When communicating with the host we need to share part of
the memory.
Let's implement the ultravisor calls for this.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Suggested-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
---
lib/s390x/asm/uv.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index 4c2fc48..19019e4 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -71,4 +71,37 @@ static inline int uv_call(unsigned long r1, unsigned long r2)
return cc;
}
+static inline int share(unsigned long addr, u16 cmd)
+{
+ struct uv_cb_share uvcb = {
+ .header.cmd = cmd,
+ .header.len = sizeof(uvcb),
+ .paddr = addr
+ };
+
+ uv_call(0, (u64)&uvcb);
+ return uvcb.header.rc;
+}
+
+/*
+ * Guest 2 request to the Ultravisor to make a page shared with the
+ * hypervisor for IO.
+ *
+ * @addr: Real or absolute address of the page to be shared
+ */
+static inline int uv_set_shared(unsigned long addr)
+{
+ return share(addr, UVC_CMD_SET_SHARED_ACCESS);
+}
+
+/*
+ * Guest 2 request to the Ultravisor to make a page unshared.
+ *
+ * @addr: Real or absolute address of the page to be unshared
+ */
+static inline int uv_remove_shared(unsigned long addr)
+{
+ return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
+}
+
#endif
--
2.25.1
