[Qemu-devel] [PATCH V2 1/1] virtio-balloon: fix internal stat name array to match Linux kernel

[Thomas Tai]

The Linux kernel commit b40000325044 ("virtio_balloon: add array
of stat names") defines an array of stat name strings for consumers
of the virtio interface to use via the virtio_balloon.h header
file, rather than requiring each consumer to define its own. But at
present, the stat names defined in this array by the Linux kernel
do not match up with those defined internally by QEMU.

This patch fixes this inconsistency by importing the header file
from linux and use the new macro to construct the balloon_stat_names
array.

Signed-off-by: Jonathan Helman <address@hidden>
Signed-off-by: Thomas Tai <address@hidden>
Cc: Rob Gardner <address@hidden>
---
 docs/virtio-balloon-stats.txt                   |  2 ++
 hw/virtio/virtio-balloon.c                      | 13 ++-----------
 include/standard-headers/linux/virtio_balloon.h | 19 ++++++++++++++++++-
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/docs/virtio-balloon-stats.txt b/docs/virtio-balloon-stats.txt
index 7a66d25..7c69fdb 100644
--- a/docs/virtio-balloon-stats.txt
+++ b/docs/virtio-balloon-stats.txt
@@ -34,6 +34,8 @@ which will return a dictionary containing:
       - stat-total-memory
       - stat-available-memory
       - stat-disk-caches
+      - stat-hugetlb-allocations
+      - stat-hugetlb-failures
 
   o A key named last-update, which contains the last stats update
     timestamp in seconds. Since this timestamp is generated by the host,
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index f456cea..646f2e0 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -43,17 +43,8 @@ static void balloon_page(void *addr, int deflate)
     }
 }
 
-static const char *balloon_stat_names[] = {
-   [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
-   [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
-   [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
-   [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
-   [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
-   [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
-   [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory",
-   [VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches",
-   [VIRTIO_BALLOON_S_NR] = NULL
-};
+static const char *balloon_stat_names[VIRTIO_BALLOON_S_NR] = \
+       VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("stat-");
 
 /*
  * reset_stats - Mark all items in the stats array as unset
diff --git a/include/standard-headers/linux/virtio_balloon.h 
b/include/standard-headers/linux/virtio_balloon.h
index 7b0a41b..4dbb7dc 100644
--- a/include/standard-headers/linux/virtio_balloon.h
+++ b/include/standard-headers/linux/virtio_balloon.h
@@ -53,7 +53,24 @@ struct virtio_balloon_config {
 #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
 #define VIRTIO_BALLOON_S_AVAIL    6   /* Available memory as in /proc */
 #define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
-#define VIRTIO_BALLOON_S_NR       8
+#define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Hugetlb page allocations */
+#define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation failures 
*/
+#define VIRTIO_BALLOON_S_NR       10
+
+#define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
+       VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
+       VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \
+       VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \
+       VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \
+       VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \
+       VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \
+       VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \
+       VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \
+       VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
+       VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures" \
+}
+
+#define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("")
 
 /*
  * Memory statistics structure.
-- 
1.8.3.1