On 1/20/21 11:48 AM, Thomas Huth wrote:
On 19/01/2021 20.52, Pierre Morel wrote:
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>
Acked-by: Cornelia Huck <cohuck@xxxxxxxxxx>
---
lib/s390x/asm/uv.h | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index 4c2fc48..1242336 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -71,4 +71,42 @@ 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
+ };
+ int cc;
+
+ cc = uv_call(0, (u64)&uvcb);
+ if (!cc && (uvcb.header.rc == 0x0001))
You can drop the innermost parentheses.
OK.
+ return 0;
+
+ report_info("cc %d response code: %04x", cc, uvcb.header.rc);
+ return -1;
+}
+
+/*
+ * 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
When is it real, and when is it absolute?
It only depends on the prefixing, the call can use both.
+ */
+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
dito
+ */
+static inline int uv_remove_shared(unsigned long addr)
+{
+ return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
+}
+
#endif
Apart from the nits:
Acked-by: Thomas Huth <thuth@xxxxxxxxxx>
Thanks thomas for reviewing.
Regards,
Pierre
--
Pierre Morel
IBM Lab Boeblingen
