(!(src->pt_dir[i] & I386_VM_PRESENT))
continue;
for(p = 0; p < I386_VM_PT_ENTRIES; p++) {
u32_t v = i * I386_VM_PT_ENTRIES * I386_PAGE_SIZE +
p * I386_PAGE_SIZE;
u32_t pa1, pa2, flags;
if(!(src->pt_pt[i][p] & I386_VM_PRESENT))
continue;
#if 0
if((dst->pt_pt[i] &&
(dst->pt_pt[i][p] & I386_VM_PRESENT)))
continue;
#endif
flags = src->pt_pt[i][p] & (PTF_WRITE | PTF_USER);
flags |= I386_VM_PRESENT;
pa1 = I386_VM_PFA(src->pt_pt[i][p]);
if(PTF_MAPALLOC & src->pt_pt[i][p]) {
PT_SANE(dst);
if(pt_allocmap(dst, v, 0,
I386_PAGE_SIZE, flags, 0, NULL) != OK) {
pt_free(dst);
return ENOMEM;
}
pa2 = I386_VM_PFA(dst->pt_pt[i][p]);
sys_abscopy(pa1, pa2, I386_PAGE_SIZE);
} else {
PT_SANE(dst);
if(pt_writemap(dst, v, pa1, I386_PAGE_SIZE, flags, 0) != OK) {
pt_free(dst);
return ENOMEM;
}
}
}
}
PT_SANE(src);
PT_SANE(dst);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
#define PHYS_MAP(a, o) \
{ int r; \
vm_assert(varmap); \

6
servers/vm/main.c
View file

@ -298,7 +298,7 @@ PRIVATE void vm_init(void)
old_stack);
proc_new(vmp,
CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_phys),
VM_PROCSTART,
CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_len),
CLICK2ABS(vmp->vm_arch.vm_seg[D].mem_len),
BASICSTACK,
@ -356,6 +356,10 @@ PRIVATE void vm_init(void)
CALLMAP(VM_VFS_REPLY_OPEN, do_vfs_reply, VFS_PROC_NR);
CALLMAP(VM_VFS_REPLY_MMAP, do_vfs_reply, VFS_PROC_NR);
CALLMAP(VM_VFS_REPLY_CLOSE, do_vfs_reply, VFS_PROC_NR);
/* Sanity checks */
if(find_kernel_top() >= VM_PROCSTART)
vm_panic("kernel loaded too high", NO_NUM);
}
#if 0

3
servers/vm/proto.h
View file

@ -85,11 +85,8 @@ _PROTOTYPE( char *pf_errstr, (u32_t err));
/* $(ARCH)/pagetable.c */
_PROTOTYPE( void pt_init, (void) );
_PROTOTYPE( int pt_new, (pt_t *pt) );
_PROTOTYPE( int pt_copy, (pt_t *src, pt_t *dst) );
_PROTOTYPE( void pt_free, (pt_t *pt) );
_PROTOTYPE( void pt_freerange, (pt_t *pt, vir_bytes lo, vir_bytes hi) );
_PROTOTYPE( int pt_allocmap, (pt_t *pt, vir_bytes minv, vir_bytes maxv,
size_t bytes, u32_t pageflags, u32_t allocflags, vir_bytes *newv));
_PROTOTYPE( int pt_writemap, (pt_t *pt, vir_bytes v, phys_bytes physaddr,
size_t bytes, u32_t flags, u32_t writemapflags));
_PROTOTYPE( int pt_bind, (pt_t *pt, struct vmproc *who) );