Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/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

drivers/virtio/virtio_balloon.c

@@ -75,7 +75,7 @@ struct virtio_balloon {
 
 	/* The array of pfns we tell the Host about. */
 	unsigned int num_pfns;
-	u32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX];
+	__virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX];
 
 	/* Memory statistics */
 	struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR];
@@ -127,14 +127,16 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
 
 }
 
-static void set_page_pfns(u32 pfns[], struct page *page)
+static void set_page_pfns(struct virtio_balloon *vb,
+			  __virtio32 pfns[], struct page *page)
 {
 	unsigned int i;
 
 	/* Set balloon pfns pointing at this page.
 	 * Note that the first pfn points at start of the page. */
 	for (i = 0; i < VIRTIO_BALLOON_PAGES_PER_PAGE; i++)
-		pfns[i] = page_to_balloon_pfn(page) + i;
+		pfns[i] = cpu_to_virtio32(vb->vdev,
+					  page_to_balloon_pfn(page) + i);
 }
 
 static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
@@ -158,7 +160,7 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
 			msleep(200);
 			break;
 		}
-		set_page_pfns(vb->pfns + vb->num_pfns, page);
+		set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
 		vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE;
 		if (!virtio_has_feature(vb->vdev,
 					VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
@@ -177,10 +179,12 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
 static void release_pages_balloon(struct virtio_balloon *vb)
 {
 	unsigned int i;
+	struct page *page;
 
 	/* Find pfns pointing at start of each page, get pages and free them. */
 	for (i = 0; i < vb->num_pfns; i += VIRTIO_BALLOON_PAGES_PER_PAGE) {
-		struct page *page = balloon_pfn_to_page(vb->pfns[i]);
+		page = balloon_pfn_to_page(virtio32_to_cpu(vb->vdev,
+							   vb->pfns[i]));
 		if (!virtio_has_feature(vb->vdev,
 					VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
 			adjust_managed_page_count(page, 1);
@@ -203,7 +207,7 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
 		page = balloon_page_dequeue(vb_dev_info);
 		if (!page)
 			break;
-		set_page_pfns(vb->pfns + vb->num_pfns, page);
+		set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
 		vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
 	}
 
@@ -471,13 +475,13 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
 	__count_vm_event(BALLOON_MIGRATE);
 	spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags);
 	vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
-	set_page_pfns(vb->pfns, newpage);
+	set_page_pfns(vb, vb->pfns, newpage);
 	tell_host(vb, vb->inflate_vq);
 
 	/* balloon's page migration 2nd step -- deflate "page" */
 	balloon_page_delete(page);
 	vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
-	set_page_pfns(vb->pfns, page);
+	set_page_pfns(vb, vb->pfns, page);
 	tell_host(vb, vb->deflate_vq);
 
 	mutex_unlock(&vb->balloon_lock);

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

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) {

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++;

tools/virtio/ringtest/virtio_ring_inorder.c

@@ -0,0 +1,2 @@
+#define INORDER 1
+#include "virtio_ring_0_9.c"