Bug 692374
| Summary: | -cpu enforce with wrong cpu flags does not cause qemu-kvm process quit | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Mike Cao <bcao> | |
| Component: | qemu-kvm | Assignee: | Eduardo Habkost <ehabkost> | |
| Status: | CLOSED WONTFIX | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | medium | |||
| Version: | 6.1 | CC: | areis, ehabkost, flang, juzhang, michen, mkenneth, qzhang, sluo, tburke, virt-maint, xfu, xutian | |
| Target Milestone: | rc | |||
| Target Release: | --- | |||
| Hardware: | x86_64 | |||
| OS: | Linux | |||
| Whiteboard: | ||||
| Fixed In Version: | upstream qemu-1.4.0 | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 822616 (view as bug list) | Environment: | ||
| Last Closed: | 2013-07-03 13:11:56 UTC | Type: | --- | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | 814426 | |||
| Bug Blocks: | 822613, 833129 | |||
|
Description
Mike Cao
2011-03-31 07:25:16 UTC
I'm not sure it is worth fixing as long as the regular models w/o additional flags work. Yes that is the default "-cpu" flag parsing of qemu, namely it doesn't
bail if unknown flags are present:
# x86_64-softmmu/qemu-system-x86_64 -smp 1 -netic -net user ../../winxp-64.img \
-m 1024 -cpu Penryn,+popcnt,+ou812,+sse4_2,check
Using CPU model "Penryn,+popcnt,+ou812,+sse4_2,check"
CPU feature ou812 not found
warning: host cpuid 0000_0001:ecx lacks requested flag 'sse4.2|sse4_2' [0x00100000]
warning: host cpuid 0000_0001:ecx lacks requested flag 'popcnt' [0x00800000]
<guest launches>
But you're right "enforce" semantics should be held (in addition to
complaining) and qemu should error exit. It's a nit and should be
cleaned up the next time we're in that section of the code.
Not only non-existing flags are not rejected properly, but also flags that exist, are supported by the host, but unsupported by the kernel. e.g.: -cpu Opteron_G3,+ht,-svm,enforce HT is not supported by the KVM kernel module and gets disabled, but Qemu continues to run without aborting. *** Bug 813132 has been marked as a duplicate of this bug. *** *** Bug 821581 has been marked as a duplicate of this bug. *** not sure if hit the same problem on Opteron_G5 host. version: # uname -r 2.6.32-339.el6.x86_64 # rpm -q qemu-kvm qemu-kvm-0.12.1.2-2.334.el6.x86_64 guest:win2008r2 host: [root@amd-pence-01 src]# cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 21 model : 2 model name : AMD Eng Sample, 1S256146U8K54_35/25/20_2/8 stepping : 0 cpu MHz : 1400.000 cache size : 2048 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 16 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nonstop_tsc extd_apicid aperfmperf pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core cpb npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold bmi1 bogomips : 4987.26 TLB size : 1536 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm 100mhzsteps hwpstate cpb eff_freq_ro steps: 1.boot guest with -cpu Opteron_G1,-nx,+sse4a,enforce..(sse4a is the flag on Opteron_G3 cpu model) /usr/libexec/qemu-kvm -M rhel6.4.0 -cpu Opteron_G1,-nx,+sse4a...... 2.use x86info to check the cpu flag results:QEMU runs and not prompt any error,check in guest ,the flag 'sse4a' expose to guest. addinfo: but boot with '-cpu Opteron_G2' : # /usr/libexec/qemu-kvm -M rhel6.4.0 -cpu Opteron_G2,-nx,+sse4a,check,enforce warning: host cpuid 8000_0001:ecx flag restricted to guest 'svm' [0x00000004] Unable to support requested x86 CPU definition |