[v4] usertools: add check for IOMMU support in dpdk-devbind
Checks
Commit Message
binding with vfio driver, when IOMMU is disabled, causes program to crash.
this patch adds a flag for noiommmu-mode. when this is set, if IOMMU is
disabled, it changes vfio into unsafe noiommu mode and prints warning
message.
Signed-off-by: Fidaullah Noonari <fidaullah.noonari@emumba.com>
---
usertools/dpdk-devbind.py | 45 +++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
Comments
On Wed, 12 Oct 2022 17:38:17 +0500
Fidaullah Noonari <fidaullah.noonari@emumba.com> wrote:
> binding with vfio driver, when IOMMU is disabled, causes program to crash.
> this patch adds a flag for noiommmu-mode. when this is set, if IOMMU is
> disabled, it changes vfio into unsafe noiommu mode and prints warning
> message.
>
> Signed-off-by: Fidaullah Noonari <fidaullah.noonari@emumba.com>
Not sure why this patch got stuck.
The flake8 tool reports:
usertools/dpdk-devbind.py:489:27: E231 missing whitespace after ','
Fix by:
diff --git a/usertools/dpdk-devbind.py b/usertools/dpdk-devbind.py
index e7a5665fa2..a089313db1 100755
--- a/usertools/dpdk-devbind.py
+++ b/usertools/dpdk-devbind.py
@@ -486,7 +486,7 @@ def check_noiommu_mode():
filename = "/sys/module/vfio/parameters/enable_unsafe_noiommu_mode"
try:
- with open(filename,"r") as f:
+ with open(filename, "r") as f:
if f.read(1) == "1":
return
except OSError as err:
@@ -100,6 +100,7 @@
b_flag = None
status_flag = False
force_flag = False
+noiommu_flag = False
args = []
@@ -470,6 +471,37 @@ def unbind_all(dev_list, force=False):
unbind_one(d, force)
+def has_iommu():
+ """Check if IOMMU is enabled on system"""
+ return len(os.listdir("/sys/class/iommu")) > 0
+
+
+def check_noiommu_mode():
+ """checks and enables the noiommu mode for vfio drivers"""
+ global noiommu_flag
+ filename = "/sys/module/vfio/parameters/enable_unsafe_noiommu_mode"
+
+ try:
+ with open(filename,"r") as f:
+ if f.read(1) == "1":
+ return
+ except OSError as err:
+ sys.exit(f"Error: failed to enable unsafe noiommu mode - Cannot open {filename}: {err}")
+
+ if not noiommu_flag:
+ print("Error: failed to bind vfio-pci - IOMMU support is disabled")
+ print("Info: use --noiommu-mode for binding in noiommu mode")
+ sys.exit()
+
+ try:
+ with open(filename, "w") as f:
+ f.write("1")
+ f.close()
+ except OSError as err:
+ sys.exit(f"Error: failed to enable unsafe noiommu mode - Cannot open {filename}: {err}")
+ print("Warning: enabling unsafe no IOMMU mode for vfio drivers")
+
+
def bind_all(dev_list, driver, force=False):
"""Bind method, takes a list of device locations"""
global devices
@@ -496,6 +528,10 @@ def bind_all(dev_list, driver, force=False):
except ValueError as ex:
sys.exit(ex)
+ # check for IOMMU support
+ if driver == "vfio-pci" and not has_iommu():
+ check_noiommu_mode()
+
for d in dev_list:
bind_one(d, driver, force)
@@ -638,6 +674,7 @@ def parse_args():
global status_flag
global status_dev
global force_flag
+ global noiommu_flag
global args
parser = argparse.ArgumentParser(
@@ -691,6 +728,12 @@ def parse_args():
Override restriction on binding devices in use by Linux"
WARNING: This can lead to loss of network connection and should be used with caution.
""")
+ parser.add_argument(
+ '--noiommu-mode',
+ action='store_true',
+ help="""
+if IOMMU is not available, Enables no IOMMU mode for vfio drivers.
+ """)
parser.add_argument(
'devices',
metavar='DEVICE',
@@ -710,6 +753,8 @@ def parse_args():
status_dev = "all"
if opt.force:
force_flag = True
+ if opt.noiommu_mode:
+ noiommu_flag = True
if opt.bind:
b_flag = opt.bind
elif opt.unbind: