[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [PATCH 1/6] x86emul: fix FMA scalar operand sizes



FMA insns, other than 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 

Also correct the scalar insn comments (they only ever use XMM registers
as operands).

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- 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;
 




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.