instr_emul: remove vm_restart_instruction and use VCPU_RETAIN_RIP

there is no need to use wrap function vm_restart_instruction, we
can use VCPU_RETAIN_RIP directly

Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>

Author: JasonChenCJ

hypervisor/arch/x86/guest/instr_emul.c

@@ -759,7 +759,7 @@ emulate_movs(struct vcpu *vcpu, __unused uint64_t gpa, struct vie *vie,
 		 * Repeat the instruction if the count register is not zero.
 		 */
 		if ((rcx & vie_size2mask(vie->addrsize)) != 0)
-			vm_restart_instruction(vcpu);
+			VCPU_RETAIN_RIP(vcpu);
 	}
 done:
 	ASSERT(error == 0, "%s: unexpected error %d", __func__, error);
@@ -823,7 +823,7 @@ emulate_stos(struct vcpu *vcpu, uint64_t gpa, struct vie *vie,
 		 * Repeat the instruction if the count register is not zero.
 		 */
 		if ((rcx & vie_size2mask(vie->addrsize)) != 0)
-			vm_restart_instruction(vcpu);
+			VCPU_RETAIN_RIP(vcpu);
 	}
 
 	return 0;

hypervisor/arch/x86/guest/instr_emul_wrapper.c

@@ -115,15 +115,6 @@ int vm_get_seg_desc(struct vcpu *vcpu, int seg, struct seg_desc *desc)
 	return 0;
 }
 
-int vm_restart_instruction(struct vcpu *vcpu)
-{
-	if (!vcpu)
-		return -EINVAL;
-
-	VCPU_RETAIN_RIP(vcpu);
-	return 0;
-}
-
 static bool is_descriptor_table(int reg)
 {
 	switch (reg) {

hypervisor/arch/x86/guest/instr_emul_wrapper.h

@@ -193,5 +193,4 @@ int vm_get_seg_desc(struct vcpu *vcpu, int reg,
 		struct seg_desc *ret_desc);
 int vm_set_seg_desc(struct vcpu *vcpu, int reg,
 		struct seg_desc *desc);
-int vm_restart_instruction(struct vcpu *vcpu);
 #endif