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[Xen-changelog] [xen master] x86emul: fix FMA scalar operand sizes



commit 31c941cc2b606ed34f8743094db19ce8f0880138
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Sep 4 11:28:30 2018 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Sep 4 11:28:30 2018 +0200

    x86emul: fix FMA scalar operand sizes
    
    FMA insns, unlike the earlier AVX additions, don't use the low opcode
    bit to distinguish between single and double vector elements. While the
    difference is benign for packed flavors, the scalar ones need to use
    VEX.W here. Oddly enough the table entries didn't even use
    simd_scalar_fp, but uniformly used simd_packed_fp (implying the
    distinction was by [VEX-encoded] opcode prefix).
    
    Split simd_scalar_fp into simd_scalar_opc and simd_scalar_vexw, and
    correct FMA scalar table entries to use the latter.
    
    Also correct the scalar insn comments (they only ever use XMM registers
    as operands).
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 79 +++++++++++++++++++++++-----------
 1 file changed, 55 insertions(+), 24 deletions(-)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index e372c4bb03..4afc3f6ca3 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -224,7 +224,13 @@ enum simd_opsize {
      * - 32 bits with low opcode bit clear (scalar single)
      * - 64 bits with low opcode bit set (scalar double)
      */
-    simd_scalar_fp,
+    simd_scalar_opc,
+
+    /*
+     * Scalar floating point:
+     * - 32/64 bits depending on VEX.W
+     */
+    simd_scalar_vexw,
 
     /*
      * 128 bits of integer or floating point data, with no further
@@ -407,7 +413,7 @@ static const struct ext0f38_table {
     [0x13] = { .simd_size = simd_other, .two_op = 1 },
     [0x14 ... 0x16] = { .simd_size = simd_packed_fp },
     [0x17] = { .simd_size = simd_packed_int, .two_op = 1 },
-    [0x18 ... 0x19] = { .simd_size = simd_scalar_fp, .two_op = 1 },
+    [0x18 ... 0x19] = { .simd_size = simd_scalar_opc, .two_op = 1 },
     [0x1a] = { .simd_size = simd_128, .two_op = 1 },
     [0x1c ... 0x1e] = { .simd_size = simd_packed_int, .two_op = 1 },
     [0x20 ... 0x25] = { .simd_size = simd_other, .two_op = 1 },
@@ -427,9 +433,30 @@ static const struct ext0f38_table {
     [0x8c] = { .simd_size = simd_other },
     [0x8e] = { .simd_size = simd_other, .to_mem = 1 },
     [0x90 ... 0x93] = { .simd_size = simd_other, .vsib = 1 },
-    [0x96 ... 0x9f] = { .simd_size = simd_packed_fp },
-    [0xa6 ... 0xaf] = { .simd_size = simd_packed_fp },
-    [0xb6 ... 0xbf] = { .simd_size = simd_packed_fp },
+    [0x96 ... 0x98] = { .simd_size = simd_packed_fp },
+    [0x99] = { .simd_size = simd_scalar_vexw },
+    [0x9a] = { .simd_size = simd_packed_fp },
+    [0x9b] = { .simd_size = simd_scalar_vexw },
+    [0x9c] = { .simd_size = simd_packed_fp },
+    [0x9d] = { .simd_size = simd_scalar_vexw },
+    [0x9e] = { .simd_size = simd_packed_fp },
+    [0x9f] = { .simd_size = simd_scalar_vexw },
+    [0xa6 ... 0xa8] = { .simd_size = simd_packed_fp },
+    [0xa9] = { .simd_size = simd_scalar_vexw },
+    [0xaa] = { .simd_size = simd_packed_fp },
+    [0xab] = { .simd_size = simd_scalar_vexw },
+    [0xac] = { .simd_size = simd_packed_fp },
+    [0xad] = { .simd_size = simd_scalar_vexw },
+    [0xae] = { .simd_size = simd_packed_fp },
+    [0xaf] = { .simd_size = simd_scalar_vexw },
+    [0xb6 ... 0xb8] = { .simd_size = simd_packed_fp },
+    [0xb9] = { .simd_size = simd_scalar_vexw },
+    [0xba] = { .simd_size = simd_packed_fp },
+    [0xbb] = { .simd_size = simd_scalar_vexw },
+    [0xbc] = { .simd_size = simd_packed_fp },
+    [0xbd] = { .simd_size = simd_scalar_vexw },
+    [0xbe] = { .simd_size = simd_packed_fp },
+    [0xbf] = { .simd_size = simd_scalar_vexw },
     [0xc8 ... 0xcd] = { .simd_size = simd_other },
     [0xdb] = { .simd_size = simd_packed_int, .two_op = 1 },
     [0xdc ... 0xdf] = { .simd_size = simd_packed_int },
@@ -454,7 +481,7 @@ static const struct ext0f3a_table {
     [0x04 ... 0x05] = { .simd_size = simd_packed_fp, .two_op = 1 },
     [0x06] = { .simd_size = simd_packed_fp },
     [0x08 ... 0x09] = { .simd_size = simd_packed_fp, .two_op = 1 },
-    [0x0a ... 0x0b] = { .simd_size = simd_scalar_fp },
+    [0x0a ... 0x0b] = { .simd_size = simd_scalar_opc },
     [0x0c ... 0x0d] = { .simd_size = simd_packed_fp },
     [0x0e ... 0x0f] = { .simd_size = simd_packed_int },
     [0x14 ... 0x17] = { .simd_size = simd_none, .to_mem = 1, .two_op = 1 },
@@ -476,13 +503,13 @@ static const struct ext0f3a_table {
     [0x5c ... 0x5f] = { .simd_size = simd_packed_fp, .four_op = 1 },
     [0x60 ... 0x63] = { .simd_size = simd_packed_int, .two_op = 1 },
     [0x68 ... 0x69] = { .simd_size = simd_packed_fp, .four_op = 1 },
-    [0x6a ... 0x6b] = { .simd_size = simd_scalar_fp, .four_op = 1 },
+    [0x6a ... 0x6b] = { .simd_size = simd_scalar_opc, .four_op = 1 },
     [0x6c ... 0x6d] = { .simd_size = simd_packed_fp, .four_op = 1 },
-    [0x6e ... 0x6f] = { .simd_size = simd_scalar_fp, .four_op = 1 },
+    [0x6e ... 0x6f] = { .simd_size = simd_scalar_opc, .four_op = 1 },
     [0x78 ... 0x79] = { .simd_size = simd_packed_fp, .four_op = 1 },
-    [0x7a ... 0x7b] = { .simd_size = simd_scalar_fp, .four_op = 1 },
+    [0x7a ... 0x7b] = { .simd_size = simd_scalar_opc, .four_op = 1 },
     [0x7c ... 0x7d] = { .simd_size = simd_packed_fp, .four_op = 1 },
-    [0x7e ... 0x7f] = { .simd_size = simd_scalar_fp, .four_op = 1 },
+    [0x7e ... 0x7f] = { .simd_size = simd_scalar_opc, .four_op = 1 },
     [0xcc] = { .simd_size = simd_other },
     [0xdf] = { .simd_size = simd_packed_int, .two_op = 1 },
     [0xf0] = {},
@@ -518,7 +545,7 @@ static const struct ext8f09_table {
 } ext8f09_table[256] = {
     [0x01 ... 0x02] = { .two_op = 1 },
     [0x80 ... 0x81] = { .simd_size = simd_packed_fp, .two_op = 1 },
-    [0x82 ... 0x83] = { .simd_size = simd_scalar_fp, .two_op = 1 },
+    [0x82 ... 0x83] = { .simd_size = simd_scalar_opc, .two_op = 1 },
     [0x90 ... 0x9b] = { .simd_size = simd_packed_int },
     [0xc1 ... 0xc3] = { .simd_size = simd_packed_int, .two_op = 1 },
     [0xc6 ... 0xc7] = { .simd_size = simd_packed_int, .two_op = 1 },
@@ -3132,10 +3159,14 @@ x86_decode(
         }
         break;
 
-    case simd_scalar_fp:
+    case simd_scalar_opc:
         op_bytes = 4 << (ctxt->opcode & 1);
         break;
 
+    case simd_scalar_vexw:
+        op_bytes = 4 << vex.w;
+        break;
+
     case simd_128:
         op_bytes = 16;
         break;
@@ -7747,33 +7778,33 @@ x86_emulate(
     case X86EMUL_OPC_VEX_66(0x0f38, 0x96): /* vfmaddsub132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0x97): /* vfmsubadd132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0x98): /* vfmadd132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0x99): /* vfmadd132s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0x99): /* vfmadd132s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0x9a): /* vfmsub132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0x9b): /* vfmsub132s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0x9b): /* vfmsub132s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0x9c): /* vfnmadd132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0x9d): /* vfnmadd132s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0x9d): /* vfnmadd132s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0x9e): /* vfnmsub132p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0x9f): /* vfnmsub132s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0x9f): /* vfnmsub132s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xa6): /* vfmaddsub213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0xa7): /* vfmsubadd213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0xa8): /* vfmadd213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xa9): /* vfmadd213s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xa9): /* vfmadd213s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xaa): /* vfmsub213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xab): /* vfmsub213s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xab): /* vfmsub213s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xac): /* vfnmadd213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xad): /* vfnmadd213s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xad): /* vfnmadd213s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xae): /* vfnmsub213p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xaf): /* vfnmsub213s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xaf): /* vfnmsub213s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xb6): /* vfmaddsub231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0xb7): /* vfmsubadd231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
     case X86EMUL_OPC_VEX_66(0x0f38, 0xb8): /* vfmadd231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xb9): /* vfmadd231s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xb9): /* vfmadd231s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xba): /* vfmsub231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xbb): /* vfmsub231s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xbb): /* vfmsub231s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xbc): /* vfnmadd231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xbd): /* vfnmadd231s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xbd): /* vfnmadd231s{s,d} xmm/mem,xmm,xmm 
*/
     case X86EMUL_OPC_VEX_66(0x0f38, 0xbe): /* vfnmsub231p{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
-    case X86EMUL_OPC_VEX_66(0x0f38, 0xbf): /* vfnmsub231s{s,d} 
{x,y}mm/mem,{x,y}mm,{x,y}mm */
+    case X86EMUL_OPC_VEX_66(0x0f38, 0xbf): /* vfnmsub231s{s,d} xmm/mem,xmm,xmm 
*/
         host_and_vcpu_must_have(fma);
         goto simd_0f_ymm;
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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