KVM: x86 emulator: use correct type for memory address in operands

Currently we use a void pointer for memory addresses.  That's wrong since
these are guest virtual addresses which are not directly dereferencable by
the host.

Use the correct type, unsigned long.

Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index cbdf76722d7dc01faf531392ebe33035fe83a4a9..0c835f7eb308b336d99684f90ab9dcea70df43d1 100644 (file)
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -156,7 +156,10 @@ struct operand {
                unsigned long orig_val;
                u64 orig_val64;
        };
-       unsigned long *ptr;
+       union {
+               unsigned long *reg;
+               unsigned long mem;
+       } addr;
        union {
                unsigned long val;
                u64 val64;

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 471f12ae29cf7eab2585509d1750e152947f40f5..5f45f66ed2773848c3ab16ec20f0b3bcee3ff245 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -489,7 +489,7 @@ static void *decode_register(u8 modrm_reg, unsigned long *regs,
 
 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
                           struct x86_emulate_ops *ops,
-                          void *ptr,
+                          ulong addr,
                           u16 *size, unsigned long *address, int op_bytes)
 {
        int rc;
@@ -497,12 +497,10 @@ static int read_descriptor(struct x86_emulate_ctxt *ctxt,
        if (op_bytes == 2)
                op_bytes = 3;
        *address = 0;
-       rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
-                          ctxt->vcpu, NULL);
+       rc = ops->read_std(addr, (unsigned long *)size, 2, ctxt->vcpu, NULL);
        if (rc != X86EMUL_CONTINUE)
                return rc;
-       rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
-                          ctxt->vcpu, NULL);
+       rc = ops->read_std(addr + 2, address, op_bytes, ctxt->vcpu, NULL);
        return rc;
 }
 
@@ -552,21 +550,21 @@ static void decode_register_operand(struct operand *op,
                reg = (c->b & 7) | ((c->rex_prefix & 1) << 3);
        op->type = OP_REG;
        if ((c->d & ByteOp) && !inhibit_bytereg) {
-               op->ptr = decode_register(reg, c->regs, highbyte_regs);
-               op->val = *(u8 *)op->ptr;
+               op->addr.reg = decode_register(reg, c->regs, highbyte_regs);
+               op->val = *(u8 *)op->addr.reg;
                op->bytes = 1;
        } else {
-               op->ptr = decode_register(reg, c->regs, 0);
+               op->addr.reg = decode_register(reg, c->regs, 0);
                op->bytes = c->op_bytes;
                switch (op->bytes) {
                case 2:
-                       op->val = *(u16 *)op->ptr;
+                       op->val = *(u16 *)op->addr.reg;
                        break;
                case 4:
-                       op->val = *(u32 *)op->ptr;
+                       op->val = *(u32 *)op->addr.reg;
                        break;
                case 8:
-                       op->val = *(u64 *) op->ptr;
+                       op->val = *(u64 *) op->addr.reg;
                        break;
                }
        }
@@ -976,23 +974,23 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
                 */
                switch (c->dst.bytes) {
                case 1:
-                       *(u8 *)c->dst.ptr = (u8)c->dst.val;
+                       *(u8 *)c->dst.addr.reg = (u8)c->dst.val;
                        break;
                case 2:
-                       *(u16 *)c->dst.ptr = (u16)c->dst.val;
+                       *(u16 *)c->dst.addr.reg = (u16)c->dst.val;
                        break;
                case 4:
-                       *c->dst.ptr = (u32)c->dst.val;
+                       *c->dst.addr.reg = (u32)c->dst.val;
                        break;  /* 64b: zero-ext */
                case 8:
-                       *c->dst.ptr = c->dst.val;
+                       *c->dst.addr.reg = c->dst.val;
                        break;
                }
                break;
        case OP_MEM:
                if (c->lock_prefix)
                        rc = ops->cmpxchg_emulated(
-                                       (unsigned long)c->dst.ptr,
+                                       c->dst.addr.mem,
                                        &c->dst.orig_val,
                                        &c->dst.val,
                                        c->dst.bytes,
@@ -1000,14 +998,13 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
                                        ctxt->vcpu);
                else
                        rc = ops->write_emulated(
-                                       (unsigned long)c->dst.ptr,
+                                       c->dst.addr.mem,
                                        &c->dst.val,
                                        c->dst.bytes,
                                        &err,
                                        ctxt->vcpu);
                if (rc == X86EMUL_PROPAGATE_FAULT)
-                       emulate_pf(ctxt,
-                                             (unsigned long)c->dst.ptr, err);
+                       emulate_pf(ctxt, c->dst.addr.mem, err);
                if (rc != X86EMUL_CONTINUE)
                        return rc;
                break;
@@ -1029,8 +1026,8 @@ static inline void emulate_push(struct x86_emulate_ctxt *ctxt,
        c->dst.bytes = c->op_bytes;
        c->dst.val = c->src.val;
        register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes);
-       c->dst.ptr = (void *) register_address(c, ss_base(ctxt, ops),
-                                              c->regs[VCPU_REGS_RSP]);
+       c->dst.addr.mem = register_address(c, ss_base(ctxt, ops),
+                                          c->regs[VCPU_REGS_RSP]);
 }
 
 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
@@ -2019,7 +2016,7 @@ static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base,
        int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
 
        register_address_increment(c, &c->regs[reg], df * op->bytes);
-       op->ptr = (unsigned long *)register_address(c,  base, c->regs[reg]);
+       op->addr.mem = register_address(c,  base, c->regs[reg]);
 }
 
 static int em_push(struct x86_emulate_ctxt *ctxt)
@@ -2456,17 +2453,17 @@ done_prefixes:
                if ((c->d & ModRM) && c->modrm_mod == 3) {
                        c->src.type = OP_REG;
                        c->src.val = c->modrm_val;
-                       c->src.ptr = c->modrm_ptr;
+                       c->src.addr.reg = c->modrm_ptr;
                        break;
                }
                c->src.type = OP_MEM;
-               c->src.ptr = (unsigned long *)c->modrm_ea;
+               c->src.addr.mem = c->modrm_ea;
                c->src.val = 0;
                break;
        case SrcImm:
        case SrcImmU:
                c->src.type = OP_IMM;
-               c->src.ptr = (unsigned long *)c->eip;
+               c->src.addr.mem = c->eip;
                c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
                if (c->src.bytes == 8)
                        c->src.bytes = 4;
@@ -2499,7 +2496,7 @@ done_prefixes:
        case SrcImmByte:
        case SrcImmUByte:
                c->src.type = OP_IMM;
-               c->src.ptr = (unsigned long *)c->eip;
+               c->src.addr.mem = c->eip;
                c->src.bytes = 1;
                if ((c->d & SrcMask) == SrcImmByte)
                        c->src.val = insn_fetch(s8, 1, c->eip);
@@ -2509,19 +2506,19 @@ done_prefixes:
        case SrcAcc:
                c->src.type = OP_REG;
                c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-               c->src.ptr = &c->regs[VCPU_REGS_RAX];
+               c->src.addr.reg = &c->regs[VCPU_REGS_RAX];
                switch (c->src.bytes) {
                        case 1:
-                               c->src.val = *(u8 *)c->src.ptr;
+                               c->src.val = *(u8 *)c->src.addr.reg;
                                break;
                        case 2:
-                               c->src.val = *(u16 *)c->src.ptr;
+                               c->src.val = *(u16 *)c->src.addr.reg;
                                break;
                        case 4:
-                               c->src.val = *(u32 *)c->src.ptr;
+                               c->src.val = *(u32 *)c->src.addr.reg;
                                break;
                        case 8:
-                               c->src.val = *(u64 *)c->src.ptr;
+                               c->src.val = *(u64 *)c->src.addr.reg;
                                break;
                }
                break;
@@ -2532,20 +2529,20 @@ done_prefixes:
        case SrcSI:
                c->src.type = OP_MEM;
                c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-               c->src.ptr = (unsigned long *)
+               c->src.addr.mem =
                        register_address(c,  seg_override_base(ctxt, ops, c),
                                         c->regs[VCPU_REGS_RSI]);
                c->src.val = 0;
                break;
        case SrcImmFAddr:
                c->src.type = OP_IMM;
-               c->src.ptr = (unsigned long *)c->eip;
+               c->src.addr.mem = c->eip;
                c->src.bytes = c->op_bytes + 2;
                insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip);
                break;
        case SrcMemFAddr:
                c->src.type = OP_MEM;
-               c->src.ptr = (unsigned long *)c->modrm_ea;
+               c->src.addr.mem = c->modrm_ea;
                c->src.bytes = c->op_bytes + 2;
                break;
        }
@@ -2563,7 +2560,7 @@ done_prefixes:
                break;
        case Src2ImmByte:
                c->src2.type = OP_IMM;
-               c->src2.ptr = (unsigned long *)c->eip;
+               c->src2.addr.mem = c->eip;
                c->src2.bytes = 1;
                c->src2.val = insn_fetch(u8, 1, c->eip);
                break;
@@ -2588,11 +2585,11 @@ done_prefixes:
                        c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
                        c->dst.type = OP_REG;
                        c->dst.val = c->dst.orig_val = c->modrm_val;
-                       c->dst.ptr = c->modrm_ptr;
+                       c->dst.addr.reg = c->modrm_ptr;
                        break;
                }
                c->dst.type = OP_MEM;
-               c->dst.ptr = (unsigned long *)c->modrm_ea;
+               c->dst.addr.mem = c->modrm_ea;
                if ((c->d & DstMask) == DstMem64)
                        c->dst.bytes = 8;
                else
@@ -2601,26 +2598,26 @@ done_prefixes:
                if (c->d & BitOp) {
                        unsigned long mask = ~(c->dst.bytes * 8 - 1);
 
-                       c->dst.ptr = (void *)c->dst.ptr +
+                       c->dst.addr.mem = c->dst.addr.mem +
                                                   (c->src.val & mask) / 8;
                }
                break;
        case DstAcc:
                c->dst.type = OP_REG;
                c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-               c->dst.ptr = &c->regs[VCPU_REGS_RAX];
+               c->dst.addr.reg = &c->regs[VCPU_REGS_RAX];
                switch (c->dst.bytes) {
                        case 1:
-                               c->dst.val = *(u8 *)c->dst.ptr;
+                               c->dst.val = *(u8 *)c->dst.addr.reg;
                                break;
                        case 2:
-                               c->dst.val = *(u16 *)c->dst.ptr;
+                               c->dst.val = *(u16 *)c->dst.addr.reg;
                                break;
                        case 4:
-                               c->dst.val = *(u32 *)c->dst.ptr;
+                               c->dst.val = *(u32 *)c->dst.addr.reg;
                                break;
                        case 8:
-                               c->dst.val = *(u64 *)c->dst.ptr;
+                               c->dst.val = *(u64 *)c->dst.addr.reg;
                                break;
                }
                c->dst.orig_val = c->dst.val;
@@ -2628,7 +2625,7 @@ done_prefixes:
        case DstDI:
                c->dst.type = OP_MEM;
                c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-               c->dst.ptr = (unsigned long *)
+               c->dst.addr.mem =
                        register_address(c, es_base(ctxt, ops),
                                         c->regs[VCPU_REGS_RDI]);
                c->dst.val = 0;
@@ -2696,7 +2693,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
        }
 
        if (c->src.type == OP_MEM) {
-               rc = read_emulated(ctxt, ops, (unsigned long)c->src.ptr,
+               rc = read_emulated(ctxt, ops, c->src.addr.mem,
                                        c->src.valptr, c->src.bytes);
                if (rc != X86EMUL_CONTINUE)
                        goto done;
@@ -2704,7 +2701,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
        }
 
        if (c->src2.type == OP_MEM) {
-               rc = read_emulated(ctxt, ops, (unsigned long)c->src2.ptr,
+               rc = read_emulated(ctxt, ops, c->src2.addr.mem,
                                        &c->src2.val, c->src2.bytes);
                if (rc != X86EMUL_CONTINUE)
                        goto done;
@@ -2716,7 +2713,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 
        if ((c->dst.type == OP_MEM) && !(c->d & Mov)) {
                /* optimisation - avoid slow emulated read if Mov */
-               rc = read_emulated(ctxt, ops, (unsigned long)c->dst.ptr,
+               rc = read_emulated(ctxt, ops, c->dst.addr.mem,
                                   &c->dst.val, c->dst.bytes);
                if (rc != X86EMUL_CONTINUE)
                        goto done;
@@ -2880,16 +2877,16 @@ special_insn:
                /* Write back the register source. */
                switch (c->dst.bytes) {
                case 1:
-                       *(u8 *) c->src.ptr = (u8) c->dst.val;
+                       *(u8 *) c->src.addr.reg = (u8) c->dst.val;
                        break;
                case 2:
-                       *(u16 *) c->src.ptr = (u16) c->dst.val;
+                       *(u16 *) c->src.addr.reg = (u16) c->dst.val;
                        break;
                case 4:
-                       *c->src.ptr = (u32) c->dst.val;
+                       *c->src.addr.reg = (u32) c->dst.val;
                        break;  /* 64b reg: zero-extend */
                case 8:
-                       *c->src.ptr = c->dst.val;
+                       *c->src.addr.reg = c->dst.val;
                        break;
                }
                /*
@@ -2936,15 +2933,15 @@ special_insn:
                        goto done;
                break;
        case 0x90: /* nop / xchg r8,rax */
-               if (c->dst.ptr == (unsigned long *)&c->regs[VCPU_REGS_RAX]) {
+               if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX]) {
                        c->dst.type = OP_NONE;  /* nop */
                        break;
                }
        case 0x91 ... 0x97: /* xchg reg,rax */
                c->src.type = OP_REG;
                c->src.bytes = c->op_bytes;
-               c->src.ptr = (unsigned long *) &c->regs[VCPU_REGS_RAX];
-               c->src.val = *(c->src.ptr);
+               c->src.addr.reg = &c->regs[VCPU_REGS_RAX];
+               c->src.val = *(c->src.addr.reg);
                goto xchg;
        case 0x9c: /* pushf */
                c->src.val =  (unsigned long) ctxt->eflags;
@@ -2952,7 +2949,7 @@ special_insn:
                break;
        case 0x9d: /* popf */
                c->dst.type = OP_REG;
-               c->dst.ptr = (unsigned long *) &ctxt->eflags;
+               c->dst.addr.reg = &ctxt->eflags;
                c->dst.bytes = c->op_bytes;
                rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes);
                if (rc != X86EMUL_CONTINUE)
@@ -2963,7 +2960,7 @@ special_insn:
                goto mov;
        case 0xa6 ... 0xa7:     /* cmps */
                c->dst.type = OP_NONE; /* Disable writeback. */
-               DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr);
+               DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.addr.mem, c->dst.addr.mem);
                goto cmp;
        case 0xa8 ... 0xa9:     /* test ax, imm */
                goto test;
@@ -2982,7 +2979,7 @@ special_insn:
                break;
        case 0xc3: /* ret */
                c->dst.type = OP_REG;
-               c->dst.ptr = &c->eip;
+               c->dst.addr.reg = &c->eip;
                c->dst.bytes = c->op_bytes;
                goto pop_instruction;
        case 0xc6 ... 0xc7:     /* mov (sole member of Grp11) */
@@ -3184,7 +3181,7 @@ twobyte_insn:
                        c->dst.type = OP_NONE;
                        break;
                case 2: /* lgdt */
-                       rc = read_descriptor(ctxt, ops, c->src.ptr,
+                       rc = read_descriptor(ctxt, ops, c->src.addr.mem,
                                             &size, &address, c->op_bytes);
                        if (rc != X86EMUL_CONTINUE)
                                goto done;
@@ -3204,7 +3201,7 @@ twobyte_insn:
                                        goto cannot_emulate;
                                }
                        } else {
-                               rc = read_descriptor(ctxt, ops, c->src.ptr,
+                               rc = read_descriptor(ctxt, ops, c->src.addr.mem,
                                                     &size, &address,
                                                     c->op_bytes);
                                if (rc != X86EMUL_CONTINUE)
@@ -3399,7 +3396,7 @@ twobyte_insn:
                } else {
                        /* Failure: write the value we saw to EAX. */
                        c->dst.type = OP_REG;
-                       c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
+                       c->dst.addr.reg = (unsigned long *)&c->regs[VCPU_REGS_RAX];
                }
                break;
        case 0xb3: