diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index bab7891d43f5..85318d7446c7 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -5,6 +5,7 @@
 
 #ifndef _ASM_POWERPC_VAS_H
 #define _ASM_POWERPC_VAS_H
+#include <uapi/asm/vas-api.h>
 
 struct vas_window;
 
@@ -48,6 +49,16 @@ enum vas_cop_type {
 	VAS_COP_TYPE_MAX,
 };
 
+/*
+ * User space window operations used for powernv and powerVM
+ */
+struct vas_user_win_ops {
+	struct vas_window * (*open_win)(struct vas_tx_win_open_attr *,
+				enum vas_cop_type);
+	u64 (*paste_addr)(struct vas_window *);
+	int (*close_win)(struct vas_window *);
+};
+
 /*
  * Receive window attributes specified by the (in-kernel) owner of window.
  */
@@ -175,7 +186,8 @@ void vas_unregister_api_powernv(void);
  * used for others in future.
  */
 int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
-				const char *name);
+			    const char *name,
+			    const struct vas_user_win_ops *vops);
 void vas_unregister_coproc_api(void);
 
 #endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c
index 72c126d87216..7cfc4b435ae8 100644
--- a/arch/powerpc/platforms/book3s/vas-api.c
+++ b/arch/powerpc/platforms/book3s/vas-api.c
@@ -42,6 +42,7 @@ static struct coproc_dev {
 	dev_t devt;
 	struct class *class;
 	enum vas_cop_type cop_type;
+	const struct vas_user_win_ops *vops;
 } coproc_device;
 
 struct coproc_instance {
@@ -72,11 +73,10 @@ static int coproc_open(struct inode *inode, struct file *fp)
 static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 {
 	void __user *uptr = (void __user *)arg;
-	struct vas_tx_win_attr txattr = {};
 	struct vas_tx_win_open_attr uattr;
 	struct coproc_instance *cp_inst;
 	struct vas_window *txwin;
-	int rc, vasid;
+	int rc;
 
 	cp_inst = fp->private_data;
 
@@ -93,27 +93,20 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 	}
 
 	if (uattr.version != 1) {
-		pr_err("Invalid version\n");
+		pr_err("Invalid window open API version\n");
 		return -EINVAL;
 	}
 
-	vasid = uattr.vas_id;
-
-	vas_init_tx_win_attr(&txattr, cp_inst->coproc->cop_type);
-
-	txattr.lpid = mfspr(SPRN_LPID);
-	txattr.pidr = mfspr(SPRN_PID);
-	txattr.user_win = true;
-	txattr.rsvd_txbuf_count = false;
-	txattr.pswid = false;
-
-	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
-				mfspr(SPRN_PID));
+	if (!cp_inst->coproc->vops && !cp_inst->coproc->vops->open_win) {
+		pr_err("VAS API is not registered\n");
+		return -EACCES;
+	}
 
-	txwin = vas_tx_win_open(vasid, cp_inst->coproc->cop_type, &txattr);
+	txwin = cp_inst->coproc->vops->open_win(&uattr,
+						cp_inst->coproc->cop_type);
 	if (IS_ERR(txwin)) {
-		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
-					PTR_ERR(txwin));
+		pr_err("%s() VAS window open failed, %ld\n", __func__,
+				PTR_ERR(txwin));
 		return PTR_ERR(txwin);
 	}
 
@@ -125,9 +118,15 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 static int coproc_release(struct inode *inode, struct file *fp)
 {
 	struct coproc_instance *cp_inst = fp->private_data;
+	int rc;
 
 	if (cp_inst->txwin) {
-		vas_win_close(cp_inst->txwin);
+		if (cp_inst->coproc->vops &&
+			cp_inst->coproc->vops->close_win) {
+			rc = cp_inst->coproc->vops->close_win(cp_inst->txwin);
+			if (rc)
+				return rc;
+		}
 		cp_inst->txwin = NULL;
 	}
 
@@ -168,7 +167,17 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
 		return -EINVAL;
 	}
 
-	vas_win_paste_addr(txwin, &paste_addr, NULL);
+	if (!cp_inst->coproc->vops && !cp_inst->coproc->vops->paste_addr) {
+		pr_err("%s(): VAS API is not registered\n", __func__);
+		return -EACCES;
+	}
+
+	paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
+	if (!paste_addr) {
+		pr_err("%s(): Window paste address failed\n", __func__);
+		return -EINVAL;
+	}
+
 	pfn = paste_addr >> PAGE_SHIFT;
 
 	/* flags, page_prot from cxl_mmap(), except we want cachable */
@@ -208,7 +217,8 @@ static struct file_operations coproc_fops = {
  * extended to other coprocessor types later.
  */
 int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
-				const char *name)
+			    const char *name,
+			    const struct vas_user_win_ops *vops)
 {
 	int rc = -EINVAL;
 	dev_t devno;
@@ -230,6 +240,7 @@ int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
 	}
 	coproc_device.class->devnode = coproc_devnode;
 	coproc_device.cop_type = cop_type;
+	coproc_device.vops = vops;
 
 	coproc_fops.owner = mod;
 	cdev_init(&coproc_device.cdev, &coproc_fops);
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 41712b4b268e..5162e95c4090 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -16,6 +16,7 @@
 #include <linux/mmu_context.h>
 #include <asm/switch_to.h>
 #include <asm/ppc-opcode.h>
+#include <asm/vas.h>
 #include "vas.h"
 #include "copy-paste.h"
 
@@ -1443,6 +1444,48 @@ struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
 	return window;
 }
 
+static struct vas_window *vas_user_win_open(struct vas_tx_win_open_attr *uattr,
+				enum vas_cop_type cop_type)
+{
+	struct vas_tx_win_attr txattr = {};
+
+	vas_init_tx_win_attr(&txattr, cop_type);
+
+	txattr.lpid = mfspr(SPRN_LPID);
+	txattr.pidr = mfspr(SPRN_PID);
+	txattr.user_win = true;
+	txattr.rsvd_txbuf_count = false;
+	txattr.pswid = false;
+
+	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
+				mfspr(SPRN_PID));
+
+	return vas_tx_win_open(uattr->vas_id, cop_type, &txattr);
+}
+
+static u64 vas_user_win_paste_addr(struct vas_window *win)
+{
+	u64 paste_addr;
+
+	vas_win_paste_addr(win, &paste_addr, NULL);
+
+	return paste_addr;
+}
+
+static int vas_user_win_close(struct vas_window *txwin)
+{
+
+	vas_win_close(txwin);
+
+	return 0;
+}
+
+static const struct vas_user_win_ops vops =  {
+	.open_win	=	vas_user_win_open,
+	.paste_addr	=	vas_user_win_paste_addr,
+	.close_win	=	vas_user_win_close,
+};
+
 /*
  * Supporting only nx-gzip coprocessor type now, but this API code
  * extended to other coprocessor types later.
@@ -1451,7 +1494,7 @@ int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
 			     const char *name)
 {
 
-	return vas_register_coproc_api(mod, cop_type, name);
+	return vas_register_coproc_api(mod, cop_type, name, &vops);
 }
 EXPORT_SYMBOL_GPL(vas_register_api_powernv);
 
