diff --git a/README.md b/README.md
index a8e8385..c1aba22 100644
--- a/README.md
+++ b/README.md
@@ -108,6 +108,13 @@ Update the host.
 $ xe host-call-plugin host-uuid=<uuid> plugin=updater.py fn=update
 ```
 
+#### `query_installed`:
+Return a JSON object of the installed packages given in arguments with an empty value string for not installed ones.
+```
+$ xe host-call-plugin host-uuid=<uuid> plugin=updater.py fn=query_installed args:packages=sm,sm-rawhba,invalid
+{"sm-rawhba": "sm-rawhba-2.30.8-2.3.0.linstor.1.xcpng8.2.x86_64", "invalid": "", "sm": "sm-2.30.8-10.1.0.linstor.1.xcpng8.2.x86_64"}
+```
+
 ### Proxy configuration
 
 #### `get_proxies()`:
diff --git a/SOURCES/etc/xapi.d/plugins/updater.py b/SOURCES/etc/xapi.d/plugins/updater.py
index 56376d6..346d556 100755
--- a/SOURCES/etc/xapi.d/plugins/updater.py
+++ b/SOURCES/etc/xapi.d/plugins/updater.py
@@ -181,6 +181,33 @@ def check_update(session, args):
 def update(session, args):
     return install_helper(session, args, 'update')
 
+@error_wrapped
+def query_installed(session, args):
+    packages = args.get('packages')
+    if not packages:
+        return '{}'
+
+    import re
+    packages = re.sub(r'\s+', ' ', packages).replace(',', ' ').split(' ')
+    packages = filter(lambda package: package, packages)
+    if not packages:
+        return '{}'
+
+    package_map = dict.fromkeys(packages, '')
+    packages = list(package_map)
+
+    command = ['rpm', '-q'] + packages
+    result = run_command(command, check=False)
+    package_info = result['stdout'].rstrip().split('\n')
+    assert len(packages) == len(package_info), 'ill-formed result'
+
+    for i, package in enumerate(packages):
+        info = package_info[i]
+        if not info.endswith('is not installed'):
+            package_map[package] = info
+
+    return json.dumps(package_map)
+
 def check_upgrade(session, args):
     # TODO:
     # check new version exists
@@ -265,6 +292,7 @@ def set_proxies(session, args):
         'install': install,
         'check_update': check_update,
         'update': update,
+        'query_installed': query_installed,
         'get_proxies': get_proxies,
         'set_proxies': set_proxies
     })
diff --git a/tests/test_updater.py b/tests/test_updater.py
index 9379a3a..d24137c 100644
--- a/tests/test_updater.py
+++ b/tests/test_updater.py
@@ -7,7 +7,14 @@
 import time
 import XenAPIPlugin
 
-from updater import install, check_update, get_proxies, set_proxies, update, DEFAULT_REPOS
+from updater import \
+    install, \
+    check_update, \
+    get_proxies, \
+    set_proxies, \
+    update, \
+    query_installed, \
+    DEFAULT_REPOS
 
 # ==============================================================================
 # Install/Update.
@@ -108,6 +115,60 @@ def test_update_with_additional_repos_and_packages(self, run_command, fs):
             ['yum', 'update', '--disablerepo=*', '--enablerepo=' + ','.join(repos), '-y', packages]
         )
 
+@mock.patch('updater.run_command', autospec=True)
+class TestIsInstalled:
+    def test_without_package(self, run_command):
+        result = query_installed(mock.MagicMock(), {})
+        assert result == '{}'
+
+    def test_one_package_installed(self, run_command):
+        run_command.return_value = {
+            'stdout': 'test.rpm',
+            'stderr': '',
+            'returncode': 0
+        }
+
+        package = 'test'
+        result = query_installed(mock.MagicMock(), {'packages': package})
+        run_command.assert_called_once_with(
+            ['rpm', '-q', package], False
+        )
+
+        assert json.loads(result) == {'test': 'test.rpm'}
+
+    def test_no_package_installed(self, run_command):
+        run_command.return_value = {
+            'stdout': 'test is not installed',
+            'stderr': '',
+            'returncode': 1
+        }
+
+        package = 'test'
+        result = query_installed(mock.MagicMock(), {'packages': package})
+        run_command.assert_called_once_with(
+            ['rpm', '-q', package], False
+        )
+
+        assert json.loads(result) == {'test': ''}
+
+    def test_with_many_packages(self, run_command, fs):
+        run_command.return_value = {
+            'stdout':
+            'toto.rpm\n'
+            'package tata is not installed\n'
+            'titi.rpm\n',
+            'stderr': '',
+            'returncode': 0
+        }
+
+        packages = 'toto,tata,titi'
+        result = query_installed(mock.MagicMock(), {'packages': packages})
+        run_command.assert_called_once_with(
+            ['rpm', '-q'] + packages.split(','), False
+        )
+
+        assert json.loads(result) == {'toto': 'toto.rpm', 'tata': '', 'titi': 'titi.rpm'}
+
 # ==============================================================================
 # Lock: Try to execute a command with a lock already locked.
 # ==============================================================================