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minix/servers/vm/utility.c
Cristiano Giuffrida 91a83fe265 Crash recovery and live update support for VM.
2010-07-20 23:03:52 +00:00

334 lines
10 KiB
C
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/* This file contains some utility routines for VM. */
#define _SYSTEM 1
#define _MINIX 1 /* To get the brk() prototype (as _brk()). */
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/type.h>
#include <minix/bitmap.h>
#include <string.h>
#include <errno.h>
#include <env.h>
#include <unistd.h>
#include <memory.h>
#include <assert.h>
#include "proto.h"
#include "glo.h"
#include "util.h"
#include "region.h"
#include "sanitycheck.h"
#include <machine/archtypes.h>
#include "kernel/const.h"
#include "kernel/config.h"
#include "kernel/type.h"
#include "kernel/proc.h"
/*===========================================================================*
* get_mem_map *
*===========================================================================*/
PUBLIC int get_mem_map(proc_nr, mem_map)
int proc_nr; /* process to get map of */
struct mem_map *mem_map; /* put memory map here */
{
struct proc p;
int s;
if ((s=sys_getproc(&p, proc_nr)) != OK)
return(s);
memcpy(mem_map, p.p_memmap, sizeof(p.p_memmap));
return(OK);
}
/*===========================================================================*
* get_mem_chunks *
*===========================================================================*/
PUBLIC void get_mem_chunks(mem_chunks)
struct memory *mem_chunks; /* store mem chunks here */
{
/* Initialize the free memory list from the 'memory' boot variable. Translate
* the byte offsets and sizes in this list to clicks, properly truncated.
*/
phys_bytes base, size, limit;
int i;
struct memory *memp;
/* Obtain and parse memory from system environment. */
if(env_memory_parse(mem_chunks, NR_MEMS) != OK)
panic("couldn't obtain memory chunks");
/* Round physical memory to clicks. Round start up, round end down. */
for (i = 0; i < NR_MEMS; i++) {
memp = &mem_chunks[i]; /* next mem chunk is stored here */
base = mem_chunks[i].base;
size = mem_chunks[i].size;
limit = base + size;
base = (phys_bytes) (CLICK_CEIL(base));
limit = (phys_bytes) (CLICK_FLOOR(limit));
if (limit <= base) {
memp->base = memp->size = 0;
} else {
memp->base = base >> CLICK_SHIFT;
memp->size = (limit - base) >> CLICK_SHIFT;
}
}
}
/*===========================================================================*
* reserve_proc_mem *
*===========================================================================*/
PUBLIC void reserve_proc_mem(mem_chunks, map_ptr)
struct memory *mem_chunks; /* store mem chunks here */
struct mem_map *map_ptr; /* memory to remove */
{
/* Remove server memory from the free memory list. The boot monitor
* promises to put processes at the start of memory chunks. The
* tasks all use same base address, so only the first task changes
* the memory lists. The servers and init have their own memory
* spaces and their memory will be removed from the list.
*/
struct memory *memp;
for (memp = mem_chunks; memp < &mem_chunks[NR_MEMS]; memp++) {
if (memp->base == map_ptr[T].mem_phys) {
memp->base += map_ptr[T].mem_len + map_ptr[S].mem_vir;
memp->size -= map_ptr[T].mem_len + map_ptr[S].mem_vir;
break;
}
}
if (memp >= &mem_chunks[NR_MEMS])
{
panic("reserve_proc_mem: can't find map in mem_chunks: 0x%lx",
map_ptr[T].mem_phys);
}
}
/*===========================================================================*
* vm_isokendpt *
*===========================================================================*/
PUBLIC int vm_isokendpt(endpoint_t endpoint, int *proc)
{
*proc = _ENDPOINT_P(endpoint);
if(*proc < 0 || *proc >= NR_PROCS)
return EINVAL;
if(*proc >= 0 && endpoint != vmproc[*proc].vm_endpoint)
return EDEADEPT;
if(*proc >= 0 && !(vmproc[*proc].vm_flags & VMF_INUSE))
return EDEADEPT;
return OK;
}
struct proc mytmpproc;
/*===========================================================================*
* get_stack_ptr *
*===========================================================================*/
PUBLIC int get_stack_ptr(proc_nr_e, sp)
int proc_nr_e; /* process to get sp of */
vir_bytes *sp; /* put stack pointer here */
{
int s;
if ((s=sys_getproc(&mytmpproc, proc_nr_e)) != OK)
return(s);
*sp = mytmpproc.p_reg.sp;
return(OK);
}
/*===========================================================================*
* do_info *
*===========================================================================*/
PUBLIC int do_info(message *m)
{
struct vm_stats_info vsi;
struct vm_usage_info vui;
static struct vm_region_info vri[MAX_VRI_COUNT];
struct vmproc *vmp;
vir_bytes addr, size, next, ptr;
int r, pr, dummy, count;
if (vm_isokendpt(m->m_source, &pr) != OK)
return EINVAL;
vmp = &vmproc[pr];
ptr = (vir_bytes) m->VMI_PTR;
switch(m->VMI_WHAT) {
case VMIW_STATS:
vsi.vsi_pagesize = VM_PAGE_SIZE;
vsi.vsi_total = total_pages;
memstats(&dummy, &vsi.vsi_free, &vsi.vsi_largest);
addr = (vir_bytes) &vsi;
size = sizeof(vsi);
break;
case VMIW_USAGE:
if (vm_isokendpt(m->VMI_EP, &pr) != OK)
return EINVAL;
get_usage_info(&vmproc[pr], &vui);
addr = (vir_bytes) &vui;
size = sizeof(vui);
break;
case VMIW_REGION:
if (vm_isokendpt(m->VMI_EP, &pr) != OK)
return EINVAL;
count = MIN(m->VMI_COUNT, MAX_VRI_COUNT);
next = m->VMI_NEXT;
count = get_region_info(&vmproc[pr], vri, count, &next);
m->VMI_COUNT = count;
m->VMI_NEXT = next;
addr = (vir_bytes) vri;
size = sizeof(vri[0]) * count;
break;
default:
return EINVAL;
}
if (size == 0)
return OK;
/* Make sure that no page faults can occur while copying out. A page
* fault would cause the kernel to send a notify to us, while we would
* be waiting for the result of the copy system call, resulting in a
* deadlock. Note that no memory mapping can be undone without the
* involvement of VM, so we are safe until we're done.
*/
r = handle_memory(vmp, arch_vir2map(vmp, ptr), size, 1 /*wrflag*/);
if (r != OK) return r;
/* Now that we know the copy out will succeed, perform the actual copy
* operation.
*/
return sys_datacopy(SELF, addr,
(vir_bytes) vmp->vm_endpoint, ptr, size);
}
/*===========================================================================*
* swap_proc_slot *
*===========================================================================*/
PUBLIC int swap_proc_slot(struct vmproc *src_vmp, struct vmproc *dst_vmp)
{
struct vmproc orig_src_vmproc, orig_dst_vmproc;
#if LU_DEBUG
printf("VM: swap_proc: swapping %d (%d) and %d (%d)\n",
src_vmp->vm_endpoint, src_vmp->vm_slot,
dst_vmp->vm_endpoint, dst_vmp->vm_slot);
#endif
/* Save existing data. */
orig_src_vmproc = *src_vmp;
orig_dst_vmproc = *dst_vmp;
/* Swap slots. */
*src_vmp = orig_dst_vmproc;
*dst_vmp = orig_src_vmproc;
/* Preserve endpoints and slot numbers. */
src_vmp->vm_endpoint = orig_src_vmproc.vm_endpoint;
src_vmp->vm_slot = orig_src_vmproc.vm_slot;
dst_vmp->vm_endpoint = orig_dst_vmproc.vm_endpoint;
dst_vmp->vm_slot = orig_dst_vmproc.vm_slot;
/* Preserve yielded blocks. */
src_vmp->vm_yielded_blocks = orig_src_vmproc.vm_yielded_blocks;
dst_vmp->vm_yielded_blocks = orig_dst_vmproc.vm_yielded_blocks;
#if LU_DEBUG
printf("VM: swap_proc: swapped %d (%d) and %d (%d)\n",
src_vmp->vm_endpoint, src_vmp->vm_slot,
dst_vmp->vm_endpoint, dst_vmp->vm_slot);
#endif
return OK;
}
/*===========================================================================*
* swap_proc_dyn_data *
*===========================================================================*/
PUBLIC int swap_proc_dyn_data(struct vmproc *src_vmp, struct vmproc *dst_vmp)
{
struct vir_region *vr;
int is_vm;
int r;
is_vm = (dst_vmp->vm_endpoint == VM_PROC_NR);
/* For VM, transfer memory regions above the stack first. */
if(is_vm) {
#if LU_DEBUG
printf("VM: swap_proc_dyn_data: tranferring regions above the stack from old VM (%d) to new VM (%d)\n",
src_vmp->vm_endpoint, dst_vmp->vm_endpoint);
#endif
assert(src_vmp->vm_stacktop == dst_vmp->vm_stacktop);
r = pt_map_in_range(src_vmp, dst_vmp,
arch_vir2map(src_vmp, src_vmp->vm_stacktop), 0);
if(r != OK) {
printf("swap_proc_dyn_data: pt_map_in_range failed\n");
return r;
}
}
#if LU_DEBUG
printf("VM: swap_proc_dyn_data: swapping regions' parents for %d (%d) and %d (%d)\n",
src_vmp->vm_endpoint, src_vmp->vm_slot,
dst_vmp->vm_endpoint, dst_vmp->vm_slot);
#endif
/* Swap vir_regions' parents. */
for(vr = src_vmp->vm_regions; vr; vr = vr->next) {
USE(vr, vr->parent = src_vmp;);
}
for(vr = dst_vmp->vm_regions; vr; vr = vr->next) {
USE(vr, vr->parent = dst_vmp;);
}
/* For regular processes, transfer regions above the stack now.
* In case of rollback, we need to skip this step. To sandbox the
* new instance and prevent state corruption on rollback, we share all
* the regions between the two instances as COW.
*/
if(!is_vm && (dst_vmp->vm_flags & VMF_HASPT)) {
vr = map_lookup(dst_vmp, arch_vir2map(dst_vmp, dst_vmp->vm_stacktop));
if(vr && !map_lookup(src_vmp, arch_vir2map(src_vmp, src_vmp->vm_stacktop))) {
#if LU_DEBUG
printf("VM: swap_proc_dyn_data: tranferring regions above the stack from %d to %d\n",
src_vmp->vm_endpoint, dst_vmp->vm_endpoint);
#endif
assert(src_vmp->vm_stacktop == dst_vmp->vm_stacktop);
r = map_proc_copy_from(src_vmp, dst_vmp, vr);
if(r != OK) {
return r;
}
}
}
return OK;
}
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