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From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
Subject: [PATCH v2 18/26] KVM: x86 emulator: implement ENTER
Date: Wed, 27 Jun 2012 18:19:21 +0300	[thread overview]
Message-ID: <1340810369-25392-24-git-send-email-avi@redhat.com> (raw)
In-Reply-To: <1340810369-25392-1-git-send-email-avi@redhat.com>

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>
---
 arch/x86/kvm/emulate.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

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 int check_perm_out(struct x86_emulate_ctxt *ctxt)
 	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 */
-- 
1.7.11


  parent reply	other threads:[~2012-06-27 15:20 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-27 15:18 [PATCH v2 00/26] Big big real mode improvements Avi Kivity
2012-06-27 15:18 ` [PATCH v2 01/26] KVM: VMX: Return correct CPL during transition to protected mode Avi Kivity
2012-06-27 15:19 ` [PATCH 1/5] KVM: x86 emulator: emulate BSWAP Avi Kivity
2012-06-27 15:19 ` [PATCH v2 02/26] KVM: Split cpuid register access from computation Avi Kivity
2012-06-27 15:19 ` [PATCH 2/5] KVM: x86 emulator: emulate LLDT Avi Kivity
2012-06-27 15:19 ` [PATCH v2 03/26] KVM: x86 emulator: change ->get_cpuid() accessor to use the x86 semantics Avi Kivity
2012-06-27 15:19 ` [PATCH 3/5] KVM: x86 emulator: make read_segment_descriptor() return the address Avi Kivity
2012-06-27 15:19 ` [PATCH v2 04/26] KVM: x86 emulator: emulate cpuid Avi Kivity
2012-06-27 15:19 ` [PATCH 4/5] KVM: x86 emulator: make loading TR set the busy bit Avi Kivity
2012-06-27 15:19 ` [PATCH v2 05/26] KVM: x86 emulator: allow loading null SS in long mode Avi Kivity
2012-06-27 15:19 ` [PATCH 5/5] KVM: x86 emulator: implement LTR Avi Kivity
2012-06-27 15:19 ` [PATCH v2 06/26] KVM: x86 emulator: fix LIDT/LGDT in long mode Avi Kivity
2012-06-27 15:19 ` [PATCH v2 07/26] KVM: VMX: Relax check on unusable segment Avi Kivity
2012-06-27 15:19 ` [PATCH v2 08/26] KVM: VMX: Limit iterations with emulator_invalid_guest_state Avi Kivity
2012-06-27 15:19 ` [PATCH v2 09/26] KVM: x86 emulator: emulate LEAVE Avi Kivity
2012-06-27 15:19 ` [PATCH v2 10/26] KVM: x86 emulator: initialize memop Avi Kivity
2012-06-27 15:19 ` [PATCH v2 11/26] KVM: Fix SS default ESP/EBP based addressing Avi Kivity
2012-06-27 15:19 ` [PATCH v2 12/26] KVM: x86 emulator: emulate SGDT/SIDT Avi Kivity
2012-06-27 15:19 ` [PATCH v2 13/26] KVM: VMX: Fix interrupt exit condition during emulation Avi Kivity
2012-06-27 15:19 ` [PATCH v2 14/26] KVM: VMX: Continue emulating after batch exhausted Avi Kivity
2012-06-27 15:19 ` [PATCH v2 15/26] KVM: x86 emulator: emulate LAHF Avi Kivity
2012-06-27 15:19 ` [PATCH v2 16/26] KVM: x86 emulator: fix byte-sized MOVZX/MOVSX Avi Kivity
2012-06-27 15:19 ` [PATCH v2 17/26] KVM: x86 emulator: split push logic from push opcode emulation Avi Kivity
2012-06-27 15:19 ` Avi Kivity [this message]
2012-06-27 15:19 ` [PATCH v2 19/26] KVM: VMX: Stop invalid guest state emulation on pending event Avi Kivity
2012-06-27 15:19 ` [PATCH v2 20/26] KVM: VMX: Improve error reporting during invalid guest state emulation Avi Kivity
2012-06-27 15:19 ` [PATCH v2 21/26] KVM: x86 emulator: emulate BSWAP Avi Kivity
2012-06-27 15:19 ` [PATCH v2 22/26] KVM: x86 emulator: emulate LLDT Avi Kivity
2012-06-27 15:19 ` [PATCH v2 23/26] KVM: x86 emulator: make read_segment_descriptor() return the address Avi Kivity
2012-06-27 15:19 ` [PATCH v2 24/26] KVM: x86 emulator: make loading TR set the busy bit Avi Kivity
2012-06-27 15:19 ` [PATCH v2 25/26] KVM: x86 emulator: implement LTR Avi Kivity
2012-06-27 15:19 ` [PATCH v2 26/26] KVM: VMX: Emulate invalid guest state by default Avi Kivity
2012-06-27 15:23 ` [PATCH v2 00/26] Big big real mode improvements Avi Kivity

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