io/iommu: Add check to validate pci device (pci_addr) input

Currently test cancel with "Device passed is not bound to any driver" log
for invalid pci device input which is incorrect. Check if the pci device
input is valid and cancel test with proper log if invalid.

Also update comments with proper description for "pci_addr" variable used.

Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>

Author: dhsrivas

io/iommu/iommu_tests.py

@@ -32,8 +32,8 @@ def change_domain_check(dom, pci_addr, def_dom):
     Check if the domain changed successfully to "dom" for "pci_addr"
 
     :param dom: domain type
-    :param def_dom: default domain of pci device(pci_addr)
-    :param pci_addr: pci device
+    :param def_dom: default domain of pci address (pci_addr)
+    :param pci_addr: full pci address including domain (0000:03:00.0)
     return: bool
     """
     output = genio.read_one_line(
@@ -49,7 +49,7 @@ def reset_check(pci_addr):
     """
     Check if reset for "pci_addr" is successful
 
-    :param pci_addr: pci device
+    :param pci_addr: full pci address including domain (0000:03:00.0)
     return: bool
     """
     cmd = f"lspci -vvs {pci_addr}"
@@ -64,7 +64,7 @@ def rescan_check(pci_addr):
     """
     Check if rescan for pci_addr is successful
 
-    :param pci_addr: pci device
+    :param pci_addr: full pci address including domain (0000:03:00.0)
     return: bool
     """
     cmd = f"lspci -vvs {pci_addr}"
@@ -81,7 +81,7 @@ class IommuTest(Test):
     reset and rescan is used to form sub-tests that test and exercise iommu
     code.
 
-    :param device: Name of the pci device
+    :param device: full pci address including domain (0000:03:00.0)
     """
 
     def setUp(self):
@@ -96,8 +96,16 @@ def setUp(self):
         smm = SoftwareManager()
         if not smm.check_installed("pciutils") and not smm.install("pciutils"):
             self.cancel("pciutils package not found and installing failed")
+
         # Check the number of devices in iommu-group for pci device passed.
         for pci_addr in self.pci_devices.split(" "):
+
+            # Check if device input is valid
+            cmd = f"lspci -s {pci_addr}"
+            out = process.run(cmd, ignore_status=True, shell=True).stdout_text
+            if not out:
+                self.cancel(f"{pci_addr} not found on the system")
+
             driver = pci.get_driver(pci_addr)
             if driver is None:
                 self.cancel("Device passed is not bound to any driver")
@@ -120,8 +128,8 @@ def unbind(self, driver, pci_addr):
         """
         Unbind the device
 
-        :param driver: driver of the pci device(pci_addr)
-        :param pci_addr: pci device to be unbind from driver
+        :param driver: driver of the pci address (pci_addr)
+        :param pci_addr: full pci address including domain (0000:03:00.0)
         return: None
         """
         genio.write_file(f'/sys/bus/pci/drivers/{driver}/unbind', pci_addr)
@@ -137,8 +145,8 @@ def change_domain(self, dom, def_dom, pci_addr):
         Change the domain of device to dom
 
         :param dom: domain type
-        :param def_dom: default domain of pci device(pci_addr)
-        :param pci_addr: pci device
+        :param def_dom: default domain of pci address (pci_addr)
+        :param pci_addr: full pci address including domain (0000:03:00.0)
         return: None
         """
         genio.write_file(f'/sys/bus/pci/devices/{pci_addr}/iommu_group/type',
@@ -154,8 +162,8 @@ def bind(self, driver, pci_addr):
         """
         Bind the device to driver
 
-        :param driver: driver of the pci device(pci_addr)
-        :param pci_addr: pci device
+        :param driver: driver of the pci address (pci_addr)
+        :param pci_addr: full pci address including domain (0000:03:00.0)
         return: None
         """
         genio.write_file(f"/sys/bus/pci/drivers/{driver}/bind", pci_addr)
@@ -171,7 +179,7 @@ def reset(self, pci_addr):
         """
         Remove the device
 
-        :param pci_addr: pci device
+        :param pci_addr: full pci address including domain (0000:03:00.0)
         return: None
         """
         genio.write_file(f'/sys/bus/pci/devices/{pci_addr}/remove', '1')
@@ -185,7 +193,7 @@ def rescan(self, pci_addr):
         """
         Rescan the system
 
-        :param pci_addr: pci device
+        :param pci_addr: full pci address including domain (0000:03:00.0)
         return: None
         """
         genio.write_file('/sys/bus/pci/rescan', '1')
@@ -198,9 +206,9 @@ def get_params(self, pci_addr):
         """
         Get device parameter-driver, group, default domain(def_dom)
 
-        :param pci_addr: pci device
-        return: driver (driver of pci device),
-                def_dom (default domain of pci device)
+        :param pci_addr: full pci address including domain (0000:03:00.0)
+        return: driver (driver of pci address (pci_addr)),
+                def_dom (default domain of pci address (pci_addr))
         """
         driver = pci.get_driver(pci_addr)
 
@@ -217,9 +225,9 @@ def check(self, def_dom, pci_addr, driver):
         """
         Check if the PCI device is in default domain
 
-        :param def_dom: default domain of pci device(pci_addr)
-        :param pci_addr: pci device
-        :param driver: driver of the pci device(pci_addr)
+        :param def_dom: default domain of pci address (pci_addr)
+        :param pci_addr: full pci address including domain (0000:03:00.0)
+        :param driver: driver of the pci address (pci_addr)
         return: None
         """
         output = genio.read_one_line(