Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "Looks like a quiet cycle for virtio.  There's a new inorder option for
  the ringtest tool, and a bugfix for balloon for ppc platforms when
  using virtio 1 mode"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  ringtest: pass buf != NULL
  virtio_balloon: fix PFN format for virtio-1
  virtio: add inorder option

4 files changed, 55 insertions, 3 deletions

diff --git a/tools/virtio/ringtest/Makefile b/tools/virtio/ringtest/Makefile
index feaa64ac4630..6ba745529833 100644
--- a/tools/virtio/ringtest/Makefile
+++ b/tools/virtio/ringtest/Makefile
@@ -1,6 +1,6 @@
 all:
 
-all: ring virtio_ring_0_9 virtio_ring_poll
+all: ring virtio_ring_0_9 virtio_ring_poll virtio_ring_inorder
 
 CFLAGS += -Wall
 CFLAGS += -pthread -O2 -ggdb
@@ -10,13 +10,16 @@ main.o: main.c main.h
 ring.o: ring.c main.h
 virtio_ring_0_9.o: virtio_ring_0_9.c main.h
 virtio_ring_poll.o: virtio_ring_poll.c virtio_ring_0_9.c main.h
+virtio_ring_inorder.o: virtio_ring_inorder.c virtio_ring_0_9.c main.h
 ring: ring.o main.o
 virtio_ring_0_9: virtio_ring_0_9.o main.o
 virtio_ring_poll: virtio_ring_poll.o main.o
+virtio_ring_inorder: virtio_ring_inorder.o main.o
 clean:
         -rm main.o
         -rm ring.o ring
         -rm virtio_ring_0_9.o virtio_ring_0_9
         -rm virtio_ring_poll.o virtio_ring_poll
+        -rm virtio_ring_inorder.o virtio_ring_inorder
 
 .PHONY: all clean
diff --git a/tools/virtio/ringtest/main.c b/tools/virtio/ringtest/main.c
index 3a5ff438bd62..147abb452a6c 100644
--- a/tools/virtio/ringtest/main.c
+++ b/tools/virtio/ringtest/main.c
@@ -115,7 +115,7 @@ static void run_guest(void)
                 do {
                         if (started < bufs &&
                             started - completed < max_outstanding) {
-                                r = add_inbuf(0, NULL, "Hello, world!");
+                                r = add_inbuf(0, "Buffer\n", "Hello, world!");
                                 if (__builtin_expect(r == 0, true)) {
                                         ++started;
                                         if (!--tokick) {
diff --git a/tools/virtio/ringtest/virtio_ring_0_9.c b/tools/virtio/ringtest/virtio_ring_0_9.c
index 47c9a1a18d36..761866212aac 100644
--- a/tools/virtio/ringtest/virtio_ring_0_9.c
+++ b/tools/virtio/ringtest/virtio_ring_0_9.c
@@ -26,6 +26,14 @@ struct vring ring;
  * high bits of ring id ^ 0x8000).
  */
 /* #ifdef RING_POLL */
+/* enabling the below activates experimental in-order code
+ * (which skips ring updates and reads and writes len in descriptor).
+ */
+/* #ifdef INORDER */
+
+#if defined(RING_POLL) && defined(INORDER)
+#error "RING_POLL and INORDER are mutually exclusive"
+#endif
 
 /* how much padding is needed to avoid false cache sharing */
 #define HOST_GUEST_PADDING 0x80
@@ -35,7 +43,11 @@ struct guest {
         unsigned short last_used_idx;
         unsigned short num_free;
         unsigned short kicked_avail_idx;
+#ifndef INORDER
         unsigned short free_head;
+#else
+        unsigned short reserved_free_head;
+#endif
         unsigned char reserved[HOST_GUEST_PADDING - 10];
 } guest;
 
@@ -66,8 +78,10 @@ void alloc_ring(void)
         guest.avail_idx = 0;
         guest.kicked_avail_idx = -1;
         guest.last_used_idx = 0;
+#ifndef INORDER
         /* Put everything in free lists. */
         guest.free_head = 0;
+#endif
         for (i = 0; i < ring_size - 1; i++)
                 ring.desc[i].next = i + 1;
         host.used_idx = 0;
@@ -84,13 +98,20 @@ void alloc_ring(void)
 /* guest side */
 int add_inbuf(unsigned len, void *buf, void *datap)
 {
-        unsigned head, avail;
+        unsigned head;
+#ifndef INORDER
+        unsigned avail;
+#endif
         struct vring_desc *desc;
 
         if (!guest.num_free)
                 return -1;
 
+#ifdef INORDER
+        head = (ring_size - 1) & (guest.avail_idx++);
+#else
         head = guest.free_head;
+#endif
         guest.num_free--;
 
         desc = ring.desc;
@@ -102,7 +123,9 @@ int add_inbuf(unsigned len, void *buf, void *datap)
          * descriptors.
          */
         desc[head].flags &= ~VRING_DESC_F_NEXT;
+#ifndef INORDER
         guest.free_head = desc[head].next;
+#endif
 
         data[head].data = datap;
 
@@ -113,8 +136,12 @@ int add_inbuf(unsigned len, void *buf, void *datap)
         ring.avail->ring[avail & (ring_size - 1)] =
                 (head | (avail & ~(ring_size - 1))) ^ 0x8000;
 #else
+#ifndef INORDER
+        /* Barrier A (for pairing) */
+        smp_release();
         avail = (ring_size - 1) & (guest.avail_idx++);
         ring.avail->ring[avail] = head;
+#endif
         /* Barrier A (for pairing) */
         smp_release();
 #endif
@@ -141,15 +168,27 @@ void *get_buf(unsigned *lenp, void **bufp)
                 return NULL;
         /* Barrier B (for pairing) */
         smp_acquire();
+#ifdef INORDER
+        head = (ring_size - 1) & guest.last_used_idx;
+        index = head;
+#else
         head = (ring_size - 1) & guest.last_used_idx;
         index = ring.used->ring[head].id;
 #endif
+
+#endif
+#ifdef INORDER
+        *lenp = ring.desc[index].len;
+#else
         *lenp = ring.used->ring[head].len;
+#endif
         datap = data[index].data;
         *bufp = (void*)(unsigned long)ring.desc[index].addr;
         data[index].data = NULL;
+#ifndef INORDER
         ring.desc[index].next = guest.free_head;
         guest.free_head = index;
+#endif
         guest.num_free++;
         guest.last_used_idx++;
         return datap;
@@ -283,16 +322,24 @@ bool use_buf(unsigned *lenp, void **bufp)
         smp_acquire();
 
         used_idx &= ring_size - 1;
+#ifdef INORDER
+        head = used_idx;
+#else
         head = ring.avail->ring[used_idx];
+#endif
         desc = &ring.desc[head];
 #endif
 
         *lenp = desc->len;
         *bufp = (void *)(unsigned long)desc->addr;
 
+#ifdef INORDER
+        desc->len = desc->len - 1;
+#else
         /* now update used ring */
         ring.used->ring[used_idx].id = head;
         ring.used->ring[used_idx].len = desc->len - 1;
+#endif
         /* Barrier B (for pairing) */
         smp_release();
         host.used_idx++;
diff --git a/tools/virtio/ringtest/virtio_ring_inorder.c b/tools/virtio/ringtest/virtio_ring_inorder.c
new file mode 100644
index 000000000000..2438ca58a2ad
--- /dev/null
+++ b/tools/virtio/ringtest/virtio_ring_inorder.c
@@ -0,0 +1,2 @@
+#define INORDER 1
+#include "virtio_ring_0_9.c"