[Qemu-devel] [PATCH 4/5] kqemu: Implement verr/verw in the monitor code interpreter

[Jan Kiszka]

This avoids user space for handling verr/verw via TCG.

Signed-off-by: Jan Kiszka <address@hidden>
---

 common/interp.c |   71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 70 insertions(+), 1 deletions(-)

diff --git a/common/interp.c b/common/interp.c
index 4c042e9..4f93bc3 100644
--- a/common/interp.c
+++ b/common/interp.c
@@ -1720,6 +1720,65 @@ void helper_lldt(struct kqemu_state *s, int selector)
     env->ldt.selector = selector;
 }
 
+static void helper_verr(struct kqemu_state *s, int selector)
+{
+    uint32_t e1, e2;
+    int rpl, dpl, cpl;
+
+    if ((selector & 0xfffc) == 0)
+        goto fail;
+    if (load_segment(s, &e1, &e2, selector) != 0)
+        goto fail;
+    if (!(e2 & DESC_S_MASK))
+        goto fail;
+    rpl = selector & 3;
+    dpl = (e2 >> DESC_DPL_SHIFT) & 3;
+    cpl = s->cpu_state.cpl;
+    if (e2 & DESC_CS_MASK) {
+        if (!(e2 & DESC_R_MASK))
+            goto fail;
+        if (!(e2 & DESC_C_MASK)) {
+            if (dpl < cpl || dpl < rpl)
+                goto fail;
+        }
+    } else {
+        if (dpl < cpl || dpl < rpl) {
+        fail:
+            set_reset_eflags(s, 0, CC_Z);
+            return;
+        }
+    }
+    set_reset_eflags(s, CC_Z, 0);
+}
+
+static void helper_verw(struct kqemu_state *s, int selector)
+{
+    uint32_t e1, e2;
+    int rpl, dpl, cpl;
+
+    if ((selector & 0xfffc) == 0)
+        goto fail;
+    if (load_segment(s, &e1, &e2, selector) != 0)
+        goto fail;
+    if (!(e2 & DESC_S_MASK))
+        goto fail;
+    rpl = selector & 3;
+    dpl = (e2 >> DESC_DPL_SHIFT) & 3;
+    cpl = s->cpu_state.cpl;
+    if (e2 & DESC_CS_MASK) {
+        goto fail;
+    } else {
+        if (dpl < cpl || dpl < rpl)
+            goto fail;
+        if (!(e2 & DESC_W_MASK)) {
+        fail:
+            set_reset_eflags(s, 0, CC_Z);
+            return;
+        }
+    }
+    set_reset_eflags(s, CC_Z, 0);
+}
+
 static void helper_wrmsr(struct kqemu_state *s)
 {
 #ifdef __x86_64__
@@ -4479,7 +4538,17 @@ QO(                 case OT_LONG | 8:\
             case 5: /* verw */
                 if (!(s->cpu_state.cr0 & CR0_PE_MASK) || get_eflags_vm(s))
                     goto illegal_op;
-                raise_exception(s, KQEMU_RET_SOFTMMU);
+                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);
+                }
+                if (op == 4)
+                    helper_verr(s, val);
+                else
+                    helper_verw(s, val);
                 break;
             default:
                 goto illegal_op;