853013 – should can see all the "cat /proc/cpuinfo " information when with "-smp 4,sockets=4,cores=1,threads=1" boot guest

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Bug 853013 - should can see all the "cat /proc/cpuinfo " information when with "-smp 4,sockets=4,cores=1,threads=1" boot guest

Summary: should can see all the "cat /proc/cpuinfo " information when with "-smp 4,s...

Keywords:
Status:	CLOSED NOTABUG
Alias:	None
Product:	Red Hat Enterprise Linux 6
Classification:	Red Hat
Component:	qemu-kvm
Sub Component:
Version:	6.4
Hardware:	Unspecified
OS:	Unspecified
Priority:	low
Severity:	medium
Target Milestone:	rc
Target Release:	---
Assignee:	Eduardo Habkost
QA Contact:	Virtualization Bugs
Docs Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+	depends on / blocked

Reported:	2012-08-30 09:26 UTC by langfang
Modified:	2012-08-31 18:16 UTC (History)
CC List:	14 users (show)
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed:	2012-08-31 18:16:17 UTC
Target Upstream Version:
Embargoed:

Attachments	(Terms of Use)

Description langfang 2012-08-30 09:26:47 UTC

Description of problem:
boot guest with "-smp 4,sockets=4,cores=1,threads=1",then run  "cat /proc/cpuinfo " in guest ,can not see "

Version-Release number of selected component (if applicable):


How reproducible:

100%
Steps to Reproduce:
1.boot guest with "-smp 4,sockets=4,cores=1,threads=1"
2.in guest
#cat /proc/cpuinfo
  
Actual results:

processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 42
model name      : Intel Xeon E312xx (Sandy Bridge)
stepping        : 1
cpu MHz         : 3092.990
cache size      : 4096 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall lm constant_tsc arch_perfmon unfair_spinlock pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 x2apic popcnt aes xsave avx hypervisor lahf_lm xsaveopt
bogomips        : 6185.98
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

---->not have items :
"physical id" " siblings"  "core id" "cpu cores" " apicid"  "initial apicid"	


Expected results:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 42
model name	: Intel(R) Xeon(R) CPU E31225 @ 3.10GHz
stepping	: 7
cpu MHz		: 1600.000
cache size	: 6144 KB
physical id	: 0
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 6
initial apicid	: 6
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall rdtscp lm constant_tsc arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 x2apic popcnt aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid
bogomips	: 6186.02
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

Additional info:
boot guest with "-smp 5,sockets=5,cores=1,threads=1"---> have the problem
boot guest with "-smp 4,sockets=2,cores=1,threads=2"--->not have the problem
boot guest with "-smp 4,sockets=2,cores=2,threads=1"--->not have the problem

Comment 2 langfang 2012-08-30 10:26:04 UTC

test this bug version:

host:
# rpm -q kernel
kernel-2.6.32-279.el6.x86_64
# rpm -q qemu-kvm
qemu-kvm-0.12.1.2-2.307.el6.x86_64

guest:
kernel-2.6.32-303.el6.x86_64

Comment 3 Eduardo Habkost 2012-08-31 18:16:17 UTC

The guest kernel simply does not show that information if the processor is not multi-core or multi-thread.

From the upstream kernel code:

static void show_cpuinfo_core(struct seq_file *m, struct cpuinfo_x86 *c,
			      unsigned int cpu)
{
#ifdef CONFIG_SMP
	if (c->x86_max_cores * smp_num_siblings > 1) {
		seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
		seq_printf(m, "siblings\t: %d\n",
			   cpumask_weight(cpu_core_mask(cpu)));
		seq_printf(m, "core id\t\t: %d\n", c->cpu_core_id);
		seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
		seq_printf(m, "apicid\t\t: %d\n", c->apicid);
		seq_printf(m, "initial apicid\t: %d\n", c->initial_apicid);
	}
#endif
}

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