When I boot two virtio-rng devices, guest will hang

[Amos Kong <akong@redhat.com>]

QEMU commandline:

./x86_64-softmmu/qemu-system-x86_64 --enable-kvm   -m 2000 -drive file=/images/nolvm.qcow2 --kernel /home/devel/linux/arch/x86/boot/bzImage -append "ro root=/dev/sda1 console=ttyS0,115200"  -monitor unix:/tmp/m,nowait,server -device virtio-net-pci,netdev=h0,vectors=17,mq=on,id=n0 -netdev tap,id=h0,queues=8 -device virtio-net-pci,netdev=h1,vectors=0,mq=on,id=n1 -netdev tap,id=h1,queues=8  -vnc :0 -mon chardev=qmp,mode=control,pretty=on -chardev socket,id=qmp,host=localhost,port=1234,server,nowait -serial stdio -object rng-random,filename=/dev/urandom,id=rng0   -device virtio-rng-pci,rng=rng0,id=h0 -object rng-random,filename=/dev/urandom,id=rng1   -device virtio-rng-pci,rng=rng1,id=h1

It works when I only add one virtio-rng device. Did you touch this
problem?

I'm using latest net-next/master (ac3d2e5a9ef2f4d8f57c50070c4883ecb7cec29f)

[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Initializing cgroup subsys cpuacct
[    0.000000] Linux version 3.16.0-rc6+ (amos@z) (gcc version 4.8.3 20140624 (Red Hat 4.8.3-1) (GCC) ) #363 SMP Mon Jul 28 15:05:44 CST 2014
[    0.000000] Command line: ro root=/dev/sda1 console=ttyS0,115200
[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
[    0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000007cffdfff] usable
[    0.000000] BIOS-e820: [mem 0x000000007cffe000-0x000000007cffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
[    0.000000] NX (Execute Disable) protection: active
[    0.000000] SMBIOS 2.8 present.
[    0.000000] Hypervisor detected: KVM
[    0.000000] AGP: No AGP bridge found
[    0.000000] e820: last_pfn = 0x7cffe max_arch_pfn = 0x400000000
[    0.000000] PAT not supported by CPU.
[    0.000000] found SMP MP-table at [mem 0x000f0e90-0x000f0e9f] mapped at [ffff8800000f0e90]
[    0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[    0.000000] init_memory_mapping: [mem 0x7cc00000-0x7cdfffff]
[    0.000000] init_memory_mapping: [mem 0x7c000000-0x7cbfffff]
[    0.000000] init_memory_mapping: [mem 0x00100000-0x7bffffff]
[    0.000000] init_memory_mapping: [mem 0x7ce00000-0x7cffdfff]
[    0.000000] ACPI: Early table checksum verification disabled
[    0.000000] ACPI: RSDP 0x00000000000F0C90 000014 (v00 BOCHS )
[    0.000000] ACPI: RSDT 0x000000007CFFFEF0 000034 (v01 BOCHS  BXPCRSDT 00000001 BXPC 00000001)
[    0.000000] ACPI: FACP 0x000000007CFFF1D3 000074 (v01 BOCHS  BXPCFACP 00000001 BXPC 00000001)
[    0.000000] ACPI: DSDT 0x000000007CFFE040 001193 (v01 BOCHS  BXPCDSDT 00000001 BXPC 00000001)
[    0.000000] ACPI: FACS 0x000000007CFFE000 000040
[    0.000000] ACPI: SSDT 0x000000007CFFF247 000BF9 (v01 BOCHS  BXPCSSDT 00000001 BXPC 00000001)
[    0.000000] ACPI: APIC 0x000000007CFFFE40 000078 (v01 BOCHS  BXPCAPIC 00000001 BXPC 00000001)
[    0.000000] ACPI: HPET 0x000000007CFFFEB8 000038 (v01 BOCHS  BXPCHPET 00000001 BXPC 00000001)
[    0.000000] No NUMA configuration found
[    0.000000] Faking a node at [mem 0x0000000000000000-0x000000007cffdfff]
[    0.000000] Initmem setup node 0 [mem 0x00000000-0x7cffdfff]
[    0.000000]   NODE_DATA [mem 0x7cfea000-0x7cffdfff]
[    0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
[    0.000000] kvm-clock: cpu 0, msr 0:7cfe8001, primary cpu clock
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x00001000-0x00ffffff]
[    0.000000]   DMA32    [mem 0x01000000-0xffffffff]
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x00001000-0x0009efff]
[    0.000000]   node   0: [mem 0x00100000-0x7cffdfff]
[    0.000000] ACPI: PM-Timer IO Port: 0x608
[    0.000000] ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
[    0.000000] ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1])
[    0.000000] ACPI: IOAPIC (id[0x00] address[0xfec00000] gsi_base[0])
[    0.000000] IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level)
[    0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level)
[    0.000000] Using ACPI (MADT) for SMP configuration information
[    0.000000] ACPI: HPET id: 0x8086a201 base: 0xfed00000
[    0.000000] smpboot: Allowing 1 CPUs, 0 hotplug CPUs
[    0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff]
[    0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000effff]
[    0.000000] PM: Registered nosave memory: [mem 0x000f0000-0x000fffff]
[    0.000000] e820: [mem 0x7d000000-0xfeffbfff] available for PCI devices
[    0.000000] Booting paravirtualized kernel on KVM
[    0.000000] setup_percpu: NR_CPUS:128 nr_cpumask_bits:128 nr_cpu_ids:1 nr_node_ids:1
[    0.000000] PERCPU: Embedded 27 pages/cpu @ffff88007cc00000 s81152 r8192 d21248 u2097152
[    0.000000] KVM setup async PF for cpu 0
[    0.000000] kvm-stealtime: cpu 0, msr 7cc0d080
[    0.000000] Built 1 zonelists in Node order, mobility grouping on.  Total pages: 503879
[    0.000000] Policy zone: DMA32
[    0.000000] Kernel command line: ro root=/dev/sda1 console=ttyS0,115200
[    0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
[    0.000000] AGP: Checking aperture...
[    0.000000] AGP: No AGP bridge found
[    0.000000] Memory: 1998212K/2047600K available (6874K kernel code, 1055K rwdata, 3048K rodata, 1416K init, 1416K bss, 49388K reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] Hierarchical RCU implementation.
[    0.000000]  RCU restricting CPUs from NR_CPUS=128 to nr_cpu_ids=1.
[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS:8448 nr_irqs:256 16
[    0.000000] Console: colour VGA+ 80x25
[    0.000000] console [ttyS0] enabled
[    0.000000] allocated 8388608 bytes of page_cgroup
[    0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups
[    0.000000] tsc: Detected 2893.428 MHz processor
[    0.002000] Calibrating delay loop (skipped) preset value.. 5786.85 BogoMIPS (lpj=2893428)
[    0.002382] pid_max: default: 32768 minimum: 301
[    0.003011] ACPI: Core revision 20140424
[    0.004747] ACPI: All ACPI Tables successfully acquired
[    0.005000] Security Framework initialized
[    0.005000] SELinux:  Initializing.
[    0.005220] Dentry cache hash table entries: 262144 (order: 9, 2097152 bytes)
[    0.006589] Inode-cache hash table entries: 131072 (order: 8, 1048576 bytes)
[    0.007188] Mount-cache hash table entries: 4096 (order: 3, 32768 bytes)
[    0.008007] Mountpoint-cache hash table entries: 4096 (order: 3, 32768 bytes)
[    0.009153] Initializing cgroup subsys memory
[    0.010038] Initializing cgroup subsys devices
[    0.011007] Initializing cgroup subsys freezer
[    0.011552] Initializing cgroup subsys net_cls
[    0.012006] Initializing cgroup subsys blkio
[    0.012534] Initializing cgroup subsys perf_event
[    0.013054] mce: CPU supports 10 MCE banks
[    0.014020] Last level iTLB entries: 4KB 0, 2MB 0, 4MB 0
[    0.014020] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0
[    0.014020] tlb_flushall_shift: 6
[    0.025553] Freeing SMP alternatives memory: 24K (ffffffff81e6b000 - ffffffff81e71000)
[    0.029326] ftrace: allocating 25929 entries in 102 pages
[    0.036206] Enabling x2apic
[    0.036598] Enabled x2apic
[    0.037003] Switched APIC routing to physical x2apic.
[    0.038554] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
[    0.039001] smpboot: CPU0: Intel QEMU Virtual CPU version 2.0.92 (fam: 06, model: 06, stepping: 03)
[    0.041000] Performance Events: Broken PMU hardware detected, using software events only.
[    0.041004] Failed to access perfctr msr (MSR c1 is 0)
[    0.042606] x86: Booted up 1 node, 1 CPUs
[    0.043002] smpboot: Total of 1 processors activated (5786.85 BogoMIPS)
[    0.044104] NMI watchdog: disabled (cpu0): hardware events not enabled
[    0.044959] devtmpfs: initialized
[    0.046107] atomic64_test: passed for x86-64 platform with CX8 and with SSE
[    0.047002] RTC time:  7:25:09, date: 07/28/14
[    0.047609] NET: Registered protocol family 16
[    0.048079] cpuidle: using governor ladder
[    0.048578] cpuidle: using governor menu
[    0.049043] ACPI: bus type PCI registered
[    0.049526] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
[    0.050090] PCI: Using configuration type 1 for base access
[    0.052452] ACPI: Added _OSI(Module Device)
[    0.052991] ACPI: Added _OSI(Processor Device)
[    0.053002] ACPI: Added _OSI(3.0 _SCP Extensions)
[    0.054001] ACPI: Added _OSI(Processor Aggregator Device)
[    0.055921] ACPI: Interpreter enabled
[    0.056004] ACPI Exception: AE_NOT_FOUND, While evaluating Sleep State [\_S1_] (20140424/hwxface-580)
[    0.057270] ACPI Exception: AE_NOT_FOUND, While evaluating Sleep State [\_S2_] (20140424/hwxface-580)
[    0.058287] ACPI: (supports S0 S3 S4 S5)
[    0.059001] ACPI: Using IOAPIC for interrupt routing
[    0.059602] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
[    0.062395] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[    0.063005] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI]
[    0.064005] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM
[    0.064840] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge.
[    0.065287] acpiphp: Slot [3] registered
[    0.066045] acpiphp: Slot [4] registered
[    0.067032] acpiphp: Slot [5] registered
[    0.067739] acpiphp: Slot [6] registered
[    0.068028] acpiphp: Slot [7] registered
[    0.068422] acpiphp: Slot [8] registered
[    0.069017] acpiphp: Slot [9] registered
[    0.069452] acpiphp: Slot [10] registered
[    0.070001] acpiphp: Slot [11] registered
[    0.070363] acpiphp: Slot [12] registered
[    0.070754] acpiphp: Slot [13] registered
[    0.071016] acpiphp: Slot [14] registered
[    0.071380] acpiphp: Slot [15] registered
[    0.071803] acpiphp: Slot [16] registered
[    0.072016] acpiphp: Slot [17] registered
[    0.072412] acpiphp: Slot [18] registered
[    0.073015] acpiphp: Slot [19] registered
[    0.073396] acpiphp: Slot [20] registered
[    0.073783] acpiphp: Slot [21] registered
[    0.074015] acpiphp: Slot [22] registered
[    0.074446] acpiphp: Slot [23] registered
[    0.075016] acpiphp: Slot [24] registered
[    0.075539] acpiphp: Slot [25] registered
[    0.076016] acpiphp: Slot [26] registered
[    0.076515] acpiphp: Slot [27] registered
[    0.077016] acpiphp: Slot [28] registered
[    0.077513] acpiphp: Slot [29] registered
[    0.078016] acpiphp: Slot [30] registered
[    0.078526] acpiphp: Slot [31] registered
[    0.079009] PCI host bridge to bus 0000:00
[    0.079504] pci_bus 0000:00: root bus resource [bus 00-ff]
[    0.080002] pci_bus 0000:00: root bus resource [io  0x0000-0x0cf7]
[    0.081002] pci_bus 0000:00: root bus resource [io  0x0d00-0xadff]
[    0.081737] pci_bus 0000:00: root bus resource [io  0xae0f-0xaeff]
[    0.082002] pci_bus 0000:00: root bus resource [io  0xaf20-0xafdf]
[    0.083002] pci_bus 0000:00: root bus resource [io  0xafe4-0xffff]
[    0.084009] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff]
[    0.085003] pci_bus 0000:00: root bus resource [mem 0x7d000000-0xfebfffff]
[    0.091716] pci 0000:00:01.1: legacy IDE quirk: reg 0x10: [io  0x01f0-0x01f7]
[    0.092002] pci 0000:00:01.1: legacy IDE quirk: reg 0x14: [io  0x03f6]
[    0.093002] pci 0000:00:01.1: legacy IDE quirk: reg 0x18: [io  0x0170-0x0177]
[    0.094002] pci 0000:00:01.1: legacy IDE quirk: reg 0x1c: [io  0x0376]
[    0.095399] pci 0000:00:01.3: quirk: [io  0x0600-0x063f] claimed by PIIX4 ACPI
[    0.096009] pci 0000:00:01.3: quirk: [io  0x0700-0x070f] claimed by PIIX4 SMB
[    0.132469] ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *10 11)
[    0.133279] ACPI: PCI Interrupt Link [LNKB] (IRQs 5 *10 11)
[    0.134293] ACPI: PCI Interrupt Link [LNKC] (IRQs 5 10 *11)
[    0.135102] ACPI: PCI Interrupt Link [LNKD] (IRQs 5 10 *11)
[    0.135871] ACPI: PCI Interrupt Link [LNKS] (IRQs *9)
[    0.136357] ACPI: Enabled 16 GPEs in block 00 to 0F
[    0.137088] vgaarb: device added: PCI:0000:00:02.0,decodes=io+mem,owns=io+mem,locks=none
[    0.138001] vgaarb: loaded
[    0.138342] vgaarb: bridge control possible 0000:00:02.0
[    0.139061] SCSI subsystem initialized
[    0.140012] ACPI: bus type USB registered
[    0.140507] usbcore: registered new interface driver usbfs
[    0.141009] usbcore: registered new interface driver hub
[    0.141655] usbcore: registered new device driver usb
[    0.142046] PCI: Using ACPI for IRQ routing
[    0.143172] NetLabel: Initializing
[    0.143587] NetLabel:  domain hash size = 128
[    0.144002] NetLabel:  protocols = UNLABELED CIPSOv4
[    0.144610] NetLabel:  unlabeled traffic allowed by default
[    0.145037] HPET: 3 timers in total, 0 timers will be used for per-cpu timer
[    0.146015] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
[    0.146653] hpet0: 3 comparators, 64-bit 100.000000 MHz counter
[    0.151059] Switched to clocksource kvm-clock
[    0.155268] pnp: PnP ACPI init
[    0.155712] ACPI: bus type PNP registered
[    0.156621] pnp: PnP ACPI: found 6 devices
[    0.157127] ACPI: bus type PNP unregistered
[    0.163277] NET: Registered protocol family 2
[    0.163949] TCP established hash table entries: 16384 (order: 5, 131072 bytes)
[    0.164866] TCP bind hash table entries: 16384 (order: 6, 262144 bytes)
[    0.165692] TCP: Hash tables configured (established 16384 bind 16384)
[    0.166488] TCP: reno registered
[    0.166886] UDP hash table entries: 1024 (order: 3, 32768 bytes)
[    0.167613] UDP-Lite hash table entries: 1024 (order: 3, 32768 bytes)
[    0.168492] NET: Registered protocol family 1
[    0.169048] pci 0000:00:00.0: Limiting direct PCI/PCI transfers
[    0.169769] pci 0000:00:01.0: PIIX3: Enabling Passive Release
[    0.170485] pci 0000:00:01.0: Activating ISA DMA hang workarounds
[    0.171866] futex hash table entries: 256 (order: 2, 16384 bytes)
[    0.172645] Initialise system trusted keyring
[    0.173222] audit: initializing netlink subsys (disabled)
[    0.173907] audit: type=2000 audit(1406532309.432:1): initialized
[    0.174810] HugeTLB registered 2 MB page size, pre-allocated 0 pages
[    0.176647] VFS: Disk quotas dquot_6.5.2
[    0.177176] Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[    0.178223] msgmni has been set to 3902
[    0.179343] alg: No test for stdrng (krng)
[    0.179884] NET: Registered protocol family 38
[    0.180427] Key type asymmetric registered
[    0.180919] Asymmetric key parser 'x509' registered
[    0.181538] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252)
[    0.182448] io scheduler noop registered
[    0.182995] io scheduler deadline registered
[    0.183632] io scheduler cfq registered (default)
[    0.184312] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[    0.184994] pciehp: PCI Express Hot Plug Controller Driver version: 0.4
[    0.185881] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
[    0.186775] ACPI: Power Button [PWRF]
[    0.187315] GHES: HEST is not enabled!
[    0.188037] ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11
[    0.189546] ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 10
[    0.191160] ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 10
[    0.193347] ACPI: PCI Interrupt Link [LNKB] enabled at IRQ 11
[    0.195317] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    0.222140] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    0.223503] Non-volatile memory driver v1.3
[    1.172293] tsc: Refined TSC clocksource calibration: 2893.436 MHz
qemu: terminating on signal 2           <---------- (I have to cancel QEMU process by Ctrl + C)


-- 
			Amos.