ref: f0f2d452c873255dec4b3359b3f93e349be0f2c5
dir: /sys/src/cmd/vmx/exith.c/
#include <u.h>
#include <libc.h>
#include "dat.h"
#include "fns.h"
#include "x86.h"
int persist = 1;
typedef struct ExitInfo ExitInfo;
struct ExitInfo {
char *raw;
char *name;
uvlong qual;
uvlong pa, va;
u32int ilen, iinfo;
};
char *x86reg[16] = {
RAX, RCX, RDX, RBX,
RSP, RBP, RSI, RDI,
R8, R9, R10, R11,
R12, R13, R14, R15
};
char *x86segreg[8] = {
"cs", "ds", "es", "fs", "gs", "ss",
};
static void
skipinstr(ExitInfo *ei)
{
rset(RPC, rget(RPC) + ei->ilen);
}
static void
iohandler(ExitInfo *ei)
{
int port, len, inc, isin;
int asz, seg;
uintptr addr;
u32int val;
uvlong vval;
uintptr cx;
static int seglook[8] = {SEGES, SEGCS, SEGSS, SEGDS, SEGFS, SEGGS};
TLB tlb;
port = ei->qual >> 16 & 0xffff;
len = (ei->qual & 7) + 1;
isin = (ei->qual & 8) != 0;
if((ei->qual & 1<<4) == 0){ /* not a string instruction */
if(isin){
val = io(1, port, 0, len);
rsetsz(RAX, val, len);
}else
io(0, port, rget(RAX), len);
skipinstr(ei);
return;
}
if((rget("flags") & 0x400) != 0) inc = -len;
else inc = len;
switch(ei->iinfo >> 7 & 7){
case 0: asz = 2; break;
default: asz = 4; break;
case 2: asz = 8; break;
}
if((ei->qual & 1<<5) != 0)
cx = rgetsz(RCX, asz);
else
cx = 1;
addr = isin ? rget(RDI) : rget(RSI);
if(isin)
seg = SEGES;
else
seg = seglook[ei->iinfo >> 15 & 7];
memset(&tlb, 0, sizeof(TLB));
for(; cx > 0; cx--){
if(isin){
vval = io(1, port, 0, len);
if(x86access(seg, addr, asz, &vval, len, ACCW, &tlb) < 0)
goto err;
}else{
if(x86access(seg, addr, asz, &vval, len, ACCR, &tlb) < 0)
goto err;
io(0, port, vval, len);
}
addr += inc;
}
skipinstr(ei);
err:
if((ei->qual & 1<<5) != 0)
rsetsz(RCX, cx, asz);
if(isin)
rsetsz(RDI, addr, asz);
else
rsetsz(RSI, addr, asz);
}
static uvlong
defaultmmio(int op, uvlong addr, uvlong val)
{
switch(op){
case MMIORD:
vmerror("read from unmapped address %#ullx (pc=%#ullx)", addr, rget(RPC));
break;
case MMIOWR:
vmerror("write to unmapped address %#ullx (val=%#ullx,pc=%#ullx)", addr, val, rget(RPC));
break;
}
return 0;
}
static void
eptfault(ExitInfo *ei)
{
if(x86step() > 0)
skipinstr(ei);
}
typedef struct CPUID CPUID;
struct CPUID {
u32int ax, bx, cx, dx;
};
static u32int cpuidmax;
static u32int cpuidmaxext;
static CPUID leaf1;
static struct {
uvlong miscen;
}msr;
static uchar _cpuid[] = {
0x5E, /* POP SI (PC) */
0x5D, /* POP BP (CPUID&) */
0x58, /* POP AX */
0x59, /* POP CX */
0x51, /* PUSH CX */
0x50, /* PUSH AX */
0x55, /* PUSH BP */
0x56, /* PUSH SI */
0x31, 0xDB, /* XOR BX, BX */
0x31, 0xD2, /* XOR DX, DX */
0x0F, 0xA2, /* CPUID */
0x89, 0x45, 0x00, /* MOV AX, 0(BP) */
0x89, 0x5d, 0x04, /* MOV BX, 4(BP) */
0x89, 0x4d, 0x08, /* MOV CX, 8(BP) */
0x89, 0x55, 0x0C, /* MOV DX, 12(BP) */
0xC3, /* RET */
};
static CPUID (*getcpuid)(ulong ax, ulong cx) = (CPUID(*)(ulong, ulong)) _cpuid;
void
cpuidinit(void)
{
CPUID r;
int f;
if(sizeof(uintptr) == 8) /* patch out POP BP -> POP AX */
_cpuid[1] = 0x58;
segflush(_cpuid, sizeof(_cpuid));
r = getcpuid(0, 0);
cpuidmax = r.ax;
r = getcpuid(0x80000000, 0);
cpuidmaxext = r.ax;
leaf1 = getcpuid(1, 0);
memset(&msr, 0, sizeof(msr));
if((f = open("/dev/msr", OREAD)) >= 0){
pread(f, &msr.miscen, 8, 0x1a0);
msr.miscen &= 1<<0; /* fast strings */
close(f);
}
}
static int xsavesz[] = {
[1] = 512+64,
[3] = 512+64,
[7] = 512+64+256,
};
static void
cpuid(ExitInfo *ei)
{
u32int ax, bx, cx, dx;
CPUID cp;
ax = rget(RAX);
cx = rget(RCX);
bx = dx = 0;
cp = getcpuid(ax, cx);
switch(ax){
case 0x00: /* highest register & GenuineIntel */
ax = MIN(cpuidmax, 0x18);
bx = cp.bx;
dx = cp.dx;
cx = cp.cx;
break;
case 0x01: /* features */
ax = cp.ax;
bx = cp.bx & 0xffff;
/* some features removed, hypervisor added */
cx = cp.cx & 0x76de3217 | 0x80000000UL;
dx = cp.dx & 0x0f8aa579;
if(leaf1.cx & 1<<27){
if(rget("cr4real") & Cr4Osxsave)
cx |= 1<<27;
}else{
cx &= ~0x1c000000;
}
break;
case 0x02: goto literal; /* cache stuff */
case 0x03: goto zero; /* processor serial number */
case 0x04: goto literal; /* cache stuff */
case 0x05: goto zero; /* monitor/mwait */
case 0x06: goto zero; /* thermal management */
case 0x07: /* more features */
if(cx == 0){
ax = 0;
bx = cp.bx & 0x2369;
cx = 0;
if((leaf1.cx & 1<<27) == 0)
bx &= ~0xdc230020;
}else{
goto zero;
}
break;
case 0x08: goto zero;
case 0x09: goto literal; /* direct cache access */
case 0x0a: goto zero; /* performance counters */
case 0x0b: goto zero; /* extended topology */
case 0x0c: goto zero;
case 0x0d: /* extended state */
if((leaf1.cx & 1<<27) == 0)
goto zero;
if(cx == 0){ /* main leaf */
ax = cp.ax & 7; /* x87, sse, avx */
bx = xsavesz[rget("xcr0")]; /* current xsave size */
cx = xsavesz[ax]; /* max xsave size */
}else if(cx == 1){ /* sub leaf */
ax = cp.ax & 7; /* xsaveopt, xsavec, xgetbv1 */
bx = xsavesz[rget("xcr0")];
cx = 0;
}else if(cx == 2){
ax = xsavesz[7] - xsavesz[3];
bx = xsavesz[3];
cx = 0;
}else{
goto zero;
}
break;
case 0x0f: goto zero; /* RDT */
case 0x10: goto zero; /* RDT */
case 0x12: goto zero; /* SGX */
case 0x14: goto zero; /* PT */
case 0x15: goto zero; /* TSC */
case 0x16: goto zero; /* cpu clock */
case 0x17: goto zero; /* SoC */
case 0x18: goto literal; /* pages, tlb */
case 0x40000000: /* hypervisor */
ax = 0;
bx = 0x4b4d564b; /* act as KVM */
cx = 0x564b4d56;
dx = 0x4d;
break;
case 0x80000000: /* highest register */
ax = MIN(cpuidmaxext, 0x80000008);
cx = 0;
break;
case 0x80000001: /* signature & ext features */
ax = cp.ax;
cx = cp.cx & 0x121;
if(sizeof(uintptr) == 8)
dx = cp.dx & 0x24100800;
else
dx = cp.dx & 0x04100000;
break;
case 0x80000002: goto literal; /* brand string */
case 0x80000003: goto literal; /* brand string */
case 0x80000004: goto literal; /* brand string */
case 0x80000005: goto zero; /* reserved */
case 0x80000006: goto literal; /* cache info */
case 0x80000007: goto zero; /* invariant tsc */
case 0x80000008: goto literal; /* address bits */
literal:
ax = cp.ax;
bx = cp.bx;
cx = cp.cx;
dx = cp.dx;
break;
default:
if((ax & 0xf0000000) != 0x40000000)
vmdebug("unknown cpuid field eax=%#ux", ax);
zero:
ax = cx = 0;
break;
}
rset(RAX, ax);
rset(RBX, bx);
rset(RCX, cx);
rset(RDX, dx);
skipinstr(ei);
}
static void
rdwrmsr(ExitInfo *ei)
{
u32int cx;
u64int val;
int rd;
rd = ei->name[1] == 'r';
cx = rget(RCX);
val = (uvlong)rget(RDX) << 32 | rget(RAX);
switch(cx){
case 0x277:
if(rd) val = rget("pat");
else rset("pat", val);
break;
case 0x8B: val = 0; break; /* microcode update */
case 0x1A0: /* IA32_MISC_ENABLE */
if(rd) val = msr.miscen;
break;
default:
if(rd){
vmdebug("read from unknown MSR %#ux ignored", cx);
val = 0;
}else
vmdebug("write to unknown MSR %#ux ignored (val=%#ullx)", cx, val);
break;
}
if(rd){
rset(RAX, (u32int)val);
rset(RDX, (u32int)(val >> 32));
}
skipinstr(ei);
}
static void
movdr(ExitInfo *ei)
{
static char *dr[8] = { "dr0", "dr1", "dr2", "dr3", nil, nil, "dr6", "dr7" };
int q;
q = ei->qual;
if((q & 6) == 4){
postexc("#gp", 0);
return;
}
if((q & 16) != 0)
rset(x86reg[q >> 8 & 15], rget(dr[q & 7]));
else
rset(dr[q & 7], rget(x86reg[q >> 8 & 15]));
skipinstr(ei);
}
static void
movcr(ExitInfo *ei)
{
u32int q;
q = ei->qual;
switch(q & 15){
case 0:
switch(q >> 4 & 3){
case 0:
vmdebug("illegal CR0 write, value %#ux", (u32int)rget(x86reg[q >> 8 & 15]));
rset("cr0real", rget(x86reg[q >> 8 & 15]));
skipinstr(ei);
break;
case 1:
vmerror("shouldn't happen: trap on MOV from CR0");
rset(x86reg[q >> 8 & 15], rget("cr0fake"));
skipinstr(ei);
break;
case 2:
vmerror("shouldn't happen: trap on CLTS");
rset("cr0real", rget("cr0real") & ~8);
skipinstr(ei);
break;
case 3:
vmerror("LMSW handler unimplemented");
postexc("#ud", NOERRC);
}
break;
case 4:
switch(q >> 4 & 3){
case 0:
vmdebug("illegal CR4 write, value %#ux", (u32int)rget(x86reg[q >> 8 & 15]));
rset("cr4real", rget(x86reg[q >> 8 & 15]));
skipinstr(ei);
break;
case 1:
vmerror("shouldn't happen: trap on MOV from CR4");
rset(x86reg[q >> 8 & 15], rget("cr3fake"));
skipinstr(ei);
break;
default:
vmerror("unknown CR4 operation %d", q);
postexc("#ud", NOERRC);
}
break;
default:
vmerror("access to unknown control register CR%ud", q & 15);
postexc("#ud", NOERRC);
}
}
static void
dbgexc(ExitInfo *ei)
{
rset("dr6", rget("dr6") | ei->qual);
postexc("#db", NOERRC);
}
static void
hlt(ExitInfo *ei)
{
if(irqactive < 0)
state = VMHALT;
skipinstr(ei);
}
static void
irqackhand(ExitInfo *ei)
{
irqack(ei->qual);
}
static void
xsetbv(ExitInfo *ei)
{
uvlong v;
/* this should also #ud if LOCK prefix is used */
v = rget(RAX)&0xffffffff | rget(RDX)<<32;
if(rget(RCX) & 0xffffffff)
postexc("#gp", 0);
else if(v != 1 && v != 3 && v != 7)
postexc("#gp", 0);
else if((leaf1.cx & 1<<26) == 0 || (rget("cr4real") & Cr4Osxsave) == 0)
postexc("#ud", NOERRC);
else{
rset("xcr0", v);
skipinstr(ei);
}
}
typedef struct ExitType ExitType;
struct ExitType {
char *name;
void (*f)(ExitInfo *);
};
static ExitType etypes[] = {
{"io", iohandler},
{".cpuid", cpuid},
{".hlt", hlt},
{"eptfault", eptfault},
{"*ack", irqackhand},
{".rdmsr", rdwrmsr},
{".wrmsr", rdwrmsr},
{".movdr", movdr},
{"#db", dbgexc},
{"movcr", movcr},
{".xsetbv", xsetbv},
};
void
processexit(char *msg)
{
static char msgc[1024];
char *f[32];
int nf;
ExitType *et;
int i;
ExitInfo ei;
extern int getexit;
strcpy(msgc, msg);
nf = tokenize(msgc, f, nelem(f));
if(nf < 2) sysfatal("invalid wait message: %s", msg);
memset(&ei, 0, sizeof(ei));
ei.raw = msg;
ei.name = f[0];
ei.qual = strtoull(f[1], nil, 0);
for(i = 2; i < nf; i += 2){
if(strcmp(f[i], "pc") == 0)
rpoke(RPC, strtoull(f[i+1], nil, 0), 1);
else if(strcmp(f[i], "sp") == 0)
rpoke(RSP, strtoull(f[i+1], nil, 0), 1);
else if(strcmp(f[i], "ax") == 0)
rpoke(RAX, strtoull(f[i+1], nil, 0), 1);
else if(strcmp(f[i], "ilen") == 0)
ei.ilen = strtoul(f[i+1], nil, 0);
else if(strcmp(f[i], "iinfo") == 0)
ei.iinfo = strtoul(f[i+1], nil, 0);
else if(strcmp(f[i], "pa") == 0)
ei.pa = strtoull(f[i+1], nil, 0);
else if(strcmp(f[i], "va") == 0)
ei.va = strtoull(f[i+1], nil, 0);
}
if(*f[0] == '*') getexit++;
for(et = etypes; et < etypes + nelem(etypes); et++)
if(strcmp(et->name, f[0]) == 0){
et->f(&ei);
return;
}
if(*f[0] == '.'){
vmerror("vmx: unknown instruction %s", f[0]+1);
postexc("#ud", NOERRC);
return;
}
if(*f[0] == '*'){
vmerror("vmx: unknown notification %s", f[0]+1);
return;
}
if(persist){
vmerror("unknown exit: %s", msg);
state = VMDEAD;
}else
sysfatal("unknown exit: %s", msg);
}