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#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
#include "x86.h"
typedef struct VMemReq VMemReq;
struct VMemReq {
QLock;
uintptr va, len;
void *buf;
uintptr rc;
};
static uintptr
translateflat(uintptr va, uintptr *pa, uintptr)
{
*pa = va;
if(va == 0)
return -1;
return 0;
}
static uintptr
translate32(uintptr va, uintptr *pa, uintptr cr4)
{
void *pd, *pt;
u32int pde, pte;
if(sizeof(uintptr) != 4 && va >> 32 != 0) return -1;
pd = gptr(rget("cr3") & ~0xfff, 4096);
if(pd == nil) return 0;
pde = GET32(pd, (va >> 22) * 4);
if((pde & 1) == 0) return 0;
if((pde & 0x80) != 0 && (cr4 & Cr4Pse) != 0){
*pa = pde & (1<<22) - 1 | (uintptr)(pde & 0xfe000) << 19;
return (1<<22) - (va & (1<<22)-1);
}
pt = gptr(pde & ~0xfff, 4096);
if(pt == nil) return 0;
pte = GET32(pt, va >> 10 & 0xffc);
if((pte & 1) == 0) return 0;
*pa = pte & ~0xfff | va & 0xfff;
return 0x1000 - (va & 0xfff);
}
static uintptr
translatepae(uintptr, uintptr *, uintptr)
{
vmerror("PAE translation not implemented");
return 0;
}
static uintptr
translate64(uintptr, uintptr *, uintptr)
{
vmerror("long mode translation not implemented");
return 0;
}
static uintptr (*
translator(uintptr *cr4p))(uintptr, uintptr *, uintptr)
{
uintptr cr0, cr4, efer;
cr0 = rget("cr0real");
if((cr0 & Cr0Pg) == 0)
return translateflat;
efer = rget("efer");
if((efer & EferLme) != 0)
return translate64;
cr4 = rget("cr4real");
*cr4p = cr4;
if((cr4 & Cr4Pae) != 0)
return translatepae;
return translate32;
}
static void
vmemread0(void *aux)
{
VMemReq *req;
uintptr va, pa, n, ok, pok, cr4;
void *v;
uintptr (*trans)(uintptr, uintptr *, uintptr);
uchar *p;
req = aux;
va = req->va;
n = req->len;
p = req->buf;
trans = translator(&cr4);
while(n > 0){
ok = trans(va, &pa, cr4);
if(ok == 0) break;
if(ok > n) ok = n;
v = gptr(pa, 1);
if(v == nil) break;
pok = gavail(v);
if(ok > pok) ok = pok;
memmove(p, v, ok);
n -= ok;
p += ok;
va += ok;
}
req->rc = req->len - n;
qunlock(req);
}
uintptr
vmemread(void *buf, uintptr len, uintptr va)
{
VMemReq req;
memset(&req, 0, sizeof(VMemReq));
req.buf = buf;
req.len = len;
req.va = va;
qlock(&req);
sendnotif(vmemread0, &req);
qlock(&req);
return req.rc;
}
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