KVM: nSVM: Set correct port for IOIO interception evaluation

Obtaining the port number from DX is bogus as a) there are immediate
port accesses and b) user space may have changed the register content
while processing the PIO access. Forward the correct value from the
instruction emulator instead.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_emulate.h

@@ -37,6 +37,7 @@ struct x86_instruction_info {
 	u8  modrm_reg;          /* index of register used               */
 	u8  modrm_rm;		/* rm part of modrm			*/
 	u64 src_val;            /* value of source operand              */
+	u64 dst_val;            /* value of destination operand         */
 	u8  src_bytes;          /* size of source operand               */
 	u8  dst_bytes;          /* size of destination operand          */
 	u8  ad_bytes;           /* size of src/dst address              */

arch/x86/kvm/emulate.c

@@ -426,6 +426,7 @@ static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
 		.modrm_reg  = ctxt->modrm_reg,
 		.modrm_rm   = ctxt->modrm_rm,
 		.src_val    = ctxt->src.val64,
+		.dst_val    = ctxt->dst.val64,
 		.src_bytes  = ctxt->src.bytes,
 		.dst_bytes  = ctxt->dst.bytes,
 		.ad_bytes   = ctxt->ad_bytes,

arch/x86/kvm/svm.c

@@ -4256,13 +4256,13 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
 		u64 exit_info;
 		u32 bytes;
 
-		exit_info = (vcpu->arch.regs[VCPU_REGS_RDX] & 0xffff) << 16;
-
 		if (info->intercept == x86_intercept_in ||
 		    info->intercept == x86_intercept_ins) {
-			exit_info |= SVM_IOIO_TYPE_MASK;
+			exit_info = ((info->src_val & 0xffff) << 16) |
+				SVM_IOIO_TYPE_MASK;
 			bytes = info->dst_bytes;
 		} else {
+			exit_info = (info->dst_val & 0xffff) << 16;
 			bytes = info->src_bytes;
 		}