From c402803b725543f690abd96175df12dbee224c58 Mon Sep 17 00:00:00 2001

Message-Id: <c402803b725543f690abd96175df12dbee224c58@dist-git>

From: Bing Niu <bing.niu@intel.com>

Date: Mon, 15 Apr 2019 17:32:47 +0200

Subject: [PATCH] util: Add MBA capability information query to resctrl

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

Introducing virResctrlInfoMemBW for the information memory bandwidth

allocation information.

Signed-off-by: Bing Niu <bing.niu@intel.com>

Reviewed-by: John Ferlan <jferlan@redhat.com>

(cherry picked from commit a24da791b8d489600807158c45451012ae1a8270)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1468650

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

Message-Id: <5bf94bb7ee189420dfd99b19ff423c9650b1e637.1555342313.git.phrdina@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/util/virresctrl.c | 84 +++++++++++++++++++++++++++++++++++++++++++

 1 file changed, 84 insertions(+)

diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c

index a38c9261b6..b12a05cb0f 100644

--- a/src/util/virresctrl.c

+++ b/src/util/virresctrl.c

@@ -80,6 +80,9 @@ typedef virResctrlInfoPerType *virResctrlInfoPerTypePtr;

 typedef struct _virResctrlInfoPerLevel virResctrlInfoPerLevel;

 typedef virResctrlInfoPerLevel *virResctrlInfoPerLevelPtr;

+typedef struct _virResctrlInfoMemBW virResctrlInfoMemBW;

+typedef virResctrlInfoMemBW *virResctrlInfoMemBWPtr;

+

 typedef struct _virResctrlAllocPerType virResctrlAllocPerType;

 typedef virResctrlAllocPerType *virResctrlAllocPerTypePtr;

@@ -116,11 +119,30 @@ struct _virResctrlInfoPerLevel {

     virResctrlInfoPerTypePtr *types;

 };

+/* Information about memory bandwidth allocation */

+struct _virResctrlInfoMemBW {

+    /* minimum memory bandwidth allowed */

+    unsigned int min_bandwidth;

+    /* bandwidth granularity */

+    unsigned int bandwidth_granularity;

+    /* Maximum number of simultaneous allocations */

+    unsigned int max_allocation;

+    /* level number of last level cache */

+    unsigned int last_level_cache;

+    /* max id of last level cache, this is used to track

+     * how many last level cache available in host system,

+     * the number of memory bandwidth allocation controller

+     * is identical with last level cache. */

+    unsigned int max_id;

+};

+

 struct _virResctrlInfo {

     virObject parent;

     virResctrlInfoPerLevelPtr *levels;

     size_t nlevels;

+

+    virResctrlInfoMemBWPtr membw_info;

 };

@@ -146,6 +168,7 @@ virResctrlInfoDispose(void *obj)

         VIR_FREE(level);

     }

+    VIR_FREE(resctrl->membw_info);

     VIR_FREE(resctrl->levels);

 }

@@ -442,6 +465,60 @@ virResctrlGetCacheInfo(virResctrlInfoPtr resctrl,

 }

+static int

+virResctrlGetMemoryBandwidthInfo(virResctrlInfoPtr resctrl)

+{

+    int ret = -1;

+    int rv = -1;

+    virResctrlInfoMemBWPtr i_membw = NULL;

+

+    /* query memory bandwidth allocation info */

+    if (VIR_ALLOC(i_membw) < 0)

+        goto cleanup;

+    rv = virFileReadValueUint(&i_membw->bandwidth_granularity,

+                              SYSFS_RESCTRL_PATH "/info/MB/bandwidth_gran");

+    if (rv == -2) {

+        /* The file doesn't exist, so it's unusable for us,

+         * probably memory bandwidth allocation unsupported */

+        VIR_INFO("The path '" SYSFS_RESCTRL_PATH "/info/MB/bandwidth_gran'"

+                 "does not exist");

+        ret = 0;

+        goto cleanup;

+    } else if (rv < 0) {

+        /* Other failures are fatal, so just quit */

+        goto cleanup;

+    }

+

+    rv = virFileReadValueUint(&i_membw->min_bandwidth,

+                              SYSFS_RESCTRL_PATH "/info/MB/min_bandwidth");

+    if (rv == -2) {

+        /* If the previous file exists, so should this one. Hence -2 is

+         * fatal in this case (errors out in next condition) - the kernel

+         * interface might've changed too much or something else is wrong. */

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("Cannot get min bandwidth from resctrl memory info"));

+    }

+    if (rv < 0)

+        goto cleanup;

+

+    rv = virFileReadValueUint(&i_membw->max_allocation,

+                              SYSFS_RESCTRL_PATH "/info/MB/num_closids");

+    if (rv == -2) {

+         /* Similar reasoning to min_bandwidth above. */

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("Cannot get max allocation from resctrl memory info"));

+    }

+    if (rv < 0)

+        goto cleanup;

+

+    VIR_STEAL_PTR(resctrl->membw_info, i_membw);

+    ret = 0;

+ cleanup:

+    VIR_FREE(i_membw);

+    return ret;

+}

+

+

 static int

 virResctrlGetInfo(virResctrlInfoPtr resctrl)

 {

@@ -452,6 +529,10 @@ virResctrlGetInfo(virResctrlInfoPtr resctrl)

     if (ret <= 0)

         goto cleanup;

+    ret = virResctrlGetMemoryBandwidthInfo(resctrl);

+    if (ret < 0)

+        goto cleanup;

+

     ret = virResctrlGetCacheInfo(resctrl, dirp);

     if (ret < 0)

         goto cleanup;

@@ -493,6 +574,9 @@ virResctrlInfoIsEmpty(virResctrlInfoPtr resctrl)

     if (!resctrl)

         return true;

+    if (resctrl->membw_info)

+        return false;

+

     for (i = 0; i < resctrl->nlevels; i++) {

         virResctrlInfoPerLevelPtr i_level = resctrl->levels[i];

-- 

2.21.0