From dd307d017b445a3af4379c7ff548cb3da5ecde31 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 12 Jul 2016 10:35:51 +0200
Subject: [PATCH] KVM: x86: emulate sldt and str
Git-commit: dd307d017b445a3af4379c7ff548cb3da5ecde31
Patch-mainline: v4.16-rc1
References: bsc#1120716
These are needed to handle the descriptor table vmexits when emulating
UMIP.
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Lin Ma <lma@suse.com>
---
arch/x86/kvm/emulate.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a7769de08ae1..8655832e3bae 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3652,17 +3652,27 @@ static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE;
}
-static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
+static int em_store_sreg(struct x86_emulate_ctxt *ctxt, int segment)
{
- if (ctxt->modrm_reg > VCPU_SREG_GS)
- return emulate_ud(ctxt);
+ if (segment > VCPU_SREG_GS &&
+ (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) &&
+ ctxt->ops->cpl(ctxt) > 0)
+ return emulate_gp(ctxt, 0);
- ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
+ ctxt->dst.val = get_segment_selector(ctxt, segment);
if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM)
ctxt->dst.bytes = 2;
return X86EMUL_CONTINUE;
}
+static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
+{
+ if (ctxt->modrm_reg > VCPU_SREG_GS)
+ return emulate_ud(ctxt);
+
+ return em_store_sreg(ctxt, ctxt->modrm_reg);
+}
+
static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
{
u16 sel = ctxt->src.val;
@@ -3678,6 +3688,11 @@ static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
}
+static int em_sldt(struct x86_emulate_ctxt *ctxt)
+{
+ return em_store_sreg(ctxt, VCPU_SREG_LDTR);
+}
+
static int em_lldt(struct x86_emulate_ctxt *ctxt)
{
u16 sel = ctxt->src.val;
@@ -3687,6 +3702,11 @@ static int em_lldt(struct x86_emulate_ctxt *ctxt)
return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR);
}
+static int em_str(struct x86_emulate_ctxt *ctxt)
+{
+ return em_store_sreg(ctxt, VCPU_SREG_TR);
+}
+
static int em_ltr(struct x86_emulate_ctxt *ctxt)
{
u16 sel = ctxt->src.val;
@@ -4393,8 +4413,8 @@ static const struct opcode group5[] = {
};
static const struct opcode group6[] = {
- DI(Prot | DstMem, sldt),
- DI(Prot | DstMem, str),
+ II(Prot | DstMem, em_sldt, sldt),
+ II(Prot | DstMem, em_str, str),
II(Prot | Priv | SrcMem16, em_lldt, lldt),
II(Prot | Priv | SrcMem16, em_ltr, ltr),
N, N, N, N,
--
2.16.2