From 5e7045b010bdb56abbfe5714e8debf03a024c016 Mon Sep 17 00:00:00 2001 From: Zhi Yong Wu Date: Mon, 9 Apr 2012 10:42:13 +0300 Subject: [PATCH 1/4] tools/virtio: fix up vhost/test module build commit ea5d404655ba3b356d0c06d6a3c4f24112124522 broke build for the vhost test module used by tools/virtio. Fix it up. Signed-off-by: Zhi Yong Wu Signed-off-by: Michael S. Tsirkin --- drivers/vhost/test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c index fc9a1d75281f3..3de00d9fae2e6 100644 --- a/drivers/vhost/test.c +++ b/drivers/vhost/test.c @@ -155,7 +155,7 @@ static int vhost_test_release(struct inode *inode, struct file *f) vhost_test_stop(n, &private); vhost_test_flush(n); - vhost_dev_cleanup(&n->dev); + vhost_dev_cleanup(&n->dev, false); /* We do an extra flush before freeing memory, * since jobs can re-queue themselves. */ vhost_test_flush(n); From c0aa3e0916d7e531e69b02e426f7162dfb1c6c0f Mon Sep 17 00:00:00 2001 From: Ren Mingxin Date: Tue, 10 Apr 2012 15:28:05 +0800 Subject: [PATCH 2/4] virtio_blk: helper function to format disk names The current virtio block's naming algorithm just supports 18278 (26^3 + 26^2 + 26) disks. If there are more virtio blocks, there will be disks with the same name. Based on commit 3e1a7ff8a0a7b948f2684930166954f9e8e776fe, add a function "virtblk_name_format()" for virtio block to support mass of disks naming. Notes: - Our naming scheme is ugly. We are stuck with it for virtio but don't use it for any new driver: new drivers should name their devices PREFIX%d where the sequence number can be allocated by ida - sd_format_disk_name has exactly the same logic. Moving it to a central place was deferred over worries that this will make people keep using the legacy naming in new drivers. We kept code idential in case someone wants to deduplicate later. Signed-off-by: Ren Mingxin Acked-by: Asias He Signed-off-by: Michael S. Tsirkin --- drivers/block/virtio_blk.c | 41 +++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c4a60badf252c..303779cb1fa24 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -374,6 +374,34 @@ static int init_vq(struct virtio_blk *vblk) return err; } +/* + * Legacy naming scheme used for virtio devices. We are stuck with it for + * virtio blk but don't ever use it for any new driver. + */ +static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) +{ + const int base = 'z' - 'a' + 1; + char *begin = buf + strlen(prefix); + char *end = buf + buflen; + char *p; + int unit; + + p = end - 1; + *p = '\0'; + unit = base; + do { + if (p == begin) + return -EINVAL; + *--p = 'a' + (index % unit); + index = (index / unit) - 1; + } while (index >= 0); + + memmove(begin, p, end - p); + memcpy(buf, prefix, strlen(prefix)); + + return 0; +} + static int __devinit virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; @@ -442,18 +470,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) q->queuedata = vblk; - if (index < 26) { - sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26); - } else if (index < (26 + 1) * 26) { - sprintf(vblk->disk->disk_name, "vd%c%c", - 'a' + index / 26 - 1, 'a' + index % 26); - } else { - const unsigned int m1 = (index / 26 - 1) / 26 - 1; - const unsigned int m2 = (index / 26 - 1) % 26; - const unsigned int m3 = index % 26; - sprintf(vblk->disk->disk_name, "vd%c%c%c", - 'a' + m1, 'a' + m2, 'a' + m3); - } + virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); vblk->disk->major = major; vblk->disk->first_minor = index_to_minor(index); From 1a87228f5f1d316002c7c161316f5524592be766 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 12 Apr 2012 15:36:34 +1000 Subject: [PATCH 3/4] virtio_balloon: Fix endian bug Although virtio config space fields are usually in guest-native endian, the spec for the virtio balloon device explicitly states that both fields in its config space are little-endian. However, the current virtio_balloon driver does not have a suitable endian swap for the 'num_pages' field, although it does have one for the 'actual' field. This patch corrects the bug, adding sparse annotation while we're at it. Signed-off-by: David Gibson Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_balloon.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 05f0a80818a2b..9e95ca602006a 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -234,11 +234,14 @@ static void virtballoon_changed(struct virtio_device *vdev) static inline s64 towards_target(struct virtio_balloon *vb) { - u32 v; + __le32 v; + s64 target; + vb->vdev->config->get(vb->vdev, offsetof(struct virtio_balloon_config, num_pages), &v, sizeof(v)); - return (s64)v - vb->num_pages; + target = le32_to_cpu(v); + return target - vb->num_pages; } static void update_balloon_size(struct virtio_balloon *vb) From 3ccc9372ed0fab33d20f10be3c1efd5776ff5913 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 12 Apr 2012 16:38:00 +0300 Subject: [PATCH 4/4] virtio_balloon: fix handling of PAGE_SIZE != 4k As reported by David Gibson, current code handles PAGE_SIZE != 4k completely wrong which can lead to guest memory corruption errors: - page_to_balloon_pfn is wrong: e.g. on system with 64K page size it gives the same pfn value for 16 different pages. - we also need to convert back to linux pfns when we free. - for each linux page we need to tell host about multiple balloon pages, but code only adds one pfn to the array. This patch fixes all that, tested with a 64k ppc64 kernel. Reported-by: David Gibson Tested-by: David Gibson Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_balloon.c | 51 ++++++++++++++++++++++++++------- 1 file changed, 41 insertions(+), 10 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 9e95ca602006a..c2d05a8279fd2 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -28,6 +28,13 @@ #include #include +/* + * Balloon device works in 4K page units. So each page is pointed to by + * multiple balloon pages. All memory counters in this driver are in balloon + * page units. + */ +#define VIRTIO_BALLOON_PAGES_PER_PAGE (PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT) + struct virtio_balloon { struct virtio_device *vdev; @@ -42,8 +49,13 @@ struct virtio_balloon /* Waiting for host to ack the pages we released. */ struct completion acked; - /* The pages we've told the Host we're not using. */ + /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + /* + * The pages we've told the Host we're not using. + * Each page on this list adds VIRTIO_BALLOON_PAGES_PER_PAGE + * to num_pages above. + */ struct list_head pages; /* The array of pfns we tell the Host about. */ @@ -66,7 +78,13 @@ static u32 page_to_balloon_pfn(struct page *page) BUILD_BUG_ON(PAGE_SHIFT < VIRTIO_BALLOON_PFN_SHIFT); /* Convert pfn from Linux page size to balloon page size. */ - return pfn >> (PAGE_SHIFT - VIRTIO_BALLOON_PFN_SHIFT); + return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE; +} + +static struct page *balloon_pfn_to_page(u32 pfn) +{ + BUG_ON(pfn % VIRTIO_BALLOON_PAGES_PER_PAGE); + return pfn_to_page(pfn / VIRTIO_BALLOON_PAGES_PER_PAGE); } static void balloon_ack(struct virtqueue *vq) @@ -96,12 +114,23 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq) wait_for_completion(&vb->acked); } +static void set_page_pfns(u32 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; +} + static void fill_balloon(struct virtio_balloon *vb, size_t num) { /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) { + for (vb->num_pfns = 0; vb->num_pfns < num; + vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { struct page *page = alloc_page(GFP_HIGHUSER | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); if (!page) { @@ -113,9 +142,9 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num) msleep(200); break; } - vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page); + set_page_pfns(vb->pfns + vb->num_pfns, page); + vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; totalram_pages--; - vb->num_pages++; list_add(&page->lru, &vb->pages); } @@ -130,8 +159,9 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned int num) { unsigned int i; - for (i = 0; i < num; i++) { - __free_page(pfn_to_page(pfns[i])); + /* Find pfns pointing at start of each page, get pages and free them. */ + for (i = 0; i < num; i += VIRTIO_BALLOON_PAGES_PER_PAGE) { + __free_page(balloon_pfn_to_page(pfns[i])); totalram_pages++; } } @@ -143,11 +173,12 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num) /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) { + for (vb->num_pfns = 0; vb->num_pfns < num; + vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { page = list_first_entry(&vb->pages, struct page, lru); list_del(&page->lru); - vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page); - vb->num_pages--; + set_page_pfns(vb->pfns + vb->num_pfns, page); + vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE; } /*