KVM: x86: Combine the lgdt and lidt emulation logic

LGDT and LIDT emulation logic is almost identical. Merge the logic into a
single point to avoid redundancy. This will be used by the next patch that
will ensure the bases of the loaded GDTR and IDTR are canonical.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 11 insertions, 16 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 9f960b428bb2..c86b3781fca2 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3327,7 +3327,7 @@ static int em_sidt(struct x86_emulate_ctxt *ctxt)
         return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt);
 }
 
-static int em_lgdt(struct x86_emulate_ctxt *ctxt)
+static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt)
 {
         struct desc_ptr desc_ptr;
         int rc;
@@ -3339,12 +3339,20 @@ static int em_lgdt(struct x86_emulate_ctxt *ctxt)
                              ctxt->op_bytes);
         if (rc != X86EMUL_CONTINUE)
                 return rc;
-        ctxt->ops->set_gdt(ctxt, &desc_ptr);
+        if (lgdt)
+                ctxt->ops->set_gdt(ctxt, &desc_ptr);
+        else
+                ctxt->ops->set_idt(ctxt, &desc_ptr);
         /* Disable writeback. */
         ctxt->dst.type = OP_NONE;
         return X86EMUL_CONTINUE;
 }
 
+static int em_lgdt(struct x86_emulate_ctxt *ctxt)
+{
+        return em_lgdt_lidt(ctxt, true);
+}
+
 static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
 {
         int rc;
@@ -3358,20 +3366,7 @@ static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
 
 static int em_lidt(struct x86_emulate_ctxt *ctxt)
 {
-        struct desc_ptr desc_ptr;
-        int rc;
-
-        if (ctxt->mode == X86EMUL_MODE_PROT64)
-                ctxt->op_bytes = 8;
-        rc = read_descriptor(ctxt, ctxt->src.addr.mem,
-                             &desc_ptr.size, &desc_ptr.address,
-                             ctxt->op_bytes);
-        if (rc != X86EMUL_CONTINUE)
-                return rc;
-        ctxt->ops->set_idt(ctxt, &desc_ptr);
-        /* Disable writeback. */
-        ctxt->dst.type = OP_NONE;
-        return X86EMUL_CONTINUE;
+        return em_lgdt_lidt(ctxt, false);
 }
 
 static int em_smsw(struct x86_emulate_ctxt *ctxt)