[RFC,v6,79/92] kvm: x86: emulate movsd xmm, m64
diff mbox series

Message ID 20190809160047.8319-80-alazar@bitdefender.com
State New
Headers show
Series
  • VM introspection
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Commit Message

Adalbert Lazăr Aug. 9, 2019, 4 p.m. UTC
From: Mihai Donțu <mdontu@bitdefender.com>

This is needed in order to be able to support guest code that uses movsd to
write into pages that are marked for write tracking.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/emulate.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

Comments

Paolo Bonzini Aug. 13, 2019, 9:17 a.m. UTC | #1
On 09/08/19 18:00, Adalbert Lazăr wrote:
> From: Mihai Donțu <mdontu@bitdefender.com>
> 
> This is needed in order to be able to support guest code that uses movsd to
> write into pages that are marked for write tracking.
> 
> Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
> Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
> ---
>  arch/x86/kvm/emulate.c | 32 +++++++++++++++++++++++++++-----
>  1 file changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index 34431cf31f74..9d38f892beea 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -1177,6 +1177,27 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
>  	return X86EMUL_CONTINUE;
>  }
>  
> +static u8 simd_prefix_to_bytes(const struct x86_emulate_ctxt *ctxt,
> +			       int simd_prefix)
> +{
> +	u8 bytes;
> +
> +	switch (ctxt->b) {
> +	case 0x11:
> +		/* movsd xmm, m64 */
> +		/* movups xmm, m128 */
> +		if (simd_prefix == 0xf2) {
> +			bytes = 8;
> +			break;
> +		}
> +		/* fallthrough */
> +	default:
> +		bytes = 16;
> +		break;
> +	}
> +	return bytes;
> +}
> +
>  static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
>  				    struct operand *op)
>  {
> @@ -1187,7 +1208,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
>  
>  	if (ctxt->d & Sse) {
>  		op->type = OP_XMM;
> -		op->bytes = 16;
> +		op->bytes = ctxt->op_bytes;
>  		op->addr.xmm = reg;
>  		read_sse_reg(ctxt, &op->vec_val, reg);
>  		return;
> @@ -1238,7 +1259,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
>  				ctxt->d & ByteOp);
>  		if (ctxt->d & Sse) {
>  			op->type = OP_XMM;
> -			op->bytes = 16;
> +			op->bytes = ctxt->op_bytes;
>  			op->addr.xmm = ctxt->modrm_rm;
>  			read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
>  			return rc;
> @@ -4529,7 +4550,7 @@ static const struct gprefix pfx_0f_2b = {
>  };
>  
>  static const struct gprefix pfx_0f_10_0f_11 = {
> -	I(Unaligned, em_mov), I(Unaligned, em_mov), N, N,
> +	I(Unaligned, em_mov), I(Unaligned, em_mov), I(Unaligned, em_mov), N,
>  };
>  
>  static const struct gprefix pfx_0f_28_0f_29 = {
> @@ -5097,7 +5118,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
>  {
>  	int rc = X86EMUL_CONTINUE;
>  	int mode = ctxt->mode;
> -	int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
> +	int def_op_bytes, def_ad_bytes, goffset, simd_prefix = 0;
>  	bool op_prefix = false;
>  	bool has_seg_override = false;
>  	struct opcode opcode;
> @@ -5320,7 +5341,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
>  			ctxt->op_bytes = 4;
>  
>  		if (ctxt->d & Sse)
> -			ctxt->op_bytes = 16;
> +			ctxt->op_bytes = simd_prefix_to_bytes(ctxt,
> +							      simd_prefix);
>  		else if (ctxt->d & Mmx)
>  			ctxt->op_bytes = 8;
>  	}
> 

Please submit all these emulator patches as a separate series, complete
with testcases for kvm-unit-tests.

Paolo

Patch
diff mbox series

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 34431cf31f74..9d38f892beea 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1177,6 +1177,27 @@  static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
 	return X86EMUL_CONTINUE;
 }
 
+static u8 simd_prefix_to_bytes(const struct x86_emulate_ctxt *ctxt,
+			       int simd_prefix)
+{
+	u8 bytes;
+
+	switch (ctxt->b) {
+	case 0x11:
+		/* movsd xmm, m64 */
+		/* movups xmm, m128 */
+		if (simd_prefix == 0xf2) {
+			bytes = 8;
+			break;
+		}
+		/* fallthrough */
+	default:
+		bytes = 16;
+		break;
+	}
+	return bytes;
+}
+
 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
 				    struct operand *op)
 {
@@ -1187,7 +1208,7 @@  static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
 
 	if (ctxt->d & Sse) {
 		op->type = OP_XMM;
-		op->bytes = 16;
+		op->bytes = ctxt->op_bytes;
 		op->addr.xmm = reg;
 		read_sse_reg(ctxt, &op->vec_val, reg);
 		return;
@@ -1238,7 +1259,7 @@  static int decode_modrm(struct x86_emulate_ctxt *ctxt,
 				ctxt->d & ByteOp);
 		if (ctxt->d & Sse) {
 			op->type = OP_XMM;
-			op->bytes = 16;
+			op->bytes = ctxt->op_bytes;
 			op->addr.xmm = ctxt->modrm_rm;
 			read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
 			return rc;
@@ -4529,7 +4550,7 @@  static const struct gprefix pfx_0f_2b = {
 };
 
 static const struct gprefix pfx_0f_10_0f_11 = {
-	I(Unaligned, em_mov), I(Unaligned, em_mov), N, N,
+	I(Unaligned, em_mov), I(Unaligned, em_mov), I(Unaligned, em_mov), N,
 };
 
 static const struct gprefix pfx_0f_28_0f_29 = {
@@ -5097,7 +5118,7 @@  int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
 {
 	int rc = X86EMUL_CONTINUE;
 	int mode = ctxt->mode;
-	int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
+	int def_op_bytes, def_ad_bytes, goffset, simd_prefix = 0;
 	bool op_prefix = false;
 	bool has_seg_override = false;
 	struct opcode opcode;
@@ -5320,7 +5341,8 @@  int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
 			ctxt->op_bytes = 4;
 
 		if (ctxt->d & Sse)
-			ctxt->op_bytes = 16;
+			ctxt->op_bytes = simd_prefix_to_bytes(ctxt,
+							      simd_prefix);
 		else if (ctxt->d & Mmx)
 			ctxt->op_bytes = 8;
 	}