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minix/servers/vm/region.c
Tomas Hruby 8214e5e284 Removed racy COW optimization 
- enabling writing in COW once phys block is reference only once is racy if VM
  is preemptible. original memory location may get overwritten before COW copies
  the memory

- problem when DEBUG_RACE is on and a big problem for SMP
2010-06-18 12:46:18 +00:00

2496 lines
64 KiB
C
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#define _SYSTEM 1
#include <minix/com.h>
#include <minix/callnr.h>
#include <minix/type.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/debug.h>
#include <minix/bitmap.h>
#include <sys/mman.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <stdint.h>
#include <memory.h>
#include "vm.h"
#include "proto.h"
#include "util.h"
#include "glo.h"
#include "region.h"
#include "sanitycheck.h"
#include "physravl.h"
#include "memlist.h"
/* LRU list. */
PRIVATE yielded_t *lru_youngest = NULL, *lru_oldest = NULL;
/* Should a physblock be mapped writable? */
#define WRITABLE(r, pb) \
(((r)->flags & (VR_DIRECT | VR_SHARED)) || \
(((r)->flags & VR_WRITABLE) && (pb)->refcount == 1))
FORWARD _PROTOTYPE(int map_new_physblock, (struct vmproc *vmp,
struct vir_region *region, vir_bytes offset, vir_bytes length,
phys_bytes what, u32_t allocflags, int written));
FORWARD _PROTOTYPE(int map_ph_writept, (struct vmproc *vmp, struct vir_region *vr,
struct phys_region *pr));
FORWARD _PROTOTYPE(phys_bytes freeyieldednode, (yielded_t *node, int freemem));
FORWARD _PROTOTYPE(struct vir_region *map_copy_region, (struct vmproc *vmp, struct vir_region *vr));
FORWARD _PROTOTYPE(struct phys_region *map_clone_ph_block, (struct vmproc *vmp,
struct vir_region *region, struct phys_region *ph, physr_iter *iter));
#if SANITYCHECKS
FORWARD _PROTOTYPE(void lrucheck, (void));
#endif
PRIVATE char *map_name(struct vir_region *vr)
{
static char name[100];
char *typename, *tag;
int type = vr->flags & (VR_ANON|VR_DIRECT);
switch(type) {
case VR_ANON:
typename = "anonymous";
break;
case VR_DIRECT:
typename = "direct";
break;
default:
panic("unknown mapping type: %d", type);
}
switch(vr->tag) {
case VRT_TEXT:
tag = "text";
break;
case VRT_STACK:
tag = "stack";
break;
case VRT_HEAP:
tag = "heap";
break;
case VRT_NONE:
tag = "untagged";
break;
default:
tag = "unknown tag value";
break;
}
sprintf(name, "%s, %s", typename, tag);
return name;
}
PUBLIC void map_printregion(struct vmproc *vmp, struct vir_region *vr)
{
physr_iter iter;
struct phys_region *ph;
printf("map_printmap: map_name: %s\n", map_name(vr));
printf("\t%s (len 0x%lx, %dkB), %s\n",
arch_map2str(vmp, vr->vaddr), vr->length,
vr->length/1024, map_name(vr));
printf("\t\tphysblocks:\n");
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
printf("\t\t@ %s (refs %d): phys 0x%lx len 0x%lx\n",
arch_map2str(vmp, vr->vaddr + ph->offset),
ph->ph->refcount, ph->ph->phys, ph->ph->length);
physr_incr_iter(&iter);
}
}
/*===========================================================================*
* map_printmap *
*===========================================================================*/
PUBLIC void map_printmap(vmp)
struct vmproc *vmp;
{
struct vir_region *vr;
printf("memory regions in process %d:\n", vmp->vm_endpoint);
for(vr = vmp->vm_regions; vr; vr = vr->next) {
map_printregion(vmp, vr);
}
}
#if SANITYCHECKS
/*===========================================================================*
* map_sanitycheck_pt *
*===========================================================================*/
PRIVATE int map_sanitycheck_pt(struct vmproc *vmp,
struct vir_region *vr, struct phys_region *pr)
{
struct phys_block *pb = pr->ph;
int rw;
int r;
if(!(vmp->vm_flags & VMF_HASPT))
return OK;
if(WRITABLE(vr, pb))
rw = PTF_WRITE;
else
rw = 0;
r = pt_writemap(&vmp->vm_pt, vr->vaddr + pr->offset,
pb->phys, pb->length, PTF_PRESENT | PTF_USER | rw, WMF_VERIFY);
if(r != OK) {
printf("proc %d phys_region 0x%lx sanity check failed\n",
vmp->vm_endpoint, pr->offset);
map_printregion(vmp, vr);
}
return r;
}
/*===========================================================================*
* map_sanitycheck *
*===========================================================================*/
PUBLIC void map_sanitycheck(char *file, int line)
{
struct vmproc *vmp;
lrucheck();
/* Macro for looping over all physical blocks of all regions of
* all processes.
*/
#define ALLREGIONS(regioncode, physcode) \
for(vmp = vmproc; vmp < &vmproc[VMP_NR]; vmp++) { \
struct vir_region *vr; \
if(!(vmp->vm_flags & VMF_INUSE)) \
continue; \
for(vr = vmp->vm_regions; vr; vr = vr->next) { \
physr_iter iter; \
struct phys_region *pr; \
regioncode; \
physr_start_iter_least(vr->phys, &iter); \
while((pr = physr_get_iter(&iter))) { \
physcode; \
physr_incr_iter(&iter); \
} \
} \
}
#define MYSLABSANE(s) MYASSERT(slabsane_f(__FILE__, __LINE__, s, sizeof(*(s))))
/* Basic pointers check. */
ALLREGIONS(MYSLABSANE(vr),MYSLABSANE(pr); MYSLABSANE(pr->ph);MYSLABSANE(pr->parent));
ALLREGIONS(/* MYASSERT(vr->parent == vmp) */,MYASSERT(pr->parent == vr););
/* Do counting for consistency check. */
ALLREGIONS(;,USE(pr->ph, pr->ph->seencount = 0;););
ALLREGIONS(;,USE(pr->ph, pr->ph->seencount++;);
if(pr->ph->seencount == 1) {
MYASSERT(usedpages_add(pr->ph->phys,
pr->ph->length) == OK);
}
);
/* Do consistency check. */
ALLREGIONS(if(vr->next) {
MYASSERT(vr->vaddr < vr->next->vaddr);
MYASSERT(vr->vaddr + vr->length <= vr->next->vaddr);
}
MYASSERT(!(vr->vaddr % VM_PAGE_SIZE));,
if(pr->ph->refcount != pr->ph->seencount) {
map_printmap(vmp);
printf("ph in vr 0x%lx: 0x%lx-0x%lx refcount %d "
"but seencount %lu\n",
vr, pr->offset,
pr->offset + pr->ph->length,
pr->ph->refcount, pr->ph->seencount);
}
{
int n_others = 0;
struct phys_region *others;
if(pr->ph->refcount > 0) {
MYASSERT(pr->ph->firstregion);
if(pr->ph->refcount == 1) {
MYASSERT(pr->ph->firstregion == pr);
}
} else {
MYASSERT(!pr->ph->firstregion);
}
for(others = pr->ph->firstregion; others;
others = others->next_ph_list) {
MYSLABSANE(others);
MYASSERT(others->ph == pr->ph);
n_others++;
}
MYASSERT(pr->ph->refcount == n_others);
}
MYASSERT(pr->ph->refcount == pr->ph->seencount);
MYASSERT(!(pr->offset % VM_PAGE_SIZE));
MYASSERT(!(pr->ph->length % VM_PAGE_SIZE)););
ALLREGIONS(,MYASSERT(map_sanitycheck_pt(vmp, vr, pr) == OK));
}
#define LRUCHECK lrucheck()
PRIVATE void lrucheck(void)
{
yielded_t *list;
/* list is empty and ok if both ends point to null. */
if(!lru_youngest && !lru_oldest)
return;
/* if not, both should point to something. */
SLABSANE(lru_youngest);
SLABSANE(lru_oldest);
assert(!lru_youngest->younger);
assert(!lru_oldest->older);
for(list = lru_youngest; list; list = list->older) {
SLABSANE(list);
if(list->younger) {
SLABSANE(list->younger);
assert(list->younger->older == list);
} else assert(list == lru_youngest);
if(list->older) {
SLABSANE(list->older);
assert(list->older->younger == list);
} else assert(list == lru_oldest);
}
}
void blockstats(void)
{
yielded_t *list;
int blocks = 0;
phys_bytes mem = 0;
clock_t ticks;
int s;
s = getuptime(&ticks);
assert(s == OK);
LRUCHECK;
for(list = lru_youngest; list; list = list->older) {
mem += list->len;
blocks++;
}
if(blocks > 0)
printf("%d blocks, %dkB; ", blocks, mem/1024);
printmemstats();
}
#else
#define LRUCHECK
#endif
/*=========================================================================*
* map_ph_writept *
*=========================================================================*/
PRIVATE int map_ph_writept(struct vmproc *vmp, struct vir_region *vr,
struct phys_region *pr)
{
int rw;
struct phys_block *pb = pr->ph;
assert(!(vr->vaddr % VM_PAGE_SIZE));
assert(!(pb->length % VM_PAGE_SIZE));
assert(!(pr->offset % VM_PAGE_SIZE));
assert(pb->refcount > 0);
if(WRITABLE(vr, pb))
rw = PTF_WRITE;
else
rw = 0;
if(pt_writemap(&vmp->vm_pt, vr->vaddr + pr->offset,
pb->phys, pb->length, PTF_PRESENT | PTF_USER | rw,
#if SANITYCHECKS
!pr->written ? 0 :
#endif
WMF_OVERWRITE) != OK) {
printf("VM: map_writept: pt_writemap failed\n");
return ENOMEM;
}
#if SANITYCHECKS
USE(pr, pr->written = 1;);
#endif
return OK;
}
/*===========================================================================*
* region_find_slot *
*===========================================================================*/
PRIVATE vir_bytes region_find_slot(struct vmproc *vmp,
vir_bytes minv, vir_bytes maxv, vir_bytes length,
struct vir_region **prev)
{
struct vir_region *firstregion = vmp->vm_regions, *prevregion = NULL;
vir_bytes startv;
int foundflag = 0;
SANITYCHECK(SCL_FUNCTIONS);
/* Length must be reasonable. */
assert(length > 0);
/* Special case: allow caller to set maxv to 0 meaning 'I want
* it to be mapped in right here.'
*/
if(maxv == 0) {
maxv = minv + length;
/* Sanity check. */
if(maxv <= minv) {
printf("region_find_slot: minv 0x%lx and bytes 0x%lx\n",
minv, length);
map_printmap(vmp);
return (vir_bytes) -1;
}
}
/* Basic input sanity checks. */
assert(!(length % VM_PAGE_SIZE));
if(minv >= maxv) {
printf("VM: 1 minv: 0x%lx maxv: 0x%lx length: 0x%lx\n",
minv, maxv, length);
}
assert(minv < maxv);
assert(minv + length <= maxv);
#define FREEVRANGE(rangestart, rangeend, foundcode) { \
vir_bytes frstart = (rangestart), frend = (rangeend); \
frstart = MAX(frstart, minv); \
frend = MIN(frend, maxv); \
if(frend > frstart && (frend - frstart) >= length) { \
startv = frstart; \
foundflag = 1; \
foundcode; \
} }
/* This is the free virtual address space before the first region. */
FREEVRANGE(0, firstregion ? firstregion->vaddr : VM_DATATOP, ;);
if(!foundflag) {
struct vir_region *vr;
for(vr = vmp->vm_regions; vr && !foundflag; vr = vr->next) {
FREEVRANGE(vr->vaddr + vr->length,
vr->next ? vr->next->vaddr : VM_DATATOP,
prevregion = vr;);
}
}
if(!foundflag) {
printf("VM: region_find_slot: no 0x%lx bytes found for %d between 0x%lx and 0x%lx\n",
length, vmp->vm_endpoint, minv, maxv);
map_printmap(vmp);
return (vir_bytes) -1;
}
#if SANITYCHECKS
if(prevregion) assert(prevregion->vaddr < startv);
#endif
/* However we got it, startv must be in the requested range. */
assert(startv >= minv);
assert(startv < maxv);
assert(startv + length <= maxv);
if (prev)
*prev = prevregion;
return startv;
}
/*===========================================================================*
* map_page_region *
*===========================================================================*/
PUBLIC struct vir_region *map_page_region(vmp, minv, maxv, length,
what, flags, mapflags)
struct vmproc *vmp;
vir_bytes minv;
vir_bytes maxv;
vir_bytes length;
vir_bytes what;
u32_t flags;
int mapflags;
{
struct vir_region *prevregion = NULL, *newregion;
vir_bytes startv;
struct phys_region *ph;
physr_avl *phavl;
assert(!(length % VM_PAGE_SIZE));
SANITYCHECK(SCL_FUNCTIONS);
startv = region_find_slot(vmp, minv, maxv, length, &prevregion);
if (startv == (vir_bytes) -1)
return NULL;
/* Now we want a new region. */
if(!SLABALLOC(newregion)) {
printf("VM: map_page_region: allocating region failed\n");
return NULL;
}
/* Fill in node details. */
USE(newregion,
newregion->vaddr = startv;
newregion->length = length;
newregion->flags = flags;
newregion->tag = VRT_NONE;
newregion->parent = vmp;);
SLABALLOC(phavl);
if(!phavl) {
printf("VM: map_page_region: allocating phys avl failed\n");
SLABFREE(newregion);
return NULL;
}
USE(newregion, newregion->phys = phavl;);
physr_init(newregion->phys);
/* If we know what we're going to map to, map it right away. */
if(what != MAP_NONE) {
assert(!(what % VM_PAGE_SIZE));
assert(!(startv % VM_PAGE_SIZE));
assert(!(mapflags & MF_PREALLOC));
if(map_new_physblock(vmp, newregion, 0, length,
what, PAF_CLEAR, 0) != OK) {
printf("VM: map_new_physblock failed\n");
USE(newregion,
SLABFREE(newregion->phys););
SLABFREE(newregion);
return NULL;
}
}
if((flags & VR_ANON) && (mapflags & MF_PREALLOC)) {
if(map_handle_memory(vmp, newregion, 0, length, 1) != OK) {
printf("VM: map_page_region: prealloc failed\n");
USE(newregion,
SLABFREE(newregion->phys););
SLABFREE(newregion);
return NULL;
}
}
/* Link it. */
if(prevregion) {
assert(prevregion->vaddr < newregion->vaddr);
USE(newregion, newregion->next = prevregion->next;);
USE(prevregion, prevregion->next = newregion;);
} else {
USE(newregion, newregion->next = vmp->vm_regions;);
vmp->vm_regions = newregion;
}
#if SANITYCHECKS
assert(startv == newregion->vaddr);
if(newregion->next) {
assert(newregion->vaddr < newregion->next->vaddr);
}
#endif
SANITYCHECK(SCL_FUNCTIONS);
return newregion;
}
/*===========================================================================*
* pb_unreferenced *
*===========================================================================*/
PUBLIC void pb_unreferenced(struct vir_region *region, struct phys_region *pr)
{
struct phys_block *pb;
int remap = 0;
pb = pr->ph;
assert(pb->refcount > 0);
USE(pb, pb->refcount--;);
assert(pb->refcount >= 0);
if(pb->firstregion == pr) {
USE(pb, pb->firstregion = pr->next_ph_list;);
} else {
struct phys_region *others;
for(others = pb->firstregion; others;
others = others->next_ph_list) {
assert(others->ph == pb);
if(others->next_ph_list == pr) {
USE(others, others->next_ph_list = pr->next_ph_list;);
break;
}
}
assert(others); /* Otherwise, wasn't on the list. */
}
if(pb->refcount == 0) {
assert(!pb->firstregion);
if(region->flags & VR_ANON) {
free_mem(ABS2CLICK(pb->phys),
ABS2CLICK(pb->length));
} else if(region->flags & VR_DIRECT) {
; /* No action required. */
} else {
panic("strange phys flags");
}
SLABFREE(pb);
}
}
PRIVATE struct phys_region *reset_physr_iter(struct vir_region *region,
physr_iter *iter, vir_bytes offset)
{
struct phys_region *ph;
physr_start_iter(region->phys, iter, offset, AVL_EQUAL);
ph = physr_get_iter(iter);
assert(ph);
assert(ph->offset == offset);
return ph;
}
/*===========================================================================*
* map_subfree *
*===========================================================================*/
PRIVATE int map_subfree(struct vmproc *vmp,
struct vir_region *region, vir_bytes len)
{
struct phys_region *pr, *nextpr;
physr_iter iter;
#if SANITYCHECKS
{
physr_start_iter_least(region->phys, &iter);
while((pr = physr_get_iter(&iter))) {
struct phys_region *others;
struct phys_block *pb;
pb = pr->ph;
for(others = pb->firstregion; others;
others = others->next_ph_list) {
assert(others->ph == pb);
}
physr_incr_iter(&iter);
}
}
#endif
physr_start_iter_least(region->phys, &iter);
while((pr = physr_get_iter(&iter))) {
physr_incr_iter(&iter);
if(pr->offset >= len)
break;
if(pr->offset + pr->ph->length <= len) {
pb_unreferenced(region, pr);
physr_remove(region->phys, pr->offset);
physr_start_iter_least(region->phys, &iter);
SLABFREE(pr);
} else {
vir_bytes sublen;
assert(len > pr->offset);
assert(len < pr->offset + pr->ph->length);
assert(pr->ph->refcount > 0);
sublen = len - pr->offset;
assert(!(sublen % VM_PAGE_SIZE));
assert(sublen < pr->ph->length);
if(pr->ph->refcount > 1) {
int r;
if(!(pr = map_clone_ph_block(vmp, region,
pr, &iter)))
return ENOMEM;
}
assert(pr->ph->refcount == 1);
if(!(region->flags & VR_DIRECT)) {
free_mem(ABS2CLICK(pr->ph->phys), ABS2CLICK(sublen));
}
USE(pr, pr->offset += sublen;);
USE(pr->ph,
pr->ph->phys += sublen;
pr->ph->length -= sublen;);
assert(!(pr->offset % VM_PAGE_SIZE));
assert(!(pr->ph->phys % VM_PAGE_SIZE));
assert(!(pr->ph->length % VM_PAGE_SIZE));
}
}
return OK;
}
/*===========================================================================*
* map_free *
*===========================================================================*/
PRIVATE int map_free(struct vmproc *vmp, struct vir_region *region)
{
int r;
if((r=map_subfree(vmp, region, region->length)) != OK) {
printf("%d\n", __LINE__);
return r;
}
USE(region,
SLABFREE(region->phys););
SLABFREE(region);
return OK;
}
/*===========================================================================*
* free_yielded_proc *
*===========================================================================*/
PRIVATE vir_bytes free_yielded_proc(struct vmproc *vmp)
{
yielded_t *yb;
int y = 0;
vir_bytes total = 0;
SANITYCHECK(SCL_FUNCTIONS);
/* Free associated regions. */
while((yb = yielded_search_least(&vmp->vm_yielded_blocks))) {
SLABSANE(yb);
total += freeyieldednode(yb, 1);
y++;
}
yielded_init(&vmp->vm_yielded_blocks);
return total;
}
PRIVATE phys_bytes freeyieldednode(yielded_t *node, int freemem)
{
yielded_t *older, *younger, *removed;
int p;
vir_bytes len;
SLABSANE(node);
LRUCHECK;
/* Update LRU. */
younger = node->younger;
older = node->older;
if(younger) {
SLABSANE(younger);
assert(younger->older == node);
USE(younger, younger->older = node->older;);
} else {
assert(node == lru_youngest);
lru_youngest = node->older;
}
if(older) {
SLABSANE(older);
assert(older->younger == node);
USE(older, older->younger = node->younger;);
} else {
assert(node == lru_oldest);
lru_oldest = node->younger;
}
LRUCHECK;
/* Update AVL. */
if(vm_isokendpt(node->owner, &p) != OK)
panic("out of date owner of yielded block %d", node->owner);
removed = yielded_remove(&vmproc[p].vm_yielded_blocks, node->id);
assert(removed == node);
/* Free associated memory if requested. */
if(freemem) {
free_mem(ABS2CLICK(node->addr), ABS2CLICK(node->len));
}
/* Free node. */
len = node->len;
SLABFREE(node);
return len;
}
/*========================================================================*
* free_yielded *
*========================================================================*/
PUBLIC vir_bytes free_yielded(vir_bytes max_bytes)
{
/* PRIVATE yielded_t *lru_youngest = NULL, *lru_oldest = NULL; */
vir_bytes freed = 0;
int blocks = 0;
while(freed < max_bytes && lru_oldest) {
SLABSANE(lru_oldest);
freed += freeyieldednode(lru_oldest, 1);
blocks++;
}
return freed;
}
/*========================================================================*
* map_free_proc *
*========================================================================*/
PUBLIC int map_free_proc(vmp)
struct vmproc *vmp;
{
struct vir_region *r, *nextr;
for(r = vmp->vm_regions; r; r = nextr) {
nextr = r->next;
SANITYCHECK(SCL_DETAIL);
#if SANITYCHECKS
nocheck++;
#endif
map_free(vmp, r);
vmp->vm_regions = nextr; /* For sanity checks. */
#if SANITYCHECKS
nocheck--;
#endif
SANITYCHECK(SCL_DETAIL);
}
vmp->vm_regions = NULL;
/* Free associated yielded blocks. */
free_yielded_proc(vmp);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*===========================================================================*
* map_lookup *
*===========================================================================*/
PUBLIC struct vir_region *map_lookup(vmp, offset)
struct vmproc *vmp;
vir_bytes offset;
{
struct vir_region *r;
SANITYCHECK(SCL_FUNCTIONS);
if(!vmp->vm_regions)
panic("process has no regions: %d", vmp->vm_endpoint);
for(r = vmp->vm_regions; r; r = r->next) {
if(offset >= r->vaddr && offset < r->vaddr + r->length)
return r;
}
SANITYCHECK(SCL_FUNCTIONS);
return NULL;
}
PRIVATE u32_t vrallocflags(u32_t flags)
{
u32_t allocflags = 0;
if(flags & VR_PHYS64K)
allocflags |= PAF_ALIGN64K;
if(flags & VR_LOWER16MB)
allocflags |= PAF_LOWER16MB;
if(flags & VR_LOWER1MB)
allocflags |= PAF_LOWER1MB;
if(flags & VR_CONTIG)
allocflags |= PAF_CONTIG;
return allocflags;
}
/*===========================================================================*
* map_new_physblock *
*===========================================================================*/
PRIVATE int map_new_physblock(vmp, region, start_offset, length,
what_mem, allocflags, written)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes start_offset;
vir_bytes length;
phys_bytes what_mem;
u32_t allocflags;
int written;
{
struct memlist *memlist, given, *ml;
int used_memlist, r;
vir_bytes mapped = 0;
vir_bytes offset = start_offset;
SANITYCHECK(SCL_FUNCTIONS);
assert(!(length % VM_PAGE_SIZE));
if((region->flags & VR_CONTIG) &&
(start_offset > 0 || length < region->length)) {
printf("VM: map_new_physblock: non-full allocation requested\n");
return EFAULT;
}
/* Memory for new physical block. */
if(what_mem == MAP_NONE) {
allocflags |= vrallocflags(region->flags);
if(!(memlist = alloc_mem_in_list(length, allocflags))) {
printf("map_new_physblock: couldn't allocate\n");
return ENOMEM;
}
used_memlist = 1;
} else {
given.phys = what_mem;
given.length = length;
given.next = NULL;
memlist = &given;
used_memlist = 0;
assert(given.length);
}
r = OK;
for(ml = memlist; ml; ml = ml->next) {
struct phys_region *newphysr = NULL;
struct phys_block *newpb = NULL;
/* Allocate things necessary for this chunk of memory. */
if(!SLABALLOC(newphysr) || !SLABALLOC(newpb)) {
printf("map_new_physblock: no memory for the ph slabs\n");
if(newphysr) SLABFREE(newphysr);
if(newpb) SLABFREE(newpb);
r = ENOMEM;
break;
}
/* New physical block. */
assert(!(ml->phys % VM_PAGE_SIZE));
USE(newpb,
newpb->phys = ml->phys;
newpb->refcount = 1;
newpb->length = ml->length;
newpb->firstregion = newphysr;);
/* New physical region. */
USE(newphysr,
newphysr->offset = offset;
newphysr->ph = newpb;
newphysr->parent = region;
/* No other references to this block. */
newphysr->next_ph_list = NULL;);
#if SANITYCHECKS
USE(newphysr, newphysr->written = written;);
#endif
/* Update pagetable. */
if(map_ph_writept(vmp, region, newphysr) != OK) {
printf("map_new_physblock: map_ph_writept failed\n");
r = ENOMEM;
break;
}
physr_insert(region->phys, newphysr);
offset += ml->length;
mapped += ml->length;
}
if(used_memlist) {
if(r != OK) {
offset = start_offset;
/* Things did not go well. Undo everything. */
for(ml = memlist; ml; ml = ml->next) {
struct phys_region *physr;
if((physr = physr_search(region->phys, offset,
AVL_EQUAL))) {
assert(physr->ph->refcount == 1);
pb_unreferenced(region, physr);
physr_remove(region->phys, physr->offset);
SLABFREE(physr);
}
offset += ml->length;
}
} else assert(mapped == length);
/* Always clean up the memlist itself, even if everything
* worked we're not using the memlist nodes any more. And
* the memory they reference is either freed above or in use.
*/
free_mem_list(memlist, 0);
}
SANITYCHECK(SCL_FUNCTIONS);
return r;
}
/*===========================================================================*
* map_clone_ph_block *
*===========================================================================*/
PRIVATE struct phys_region *map_clone_ph_block(vmp, region, ph, iter)
struct vmproc *vmp;
struct vir_region *region;
struct phys_region *ph;
physr_iter *iter;
{
vir_bytes offset, length;
u32_t allocflags;
phys_bytes physaddr;
struct phys_region *newpr;
int written = 0;
#if SANITYCHECKS
written = ph->written;
#endif
SANITYCHECK(SCL_FUNCTIONS);
/* Warning: this function will free the passed
* phys_region *ph and replace it (in the same offset)
* with one or more others! So both the pointer to it
* and any iterators over the phys_regions in the vir_region
* will be invalid on successful return. (Iterators over
* the vir_region could be invalid on unsuccessful return too.)
*/
/* This is only to be done if there is more than one copy. */
assert(ph->ph->refcount > 1);
/* This function takes a physical block, copies its contents
* into newly allocated memory, and replaces the single physical
* block by one or more physical blocks with refcount 1 with the
* same contents as the original. In other words, a fragmentable
* version of map_copy_ph_block().
*/
/* Remember where and how much. */
offset = ph->offset;
length = ph->ph->length;
physaddr = ph->ph->phys;
/* Now unlink the original physical block so we can replace
* it with new ones.
*/
SLABSANE(ph);
SLABSANE(ph->ph);
assert(ph->ph->refcount > 1);
pb_unreferenced(region, ph);
assert(ph->ph->refcount >= 1);
physr_remove(region->phys, offset);
SLABFREE(ph);
SANITYCHECK(SCL_DETAIL);
/* Put new free memory in. */
allocflags = vrallocflags(region->flags);
assert(!(allocflags & PAF_CONTIG));
assert(!(allocflags & PAF_CLEAR));
if(map_new_physblock(vmp, region, offset, length,
MAP_NONE, allocflags, written) != OK) {
/* XXX original range now gone. */
printf("VM: map_clone_ph_block: map_new_physblock failed.\n");
return NULL;
}
/* Copy the block to the new memory.
* Can only fail if map_new_physblock didn't do what we asked.
*/
if(copy_abs2region(physaddr, region, offset, length) != OK)
panic("copy_abs2region failed, no good reason for that");
newpr = physr_search(region->phys, offset, AVL_EQUAL);
assert(newpr);
assert(newpr->offset == offset);
if(iter) {
physr_start_iter(region->phys, iter, offset, AVL_EQUAL);
assert(physr_get_iter(iter) == newpr);
}
SANITYCHECK(SCL_FUNCTIONS);
return newpr;
}
/*===========================================================================*
* map_pf *
*===========================================================================*/
PUBLIC int map_pf(vmp, region, offset, write)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes offset;
int write;
{
vir_bytes virpage;
struct phys_region *ph;
int r = OK;
assert(offset >= 0);
assert(offset < region->length);
assert(region->flags & VR_ANON);
assert(!(region->vaddr % VM_PAGE_SIZE));
virpage = offset - offset % VM_PAGE_SIZE;
SANITYCHECK(SCL_FUNCTIONS);
if((ph = physr_search(region->phys, offset, AVL_LESS_EQUAL)) &&
(ph->offset <= offset && offset < ph->offset + ph->ph->length)) {
phys_bytes blockoffset = ph->offset;
/* Pagefault in existing block. Do copy-on-write. */
assert(write);
assert(region->flags & VR_WRITABLE);
assert(ph->ph->refcount > 0);
if(WRITABLE(region, ph->ph)) {
r = map_ph_writept(vmp, region, ph);
if(r != OK)
printf("map_ph_writept failed\n");
} else {
if(ph->ph->refcount > 0
&& ph->ph->share_flag != PBSH_COW) {
printf("VM: write RO mapped pages.\n");
return EFAULT;
} else {
if(!map_clone_ph_block(vmp, region, ph, NULL))
r = ENOMEM;
}
}
} else {
/* Pagefault in non-existing block. Map in new block. */
if(map_new_physblock(vmp, region, virpage,
VM_PAGE_SIZE, MAP_NONE, PAF_CLEAR, 0) != OK) {
printf("map_new_physblock failed\n");
r = ENOMEM;
}
}
SANITYCHECK(SCL_FUNCTIONS);
if(r != OK) {
printf("VM: map_pf: failed (%d)\n", r);
return r;
}
#if SANITYCHECKS
if(OK != pt_checkrange(&vmp->vm_pt, region->vaddr+virpage,
VM_PAGE_SIZE, write)) {
panic("map_pf: pt_checkrange failed: %d", r);
}
#endif
return r;
}
/*===========================================================================*
* map_handle_memory *
*===========================================================================*/
PUBLIC int map_handle_memory(vmp, region, offset, length, write)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes offset, length;
int write;
{
struct phys_region *physr, *nextphysr;
int changes = 0;
physr_iter iter;
#define FREE_RANGE_HERE(er1, er2) { \
struct phys_region *r1 = (er1), *r2 = (er2); \
vir_bytes start = offset, end = offset + length; \
if(r1) { \
start = MAX(start, r1->offset + r1->ph->length); } \
if(r2) { \
end = MIN(end, r2->offset); } \
if(start < end) { \
int r; \
SANITYCHECK(SCL_DETAIL); \
if(map_new_physblock(vmp, region, start, \
end-start, MAP_NONE, PAF_CLEAR, 0) != OK) { \
SANITYCHECK(SCL_DETAIL); \
return ENOMEM; \
} \
changes++; \
} }
SANITYCHECK(SCL_FUNCTIONS);
assert(region->flags & VR_ANON);
assert(!(region->vaddr % VM_PAGE_SIZE));
assert(!(offset % VM_PAGE_SIZE));
assert(!(length % VM_PAGE_SIZE));
assert(!write || (region->flags & VR_WRITABLE));
physr_start_iter(region->phys, &iter, offset, AVL_LESS_EQUAL);
physr = physr_get_iter(&iter);
if(!physr) {
physr_start_iter(region->phys, &iter, offset, AVL_GREATER_EQUAL);
physr = physr_get_iter(&iter);
}
FREE_RANGE_HERE(NULL, physr);
if(physr) {
physr = reset_physr_iter(region, &iter, physr->offset);
if(physr->offset + physr->ph->length <= offset) {
physr_incr_iter(&iter);
physr = physr_get_iter(&iter);
FREE_RANGE_HERE(NULL, physr);
if(physr) {
physr = reset_physr_iter(region, &iter,
physr->offset);
}
}
}
while(physr) {
int r;
SANITYCHECK(SCL_DETAIL);
if(write) {
assert(physr->ph->refcount > 0);
if(!WRITABLE(region, physr->ph)) {
if(!(physr = map_clone_ph_block(vmp, region,
physr, &iter))) {
printf("VM: map_handle_memory: no copy\n");
return ENOMEM;
}
changes++;
} else {
SANITYCHECK(SCL_DETAIL);
if((r=map_ph_writept(vmp, region, physr)) != OK) {
printf("VM: map_ph_writept failed\n");
return r;
}
changes++;
SANITYCHECK(SCL_DETAIL);
}
}
SANITYCHECK(SCL_DETAIL);
physr_incr_iter(&iter);
nextphysr = physr_get_iter(&iter);
FREE_RANGE_HERE(physr, nextphysr);
SANITYCHECK(SCL_DETAIL);
if(nextphysr) {
if(nextphysr->offset >= offset + length)
break;
nextphysr = reset_physr_iter(region, &iter,
nextphysr->offset);
}
physr = nextphysr;
}
SANITYCHECK(SCL_FUNCTIONS);
if(changes < 1) {
#if VERBOSE
printf("region start at 0x%lx offset 0x%lx len 0x%lx write %d\n",
region->vaddr, offset, length, write);
printf("no changes in map_handle_memory\n");
#endif
return EFAULT;
}
#if SANITYCHECKS
if(OK != pt_checkrange(&vmp->vm_pt, region->vaddr+offset, length, write)) {
printf("handle mem %s-", arch_map2str(vmp, region->vaddr+offset));
printf("%s failed\n", arch_map2str(vmp, region->vaddr+offset+length));
map_printregion(vmp, region);
panic("checkrange failed");
}
#endif
return OK;
}
#if SANITYCHECKS
static int countregions(struct vir_region *vr)
{
int n = 0;
struct phys_region *ph;
physr_iter iter;
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
n++;
physr_incr_iter(&iter);
}
return n;
}
#endif
/*===========================================================================*
* map_copy_region *
*===========================================================================*/
PRIVATE struct vir_region *map_copy_region(struct vmproc *vmp, struct vir_region *vr)
{
/* map_copy_region creates a complete copy of the vir_region
* data structure, linking in the same phys_blocks directly,
* but all in limbo, i.e., the caller has to link the vir_region
* to a process. Therefore it doesn't increase the refcount in
* the phys_block; the caller has to do this once it's linked.
* The reason for this is to keep the sanity checks working
* within this function.
*/
struct vir_region *newvr;
struct phys_region *ph;
physr_iter iter;
physr_avl *phavl;
#if SANITYCHECKS
int cr;
cr = countregions(vr);
#endif
if(!SLABALLOC(newvr))
return NULL;
SLABALLOC(phavl);
if(!phavl) {
SLABFREE(newvr);
return NULL;
}
USE(newvr,
*newvr = *vr;
newvr->next = NULL;
newvr->phys = phavl;
);
physr_init(newvr->phys);
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
struct phys_region *newph;
if(!SLABALLOC(newph)) {
map_free(vmp, newvr);
return NULL;
}
USE(newph,
newph->ph = ph->ph;
newph->next_ph_list = NULL;
newph->parent = newvr;
newph->offset = ph->offset;);
#if SANITYCHECKS
USE(newph, newph->written = 0;);
#endif
physr_insert(newvr->phys, newph);
#if SANITYCHECKS
assert(countregions(vr) == cr);
#endif
physr_incr_iter(&iter);
}
#if SANITYCHECKS
assert(countregions(vr) == countregions(newvr));
#endif
return newvr;
}
/*===========================================================================*
* copy_abs2region *
*===========================================================================*/
PUBLIC int copy_abs2region(phys_bytes abs, struct vir_region *destregion,
phys_bytes offset, phys_bytes len)
{
assert(destregion);
assert(destregion->phys);
while(len > 0) {
phys_bytes sublen, suboffset;
struct phys_region *ph;
assert(destregion);
assert(destregion->phys);
if(!(ph = physr_search(destregion->phys, offset, AVL_LESS_EQUAL))) {
printf("VM: copy_abs2region: no phys region found (1).\n");
return EFAULT;
}
assert(ph->offset <= offset);
if(ph->offset+ph->ph->length <= offset) {
printf("VM: copy_abs2region: no phys region found (2).\n");
return EFAULT;
}
suboffset = offset - ph->offset;
assert(suboffset < ph->ph->length);
sublen = len;
if(sublen > ph->ph->length - suboffset)
sublen = ph->ph->length - suboffset;
assert(suboffset + sublen <= ph->ph->length);
if(ph->ph->refcount != 1) {
printf("VM: copy_abs2region: refcount not 1.\n");
return EFAULT;
}
if(sys_abscopy(abs, ph->ph->phys + suboffset, sublen) != OK) {
printf("VM: copy_abs2region: abscopy failed.\n");
return EFAULT;
}
abs += sublen;
offset += sublen;
len -= sublen;
}
return OK;
}
/*=========================================================================*
* map_writept *
*=========================================================================*/
PUBLIC int map_writept(struct vmproc *vmp)
{
struct vir_region *vr;
struct phys_region *ph;
int r;
for(vr = vmp->vm_regions; vr; vr = vr->next) {
physr_iter iter;
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
physr_incr_iter(&iter);
/* If this phys block is shared as SMAP, then do
* not update the page table. */
if(ph->ph->refcount > 1
&& ph->ph->share_flag == PBSH_SMAP) {
continue;
}
if((r=map_ph_writept(vmp, vr, ph)) != OK) {
printf("VM: map_writept: failed\n");
return r;
}
}
}
return OK;
}
/*========================================================================*
* map_proc_copy *
*========================================================================*/
PUBLIC int map_proc_copy(dst, src)
struct vmproc *dst;
struct vmproc *src;
{
struct vir_region *vr, *prevvr = NULL;
dst->vm_regions = NULL;
SANITYCHECK(SCL_FUNCTIONS);
for(vr = src->vm_regions; vr; vr = vr->next) {
physr_iter iter_orig, iter_new;
struct vir_region *newvr;
struct phys_region *orig_ph, *new_ph;
if(!(newvr = map_copy_region(dst, vr))) {
map_free_proc(dst);
return ENOMEM;
}
USE(newvr, newvr->parent = dst;);
if(prevvr) { USE(prevvr, prevvr->next = newvr;); }
else { dst->vm_regions = newvr; }
physr_start_iter_least(vr->phys, &iter_orig);
physr_start_iter_least(newvr->phys, &iter_new);
while((orig_ph = physr_get_iter(&iter_orig))) {
struct phys_block *pb;
new_ph = physr_get_iter(&iter_new);
/* Check two physregions both are nonnull,
* are different, and match physblocks.
*/
assert(new_ph);
assert(orig_ph);
assert(orig_ph != new_ph);
pb = orig_ph->ph;
assert(pb == new_ph->ph);
/* Link in new physregion. */
assert(!new_ph->next_ph_list);
USE(new_ph, new_ph->next_ph_list = pb->firstregion;);
USE(pb, pb->firstregion = new_ph;);
/* Increase phys block refcount */
assert(pb->refcount > 0);
USE(pb, pb->refcount++;);
assert(pb->refcount > 1);
/* If the phys block has been shared as SMAP,
* do the regular copy. */
if(pb->refcount > 2 && pb->share_flag == PBSH_SMAP) {
map_clone_ph_block(dst, newvr,new_ph,
&iter_new);
} else {
USE(pb, pb->share_flag = PBSH_COW;);
}
/* Get next new physregion */
physr_incr_iter(&iter_orig);
physr_incr_iter(&iter_new);
}
assert(!physr_get_iter(&iter_new));
prevvr = newvr;
}
map_writept(src);
map_writept(dst);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_proc_kernel *
*========================================================================*/
PUBLIC struct vir_region *map_proc_kernel(struct vmproc *vmp)
{
struct vir_region *vr;
/* We assume these are the first regions to be mapped to
* make the function a bit simpler (free all regions on error).
*/
assert(!vmp->vm_regions);
assert(vmproc[VMP_SYSTEM].vm_flags & VMF_INUSE);
assert(!(KERNEL_TEXT % VM_PAGE_SIZE));
assert(!(KERNEL_TEXT_LEN % VM_PAGE_SIZE));
assert(!(KERNEL_DATA % VM_PAGE_SIZE));
assert(!(KERNEL_DATA_LEN % VM_PAGE_SIZE));
if(!(vr = map_page_region(vmp, KERNEL_TEXT, 0, KERNEL_TEXT_LEN,
KERNEL_TEXT, VR_DIRECT | VR_WRITABLE | VR_NOPF, 0)) ||
!(vr = map_page_region(vmp, KERNEL_DATA, 0, KERNEL_DATA_LEN,
KERNEL_DATA, VR_DIRECT | VR_WRITABLE | VR_NOPF, 0))) {
map_free_proc(vmp);
return NULL;
}
return vr; /* Return pointer not useful, just non-NULL. */
}
/*========================================================================*
* map_region_extend *
*========================================================================*/
PUBLIC int map_region_extend(struct vmproc *vmp, struct vir_region *vr,
vir_bytes delta)
{
vir_bytes end;
assert(vr);
assert(vr->flags & VR_ANON);
assert(!(delta % VM_PAGE_SIZE));
if(!delta) return OK;
end = vr->vaddr + vr->length;
assert(end >= vr->vaddr);
if(end + delta <= end) {
printf("VM: strange delta 0x%lx\n", delta);
return ENOMEM;
}
if(!vr->next || end + delta <= vr->next->vaddr) {
USE(vr, vr->length += delta;);
return OK;
}
map_printmap(vmp);
return ENOMEM;
}
/*========================================================================*
* map_region_shrink *
*========================================================================*/
PUBLIC int map_region_shrink(struct vir_region *vr, vir_bytes delta)
{
assert(vr);
assert(vr->flags & VR_ANON);
assert(!(delta % VM_PAGE_SIZE));
#if 0
printf("VM: ignoring region shrink\n");
#endif
return OK;
}
PUBLIC struct vir_region *map_region_lookup_tag(vmp, tag)
struct vmproc *vmp;
u32_t tag;
{
struct vir_region *vr;
for(vr = vmp->vm_regions; vr; vr = vr->next)
if(vr->tag == tag)
return vr;
return NULL;
}
PUBLIC void map_region_set_tag(struct vir_region *vr, u32_t tag)
{
USE(vr, vr->tag = tag;);
}
PUBLIC u32_t map_region_get_tag(struct vir_region *vr)
{
return vr->tag;
}
/*========================================================================*
* map_unmap_region *
*========================================================================*/
PUBLIC int map_unmap_region(struct vmproc *vmp, struct vir_region *region,
vir_bytes len)
{
/* Shrink the region by 'len' bytes, from the start. Unreference
* memory it used to reference if any.
*/
struct vir_region *r, *nextr, *prev = NULL;
vir_bytes regionstart;
SANITYCHECK(SCL_FUNCTIONS);
for(r = vmp->vm_regions; r; r = r->next) {
if(r == region)
break;
prev = r;
}
SANITYCHECK(SCL_DETAIL);
if(r == NULL)
panic("map_unmap_region: region not found");
if(len > r->length || (len % VM_PAGE_SIZE)) {
printf("VM: bogus length 0x%lx\n", len);
return EINVAL;
}
if(!(r->flags & (VR_ANON|VR_DIRECT))) {
printf("VM: only unmap anonymous or direct memory\n");
return EINVAL;
}
regionstart = r->vaddr;
if(len == r->length) {
/* Whole region disappears. Unlink and free it. */
if(!prev) {
vmp->vm_regions = r->next;
} else {
USE(prev, prev->next = r->next;);
}
map_free(vmp, r);
} else {
struct phys_region *pr;
physr_iter iter;
/* Region shrinks. First unreference its memory
* and then shrink the region.
*/
map_subfree(vmp, r, len);
USE(r,
r->vaddr += len;
r->length -= len;);
physr_start_iter_least(r->phys, &iter);
/* vaddr has increased; to make all the phys_regions
* point to the same addresses, make them shrink by the
* same amount.
*/
while((pr = physr_get_iter(&iter))) {
assert(pr->offset >= len);
USE(pr, pr->offset -= len;);
physr_incr_iter(&iter);
}
}
SANITYCHECK(SCL_DETAIL);
if(pt_writemap(&vmp->vm_pt, regionstart,
MAP_NONE, len, 0, WMF_OVERWRITE) != OK) {
printf("VM: map_unmap_region: pt_writemap failed\n");
return ENOMEM;
}
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_remap *
*========================================================================*/
PUBLIC int map_remap(struct vmproc *dvmp, vir_bytes da, size_t size,
struct vir_region *region, vir_bytes *r)
{
struct vir_region *vr, *prev;
struct phys_region *ph;
vir_bytes startv, dst_addr;
physr_iter iter;
SANITYCHECK(SCL_FUNCTIONS);
assert(region->flags & VR_SHARED);
/* da is handled differently */
if (!da)
dst_addr = dvmp->vm_stacktop;
else
dst_addr = da;
dst_addr = arch_vir2map(dvmp, dst_addr);
prev = NULL;
/* round up to page size */
assert(!(size % VM_PAGE_SIZE));
startv = region_find_slot(dvmp, dst_addr, VM_DATATOP, size, &prev);
if (startv == (vir_bytes) -1) {
printf("map_remap: search 0x%x...\n", dst_addr);
map_printmap(dvmp);
return ENOMEM;
}
/* when the user specifies the address, we cannot change it */
if (da && (startv != dst_addr))
return EINVAL;
vr = map_copy_region(dvmp, region);
if(!vr)
return ENOMEM;
USE(vr,
vr->vaddr = startv;
vr->length = size;
vr->flags = region->flags;
vr->tag = VRT_NONE;
vr->parent = dvmp;);
assert(vr->flags & VR_SHARED);
if (prev) {
USE(vr,
vr->next = prev->next;);
USE(prev, prev->next = vr;);
} else {
USE(vr,
vr->next = dvmp->vm_regions;);
dvmp->vm_regions = vr;
}
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
struct phys_block *pb = ph->ph;
assert(!ph->next_ph_list);
USE(ph, ph->next_ph_list = pb->firstregion;);
USE(pb, pb->firstregion = ph;);
USE(pb, pb->refcount++;);
if(map_ph_writept(dvmp, vr, ph) != OK) {
panic("map_remap: map_ph_writept failed");
}
physr_incr_iter(&iter);
}
*r = startv;
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_get_phys *
*========================================================================*/
PUBLIC int map_get_phys(struct vmproc *vmp, vir_bytes addr, phys_bytes *r)
{
struct vir_region *vr;
struct phys_region *ph;
physr_iter iter;
if (!(vr = map_lookup(vmp, addr)) ||
(vr->vaddr != addr))
return EINVAL;
if (!(vr->flags & VR_SHARED))
return EINVAL;
physr_start_iter_least(vr->phys, &iter);
ph = physr_get_iter(&iter);
assert(ph);
assert(ph->ph);
if (r)
*r = ph->ph->phys;
return OK;
}
/*========================================================================*
* map_get_ref *
*========================================================================*/
PUBLIC int map_get_ref(struct vmproc *vmp, vir_bytes addr, u8_t *cnt)
{
struct vir_region *vr;
struct phys_region *ph;
physr_iter iter;
if (!(vr = map_lookup(vmp, addr)) ||
(vr->vaddr != addr))
return EINVAL;
if (!(vr->flags & VR_SHARED))
return EINVAL;
physr_start_iter_least(vr->phys, &iter);
ph = physr_get_iter(&iter);
assert(ph);
assert(ph->ph);
if (cnt)
*cnt = ph->ph->refcount;
return OK;
}
/*========================================================================*
* get_usage_info *
*========================================================================*/
PUBLIC void get_usage_info(struct vmproc *vmp, struct vm_usage_info *vui)
{
struct vir_region *vr;
physr_iter iter;
struct phys_region *ph;
vir_bytes len;
memset(vui, 0, sizeof(*vui));
for(vr = vmp->vm_regions; vr; vr = vr->next) {
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
len = ph->ph->length;
/* All present pages are counted towards the total. */
vui->vui_total += len;
if (ph->ph->refcount > 1) {
/* Any page with a refcount > 1 is common. */
vui->vui_common += len;
/* Any common, non-COW page is shared. */
if (vr->flags & VR_SHARED ||
ph->ph->share_flag == PBSH_SMAP)
vui->vui_shared += len;
}
physr_incr_iter(&iter);
}
}
}
/*===========================================================================*
* get_region_info *
*===========================================================================*/
PUBLIC int get_region_info(struct vmproc *vmp, struct vm_region_info *vri,
int max, vir_bytes *nextp)
{
struct vir_region *vr;
vir_bytes next;
int count;
next = *nextp;
if (!max) return 0;
for(vr = vmp->vm_regions; vr; vr = vr->next)
if (vr->vaddr >= next) break;
if (!vr) return 0;
for(count = 0; vr && count < max; vr = vr->next, count++, vri++) {
vri->vri_addr = arch_map2info(vmp, vr->vaddr, &vri->vri_seg,
&vri->vri_prot);
vri->vri_length = vr->length;
/* "AND" the provided protection with per-page protection. */
if (!(vr->flags & VR_WRITABLE))
vri->vri_prot &= ~PROT_WRITE;
vri->vri_flags = (vr->flags & VR_SHARED) ? MAP_SHARED : 0;
next = vr->vaddr + vr->length;
}
*nextp = next;
return count;
}
/*========================================================================*
* regionprintstats *
*========================================================================*/
PUBLIC void printregionstats(struct vmproc *vmp)
{
struct vir_region *vr;
struct phys_region *pr;
physr_iter iter;
vir_bytes used = 0, weighted = 0;
for(vr = vmp->vm_regions; vr; vr = vr->next) {
if(vr->flags & VR_DIRECT)
continue;
physr_start_iter_least(vr->phys, &iter);
while((pr = physr_get_iter(&iter))) {
physr_incr_iter(&iter);
used += pr->ph->length;
weighted += pr->ph->length / pr->ph->refcount;
}
}
printf("%6dkB %6dkB\n", used/1024, weighted/1024);
return;
}
/*===========================================================================*
* do_map_memory *
*===========================================================================*/
PRIVATE int do_map_memory(struct vmproc *vms, struct vmproc *vmd,
struct vir_region *vrs, struct vir_region *vrd,
vir_bytes offset_s, vir_bytes offset_d,
vir_bytes length, int flag)
{
struct phys_region *prs;
struct phys_region *newphysr;
struct phys_block *pb;
physr_iter iter;
u32_t pt_flag = PTF_PRESENT | PTF_USER;
vir_bytes end;
/* Search for the first phys region in the source process. */
physr_start_iter(vrs->phys, &iter, offset_s, AVL_EQUAL);
prs = physr_get_iter(&iter);
if(!prs)
panic("do_map_memory: no aligned phys region: %d", 0);
/* flag: 0 -> read-only
* 1 -> writable
* -1 -> share as COW, so read-only
*/
if(flag > 0)
pt_flag |= PTF_WRITE;
/* Map phys blocks in the source process to the destination process. */
end = offset_d + length;
while((prs = physr_get_iter(&iter)) && offset_d < end) {
/* If a SMAP share was requested but the phys block has already
* been shared as COW, copy the block for the source phys region
* first.
*/
pb = prs->ph;
if(flag >= 0 && pb->refcount > 1
&& pb->share_flag == PBSH_COW) {
if(!(prs = map_clone_ph_block(vms, vrs, prs, &iter)))
return ENOMEM;
pb = prs->ph;
}
/* Allocate a new phys region. */
if(!SLABALLOC(newphysr))
return ENOMEM;
/* Set and link the new phys region to the block. */
newphysr->ph = pb;
newphysr->offset = offset_d;
newphysr->parent = vrd;
newphysr->next_ph_list = pb->firstregion;
pb->firstregion = newphysr;
physr_insert(newphysr->parent->phys, newphysr);
pb->refcount++;
/* If a COW share was requested but the phys block has already
* been shared as SMAP, give up on COW and copy the block for
* the destination phys region now.
*/
if(flag < 0 && pb->refcount > 1
&& pb->share_flag == PBSH_SMAP) {
if(!(newphysr = map_clone_ph_block(vmd, vrd,
newphysr, NULL))) {
return ENOMEM;
}
}
else {
/* See if this is a COW share or SMAP share. */
if(flag < 0) { /* COW share */
pb->share_flag = PBSH_COW;
/* Update the page table for the src process. */
pt_writemap(&vms->vm_pt, offset_s + vrs->vaddr,
pb->phys, pb->length,
pt_flag, WMF_OVERWRITE);
}
else { /* SMAP share */
pb->share_flag = PBSH_SMAP;
}
/* Update the page table for the destination process. */
pt_writemap(&vmd->vm_pt, offset_d + vrd->vaddr,
pb->phys, pb->length, pt_flag, WMF_OVERWRITE);
}
physr_incr_iter(&iter);
offset_d += pb->length;
offset_s += pb->length;
}
return OK;
}
/*===========================================================================*
* unmap_memory *
*===========================================================================*/
PUBLIC int unmap_memory(endpoint_t sour, endpoint_t dest,
vir_bytes virt_s, vir_bytes virt_d, vir_bytes length, int flag)
{
struct vmproc *vmd;
struct vir_region *vrd;
struct phys_region *pr;
struct phys_block *pb;
physr_iter iter;
vir_bytes off, end;
int p;
/* Use information on the destination process to unmap. */
if(vm_isokendpt(dest, &p) != OK)
panic("unmap_memory: bad endpoint: %d", dest);
vmd = &vmproc[p];
vrd = map_lookup(vmd, virt_d);
assert(vrd);
/* Search for the first phys region in the destination process. */
off = virt_d - vrd->vaddr;
physr_start_iter(vrd->phys, &iter, off, AVL_EQUAL);
pr = physr_get_iter(&iter);
if(!pr)
panic("unmap_memory: no aligned phys region: %d", 0);
/* Copy the phys block now rather than doing COW. */
end = off + length;
while((pr = physr_get_iter(&iter)) && off < end) {
pb = pr->ph;
assert(pb->refcount > 1);
assert(pb->share_flag == PBSH_SMAP);
if(!(pr = map_clone_ph_block(vmd, vrd, pr, &iter)))
return ENOMEM;
physr_incr_iter(&iter);
off += pb->length;
}
return OK;
}
/*===========================================================================*
* split_phys *
*===========================================================================*/
PRIVATE int split_phys(struct phys_region *pr, vir_bytes point)
{
struct phys_region *newpr, *q, *prev;
struct phys_block *newpb;
struct phys_block *pb = pr->ph;
/* Split the phys region into 2 parts by @point. */
if(pr->offset >= point || pr->offset + pb->length <= point)
return OK;
if(!SLABALLOC(newpb))
return ENOMEM;
/* Split phys block. */
*newpb = *pb;
pb->length = point - pr->offset;
newpb->length -= pb->length;
newpb->phys += pb->length;
/* Split phys regions in a list. */
for(q = pb->firstregion; q; q = q->next_ph_list) {
if(!SLABALLOC(newpr))
return ENOMEM;
*newpr = *q;
newpr->ph = newpb;
newpr->offset += pb->length;
/* Link to the vir region's phys region list. */
physr_insert(newpr->parent->phys, newpr);
/* Link to the next_ph_list. */
if(q == pb->firstregion) {
newpb->firstregion = newpr;
prev = newpr;
} else {
prev->next_ph_list = newpr;
prev = newpr;
}
}
prev->next_ph_list = NULL;
return OK;
}
/*===========================================================================*
* clean_phys_regions *
*===========================================================================*/
PRIVATE void clean_phys_regions(struct vir_region *region,
vir_bytes offset, vir_bytes length)
{
/* Consider @offset as the start address and @offset+length as the end address.
* If there are phys regions crossing the start address or the end address,
* split them into 2 parts.
*
* We assume that the phys regions are listed in order and don't overlap.
*/
struct phys_region *pr;
physr_iter iter;
physr_start_iter_least(region->phys, &iter);
while((pr = physr_get_iter(&iter))) {
/* If this phys region crosses the start address, split it. */
if(pr->offset < offset
&& pr->offset + pr->ph->length > offset) {
split_phys(pr, offset);
physr_start_iter_least(region->phys, &iter);
}
/* If this phys region crosses the end address, split it. */
else if(pr->offset < offset + length
&& pr->offset + pr->ph->length > offset + length) {
split_phys(pr, offset + length);
physr_start_iter_least(region->phys, &iter);
}
else {
physr_incr_iter(&iter);
}
}
}
/*===========================================================================*
* rm_phys_regions *
*===========================================================================*/
PRIVATE void rm_phys_regions(struct vir_region *region,
vir_bytes begin, vir_bytes length)
{
/* Remove all phys regions between @begin and @begin+length.
*
* Don't update the page table, because we will update it at map_memory()
* later.
*/
struct phys_region *pr;
physr_iter iter;
physr_start_iter(region->phys, &iter, begin, AVL_GREATER_EQUAL);
while((pr = physr_get_iter(&iter)) && pr->offset < begin + length) {
pb_unreferenced(region, pr);
physr_remove(region->phys, pr->offset);
physr_start_iter(region->phys, &iter, begin,
AVL_GREATER_EQUAL);
SLABFREE(pr);
}
}
/*===========================================================================*
* map_memory *
*===========================================================================*/
PUBLIC int map_memory(endpoint_t sour, endpoint_t dest,
vir_bytes virt_s, vir_bytes virt_d, vir_bytes length, int flag)
{
/* This is the entry point. This function will be called by handle_memory() when
* VM recieves a map-memory request.
*/
struct vmproc *vms, *vmd;
struct vir_region *vrs, *vrd;
physr_iter iterd;
vir_bytes offset_s, offset_d;
int p;
int r;
if(vm_isokendpt(sour, &p) != OK)
panic("map_memory: bad endpoint: %d", sour);
vms = &vmproc[p];
if(vm_isokendpt(dest, &p) != OK)
panic("map_memory: bad endpoint: %d", dest);
vmd = &vmproc[p];
vrs = map_lookup(vms, virt_s);
assert(vrs);
vrd = map_lookup(vmd, virt_d);
assert(vrd);
/* Linear address -> offset from start of vir region. */
offset_s = virt_s - vrs->vaddr;
offset_d = virt_d - vrd->vaddr;
/* Make sure that the range in the source process has been mapped
* to physical memory.
*/
map_handle_memory(vms, vrs, offset_s, length, 0);
/* Prepare work. */
clean_phys_regions(vrs, offset_s, length);
clean_phys_regions(vrd, offset_d, length);
rm_phys_regions(vrd, offset_d, length);
/* Map memory. */
r = do_map_memory(vms, vmd, vrs, vrd, offset_s, offset_d, length, flag);
return r;
}
/*========================================================================*
* map_lookup_phys *
*========================================================================*/
phys_bytes
map_lookup_phys(struct vmproc *vmp, u32_t tag)
{
struct vir_region *vr;
struct phys_region *pr;
physr_iter iter;
if(!(vr = map_region_lookup_tag(vmp, tag))) {
printf("VM: request for phys of missing region\n");
return MAP_NONE;
}
physr_start_iter_least(vr->phys, &iter);
if(!(pr = physr_get_iter(&iter))) {
printf("VM: request for phys of unmapped region\n");
return MAP_NONE;
}
if(pr->offset != 0 || pr->ph->length != vr->length) {
printf("VM: request for phys of partially mapped region\n");
return MAP_NONE;
}
return pr->ph->phys;
}
/*===========================================================================*
* get_clean_phys_region *
*===========================================================================*/
PRIVATE struct phys_region *
get_clean_phys_region(struct vmproc *vmp, vir_bytes vaddr, vir_bytes length,
struct vir_region **ret_region)
{
struct vir_region *region;
vir_bytes regionoffset, mapaddr;
struct phys_region *ph;
mapaddr = arch_vir2map(vmp, vaddr);
if(!(region = map_lookup(vmp, mapaddr))) {
printf("VM: get_clean_phys_region: 0x%lx not found\n", vaddr);
return NULL;
}
if(!(region->flags & VR_ANON)) {
printf("VM: get_clean_phys_region: non-anon 0x%lx\n", vaddr);
return NULL;
}
assert(mapaddr >= region->vaddr);
assert(mapaddr < region->vaddr + region->length);
regionoffset = mapaddr-region->vaddr;
/* For now, only support the yielding of blocks that are
* exactly a mapped phys_region. Go get that phys_region.
* (This can be improved without changing the interface.)
*/
if(!(ph = physr_search(region->phys, regionoffset,
AVL_EQUAL))) {
printf("VM: get_clean_phys_region: exact block not found\n");
return NULL;
}
/* Make sure this is what we asked for. */
assert(ph->offset == regionoffset);
if(ph->ph->length != length) {
printf("VM: get_clean_phys_region: len mismatch (%d, %d)\n",
ph->ph->length, length);
return NULL;
}
/* If it's mapped more than once, make a copy. */
assert(ph->ph->refcount > 0);
if(ph->ph->refcount > 1) {
int r;
if(!(ph = map_clone_ph_block(vmp, region,
ph, NULL))) {
printf("VM: get_clean_phys_region: ph copy failed\n");
return NULL;
}
}
assert(ph->ph->refcount == 1);
*ret_region = region;
return ph;
}
PRIVATE int getblock(struct vmproc *vmp, u64_t id,
vir_bytes vaddr, vir_bytes len)
{
yielded_t *yb;
struct phys_region *ph;
struct vir_region *region;
/* Try to get the yielded block */
if(!(yb = yielded_search(&vmp->vm_yielded_blocks, id, AVL_EQUAL))) {
return ESRCH;
}
/* Check the size as a sanity check. */
if(yb->len != len) {
printf("VM: id 0x%lx%08lx mismatched size (%d, %d) for %d\n",
ex64hi(id), ex64lo(id), yb->len, len, vmp->vm_endpoint);
return ESRCH;
}
/* Get the intended phys region, make sure refcount is 1. */
if(!(ph = get_clean_phys_region(vmp, vaddr, len, &region))) {
printf("VM: getblock: not found for %d\n", vmp->vm_endpoint);
return EINVAL;
}
assert(ph->ph->refcount == 1);
/* Free the block that is currently there. */
free_mem(ABS2CLICK(ph->ph->phys), ABS2CLICK(ph->ph->length));
/* Set the phys block to new addr and update pagetable. */
USE(ph->ph, ph->ph->phys = yb->addr;);
if(map_ph_writept(vmp, region, ph) != OK) {
/* Presumably it was mapped, so there is no reason
* updating should fail.
*/
panic("do_get_block: couldn't write pt");
}
/* Forget about the yielded block and free the struct. */
freeyieldednode(yb, 0);
return OK;
}
PRIVATE int yieldblock(struct vmproc *vmp, u64_t id,
vir_bytes vaddr, vir_bytes len, yielded_t **retyb)
{
yielded_t *newyb;
vir_bytes mem_clicks, newmem, clicks;
struct vir_region *region;
struct phys_region *ph;
/* Makes no sense if yielded block ID already exists, and
* is likely a serious bug in the caller.
*/
if(yielded_search(&vmp->vm_yielded_blocks, id, AVL_EQUAL)) {
printf("!");
return EINVAL;
}
if(!(ph = get_clean_phys_region(vmp, vaddr, len, &region))) {
printf("VM: do_yield_block: not found for %d\n",
vmp->vm_endpoint);
return EINVAL;
}
/* Make a new block to record the yielding in. */
if(!SLABALLOC(newyb)) {
return ENOMEM;
}
assert(!(ph->ph->phys % VM_PAGE_SIZE));
assert(!(ph->ph->length % VM_PAGE_SIZE));
clicks = CLICKSPERPAGE * ph->ph->length / VM_PAGE_SIZE;
if((mem_clicks = alloc_mem(clicks, PAF_CLEAR)) == NO_MEM) {
SLABFREE(newyb);
return ENOMEM;
}
/* Update yielded block info. */
USE(newyb,
newyb->id = id;
newyb->addr = ph->ph->phys;
newyb->len = ph->ph->length;
newyb->owner = vmp->vm_endpoint;
newyb->younger = NULL;);
/* Set new phys block to new addr and update pagetable. */
USE(ph->ph,
ph->ph->phys = CLICK2ABS(mem_clicks););
if(map_ph_writept(vmp, region, ph) != OK) {
/* Presumably it was mapped, so there is no reason
* updating should fail.
*/
panic("yield_block: couldn't write pt");
}
/* Remember yielded block. */
yielded_insert(&vmp->vm_yielded_blocks, newyb);
/* Add to LRU list too. It's the youngest block. */
LRUCHECK;
if(lru_youngest) {
USE(lru_youngest,
lru_youngest->younger = newyb;);
} else {
lru_oldest = newyb;
}
USE(newyb,
newyb->older = lru_youngest;);
lru_youngest = newyb;
LRUCHECK;
if(retyb)
*retyb = newyb;
return OK;
}
/*===========================================================================*
* do_forgetblocks *
*===========================================================================*/
PUBLIC int do_forgetblocks(message *m)
{
int n;
struct vmproc *vmp;
endpoint_t caller = m->m_source;
if(vm_isokendpt(caller, &n) != OK)
panic("do_yield_block: message from strange source: %d",
m->m_source);
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT)) {
printf("do_forgetblocks: no pt\n");
return EFAULT;
}
free_yielded_proc(vmp);
return OK;
}
/*===========================================================================*
* do_forgetblock *
*===========================================================================*/
PUBLIC int do_forgetblock(message *m)
{
int n;
struct vmproc *vmp;
endpoint_t caller = m->m_source;
yielded_t *yb;
u64_t id;
if(vm_isokendpt(caller, &n) != OK)
panic("do_yield_block: message from strange source: %d",
m->m_source);
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT)) {
printf("do_forgetblock: no pt\n");
return EFAULT;
}
id = make64(m->VMFB_IDLO, m->VMFB_IDHI);
if((yb = yielded_search(&vmp->vm_yielded_blocks, id, AVL_EQUAL))) {
freeyieldednode(yb, 1);
}
return OK;
}
/*===========================================================================*
* do_yieldblockgetblock *
*===========================================================================*/
PUBLIC int do_yieldblockgetblock(message *m)
{
u64_t yieldid, getid;
int n, get = 0;
endpoint_t caller = m->m_source;
struct vmproc *vmp;
yielded_t *yb = NULL;
int r = ESRCH;
size_t len;
if(vm_isokendpt(caller, &n) != OK)
panic("do_yieldblockgetblock: message from strange source: %d",
m->m_source);
vmp = &vmproc[n];
if(!(vmp->vm_flags & VMF_HASPT)) {
printf("do_yieldblockgetblock: no pt\n");
return EFAULT;
}
len = m->VMYBGB_LEN;
if((len % VM_PAGE_SIZE)) {
len += VM_PAGE_SIZE - len % VM_PAGE_SIZE;
}
yieldid = make64(m->VMYBGB_YIELDIDLO, m->VMYBGB_YIELDIDHI);
getid = make64(m->VMYBGB_GETIDLO, m->VMYBGB_GETIDHI);
if(cmp64(yieldid, VM_BLOCKID_NONE) != 0) {
/* A block was given to yield. */
yieldblock(vmp, yieldid, (vir_bytes) m->VMYBGB_VADDR, len, &yb);
}
if(cmp64(getid, VM_BLOCKID_NONE) != 0) {
/* A block was given to get. */
r = getblock(vmp, getid, (vir_bytes) m->VMYBGB_VADDR, len);
}
return r;
}
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