[Qemu-devel] 3.1.0-rc{0,1} doesn't start

[balducci]

hello

I'm building qemu from source and happily using it since a bit
(2.3.0)

Since 3.1.0-rc0 (including latest 3.1.0-rc1) I'm no more able to start
qemu, getting:

    ----8<----
    install:115> qemu
    qemu: error: failed to set MSR 0x10a to 0x0
    qemu: 
/home/balducci/tmp/install-us-d/qemu-3.1.0-rc1.d/qemu-3.1.0-rc0/target/i386/kvm.c:2185:
 kvm_put_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.
    Aborted
    ---->8----

I have no idea about what the reason might be, apologies.

Actually, I have found a recent (2018-10-16) post which might be
related to this (it mentions the same error message from qemu):
https://lkml.org/lkml/2018/10/16/440; but I'm not in the position to
go through. AFAICS, the commit mentioned in the link is present in the
4.19.2 kernel I'm using, so...?

I can add that 3.0.0 works nicely (everything else unchanged,
including running kernel 4.19.2)

OTOH, 3.1.0-rc0 dumps the same error message if I boot into 4.17.14 or
4.18.16 kernels.

I enclose my specs hoping that somebody can spot where the problem
might be. I will be happy to send any other detail which might be
useful.

I suspect that this might be some problem on my side, as I couldn't
find any similar report (apart some old (qemu-2.8.50) threads, that
didn't help)


thanks a lot in advance for any hint/help

ciao
gabriele


Here are my specs:

# --------------------------------
# command to run qemu is:
qemu -m 2G /opt/windog  \
    -accel kvm,thread=multi \
    -netdev user,id=net0,smb=/home/balducci \
    -device rtl8139,netdev=net0

# --------------------------------
# qemu build configuration:
--prefix=/opt/stow.d/versions/qemu-3.1.0-rc1/usr
--libdir=/opt/stow.d/versions/qemu-3.1.0-rc1/usr/lib64
--sysconfdir=/opt/stow.d/versions/qemu-3.1.0-rc1/etc
--localstatedir=/var/run
--docdir=/opt/stow.d/versions/qemu-3.1.0-rc1/usr/share/doc/qemu
--target-list=x86_64-softmmu
--audio-drv-list=alsa


# --------------------------------
install:154> uname -sr
Linux 4.19.2

# --------------------------------
install:155> cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 21
model           : 48
model name      : AMD Athlon(tm) X4 860K Quad Core Processor
stepping        : 1
microcode       : 0x6003106
cpu MHz         : 3473.492
cache size      : 2048 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 2
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 nopl nonstop_tsc cpuid 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 
perfctr_nb bpext ptsc cpb hw_pstate ssbd vmmcall fsgsbase bmi1 xsaveopt arat 
npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists 
pausefilter pfthreshold overflow_recov
bugs            : fxsave_leak sysret_ss_attrs null_seg spectre_v1 spectre_v2 
spec_store_bypass
bogomips        : 7380.73
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 [13]

[...cpus 1 2 3 omitted...]


# --------------------------------
install:156> egrep KVM .config-4.19.2
CONFIG_HAVE_KVM=y
CONFIG_HAVE_KVM_IRQCHIP=y
CONFIG_HAVE_KVM_IRQFD=y
CONFIG_HAVE_KVM_IRQ_ROUTING=y
CONFIG_HAVE_KVM_EVENTFD=y
CONFIG_KVM_MMIO=y
CONFIG_KVM_ASYNC_PF=y
CONFIG_HAVE_KVM_MSI=y
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT=y
CONFIG_KVM_VFIO=y
CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT=y
CONFIG_KVM_COMPAT=y
CONFIG_HAVE_KVM_IRQ_BYPASS=y
CONFIG_KVM=y
# CONFIG_KVM_INTEL is not set
CONFIG_KVM_AMD=y

[of course, I can send the whole kernel configuration file, if needed]