On 12/15/20 5:24 PM, Tim Wiederhake wrote:
Fixes the leaking file descriptors. Does not silently ignore errors
(e.g. permission denied on /dev/cpu/0/msr if run as non-root) and
always attempt to read from /dev/kvm if /dev/cpu/0/msr failed.
'gather_msr()' returns a dictionary of values, as a later patch will
add more registers to be interrogated.
Signed-off-by: Tim Wiederhake <twiederh@xxxxxxxxxx>
---
tests/cputestdata/cpu-gather.py | 34 ++++++++++++++++++++++++++++
tests/cputestdata/cpu-gather.sh | 40 ---------------------------------
2 files changed, 34 insertions(+), 40 deletions(-)
diff --git a/tests/cputestdata/cpu-gather.py b/tests/cputestdata/cpu-gather.py
index 75cf290a28..db2348b460 100755
--- a/tests/cputestdata/cpu-gather.py
+++ b/tests/cputestdata/cpu-gather.py
@@ -1,8 +1,11 @@
#!/usr/bin/env python3
import argparse
+import fcntl
import os
+import struct
import subprocess
+import sys
def gather_name(args):
@@ -38,6 +41,31 @@ def gather_cpuid_leaves(args):
yield line.strip()
+def gather_msr():
+ IA32_ARCH_CAPABILITIES_MSR = 0x10a
+ KVM_GET_MSRS = 0xc008ae88
+
+ try:
+ with open("/dev/cpu/0/msr", "rb") as f:
+ f.seek(IA32_ARCH_CAPABILITIES_MSR)
+ buf = f.read(8)
+ msr = struct.unpack("=Q", buf)[0]
+ return "", {IA32_ARCH_CAPABILITIES_MSR: msr}
+ except IOError as e:
+ print("Warning: {}".format(e), file=sys.stderr)
Previously, if /dev/cpu/0/msr was not present, then no warning was
written. Now I get this warning, fortunately on stderr so cpu-parse.sh
is not affected. I'm not saying it's a bad thing, these scripts are
expected to be called by advanced users (if not developers) and this
warning may shed more light. Just want to point out it was noticed ;-)
+
+ try:
+ bufIn = struct.pack("=LLLLQ", 1, 0, IA32_ARCH_CAPABILITIES_MSR, 0, 0)
+ with open("/dev/kvm", "rb") as f:
+ bufOut = fcntl.ioctl(f, KVM_GET_MSRS, bufIn)
+ msr = struct.unpack("=LLLLQ", bufOut)[4]
+ return " via KVM", {IA32_ARCH_CAPABILITIES_MSR: msr}
+ except IOError as e:
+ print("Warning: {}".format(e), file=sys.stderr)
+
+ return None, {}
+
+
Michal
