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| author | Avi Kivity <avi@redhat.com> | 2012-06-12 17:03:23 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-07-09 11:19:03 (GMT) |
| commit | 612e89f01569f562dfa76cd5b76310a42b34a214 (patch) | |
| tree | 44dffc8c7aaa386a3e2e147499cad2b1adf3d386 /arch | |
| parent | 51ddff50cbd77568fe40e17a966b3a2ef1231b36 (diff) | |
| download | linux-fsl-qoriq-612e89f01569f562dfa76cd5b76310a42b34a214.tar.xz | |
KVM: x86 emulator: implement ENTER
Opcode C8.
Only ENTER with lexical nesting depth 0 is implemented, since others are
very rare. We'll fail emulation if nonzero lexical depth is used so data
is not corrupted.
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index acc647d..b4b326e 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -454,6 +454,11 @@ static ulong stack_mask(struct x86_emulate_ctxt *ctxt) return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */ } +static int stack_size(struct x86_emulate_ctxt *ctxt) +{ + return (__fls(stack_mask(ctxt)) + 1) >> 3; +} + /* Access/update address held in a register, based on addressing mode. */ static inline unsigned long address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg) @@ -1592,6 +1597,26 @@ static int em_popf(struct x86_emulate_ctxt *ctxt) return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes); } +static int em_enter(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned frame_size = ctxt->src.val; + unsigned nesting_level = ctxt->src2.val & 31; + + if (nesting_level) + return X86EMUL_UNHANDLEABLE; + + rc = push(ctxt, &ctxt->regs[VCPU_REGS_RBP], stack_size(ctxt)); + if (rc != X86EMUL_CONTINUE) + return rc; + assign_masked(&ctxt->regs[VCPU_REGS_RBP], ctxt->regs[VCPU_REGS_RSP], + stack_mask(ctxt)); + assign_masked(&ctxt->regs[VCPU_REGS_RSP], + ctxt->regs[VCPU_REGS_RSP] - frame_size, + stack_mask(ctxt)); + return X86EMUL_CONTINUE; +} + static int em_leave(struct x86_emulate_ctxt *ctxt) { assign_masked(&ctxt->regs[VCPU_REGS_RSP], ctxt->regs[VCPU_REGS_RBP], @@ -3657,7 +3682,8 @@ static struct opcode opcode_table[256] = { I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), G(ByteOp, group11), G(0, group11), /* 0xC8 - 0xCF */ - N, I(Stack, em_leave), N, I(ImplicitOps | Stack, em_ret_far), + I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave), + N, I(ImplicitOps | Stack, em_ret_far), D(ImplicitOps), DI(SrcImmByte, intn), D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret), /* 0xD0 - 0xD7 */ |