diff options
| -rw-r--r-- | tools/lguest/lguest.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c index 35d7aa90aa24..e52a3571076a 100644 --- a/tools/lguest/lguest.c +++ b/tools/lguest/lguest.c @@ -99,6 +99,9 @@ static int lguest_fd; /* a per-cpu variable indicating whose vcpu is currently running */ static unsigned int __thread cpu_id; +/* 5 bit device number in the PCI_CONFIG_ADDR => 32 only */ +#define MAX_PCI_DEVICES 32 + /* This is our list of devices. */ struct device_list { /* Counter to assign interrupt numbers. */ @@ -114,6 +117,9 @@ struct device_list { struct device *dev; /* And a pointer to the last device for easy append. */ struct device *lastdev; + + /* PCI devices. */ + struct device *pci[MAX_PCI_DEVICES]; }; /* The list of Guest devices, based on command line arguments. */ @@ -140,6 +146,10 @@ struct device { /* Is it operational */ bool running; + /* PCI MMIO resources (all in BAR0) */ + size_t mmio_size; + u32 mmio_addr; + /* Device-specific data. */ void *priv; }; @@ -1197,6 +1207,77 @@ static void setreg_off(size_t offset, u32 val) err(1, "Setting register %u", offset); } +/* Get register by instruction encoding */ +static u32 getreg_num(unsigned regnum, u32 mask) +{ + /* 8 bit ops use regnums 4-7 for high parts of word */ + if (mask == 0xFF && (regnum & 0x4)) + return getreg_num(regnum & 0x3, 0xFFFF) >> 8; + + switch (regnum) { + case 0: return getreg(eax) & mask; + case 1: return getreg(ecx) & mask; + case 2: return getreg(edx) & mask; + case 3: return getreg(ebx) & mask; + case 4: return getreg(esp) & mask; + case 5: return getreg(ebp) & mask; + case 6: return getreg(esi) & mask; + case 7: return getreg(edi) & mask; + } + abort(); +} + +/* Set register by instruction encoding */ +static void setreg_num(unsigned regnum, u32 val, u32 mask) +{ + /* Don't try to set bits out of range */ + assert(~(val & ~mask)); + + /* 8 bit ops use regnums 4-7 for high parts of word */ + if (mask == 0xFF && (regnum & 0x4)) { + /* Construct the 16 bits we want. */ + val = (val << 8) | getreg_num(regnum & 0x3, 0xFF); + setreg_num(regnum & 0x3, val, 0xFFFF); + return; + } + + switch (regnum) { + case 0: setreg(eax, val | (getreg(eax) & ~mask)); return; + case 1: setreg(ecx, val | (getreg(ecx) & ~mask)); return; + case 2: setreg(edx, val | (getreg(edx) & ~mask)); return; + case 3: setreg(ebx, val | (getreg(ebx) & ~mask)); return; + case 4: setreg(esp, val | (getreg(esp) & ~mask)); return; + case 5: setreg(ebp, val | (getreg(ebp) & ~mask)); return; + case 6: setreg(esi, val | (getreg(esi) & ~mask)); return; + case 7: setreg(edi, val | (getreg(edi) & ~mask)); return; + } + abort(); +} + +/* Get bytes of displacement appended to instruction, from r/m encoding */ +static u32 insn_displacement_len(u8 mod_reg_rm) +{ + /* Switch on the mod bits */ + switch (mod_reg_rm >> 6) { + case 0: + /* If mod == 0, and r/m == 101, 16-bit displacement follows */ + if ((mod_reg_rm & 0x7) == 0x5) + return 2; + /* Normally, mod == 0 means no literal displacement */ + return 0; + case 1: + /* One byte displacement */ + return 1; + case 2: + /* Four byte displacement */ + return 4; + case 3: + /* Register mode */ + return 0; + } + abort(); +} + static void emulate_insn(const u8 insn[]) { unsigned long args[] = { LHREQ_TRAP, 13 }; @@ -1310,6 +1391,88 @@ no_emulate: err(1, "Reinjecting trap 13 for fault at %#x", getreg(eip)); } +static struct device *find_mmio_region(unsigned long paddr, u32 *off) +{ + unsigned int i; + + for (i = 1; i < MAX_PCI_DEVICES; i++) { + struct device *d = devices.pci[i]; + + if (!d) + continue; + if (paddr < d->mmio_addr) + continue; + if (paddr >= d->mmio_addr + d->mmio_size) + continue; + *off = paddr - d->mmio_addr; + return d; + } + return NULL; +} + +static void emulate_mmio_write(struct device *d, u32 off, u32 val, u32 mask) +{ +} + +static u32 emulate_mmio_read(struct device *d, u32 off, u32 mask) +{ + return 0xFFFFFFFF; +} + +static void emulate_mmio(unsigned long paddr, const u8 *insn) +{ + u32 val, off, mask = 0xFFFFFFFF, insnlen = 0; + struct device *d = find_mmio_region(paddr, &off); + unsigned long args[] = { LHREQ_TRAP, 14 }; + + if (!d) { + warnx("MMIO touching %#08lx (not a device)", paddr); + goto reinject; + } + + /* Prefix makes it a 16 bit op */ + if (insn[0] == 0x66) { + mask = 0xFFFF; + insnlen++; + } + + /* iowrite */ + if (insn[insnlen] == 0x89) { + /* Next byte is r/m byte: bits 3-5 are register. */ + val = getreg_num((insn[insnlen+1] >> 3) & 0x7, mask); + emulate_mmio_write(d, off, val, mask); + insnlen += 2 + insn_displacement_len(insn[insnlen+1]); + } else if (insn[insnlen] == 0x8b) { /* ioread */ + /* Next byte is r/m byte: bits 3-5 are register. */ + val = emulate_mmio_read(d, off, mask); + setreg_num((insn[insnlen+1] >> 3) & 0x7, val, mask); + insnlen += 2 + insn_displacement_len(insn[insnlen+1]); + } else if (insn[0] == 0x88) { /* 8-bit iowrite */ + mask = 0xff; + /* Next byte is r/m byte: bits 3-5 are register. */ + val = getreg_num((insn[1] >> 3) & 0x7, mask); + emulate_mmio_write(d, off, val, mask); + insnlen = 2 + insn_displacement_len(insn[1]); + } else if (insn[0] == 0x8a) { /* 8-bit ioread */ + mask = 0xff; + val = emulate_mmio_read(d, off, mask); + setreg_num((insn[1] >> 3) & 0x7, val, mask); + insnlen = 2 + insn_displacement_len(insn[1]); + } else { + warnx("Unknown MMIO instruction touching %#08lx:" + " %02x %02x %02x %02x at %u", + paddr, insn[0], insn[1], insn[2], insn[3], getreg(eip)); + reinject: + /* Inject trap into Guest. */ + if (write(lguest_fd, args, sizeof(args)) < 0) + err(1, "Reinjecting trap 14 for fault at %#x", + getreg(eip)); + return; + } + + /* Finally, we've "done" the instruction, so move past it. */ + setreg(eip, getreg(eip) + insnlen); +} /*L:190 * Device Setup @@ -2004,6 +2167,10 @@ static void __attribute__((noreturn)) run_guest(void) verbose("Emulating instruction at %#x\n", getreg(eip)); emulate_insn(notify.insn); + } else if (notify.trap == 14) { + verbose("Emulating MMIO at %#x\n", + getreg(eip)); + emulate_mmio(notify.addr, notify.insn); } else errx(1, "Unknown trap %i addr %#08x\n", notify.trap, notify.addr); |