[PATCH 3/6] kvm_stat: Rework platform detection

From: Michael Ellerman <mpe@ellerman.id.au>
To: qemu-devel@nongnu.org
Cc: <kvm@vger.kernel.org>,
	alfs@linux.vnet.ibm.com, jfrei@linux.vnet.ibm.com, agraf@suse.de,
	jan.kiszka@siemens.com, pbonzini@redhat.com, aik@ozlabs.ru
Subject: [PATCH 3/6] kvm_stat: Rework platform detection
Date: Tue, 17 Jun 2014 17:54:32 +1000	[thread overview]
Message-ID: <1402991675-24905-3-git-send-email-mpe@ellerman.id.au> (raw)
In-Reply-To: <1402991675-24905-1-git-send-email-mpe@ellerman.id.au>

The current platform detection is a little bit messy. We look for lines
in /proc/cpuinfo starting with 'flags' OR 'vendor-id', and scan both
for values we know will only occur in one or the other. We also keep
scanning once we've found a value, which could be a feature, but isn't
in this case.

We'd also like to add another platform, powerpc, which will just make it
worse. So clean it up in preparation.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 scripts/kvm/kvm_stat | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat
index fe2eae3..98c81a8 100755
--- a/scripts/kvm/kvm_stat
+++ b/scripts/kvm/kvm_stat
@@ -169,27 +169,41 @@ generic_exit_reasons = {
     23: 'EPR',
 }
 
-vendor_exit_reasons = {
+x86_exit_reasons = {
     'vmx': vmx_exit_reasons,
     'svm': svm_exit_reasons,
-    'IBM/S390': generic_exit_reasons,
 }
 
-syscall_numbers = {
-    'IBM/S390': 331,
-}
-
-sc_perf_evt_open = 298
-
+sc_perf_evt_open = None
 exit_reasons = None
 
-for line in file('/proc/cpuinfo').readlines():
-    if line.startswith('flags') or line.startswith('vendor_id'):
-        for flag in line.split():
-            if flag in vendor_exit_reasons:
-                exit_reasons = vendor_exit_reasons[flag]
-            if flag in syscall_numbers:
-                sc_perf_evt_open = syscall_numbers[flag]
+def x86_init(flag):
+    globals().update({
+        'sc_perf_evt_open' : 298,
+        'exit_reasons' : x86_exit_reasons[flag],
+    })
+
+def s390_init():
+    globals().update({
+        'sc_perf_evt_open' : 331,
+        'exit_reasons' : generic_exit_reasons,
+    })
+
+def detect_platform():
+    for line in file('/proc/cpuinfo').readlines():
+        if line.startswith('flags'):
+            for flag in line.split():
+                if flag in x86_exit_reasons:
+                    x86_init(flag)
+                    return
+        elif line.startswith('vendor_id'):
+            for flag in line.split():
+                if flag == 'IBM/S390':
+                    s390_init()
+                    return
+
+detect_platform()
+
 filters = {
     'kvm_exit': ('exit_reason', exit_reasons)
 }
-- 
1.9.1

