On 12/9/19 10:52 PM, Cleber Rosa wrote:
On Fri, Dec 06, 2019 at 04:34:31PM -0500, Wainer dos Santos Moschetta wrote:
Since commit cbe6d6365a48 the command `qemu -accel help` returns
the list of accelerators enabled in the QEMU binary. This adds
the list_accel() method which return that same list.
Signed-off-by: Wainer dos Santos Moschetta <waine...@redhat.com>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
---
python/qemu/accel.py | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/python/qemu/accel.py b/python/qemu/accel.py
index cbeac10dd1..746b7e68f5 100644
--- a/python/qemu/accel.py
+++ b/python/qemu/accel.py
@@ -14,7 +14,11 @@ accelerators.
# the COPYING file in the top-level directory.
#
+import logging
import os
+import subprocess
+
+LOG = logging.getLogger(__name__)
# Mapping host architecture to any additional architectures it can
# support which often includes its 32 bit cousin.
@@ -23,6 +27,25 @@ ADDITIONAL_ARCHES = {
"aarch64" : "armhf"
}
+def list_accel(qemu_bin):
+ """
+ List accelerators enabled in the QEMU binary.
+
+ @param qemu_bin (str): path to the QEMU binary.
+ @raise Exception: if failed to run `qemu -accel help`
+ @return a list of accelerator names.
+ """
+ if not qemu_bin:
+ return []
+ try:
+ out = subprocess.check_output("%s -accel help" % qemu_bin, shell=True)
There's no need to use a shell here. This could become:
out = subprocess.check_output([qemu_bin, '-accel' 'help'])
Ack
+ except:
+ LOG.debug("Failed to get the list of accelerators in %s" % qemu_bin)
+ raise
+ lines = out.decode().splitlines()
And maybe discard the first line earlier with:
lines = out.decode().splitlines()[1:]
Also, you could avoid the manual decode() with the `universal_newlines`
option to subprocess.check_output(), ie:
accels = subprocess.check_output([qemu-bin, '-accel', 'help'],
universal_newlines=True).splitlines()[1:]
Nice. v3 will have universal_newlines=True.
+ # Skip the first line which is the header.
+ return [l.strip() for l in lines[1:] if l]
+
I think that the `if l` check can actually hide undesirable behavior
(bugs) in the `qemu -accel ?` output. I don't remember seeing
`-$(option) ?` returning empty strings but doesn't mean it couldn't
and shouldn't).
I do remember `-machine ?` returning random non-printable characters
that turned out to be a bug, though.
Double-checking: are you suggesting to remove the 'if not empty' check
so that bugs on output could emerge?
Thanks!
- Wainer
def kvm_available(target_arch=None):
host_arch = os.uname()[4]
if target_arch and target_arch != host_arch:
--
2.21.0
- Cleber.
