[Qemu-devel] [PATCH 5/5] kqemu: Implement lar/lsl in the monitor code interpreter

[Jan Kiszka <jan.kiszka@siemens.com>]

This avoids user space for handling lar/lsl via TCG.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

 common/interp.c |  111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 109 insertions(+), 2 deletions(-)

diff --git a/common/interp.c b/common/interp.c
index 4f93bc3..577d666 100644
--- a/common/interp.c
+++ b/common/interp.c
@@ -1720,6 +1720,93 @@ void helper_lldt(struct kqemu_state *s, int selector)
     env->ldt.selector = selector;
 }
 
+static int helper_lar(struct kqemu_state *s, int selector)
+{
+    uint32_t e1, e2;
+    int rpl, dpl, cpl, type;
+
+    if ((selector & 0xfffc) == 0)
+        goto fail;
+    if (load_segment(s, &e1, &e2, selector) != 0)
+        goto fail;
+    rpl = selector & 3;
+    dpl = (e2 >> DESC_DPL_SHIFT) & 3;
+    cpl = s->cpu_state.cpl;
+    if (e2 & DESC_S_MASK) {
+        if ((e2 & DESC_CS_MASK) && (e2 & DESC_C_MASK)) {
+            /* conforming */
+        } else {
+            if (dpl < cpl || dpl < rpl)
+                goto fail;
+        }
+    } else {
+        type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
+        switch(type) {
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+        case 5:
+        case 9:
+        case 11:
+        case 12:
+            break;
+        default:
+            goto fail;
+        }
+        if (dpl < cpl || dpl < rpl) {
+        fail:
+            set_reset_eflags(s, 0, CC_Z);
+            return 0;
+        }
+    }
+    set_reset_eflags(s, CC_Z, 0);
+    return e2 & 0x00f0ff00;
+}
+
+static int helper_lsl(struct kqemu_state *s, int selector)
+{
+    unsigned int limit;
+    uint32_t e1, e2;
+    int rpl, dpl, cpl, type;
+
+    if ((selector & 0xfffc) == 0)
+        goto fail;
+    if (load_segment(s, &e1, &e2, selector) != 0)
+        goto fail;
+    rpl = selector & 3;
+    dpl = (e2 >> DESC_DPL_SHIFT) & 3;
+    cpl = s->cpu_state.cpl;
+    if (e2 & DESC_S_MASK) {
+        if ((e2 & DESC_CS_MASK) && (e2 & DESC_C_MASK)) {
+            /* conforming */
+        } else {
+            if (dpl < cpl || dpl < rpl)
+                goto fail;
+        }
+    } else {
+        type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
+        switch(type) {
+        case 1:
+        case 2:
+        case 3:
+        case 9:
+        case 11:
+            break;
+        default:
+            goto fail;
+        }
+        if (dpl < cpl || dpl < rpl) {
+        fail:
+            set_reset_eflags(s, 0, CC_Z);
+            return 0;
+        }
+    }
+    limit = get_seg_limit(e1, e2);
+    set_reset_eflags(s, CC_Z, 0);
+    return limit;
+}
+
 static void helper_verr(struct kqemu_state *s, int selector)
 {
     uint32_t e1, e2;
@@ -4616,6 +4703,28 @@ QO(                 case OT_LONG | 8:\
                 goto illegal_op;
             }
             goto insn_next;
+        LABEL(102) /* lar */
+        LABEL(103) /* lsl */
+            if (!(s->cpu_state.cr0 & CR0_PE_MASK) || get_eflags_vm(s))
+                goto illegal_op;
+            ot = s->dflag + OT_WORD;
+            modrm = ldub_code(s);
+            mod = (modrm >> 6);
+            if (mod == 3) {
+                rm = (modrm & 7) | REX_B(s);
+                val = get_regS(s, OT_WORD, rm) & 0xffff;
+            } else {
+                addr = get_modrm(s, modrm);
+                val = ldS(s, OT_WORD, addr);
+            }
+            rm = ((modrm >> 3) & 7) | REX_R(s);
+            if (b == 0x102)
+                val = helper_lar(s, val);
+            else
+                val = helper_lsl(s, val);
+            if (s->regs1.eflags & CC_Z)
+                set_regS(s, ot, rm, val);
+            goto insn_next;
         LABEL(108) /* invd */
         LABEL(109) /* wbinvd */
             if (s->cpu_state.cpl != 0) 
@@ -5214,8 +5323,6 @@ QO(                 case OT_LONG | 8:\
     LABEL(10b)
     LABEL(10a)
     LABEL(104)
-    LABEL(103)
-    LABEL(102)
     LABEL(f1)
     LABEL(e2)
     LABEL(e1)