[xen master] x86emul: convert op_bytes/opc checks in SIMD emulation

[patchbot@xxxxxxx]

commit 5231765a4e6528a3208e49885b9eeff42519a6c1
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Aug 23 09:13:07 2024 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Aug 23 09:13:07 2024 +0200

    x86emul: convert op_bytes/opc checks in SIMD emulation
    
    Raising #UD for an internal shortcoming of the emulator isn't quite
    right. Similarly BUG() is bigger a hammer than needed.
    
    Switch to using EXPECT() instead. This way even for insns not covered by
    the test harness fuzzers will have a chance of noticing issues, should
    any still exist or new ones be introduced.
    
    Suggested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index 0a7552de96..0a6d5a35b1 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -8116,13 +8116,13 @@ x86_emulate(
     }
     else if ( state->simd_size != simd_none )
     {
-        generate_exception_if(!op_bytes, X86_EXC_UD);
         generate_exception_if((vex.opcx && (d & TwoOp) &&
                                (vex.reg != 0xf || (evex_encoded() && 
!evex.RX))),
                               X86_EXC_UD);
 
-        if ( !opc )
-            BUG();
+        EXPECT(op_bytes);
+        EXPECT(opc);
+
         if ( evex_encoded() )
         {
             opc[insn_bytes - EVEX_PFX_BYTES] = 0xc3;
--
generated by git-patchbot for /home/xen/git/xen.git#master