--- arch/x86/kvm/emulate.c
+++ arch/x86/kvm/emulate.c
@@ -75,6 +75,7 @@
#define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
#define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
#define GroupMask 0xff /* Group number stored in bits 0:7 */
+#define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
/* Source 2 operand type */
#define Src2None (0<<29)
#define Src2CL (1<<29)
@@ -86,6 +87,7 @@
enum {
Group1_80, Group1_81, Group1_82, Group1_83,
Group1A, Group3_Byte, Group3, Group4, Group5, Group7,
+ Group8, Group9,
};
static u32 opcode_table[256] = {
@@ -203,7 +205,7 @@ static u32 opcode_table[256] = {
SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
/* 0xF0 - 0xF7 */
0, 0, 0, 0,
- ImplicitOps, ImplicitOps, Group | Group3_Byte, Group | Group3,
+ ImplicitOps | Priv, ImplicitOps, Group | Group3_Byte, Group | Group3,
/* 0xF8 - 0xFF */
ImplicitOps, 0, ImplicitOps, ImplicitOps,
ImplicitOps, ImplicitOps, Group | Group4, Group | Group5,
@@ -211,16 +213,20 @@ static u32 opcode_table[256] = {
static u32 twobyte_table[256] = {
/* 0x00 - 0x0F */
- 0, Group | GroupDual | Group7, 0, 0, 0, ImplicitOps, ImplicitOps, 0,
- ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps | ModRM, 0, 0,
+ 0, Group | GroupDual | Group7, 0, 0,
+ 0, ImplicitOps, ImplicitOps | Priv, 0,
+ ImplicitOps | Priv, ImplicitOps | Priv, 0, 0,
+ 0, ImplicitOps | ModRM, 0, 0,
/* 0x10 - 0x1F */
0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
/* 0x20 - 0x2F */
- ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,
+ ModRM | ImplicitOps | Priv, ModRM | Priv,
+ ModRM | ImplicitOps | Priv, ModRM | Priv,
+ 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
/* 0x30 - 0x3F */
- ImplicitOps, 0, ImplicitOps, 0,
- ImplicitOps, ImplicitOps, 0, 0,
+ ImplicitOps | Priv, 0, ImplicitOps | Priv, 0,
+ ImplicitOps, ImplicitOps | Priv, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
/* 0x40 - 0x47 */
DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
@@ -258,11 +264,12 @@ static u32 twobyte_table[256] = {
0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
DstReg | SrcMem16 | ModRM | Mov,
/* 0xB8 - 0xBF */
- 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM | BitOp,
+ 0, 0, Group | Group8, DstMem | SrcReg | ModRM | BitOp,
0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
DstReg | SrcMem16 | ModRM | Mov,
/* 0xC0 - 0xCF */
- 0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, ImplicitOps | ModRM,
+ 0, 0, 0, DstMem | SrcReg | ModRM | Mov,
+ 0, 0, 0, Group | GroupDual | Group9,
0, 0, 0, 0, 0, 0, 0, 0,
/* 0xD0 - 0xDF */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -311,24 +318,39 @@ static u32 group_table[] = {
SrcMem | ModRM | Stack, 0,
SrcMem | ModRM | Stack, 0, SrcMem | ModRM | Stack, 0,
[Group7*8] =
- 0, 0, ModRM | SrcMem, ModRM | SrcMem,
+ 0, 0, ModRM | SrcMem | Priv, ModRM | SrcMem | Priv,
SrcNone | ModRM | DstMem | Mov, 0,
- SrcMem16 | ModRM | Mov, SrcMem | ModRM | ByteOp,
+ SrcMem16 | ModRM | Mov | Priv, SrcMem | ModRM | ByteOp | Priv,
+ [Group8*8] =
+ 0, 0, 0, 0,
+ DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
+ DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
+ [Group9*8] =
+ 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0,
};
static u32 group2_table[] = {
[Group7*8] =
- SrcNone | ModRM, 0, 0, SrcNone | ModRM,
+ SrcNone | ModRM | Priv, 0, 0, SrcNone | ModRM,
SrcNone | ModRM | DstMem | Mov, 0,
SrcMem16 | ModRM | Mov, 0,
+ [Group9*8] =
+ 0, 0, 0, 0, 0, 0, 0, 0,
};
/* EFLAGS bit definitions. */
+#define EFLG_ID (1<<21)
+#define EFLG_VIP (1<<20)
+#define EFLG_VIF (1<<19)
+#define EFLG_AC (1<<18)
#define EFLG_VM (1<<17)
#define EFLG_RF (1<<16)
+#define EFLG_IOPL (3<<12)
+#define EFLG_NT (1<<14)
#define EFLG_OF (1<<11)
#define EFLG_DF (1<<10)
#define EFLG_IF (1<<9)
+#define EFLG_TF (1<<8)
#define EFLG_SF (1<<7)
#define EFLG_ZF (1<<6)
#define EFLG_AF (1<<4)
@@ -597,7 +619,7 @@ static int do_fetch_insn_byte(struct x86
if (linear < fc->start || linear >= fc->end) {
size = min(15UL, PAGE_SIZE - offset_in_page(linear));
- rc = ops->read_std(linear, fc->data, size, ctxt->vcpu);
+ rc = ops->fetch(linear, fc->data, size, ctxt->vcpu, NULL);
if (rc)
return rc;
fc->start = linear;
@@ -652,11 +674,11 @@ static int read_descriptor(struct x86_em
op_bytes = 3;
*address = 0;
rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
- ctxt->vcpu);
+ ctxt->vcpu, NULL);
if (rc)
return rc;
rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
- ctxt->vcpu);
+ ctxt->vcpu, NULL);
return rc;
}
@@ -880,6 +902,7 @@ x86_decode_insn(struct x86_emulate_ctxt
switch (mode) {
case X86EMUL_MODE_REAL:
+ case X86EMUL_MODE_VM86:
case X86EMUL_MODE_PROT16:
def_op_bytes = def_ad_bytes = 2;
break;
@@ -1189,6 +1212,49 @@ static int emulate_pop(struct x86_emulat
return rc;
}
+static int emulate_popf(struct x86_emulate_ctxt *ctxt,
+ struct x86_emulate_ops *ops,
+ void *dest, int len)
+{
+ int rc;
+ unsigned long val, change_mask;
+ int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
+ int cpl = kvm_x86_ops->get_cpl(ctxt->vcpu);
+
+ rc = emulate_pop(ctxt, ops, &val, len);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+
+ change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
+ | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
+
+ switch(ctxt->mode) {
+ case X86EMUL_MODE_PROT64:
+ case X86EMUL_MODE_PROT32:
+ case X86EMUL_MODE_PROT16:
+ if (cpl == 0)
+ change_mask |= EFLG_IOPL;
+ if (cpl <= iopl)
+ change_mask |= EFLG_IF;
+ break;
+ case X86EMUL_MODE_VM86:
+ if (iopl < 3) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ return X86EMUL_PROPAGATE_FAULT;
+ }
+ change_mask |= EFLG_IF;
+ break;
+ default: /* real mode */
+ change_mask |= (EFLG_IOPL | EFLG_IF);
+ break;
+ }
+
+ *(unsigned long *)dest =
+ (ctxt->eflags & ~change_mask) | (val & change_mask);
+
+ return rc;
+}
+
static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops)
{
@@ -1330,7 +1396,7 @@ static int emulate_ret_far(struct x86_em
rc = emulate_pop(ctxt, ops, &cs, c->op_bytes);
if (rc)
return rc;
- rc = kvm_load_segment_descriptor(ctxt->vcpu, (u16)cs, 1, VCPU_SREG_CS);
+ rc = kvm_load_segment_descriptor(ctxt->vcpu, (u16)cs, VCPU_SREG_CS);
return rc;
}
@@ -1438,7 +1504,7 @@ emulate_syscall(struct x86_emulate_ctxt
/* syscall is not available in real mode */
if (c->lock_prefix || ctxt->mode == X86EMUL_MODE_REAL
- || !(ctxt->vcpu->arch.cr0 & X86_CR0_PE))
+ || ctxt->mode == X86EMUL_MODE_VM86)
return -1;
setup_syscalls_segments(ctxt, &cs, &ss);
@@ -1490,9 +1556,8 @@ emulate_sysenter(struct x86_emulate_ctxt
if (c->lock_prefix)
return -1;
- /* inject #GP if in real mode or paging is disabled */
- if (ctxt->mode == X86EMUL_MODE_REAL ||
- !(ctxt->vcpu->arch.cr0 & X86_CR0_PE)) {
+ /* inject #GP if in real mode */
+ if (ctxt->mode == X86EMUL_MODE_REAL) {
kvm_inject_gp(ctxt->vcpu, 0);
return -1;
}
@@ -1556,15 +1621,9 @@ emulate_sysexit(struct x86_emulate_ctxt
if (c->lock_prefix)
return -1;
- /* inject #GP if in real mode or paging is disabled */
- if (ctxt->mode == X86EMUL_MODE_REAL
- || !(ctxt->vcpu->arch.cr0 & X86_CR0_PE)) {
- kvm_inject_gp(ctxt->vcpu, 0);
- return -1;
- }
-
- /* sysexit must be called from CPL 0 */
- if (kvm_x86_ops->get_cpl(ctxt->vcpu) != 0) {
+ /* inject #GP if in real mode or Virtual 8086 mode */
+ if (ctxt->mode == X86EMUL_MODE_REAL ||
+ ctxt->mode == X86EMUL_MODE_VM86) {
kvm_inject_gp(ctxt->vcpu, 0);
return -1;
}
@@ -1611,6 +1670,57 @@ emulate_sysexit(struct x86_emulate_ctxt
return 0;
}
+static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
+{
+ int iopl;
+ if (ctxt->mode == X86EMUL_MODE_REAL)
+ return false;
+ if (ctxt->mode == X86EMUL_MODE_VM86)
+ return true;
+ iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
+ return kvm_x86_ops->get_cpl(ctxt->vcpu) > iopl;
+}
+
+static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
+ struct x86_emulate_ops *ops,
+ u16 port, u16 len)
+{
+ struct kvm_segment tr_seg;
+ int r;
+ u16 io_bitmap_ptr;
+ u8 perm, bit_idx = port & 0x7;
+ unsigned mask = (1 << len) - 1;
+
+ kvm_get_segment(ctxt->vcpu, &tr_seg, VCPU_SREG_TR);
+ if (tr_seg.unusable)
+ return false;
+ if (tr_seg.limit < 103)
+ return false;
+ r = ops->read_std(tr_seg.base + 102, &io_bitmap_ptr, 2, ctxt->vcpu,
+ NULL);
+ if (r != X86EMUL_CONTINUE)
+ return false;
+ if (io_bitmap_ptr + port/8 > tr_seg.limit)
+ return false;
+ r = ops->read_std(tr_seg.base + io_bitmap_ptr + port/8, &perm, 1,
+ ctxt->vcpu, NULL);
+ if (r != X86EMUL_CONTINUE)
+ return false;
+ if ((perm >> bit_idx) & mask)
+ return false;
+ return true;
+}
+
+static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
+ struct x86_emulate_ops *ops,
+ u16 port, u16 len)
+{
+ if (emulator_bad_iopl(ctxt))
+ if (!emulator_io_port_access_allowed(ctxt, ops, port, len))
+ return false;
+ return true;
+}
+
int
x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
@@ -1632,6 +1742,12 @@ x86_emulate_insn(struct x86_emulate_ctxt
memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
saved_eip = c->eip;
+ /* Privileged instruction can be executed only in CPL=0 */
+ if ((c->d & Priv) && kvm_x86_ops->get_cpl(ctxt->vcpu)) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
+
if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs))
memop = c->modrm_ea;
@@ -1764,7 +1880,12 @@ special_insn:
break;
case 0x6c: /* insb */
case 0x6d: /* insw/insd */
- if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
+ if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX],
+ (c->d & ByteOp) ? 1 : c->op_bytes)) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
+ if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
1,
(c->d & ByteOp) ? 1 : c->op_bytes,
c->rep_prefix ?
@@ -1780,6 +1901,11 @@ special_insn:
return 0;
case 0x6e: /* outsb */
case 0x6f: /* outsw/outsd */
+ if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX],
+ (c->d & ByteOp) ? 1 : c->op_bytes)) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
0,
(c->d & ByteOp) ? 1 : c->op_bytes,
@@ -1866,25 +1992,19 @@ special_insn:
break;
case 0x8e: { /* mov seg, r/m16 */
uint16_t sel;
- int type_bits;
- int err;
sel = c->src.val;
- if (c->modrm_reg == VCPU_SREG_SS)
- toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS);
- if (c->modrm_reg <= 5) {
- type_bits = (c->modrm_reg == 1) ? 9 : 1;
- err = kvm_load_segment_descriptor(ctxt->vcpu, sel,
- type_bits, c->modrm_reg);
- } else {
- printk(KERN_INFO "Invalid segreg in modrm byte 0x%02x\n",
- c->modrm);
- goto cannot_emulate;
+ if (c->modrm_reg == VCPU_SREG_CS ||
+ c->modrm_reg > VCPU_SREG_GS) {
+ kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+ goto done;
}
- if (err < 0)
- goto cannot_emulate;
+ if (c->modrm_reg == VCPU_SREG_SS)
+ toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS);
+
+ rc = kvm_load_segment_descriptor(ctxt->vcpu, sel, c->modrm_reg);
c->dst.type = OP_NONE; /* Disable writeback. */
break;
@@ -1913,7 +2033,10 @@ special_insn:
c->dst.type = OP_REG;
c->dst.ptr = (unsigned long *) &ctxt->eflags;
c->dst.bytes = c->op_bytes;
- goto pop_instruction;
+ rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes);
+ if (rc != X86EMUL_CONTINUE)
+ goto done;
+ break;
case 0xa0 ... 0xa1: /* mov */
c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
c->dst.val = c->src.val;
@@ -2051,11 +2174,9 @@ special_insn:
case 0xe9: /* jmp rel */
goto jmp;
case 0xea: /* jmp far */
- if (kvm_load_segment_descriptor(ctxt->vcpu, c->src2.val, 9,
- VCPU_SREG_CS) < 0) {
- DPRINTF("jmp far: Failed to load CS descriptor\n");
- goto cannot_emulate;
- }
+ if (kvm_load_segment_descriptor(ctxt->vcpu, c->src2.val,
+ VCPU_SREG_CS))
+ goto done;
c->eip = c->src.val;
break;
@@ -2073,7 +2194,13 @@ special_insn:
case 0xef: /* out (e/r)ax,dx */
port = c->regs[VCPU_REGS_RDX];
io_dir_in = 0;
- do_io: if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in,
+ do_io:
+ if (!emulator_io_permited(ctxt, ops, port,
+ (c->d & ByteOp) ? 1 : c->op_bytes)) {
+ kvm_inject_gp(ctxt->vcpu, 0);
+ goto done;
+ }
+ if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in,
(c->d & ByteOp) ? 1 : c->op_bytes,
port) != 0) {
c->eip = saved_eip;
@@ -2098,13 +2225,21 @@ special_insn:
c->dst.type = OP_NONE; /* Disable writeback. */
break;
case 0xfa: /* cli */
- ctxt->eflags &= ~X86_EFLAGS_IF;
- c->dst.type = OP_NONE; /* Disable writeback. */
+ if (emulator_bad_iopl(ctxt))
+ kvm_inject_gp(ctxt->vcpu, 0);
+ else {
+ ctxt->eflags &= ~X86_EFLAGS_IF;
+ c->dst.type = OP_NONE; /* Disable writeback. */
+ }
break;
case 0xfb: /* sti */
- toggle_interruptibility(ctxt, X86_SHADOW_INT_STI);
- ctxt->eflags |= X86_EFLAGS_IF;
- c->dst.type = OP_NONE; /* Disable writeback. */
+ if (emulator_bad_iopl(ctxt))
+ kvm_inject_gp(ctxt->vcpu, 0);
+ else {
+ toggle_interruptibility(ctxt, X86_SHADOW_INT_STI);
+ ctxt->eflags |= X86_EFLAGS_IF;
+ c->dst.type = OP_NONE; /* Disable writeback. */
+ }
break;
case 0xfc: /* cld */
ctxt->eflags &= ~EFLG_DF;
projects / ziggy471-frankenstein-kernel.git / blobdiff