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minix/kernel/arch/i386/memory.c
Tomas Hruby 5efa92f754 NMI watchdog is an awesome feature for debugging locked up kernels. 
There is not that much use for it on a single CPU, however, deadlock
between kernel and system task can be delected. Or a runaway loop.

If a kernel gets locked up the timer interrupts don't occure (as all
interrupts are disabled in kernel mode). The only chance is to
interrupt the kernel by a non-maskable interrupt.

This patch generates NMIs using performance counters. It uses the most
widely available performace counters. As the performance counters are 
highly model-specific this patch is not guaranteed to work on every
machine.  Unfortunately this is also true for KVM :-/ On the other
hand adding this feature for other models is not extremely difficult
and the framework makes it hopefully easy enough.

Depending on the frequency of the CPU an NMI is generated at most
about every 0.5s If the cpu's speed is less then 2Ghz it is generated
at most every 1s. In general an NMI is generated much less often as
the performance counter counts down only if the cpu is not idle.
Therefore the overhead of this feature is fairly minimal even if the
load is high.

Uppon detecting that the kernel is locked up the kernel dumps the 
state of the kernel registers and panics.

Local APIC must be enabled for the watchdog to work.

The code is _always_ compiled in, however, it is only enabled if  
watchdog=<non-zero> is set in the boot monitor.

One corner case is serial console debugging. As dumping a lot of stuff
to the serial link may take a lot of time, the watchdog does not 
detect lockups during this time!!! as it would result in too many
false positives. 10 nmi have to be handled before the lockup is
detected. This means something between ~5s to 10s.

Another corner case is that the watchdog is enabled only after the
paging is enabled as it would be pure madness to try to get it right.
2010-01-16 20:53:55 +00:00

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#include "../../kernel.h"
#include "../../proc.h"
#include "../../vm.h"
#include <minix/type.h>
#include <minix/syslib.h>
#include <minix/cpufeature.h>
#include <string.h>
#include <sys/vm_i386.h>
#include <minix/portio.h>
#include "proto.h"
#include "../../proto.h"
#include "../../proto.h"
#include "../../debug.h"
#ifdef CONFIG_APIC
#include "apic.h"
#ifdef CONFIG_WATCHDOG
#include "../../watchdog.h"
#endif
#endif
PRIVATE int psok = 0;
#define PROCPDEPTR(pr, pi) ((u32_t *) ((u8_t *) vm_pagedirs +\
I386_PAGE_SIZE * pr->p_nr + \
I386_VM_PT_ENT_SIZE * pi))
u8_t *vm_pagedirs = NULL;
#define NOPDE (-1)
#define PDEMASK(n) (1L << (n))
PUBLIC u32_t dirtypde;
#define WANT_FREEPDES (sizeof(dirtypde)*8-5)
PRIVATE int nfreepdes = 0, freepdes[WANT_FREEPDES], inusepde = NOPDE;
#define HASPT(procptr) ((procptr)->p_seg.p_cr3 != 0)
FORWARD _PROTOTYPE( u32_t phys_get32, (vir_bytes v) );
FORWARD _PROTOTYPE( void vm_enable_paging, (void) );
FORWARD _PROTOTYPE( void set_cr3, (void) );
/* *** Internal VM Functions *** */
PUBLIC void vm_init(struct proc *newptproc)
{
int i;
if(vm_running)
minix_panic("vm_init: vm_running", NO_NUM);
vm_set_cr3(newptproc);
level0(vm_enable_paging);
vm_running = 1;
}
#define TYPEDIRECT 0
#define TYPEPROCMAP 1
#define TYPEPHYS 2
/* This macro sets up a mapping from within the kernel's address
* space to any other area of memory, either straight physical
* memory (PROC == NULL) or a process view of memory, in 4MB chunks.
* It recognizes PROC having kernel address space as a special case.
*
* It sets PTR to the pointer within kernel address space at the start
* of the 4MB chunk, and OFFSET to the offset within that chunk
* that corresponds to LINADDR.
*
* It needs FREEPDE (available and addressable PDE within kernel
* address space), SEG (hardware segment), VIRT (in-datasegment
* address if known).
*/
#define CREATEPDE(PROC, PTR, LINADDR, REMAIN, BYTES, PDE, TYPE) { \
u32_t *pdeptr = NULL; \
int proc_pde_index; \
proc_pde_index = I386_VM_PDE(LINADDR); \
PDE = NOPDE; \
if((PROC) && (((PROC) == ptproc) || !HASPT(PROC))) { \
PTR = LINADDR; \
TYPE = TYPEDIRECT; \
} else { \
int fp; \
int mustinvl; \
u32_t pdeval, *pdevalptr, mask; \
phys_bytes offset; \
vmassert(psok); \
if(PROC) { \
TYPE = TYPEPROCMAP; \
vmassert(!iskernelp(PROC)); \
vmassert(HASPT(PROC)); \
pdeptr = PROCPDEPTR(PROC, proc_pde_index); \
pdeval = *pdeptr; \
} else { \
TYPE = TYPEPHYS; \
pdeval = (LINADDR & I386_VM_ADDR_MASK_4MB) | \
I386_VM_BIGPAGE | I386_VM_PRESENT | \
I386_VM_WRITE | I386_VM_USER; \
} \
for(fp = 0; fp < nfreepdes; fp++) { \
int k = freepdes[fp]; \
if(inusepde == k) \
continue; \
*PROCPDEPTR(ptproc, k) = 0; \
PDE = k; \
vmassert(k >= 0); \
vmassert(k < sizeof(dirtypde)*8); \
mask = PDEMASK(PDE); \
if(dirtypde & mask) \
continue; \
break; \
} \
vmassert(PDE != NOPDE); \
vmassert(mask); \
if(dirtypde & mask) { \
mustinvl = 1; \
} else { \
mustinvl = 0; \
} \
inusepde = PDE; \
*PROCPDEPTR(ptproc, PDE) = pdeval; \
offset = LINADDR & I386_VM_OFFSET_MASK_4MB; \
PTR = I386_BIG_PAGE_SIZE*PDE + offset; \
REMAIN = MIN(REMAIN, I386_BIG_PAGE_SIZE - offset); \
if(1 || mustinvl) { \
level0(reload_cr3); \
} \
} \
}
#define DONEPDE(PDE) { \
if(PDE != NOPDE) { \
vmassert(PDE > 0); \
vmassert(PDE < sizeof(dirtypde)*8); \
dirtypde |= PDEMASK(PDE); \
} \
}
#define WIPEPDE(PDE) { \
if(PDE != NOPDE) { \
vmassert(PDE > 0); \
vmassert(PDE < sizeof(dirtypde)*8); \
*PROCPDEPTR(ptproc, PDE) = 0; \
} \
}
/*===========================================================================*
* lin_lin_copy *
*===========================================================================*/
int lin_lin_copy(struct proc *srcproc, vir_bytes srclinaddr,
struct proc *dstproc, vir_bytes dstlinaddr, vir_bytes bytes)
{
u32_t addr;
int o1, o2;
int procslot;
int firstloop = 1;
NOREC_ENTER(linlincopy);
vmassert(vm_running);
vmassert(nfreepdes >= 3);
vmassert(ptproc);
vmassert(proc_ptr);
vmassert(read_cr3() == ptproc->p_seg.p_cr3);
procslot = ptproc->p_nr;
vmassert(procslot >= 0 && procslot < I386_VM_DIR_ENTRIES);
while(bytes > 0) {
phys_bytes srcptr, dstptr;
vir_bytes chunk = bytes;
int srcpde, dstpde;
int srctype, dsttype;
/* Set up 4MB ranges. */
inusepde = NOPDE;
CREATEPDE(srcproc, srcptr, srclinaddr, chunk, bytes, srcpde, srctype);
CREATEPDE(dstproc, dstptr, dstlinaddr, chunk, bytes, dstpde, dsttype);
/* Copy pages. */
PHYS_COPY_CATCH(srcptr, dstptr, chunk, addr);
DONEPDE(srcpde);
DONEPDE(dstpde);
if(addr) {
/* If addr is nonzero, a page fault was caught. */
if(addr >= srcptr && addr < (srcptr + chunk)) {
WIPEPDE(srcpde);
WIPEPDE(dstpde);
NOREC_RETURN(linlincopy, EFAULT_SRC);
}
if(addr >= dstptr && addr < (dstptr + chunk)) {
WIPEPDE(srcpde);
WIPEPDE(dstpde);
NOREC_RETURN(linlincopy, EFAULT_DST);
}
minix_panic("lin_lin_copy fault out of range", NO_NUM);
/* Not reached. */
NOREC_RETURN(linlincopy, EFAULT);
}
WIPEPDE(srcpde);
WIPEPDE(dstpde);
/* Update counter and addresses for next iteration, if any. */
bytes -= chunk;
srclinaddr += chunk;
dstlinaddr += chunk;
firstloop = 0;
}
NOREC_RETURN(linlincopy, OK);
}
PRIVATE u32_t phys_get32(addr)
phys_bytes addr;
{
u32_t v;
int r;
if(!vm_running) {
phys_copy(addr, vir2phys(&v), sizeof(v));
return v;
}
if((r=lin_lin_copy(NULL, addr,
proc_addr(SYSTEM), vir2phys(&v), sizeof(v))) != OK) {
minix_panic("lin_lin_copy for phys_get32 failed", r);
}
return v;
}
PRIVATE u32_t vm_cr3; /* temp arg to level0() func */
PRIVATE void set_cr3()
{
write_cr3(vm_cr3);
}
PUBLIC void vm_set_cr3(struct proc *newptproc)
{
int u = 0;
if(!intr_disabled()) { lock; u = 1; }
vm_cr3= newptproc->p_seg.p_cr3;
if(vm_cr3) {
level0(set_cr3);
ptproc = newptproc;
}
if(u) { unlock; }
}
char *cr0_str(u32_t e)
{
static char str[80];
strcpy(str, "");
#define FLAG(v) do { if(e & (v)) { strcat(str, #v " "); e &= ~v; } } while(0)
FLAG(I386_CR0_PE);
FLAG(I386_CR0_MP);
FLAG(I386_CR0_EM);
FLAG(I386_CR0_TS);
FLAG(I386_CR0_ET);
FLAG(I386_CR0_PG);
FLAG(I386_CR0_WP);
if(e) { strcat(str, " (++)"); }
return str;
}
char *cr4_str(u32_t e)
{
static char str[80];
strcpy(str, "");
FLAG(I386_CR4_VME);
FLAG(I386_CR4_PVI);
FLAG(I386_CR4_TSD);
FLAG(I386_CR4_DE);
FLAG(I386_CR4_PSE);
FLAG(I386_CR4_PAE);
FLAG(I386_CR4_MCE);
FLAG(I386_CR4_PGE);
if(e) { strcat(str, " (++)"); }
return str;
}
PRIVATE void vm_enable_paging(void)
{
u32_t cr0, cr4;
int pgeok;
psok = _cpufeature(_CPUF_I386_PSE);
pgeok = _cpufeature(_CPUF_I386_PGE);
cr0= read_cr0();
cr4= read_cr4();
/* First clear PG and PGE flag, as PGE must be enabled after PG. */
write_cr0(cr0 & ~I386_CR0_PG);
write_cr4(cr4 & ~(I386_CR4_PGE | I386_CR4_PSE));
cr0= read_cr0();
cr4= read_cr4();
/* Our first page table contains 4MB entries. */
if(psok)
cr4 |= I386_CR4_PSE;
write_cr4(cr4);
/* First enable paging, then enable global page flag. */
cr0 |= I386_CR0_PG;
write_cr0(cr0 );
cr0 |= I386_CR0_WP;
write_cr0(cr0);
/* May we enable these features? */
if(pgeok)
cr4 |= I386_CR4_PGE;
write_cr4(cr4);
}
PUBLIC vir_bytes alloc_remote_segment(u32_t *selector,
segframe_t *segments, int index, phys_bytes phys, vir_bytes size,
int priv)
{
phys_bytes offset = 0;
/* Check if the segment size can be recorded in bytes, that is, check
* if descriptor's limit field can delimited the allowed memory region
* precisely. This works up to 1MB. If the size is larger, 4K pages
* instead of bytes are used.
*/
if (size < BYTE_GRAN_MAX) {
init_dataseg(&segments->p_ldt[EXTRA_LDT_INDEX+index],
phys, size, priv);
*selector = ((EXTRA_LDT_INDEX+index)*0x08) | (1*0x04) | priv;
offset = 0;
} else {
init_dataseg(&segments->p_ldt[EXTRA_LDT_INDEX+index],
phys & ~0xFFFF, 0, priv);
*selector = ((EXTRA_LDT_INDEX+index)*0x08) | (1*0x04) | priv;
offset = phys & 0xFFFF;
}
return offset;
}
PUBLIC phys_bytes umap_remote(struct proc* rp, int seg,
vir_bytes vir_addr, vir_bytes bytes)
{
/* Calculate the physical memory address for a given virtual address. */
struct far_mem *fm;
#if 0
if(rp->p_misc_flags & MF_FULLVM) return 0;
#endif
if (bytes <= 0) return( (phys_bytes) 0);
if (seg < 0 || seg >= NR_REMOTE_SEGS) return( (phys_bytes) 0);
fm = &rp->p_priv->s_farmem[seg];
if (! fm->in_use) return( (phys_bytes) 0);
if (vir_addr + bytes > fm->mem_len) return( (phys_bytes) 0);
return(fm->mem_phys + (phys_bytes) vir_addr);
}
/*===========================================================================*
* umap_local *
*===========================================================================*/
PUBLIC phys_bytes umap_local(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
/* Calculate the physical memory address for a given virtual address. */
vir_clicks vc; /* the virtual address in clicks */
phys_bytes pa; /* intermediate variables as phys_bytes */
phys_bytes seg_base;
if(seg != T && seg != D && seg != S)
minix_panic("umap_local: wrong seg", seg);
if (bytes <= 0) return( (phys_bytes) 0);
if (vir_addr + bytes <= vir_addr) return 0; /* overflow */
vc = (vir_addr + bytes - 1) >> CLICK_SHIFT; /* last click of data */
if (seg != T)
seg = (vc < rp->p_memmap[D].mem_vir + rp->p_memmap[D].mem_len ? D : S);
else if (rp->p_memmap[T].mem_len == 0) /* common I&D? */
seg = D; /* ptrace needs this */
if ((vir_addr>>CLICK_SHIFT) >= rp->p_memmap[seg].mem_vir +
rp->p_memmap[seg].mem_len) return( (phys_bytes) 0 );
if (vc >= rp->p_memmap[seg].mem_vir +
rp->p_memmap[seg].mem_len) return( (phys_bytes) 0 );
seg_base = (phys_bytes) rp->p_memmap[seg].mem_phys;
seg_base = seg_base << CLICK_SHIFT; /* segment origin in bytes */
pa = (phys_bytes) vir_addr;
pa -= rp->p_memmap[seg].mem_vir << CLICK_SHIFT;
return(seg_base + pa);
}
/*===========================================================================*
* umap_virtual *
*===========================================================================*/
PUBLIC phys_bytes umap_virtual(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
vir_bytes linear;
u32_t phys = 0;
if(seg == MEM_GRANT) {
phys = umap_grant(rp, vir_addr, bytes);
} else {
if(!(linear = umap_local(rp, seg, vir_addr, bytes))) {
kprintf("SYSTEM:umap_virtual: umap_local failed\n");
phys = 0;
} else {
if(vm_lookup(rp, linear, &phys, NULL) != OK) {
kprintf("SYSTEM:umap_virtual: vm_lookup of %s: seg 0x%lx: 0x%lx failed\n", rp->p_name, seg, vir_addr);
phys = 0;
}
if(phys == 0)
minix_panic("vm_lookup returned phys", phys);
}
}
if(phys == 0) {
kprintf("SYSTEM:umap_virtual: lookup failed\n");
return 0;
}
/* Now make sure addresses are contiguous in physical memory
* so that the umap makes sense.
*/
if(bytes > 0 && !vm_contiguous(rp, linear, bytes)) {
kprintf("umap_virtual: %s: %d at 0x%lx (vir 0x%lx) not contiguous\n",
rp->p_name, bytes, linear, vir_addr);
return 0;
}
/* phys must be larger than 0 (or the caller will think the call
* failed), and address must not cross a page boundary.
*/
vmassert(phys);
return phys;
}
/*===========================================================================*
* vm_lookup *
*===========================================================================*/
PUBLIC int vm_lookup(struct proc *proc, vir_bytes virtual, vir_bytes *physical, u32_t *ptent)
{
u32_t *root, *pt;
int pde, pte;
u32_t pde_v, pte_v;
NOREC_ENTER(vmlookup);
vmassert(proc);
vmassert(physical);
vmassert(!isemptyp(proc));
if(!HASPT(proc)) {
*physical = virtual;
NOREC_RETURN(vmlookup, OK);
}
/* Retrieve page directory entry. */
root = (u32_t *) proc->p_seg.p_cr3;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
pde = I386_VM_PDE(virtual);
vmassert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT)) {
NOREC_RETURN(vmlookup, EFAULT);
}
/* We don't expect to ever see this. */
if(pde_v & I386_VM_BIGPAGE) {
*physical = pde_v & I386_VM_ADDR_MASK_4MB;
if(ptent) *ptent = pde_v;
*physical += virtual & I386_VM_OFFSET_MASK_4MB;
} else {
/* Retrieve page table entry. */
pt = (u32_t *) I386_VM_PFA(pde_v);
vmassert(!((u32_t) pt % I386_PAGE_SIZE));
pte = I386_VM_PTE(virtual);
vmassert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
pte_v = phys_get32((u32_t) (pt + pte));
if(!(pte_v & I386_VM_PRESENT)) {
NOREC_RETURN(vmlookup, EFAULT);
}
if(ptent) *ptent = pte_v;
/* Actual address now known; retrieve it and add page offset. */
*physical = I386_VM_PFA(pte_v);
*physical += virtual % I386_PAGE_SIZE;
}
NOREC_RETURN(vmlookup, OK);
}
/* From virtual address v in process p,
* lookup physical address and assign it to d.
* If p is NULL, assume it's already a physical address.
*/
#define LOOKUP(d, p, v, flagsp) { \
int r; \
if(!(p)) { (d) = (v); } \
else { \
if((r=vm_lookup((p), (v), &(d), flagsp)) != OK) { \
kprintf("vm_copy: lookup failed of 0x%lx in %d (%s)\n"\
"kernel stacktrace: ", (v), (p)->p_endpoint, \
(p)->p_name); \
util_stacktrace(); \
return r; \
} } }
/*===========================================================================*
* vm_contiguous *
*===========================================================================*/
PUBLIC int vm_contiguous(struct proc *targetproc, u32_t vir_buf, size_t bytes)
{
int first = 1, r, boundaries = 0;
u32_t prev_phys, po;
u32_t prev_vir;
vmassert(targetproc);
vmassert(bytes > 0);
if(!HASPT(targetproc))
return 1;
/* Start and end at page boundary to make logic simpler. */
po = vir_buf % I386_PAGE_SIZE;
if(po > 0) {
bytes += po;
vir_buf -= po;
}
po = (vir_buf + bytes) % I386_PAGE_SIZE;
if(po > 0)
bytes += I386_PAGE_SIZE - po;
/* Keep going as long as we cross a page boundary. */
while(bytes > 0) {
u32_t phys;
if((r=vm_lookup(targetproc, vir_buf, &phys, NULL)) != OK) {
kprintf("vm_contiguous: vm_lookup failed, %d\n", r);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
if(!first) {
if(prev_phys+I386_PAGE_SIZE != phys) {
kprintf("vm_contiguous: no (0x%lx, 0x%lx)\n",
prev_phys, phys);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
}
first = 0;
prev_phys = phys;
prev_vir = vir_buf;
vir_buf += I386_PAGE_SIZE;
bytes -= I386_PAGE_SIZE;
boundaries++;
}
return 1;
}
/*===========================================================================*
* vm_suspend *
*===========================================================================*/
PUBLIC int vm_suspend(struct proc *caller, struct proc *target,
vir_bytes linaddr, vir_bytes len, int wrflag, int type)
{
/* This range is not OK for this process. Set parameters
* of the request and notify VM about the pending request.
*/
vmassert(!RTS_ISSET(caller, RTS_VMREQUEST));
vmassert(!RTS_ISSET(target, RTS_VMREQUEST));
RTS_LOCK_SET(caller, RTS_VMREQUEST);
#if DEBUG_VMASSERT
caller->p_vmrequest.stacktrace[0] = '\0';
util_stacktrace_strcat(caller->p_vmrequest.stacktrace);
#endif
caller->p_vmrequest.req_type = VMPTYPE_CHECK;
caller->p_vmrequest.target = target->p_endpoint;
caller->p_vmrequest.params.check.start = linaddr;
caller->p_vmrequest.params.check.length = len;
caller->p_vmrequest.params.check.writeflag = 1;
caller->p_vmrequest.type = type;
/* Connect caller on vmrequest wait queue. */
if(!(caller->p_vmrequest.nextrequestor = vmrequest))
mini_notify(proc_addr(SYSTEM), VM_PROC_NR);
vmrequest = caller;
}
/*===========================================================================*
* delivermsg *
*===========================================================================*/
int delivermsg(struct proc *rp)
{
phys_bytes addr;
int r;
NOREC_ENTER(deliver);
vmassert(rp->p_misc_flags & MF_DELIVERMSG);
vmassert(rp->p_delivermsg.m_source != NONE);
vmassert(rp->p_delivermsg_lin);
#if DEBUG_VMASSERT
if(rp->p_delivermsg_lin !=
umap_local(rp, D, rp->p_delivermsg_vir, sizeof(message))) {
printf("vir: 0x%lx lin was: 0x%lx umap now: 0x%lx\n",
rp->p_delivermsg_vir, rp->p_delivermsg_lin,
umap_local(rp, D, rp->p_delivermsg_vir, sizeof(message)));
minix_panic("that's wrong", NO_NUM);
}
#endif
vm_set_cr3(rp);
PHYS_COPY_CATCH(vir2phys(&rp->p_delivermsg),
rp->p_delivermsg_lin, sizeof(message), addr);
if(addr) {
vm_suspend(rp, rp, rp->p_delivermsg_lin, sizeof(message), 1,
VMSTYPE_DELIVERMSG);
r = VMSUSPEND;
} else {
#if DEBUG_VMASSERT
rp->p_delivermsg.m_source = NONE;
rp->p_delivermsg_lin = 0;
#endif
rp->p_misc_flags &= ~MF_DELIVERMSG;
r = OK;
}
NOREC_RETURN(deliver, r);
}
char *flagstr(u32_t e, int dir)
{
static char str[80];
strcpy(str, "");
FLAG(I386_VM_PRESENT);
FLAG(I386_VM_WRITE);
FLAG(I386_VM_USER);
FLAG(I386_VM_PWT);
FLAG(I386_VM_PCD);
FLAG(I386_VM_GLOBAL);
if(dir)
FLAG(I386_VM_BIGPAGE); /* Page directory entry only */
else
FLAG(I386_VM_DIRTY); /* Page table entry only */
return str;
}
void vm_pt_print(u32_t *pagetable, u32_t v)
{
int pte, l = 0;
int col = 0;
vmassert(!((u32_t) pagetable % I386_PAGE_SIZE));
for(pte = 0; pte < I386_VM_PT_ENTRIES; pte++) {
u32_t pte_v, pfa;
pte_v = phys_get32((u32_t) (pagetable + pte));
if(!(pte_v & I386_VM_PRESENT))
continue;
pfa = I386_VM_PFA(pte_v);
kprintf("%4d:%08lx:%08lx %2s ",
pte, v + I386_PAGE_SIZE*pte, pfa,
(pte_v & I386_VM_WRITE) ? "rw":"RO");
col++;
if(col == 3) { kprintf("\n"); col = 0; }
}
if(col > 0) kprintf("\n");
return;
}
void vm_print(u32_t *root)
{
int pde;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
printf("page table 0x%lx:\n", root);
for(pde = 0; pde < I386_VM_DIR_ENTRIES; pde++) {
u32_t pde_v;
u32_t *pte_a;
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT))
continue;
if(pde_v & I386_VM_BIGPAGE) {
kprintf("%4d: 0x%lx, flags %s\n",
pde, I386_VM_PFA(pde_v), flagstr(pde_v, 1));
} else {
pte_a = (u32_t *) I386_VM_PFA(pde_v);
kprintf("%4d: pt %08lx %s\n",
pde, pte_a, flagstr(pde_v, 1));
vm_pt_print(pte_a, pde * I386_VM_PT_ENTRIES * I386_PAGE_SIZE);
kprintf("\n");
}
}
return;
}
u32_t thecr3;
u32_t read_cr3(void)
{
level0(getcr3val);
return thecr3;
}
/*===========================================================================*
* lin_memset *
*===========================================================================*/
int vm_phys_memset(phys_bytes ph, u8_t c, phys_bytes bytes)
{
char *v;
u32_t p;
NOREC_ENTER(physmemset);
p = c | (c << 8) | (c << 16) | (c << 24);
if(!vm_running) {
phys_memset(ph, p, bytes);
NOREC_RETURN(physmemset, OK);
}
vmassert(nfreepdes >= 3);
/* With VM, we have to map in the physical memory.
* We can do this 4MB at a time.
*/
while(bytes > 0) {
int pde, t;
vir_bytes chunk = bytes;
phys_bytes ptr;
inusepde = NOPDE;
CREATEPDE(((struct proc *) NULL), ptr, ph, chunk, bytes, pde, t);
/* We can memset as many bytes as we have remaining,
* or as many as remain in the 4MB chunk we mapped in.
*/
phys_memset(ptr, p, chunk);
DONEPDE(pde);
bytes -= chunk;
ph += chunk;
}
NOREC_RETURN(physmemset, OK);
}
/*===========================================================================*
* virtual_copy_f *
*===========================================================================*/
PUBLIC int virtual_copy_f(src_addr, dst_addr, bytes, vmcheck)
struct vir_addr *src_addr; /* source virtual address */
struct vir_addr *dst_addr; /* destination virtual address */
vir_bytes bytes; /* # of bytes to copy */
int vmcheck; /* if nonzero, can return VMSUSPEND */
{
/* Copy bytes from virtual address src_addr to virtual address dst_addr.
* Virtual addresses can be in ABS, LOCAL_SEG, REMOTE_SEG, or BIOS_SEG.
*/
struct vir_addr *vir_addr[2]; /* virtual source and destination address */
phys_bytes phys_addr[2]; /* absolute source and destination */
int seg_index;
int i, r;
struct proc *procs[2];
NOREC_ENTER(virtualcopy);
/* Check copy count. */
if (bytes <= 0) return(EDOM);
/* Do some more checks and map virtual addresses to physical addresses. */
vir_addr[_SRC_] = src_addr;
vir_addr[_DST_] = dst_addr;
for (i=_SRC_; i<=_DST_; i++) {
int proc_nr, type;
struct proc *p;
type = vir_addr[i]->segment & SEGMENT_TYPE;
if((type != PHYS_SEG && type != BIOS_SEG) &&
isokendpt(vir_addr[i]->proc_nr_e, &proc_nr))
p = proc_addr(proc_nr);
else
p = NULL;
procs[i] = p;
/* Get physical address. */
switch(type) {
case LOCAL_SEG:
case LOCAL_VM_SEG:
if(!p) {
NOREC_RETURN(virtualcopy, EDEADSRCDST);
}
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
if(type == LOCAL_SEG)
phys_addr[i] = umap_local(p, seg_index, vir_addr[i]->offset,
bytes);
else
phys_addr[i] = umap_virtual(p, seg_index, vir_addr[i]->offset,
bytes);
if(phys_addr[i] == 0) {
kprintf("virtual_copy: map 0x%x failed for %s seg %d, "
"offset %lx, len %d, i %d\n",
type, p->p_name, seg_index, vir_addr[i]->offset,
bytes, i);
}
break;
case REMOTE_SEG:
if(!p) {
NOREC_RETURN(virtualcopy, EDEADSRCDST);
}
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
phys_addr[i] = umap_remote(p, seg_index, vir_addr[i]->offset, bytes);
break;
#if _MINIX_CHIP == _CHIP_INTEL
case BIOS_SEG:
phys_addr[i] = umap_bios(vir_addr[i]->offset, bytes );
break;
#endif
case PHYS_SEG:
phys_addr[i] = vir_addr[i]->offset;
break;
default:
kprintf("virtual_copy: strange type 0x%x\n", type);
NOREC_RETURN(virtualcopy, EINVAL);
}
/* Check if mapping succeeded. */
if (phys_addr[i] <= 0 && vir_addr[i]->segment != PHYS_SEG) {
kprintf("virtual_copy EFAULT\n");
NOREC_RETURN(virtualcopy, EFAULT);
}
}
if(vm_running) {
int r;
struct proc *caller;
caller = proc_addr(who_p);
if(RTS_ISSET(caller, RTS_VMREQUEST)) {
struct proc *target;
int pn;
vmassert(caller->p_vmrequest.vmresult != VMSUSPEND);
RTS_LOCK_UNSET(caller, RTS_VMREQUEST);
if(caller->p_vmrequest.vmresult != OK) {
#if DEBUG_VMASSERT
printf("virtual_copy: returning VM error %d\n",
caller->p_vmrequest.vmresult);
#endif
NOREC_RETURN(virtualcopy, caller->p_vmrequest.vmresult);
}
}
if((r=lin_lin_copy(procs[_SRC_], phys_addr[_SRC_],
procs[_DST_], phys_addr[_DST_], bytes)) != OK) {
struct proc *target;
int wr;
phys_bytes lin;
if(r != EFAULT_SRC && r != EFAULT_DST)
minix_panic("lin_lin_copy failed", r);
if(!vmcheck) {
NOREC_RETURN(virtualcopy, r);
}
vmassert(procs[_SRC_] && procs[_DST_]);
if(r == EFAULT_SRC) {
lin = phys_addr[_SRC_];
target = procs[_SRC_];
wr = 0;
} else if(r == EFAULT_DST) {
lin = phys_addr[_DST_];
target = procs[_DST_];
wr = 1;
} else {
minix_panic("r strange", r);
}
#if 0
printf("virtual_copy: suspending caller %d / %s, target %d / %s\n",
caller->p_endpoint, caller->p_name,
target->p_endpoint, target->p_name);
#endif
vmassert(proc_ptr->p_endpoint == SYSTEM);
vm_suspend(caller, target, lin, bytes, wr, VMSTYPE_KERNELCALL);
NOREC_RETURN(virtualcopy, VMSUSPEND);
}
NOREC_RETURN(virtualcopy, OK);
}
vmassert(!vm_running);
/* can't copy to/from process with PT without VM */
#define NOPT(p) (!(p) || !HASPT(p))
if(!NOPT(procs[_SRC_])) {
kprintf("ignoring page table src: %s / %d at 0x%lx\n",
procs[_SRC_]->p_name, procs[_SRC_]->p_endpoint, procs[_SRC_]->p_seg.p_cr3);
}
if(!NOPT(procs[_DST_])) {
kprintf("ignoring page table dst: %s / %d at 0x%lx\n",
procs[_DST_]->p_name, procs[_DST_]->p_endpoint,
procs[_DST_]->p_seg.p_cr3);
}
/* Now copy bytes between physical addresseses. */
if(phys_copy(phys_addr[_SRC_], phys_addr[_DST_], (phys_bytes) bytes))
NOREC_RETURN(virtualcopy, EFAULT);
NOREC_RETURN(virtualcopy, OK);
}
/*===========================================================================*
* data_copy *
*===========================================================================*/
PUBLIC int data_copy(
endpoint_t from_proc, vir_bytes from_addr,
endpoint_t to_proc, vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.segment = dst.segment = D;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
return virtual_copy(&src, &dst, bytes);
}
/*===========================================================================*
* data_copy_vmcheck *
*===========================================================================*/
PUBLIC int data_copy_vmcheck(
endpoint_t from_proc, vir_bytes from_addr,
endpoint_t to_proc, vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.segment = dst.segment = D;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
return virtual_copy_vmcheck(&src, &dst, bytes);
}
/*===========================================================================*
* arch_pre_exec *
*===========================================================================*/
PUBLIC int arch_pre_exec(struct proc *pr, u32_t ip, u32_t sp)
{
/* wipe extra LDT entries, set program counter, and stack pointer. */
memset(pr->p_seg.p_ldt + EXTRA_LDT_INDEX, 0,
sizeof(pr->p_seg.p_ldt[0]) * (LDT_SIZE - EXTRA_LDT_INDEX));
pr->p_reg.pc = ip;
pr->p_reg.sp = sp;
}
/*===========================================================================*
* arch_umap *
*===========================================================================*/
PUBLIC int arch_umap(struct proc *pr, vir_bytes offset, vir_bytes count,
int seg, phys_bytes *addr)
{
switch(seg) {
case BIOS_SEG:
*addr = umap_bios(offset, count);
return OK;
}
/* This must be EINVAL; the umap fallback function in
* lib/syslib/alloc_util.c depends on it to detect an
* older kernel (as opposed to mapping error).
*/
return EINVAL;
}
/* VM reports page directory slot we're allowed to use freely. */
void i386_freepde(int pde)
{
if(nfreepdes >= WANT_FREEPDES)
return;
freepdes[nfreepdes++] = pde;
}
PUBLIC arch_phys_map(int index, phys_bytes *addr, phys_bytes *len, int *flags)
{
#ifdef CONFIG_APIC
/* map the local APIC if enabled */
if (index == 0 && lapic_addr) {
*addr = vir2phys(lapic_addr);
*len = 4 << 10 /* 4kB */;
*flags = VMMF_UNCACHED;
return OK;
}
return EINVAL;
#else
/* we don't want anything */
return EINVAL;
#endif
}
PUBLIC arch_phys_map_reply(int index, vir_bytes addr)
{
#ifdef CONFIG_APIC
/* if local APIC is enabled */
if (index == 0 && lapic_addr) {
lapic_addr_vaddr = addr;
}
#endif
return OK;
}
PUBLIC int arch_enable_paging(void)
{
#ifdef CONFIG_APIC
/* if local APIC is enabled */
if (lapic_addr) {
lapic_addr = lapic_addr_vaddr;
lapic_eoi_addr = LAPIC_EOI;
}
#endif
#ifdef CONFIG_WATCHDOG
/*
* We make sure that we don't enable the watchdog until paging is turned
* on as we might get a NMI while switching and we might still use wrong
* lapic address. Bad things would happen. It is unfortunate but such is
* life
*/
level0(i386_watchdog_start);
#endif
return OK;
}
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