KVM: x86 emulator: SSE support

Add support for marking an instruction as SSE, switching registers used
to the SSE register file.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 99 insertions, 3 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index fcce7aeacc8..4e11102f560 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -76,6 +76,7 @@
 #define Group       (1<<14)     /* Bits 3:5 of modrm byte extend opcode */
 #define GroupDual   (1<<15)     /* Alternate decoding of mod == 3 */
 #define Prefix      (1<<16)     /* Instruction varies with 66/f2/f3 prefix */
+#define Sse         (1<<17)     /* SSE Vector instruction */
 /* Misc flags */
 #define VendorSpecific (1<<22) /* Vendor specific instruction */
 #define NoAccess    (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
@@ -505,6 +506,11 @@ static int emulate_de(struct x86_emulate_ctxt *ctxt)
         return emulate_exception(ctxt, DE_VECTOR, 0, false);
 }
 
+static int emulate_nm(struct x86_emulate_ctxt *ctxt)
+{
+        return emulate_exception(ctxt, NM_VECTOR, 0, false);
+}
+
 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
                               struct x86_emulate_ops *ops,
                               unsigned long eip, u8 *dest)
@@ -632,7 +638,63 @@ static void fetch_register_operand(struct operand *op)
         }
 }
 
-static void decode_register_operand(struct operand *op,
+static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
+{
+        ctxt->ops->get_fpu(ctxt);
+        switch (reg) {
+        case 0: asm("movdqu %%xmm0, %0" : "=m"(*data)); break;
+        case 1: asm("movdqu %%xmm1, %0" : "=m"(*data)); break;
+        case 2: asm("movdqu %%xmm2, %0" : "=m"(*data)); break;
+        case 3: asm("movdqu %%xmm3, %0" : "=m"(*data)); break;
+        case 4: asm("movdqu %%xmm4, %0" : "=m"(*data)); break;
+        case 5: asm("movdqu %%xmm5, %0" : "=m"(*data)); break;
+        case 6: asm("movdqu %%xmm6, %0" : "=m"(*data)); break;
+        case 7: asm("movdqu %%xmm7, %0" : "=m"(*data)); break;
+#ifdef CONFIG_X86_64
+        case 8: asm("movdqu %%xmm8, %0" : "=m"(*data)); break;
+        case 9: asm("movdqu %%xmm9, %0" : "=m"(*data)); break;
+        case 10: asm("movdqu %%xmm10, %0" : "=m"(*data)); break;
+        case 11: asm("movdqu %%xmm11, %0" : "=m"(*data)); break;
+        case 12: asm("movdqu %%xmm12, %0" : "=m"(*data)); break;
+        case 13: asm("movdqu %%xmm13, %0" : "=m"(*data)); break;
+        case 14: asm("movdqu %%xmm14, %0" : "=m"(*data)); break;
+        case 15: asm("movdqu %%xmm15, %0" : "=m"(*data)); break;
+#endif
+        default: BUG();
+        }
+        ctxt->ops->put_fpu(ctxt);
+}
+
+static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
+                          int reg)
+{
+        ctxt->ops->get_fpu(ctxt);
+        switch (reg) {
+        case 0: asm("movdqu %0, %%xmm0" : : "m"(*data)); break;
+        case 1: asm("movdqu %0, %%xmm1" : : "m"(*data)); break;
+        case 2: asm("movdqu %0, %%xmm2" : : "m"(*data)); break;
+        case 3: asm("movdqu %0, %%xmm3" : : "m"(*data)); break;
+        case 4: asm("movdqu %0, %%xmm4" : : "m"(*data)); break;
+        case 5: asm("movdqu %0, %%xmm5" : : "m"(*data)); break;
+        case 6: asm("movdqu %0, %%xmm6" : : "m"(*data)); break;
+        case 7: asm("movdqu %0, %%xmm7" : : "m"(*data)); break;
+#ifdef CONFIG_X86_64
+        case 8: asm("movdqu %0, %%xmm8" : : "m"(*data)); break;
+        case 9: asm("movdqu %0, %%xmm9" : : "m"(*data)); break;
+        case 10: asm("movdqu %0, %%xmm10" : : "m"(*data)); break;
+        case 11: asm("movdqu %0, %%xmm11" : : "m"(*data)); break;
+        case 12: asm("movdqu %0, %%xmm12" : : "m"(*data)); break;
+        case 13: asm("movdqu %0, %%xmm13" : : "m"(*data)); break;
+        case 14: asm("movdqu %0, %%xmm14" : : "m"(*data)); break;
+        case 15: asm("movdqu %0, %%xmm15" : : "m"(*data)); break;
+#endif
+        default: BUG();
+        }
+        ctxt->ops->put_fpu(ctxt);
+}
+
+static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
+                                    struct operand *op,
                                     struct decode_cache *c,
                                     int inhibit_bytereg)
 {
@@ -641,6 +703,15 @@ static void decode_register_operand(struct operand *op,
 
         if (!(c->d & ModRM))
                 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3);
+
+        if (c->d & Sse) {
+                op->type = OP_XMM;
+                op->bytes = 16;
+                op->addr.xmm = reg;
+                read_sse_reg(ctxt, &op->vec_val, reg);
+                return;
+        }
+
         op->type = OP_REG;
         if ((c->d & ByteOp) && !inhibit_bytereg) {
                 op->addr.reg = decode_register(reg, c->regs, highbyte_regs);
@@ -680,6 +751,13 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
                 op->bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
                 op->addr.reg = decode_register(c->modrm_rm,
                                                c->regs, c->d & ByteOp);
+                if (c->d & Sse) {
+                        op->type = OP_XMM;
+                        op->bytes = 16;
+                        op->addr.xmm = c->modrm_rm;
+                        read_sse_reg(ctxt, &op->vec_val, c->modrm_rm);
+                        return rc;
+                }
                 fetch_register_operand(op);
                 return rc;
         }
@@ -1107,6 +1185,9 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
                 if (rc != X86EMUL_CONTINUE)
                         return rc;
                 break;
+        case OP_XMM:
+                write_sse_reg(ctxt, &c->dst.vec_val, c->dst.addr.xmm);
+                break;
         case OP_NONE:
                 /* no writeback */
                 break;
@@ -2785,6 +2866,9 @@ done_prefixes:
                         c->op_bytes = 4;
         }
 
+        if (c->d & Sse)
+                c->op_bytes = 16;
+
         /* ModRM and SIB bytes. */
         if (c->d & ModRM) {
                 rc = decode_modrm(ctxt, ops, &memop);
@@ -2814,7 +2898,7 @@ done_prefixes:
         case SrcNone:
                 break;
         case SrcReg:
-                decode_register_operand(&c->src, c, 0);
+                decode_register_operand(ctxt, &c->src, c, 0);
                 break;
         case SrcMem16:
                 memop.bytes = 2;
@@ -2905,7 +2989,7 @@ done_prefixes:
         /* Decode and fetch the destination operand: register or memory. */
         switch (c->d & DstMask) {
         case DstReg:
-                decode_register_operand(&c->dst, c,
+                decode_register_operand(ctxt, &c->dst, c,
                          c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
                 break;
         case DstImmUByte:
@@ -3001,6 +3085,18 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
                 goto done;
         }
 
+        if ((c->d & Sse)
+            && ((ops->get_cr(0, ctxt->vcpu) & X86_CR0_EM)
+                || !(ops->get_cr(4, ctxt->vcpu) & X86_CR4_OSFXSR))) {
+                rc = emulate_ud(ctxt);
+                goto done;
+        }
+
+        if ((c->d & Sse) && (ops->get_cr(0, ctxt->vcpu) & X86_CR0_TS)) {
+                rc = emulate_nm(ctxt);
+                goto done;
+        }
+
         /* Privileged instruction can be executed only in CPL=0 */
         if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {
                 rc = emulate_gp(ctxt, 0);