[libvirt] [PATCH v3 1/4] virutil: Introduce virHostHasIOMMU

[Filip Alac]

---
 src/conf/capabilities.c |  6 ++++++
 src/conf/capabilities.h |  3 +++
 src/util/virutil.c      | 28 ++++++++++++++++++++++++++++
 src/util/virutil.h      |  2 ++
 4 files changed, 39 insertions(+)

diff --git a/src/conf/capabilities.c b/src/conf/capabilities.c
index dd2fc77f91..ba19d5db8c 100644
--- a/src/conf/capabilities.c
+++ b/src/conf/capabilities.c
@@ -1743,3 +1743,9 @@ virCapabilitiesInitCaches(virCapsPtr caps)
     virBitmapFree(cpus);
     return ret;
 }
+
+void
+virCapabilitiesHostInitIOMMU(virCapsPtr caps)
+{
+    caps->host.iommu = virHostHasIOMMU();
+}
diff --git a/src/conf/capabilities.h b/src/conf/capabilities.h
index f0a06a24df..fe1b9ea455 100644
--- a/src/conf/capabilities.h
+++ b/src/conf/capabilities.h
@@ -183,6 +183,7 @@ struct _virCapsHost {
     int nPagesSize;             /* size of pagesSize array */
     unsigned int *pagesSize;    /* page sizes support on the system */
     unsigned char host_uuid[VIR_UUID_BUFLEN];
+    bool iommu;
 };
 
 typedef int (*virDomainDefNamespaceParse)(xmlDocPtr, xmlNodePtr,
@@ -327,4 +328,6 @@ void virCapsHostCacheBankFree(virCapsHostCacheBankPtr ptr);
 
 int virCapabilitiesInitCaches(virCapsPtr caps);
 
+void virCapabilitiesHostInitIOMMU(virCapsPtr caps);
+
 #endif /* __VIR_CAPABILITIES_H */
diff --git a/src/util/virutil.c b/src/util/virutil.c
index bb4474acd5..7edcda0ee7 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -2090,3 +2090,31 @@ virMemoryMaxValue(bool capped)
     else
         return LLONG_MAX;
 }
+
+bool
+virHostHasIOMMU(void)
+{
+    DIR *iommuDir = NULL;
+    struct dirent *iommuGroup = NULL;
+    bool ret = false;
+    int direrr;
+
+    /* condition 1 - /sys/kernel/iommu_groups/ contains entries */
+    if (virDirOpenQuiet(&iommuDir, "/sys/kernel/iommu_groups/") < 0)
+        goto cleanup;
+
+    while ((direrr = virDirRead(iommuDir, &iommuGroup, NULL)) > 0) {
+        /* assume we found a group */
+        break;
+    }
+
+    if (direrr < 0 || !iommuGroup)
+        goto cleanup;
+    /* okay, iommu is on and recognizes groups */
+
+    ret = true;
+
+ cleanup:
+    VIR_DIR_CLOSE(iommuDir);
+    return ret;
+}
diff --git a/src/util/virutil.h b/src/util/virutil.h
index be0f6b0ea8..1ba9635bd9 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -216,6 +216,8 @@ unsigned long long virMemoryLimitTruncate(unsigned long long value);
 bool virMemoryLimitIsSet(unsigned long long value);
 unsigned long long virMemoryMaxValue(bool ulong) ATTRIBUTE_NOINLINE;
 
+bool virHostHasIOMMU(void);
+
 /**
  * VIR_ASSIGN_IS_OVERFLOW:
  * @rvalue: value that is checked (evaluated twice)
-- 
2.17.0