diff mbox series

[v1,3/4] s390: define UV compatible I/O allocation

Message ID 1601049764-11784-4-git-send-email-pmorel@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: css: pv: css test adaptation for PV | expand

Commit Message

Pierre Morel Sept. 25, 2020, 4:02 p.m. UTC 
To centralize the memory allocation for I/O we define
the alloc/free_io_page() functions which share the I/O
memory with the host in case the guest runs with
protected virtualization.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 lib/s390x/malloc_io.c | 50 +++++++++++++++++++++++++++++++++++++++++++
 lib/s390x/malloc_io.h | 18 ++++++++++++++++
 s390x/Makefile        |  1 +
 3 files changed, 69 insertions(+)
 create mode 100644 lib/s390x/malloc_io.c
 create mode 100644 lib/s390x/malloc_io.h
diff mbox series

Patch

diff --git a/lib/s390x/malloc_io.c b/lib/s390x/malloc_io.c
new file mode 100644
index 0000000..b84a06a
--- /dev/null
+++ b/lib/s390x/malloc_io.c
@@ -0,0 +1,50 @@ 
+/*
+ * I/O page allocation
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ *  Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ *
+ * Using this interface provide host access to the allocated pages in
+ * case the guest is a secure guest.
+ * This is needed for I/O buffers.
+ *
+ */
+#include <libcflat.h>
+#include <alloc_dma_page.h>
+#include <asm/uv.h>
+#include <malloc_io.h>
+#include <asm/facility.h>
+
+void *alloc_io_page(int size)
+{
+	void *p;
+
+	assert(size <= PAGE_SIZE);
+	p = get_dma_page();
+	if (!p) {
+		report(0, "Memory allocation");
+		return NULL;
+	}
+
+	if (!test_facility(158))
+		return p;
+
+	if (!uv_set_shared((unsigned long)p)) {
+		report(0, "Sharing memory");
+		return NULL;
+	}
+
+	return p;
+}
+
+void free_io_page(void *p)
+{
+	if (test_facility(158) && !uv_remove_shared((unsigned long)p))
+		report(0, "Unsharing memory");
+	put_dma_page(p);
+}
diff --git a/lib/s390x/malloc_io.h b/lib/s390x/malloc_io.h
new file mode 100644
index 0000000..c6ed481
--- /dev/null
+++ b/lib/s390x/malloc_io.h
@@ -0,0 +1,18 @@ 
+/*
+ * I/O allocations
+ *
+ * Copyright (c) 2020 IBM Corp
+ *
+ * Authors:
+ *  Pierre Morel <pmorel@linux.ibm.com>
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2.
+ */
+#ifndef _S390X_MALLOC_IO_H_
+#define _S390X_MALLOC_IO_H_
+
+void *alloc_io_page(int size);
+void free_io_page(void *p);
+
+#endif /* _S390X_MALLOC_IO_H_ */
diff --git a/s390x/Makefile b/s390x/Makefile
index 109ef9f..1b1dc9f 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -63,6 +63,7 @@  cflatobjs += lib/s390x/smp.o
 cflatobjs += lib/s390x/vm.o
 cflatobjs += lib/s390x/css_dump.o
 cflatobjs += lib/s390x/css_lib.o
+cflatobjs += lib/s390x/malloc_io.o
 
 OBJDIRS += lib/s390x