other: 0.620 boot: 0.481 KVM: 0.476 device: 0.455 vnc: 0.441 graphic: 0.391 performance: 0.349 debug: 0.312 permissions: 0.307 semantic: 0.302 PID: 0.292 network: 0.286 socket: 0.266 files: 0.215 -cpu haswell / broadwell have no MONITOR in features1 In qemu 2.9.0 if you run qemu-system-x86_64 -cpu Broadwell (or Haswell) then the CPU features1 flag include the SSE3 bit, but do NOT include the MONITOR/MWAIT bit. This is so even when the host includes the features. Additionally, running qemu in this manner results in several error messages: warning: TCG doesn't support requested feature: CPUID.01H:ECX.fma [bit 12] warning: TCG doesn't support requested feature: CPUID.01H:ECX.pcid [bit 17] warning: TCG doesn't support requested feature: CPUID.01H:ECX.x2apic [bit 21] warning: TCG doesn't support requested feature: CPUID.01H:ECX.tsc-deadline [bit 24] warning: TCG doesn't support requested feature: CPUID.01H:ECX.avx [bit 28] warning: TCG doesn't support requested feature: CPUID.01H:ECX.f16c [bit 29] warning: TCG doesn't support requested feature: CPUID.01H:ECX.rdrand [bit 30] warning: TCG doesn't support requested feature: CPUID.07H:EBX.hle [bit 4] warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx2 [bit 5] warning: TCG doesn't support requested feature: CPUID.07H:EBX.invpcid [bit 10] warning: TCG doesn't support requested feature: CPUID.07H:EBX.rtm [bit 11] warning: TCG doesn't support requested feature: CPUID.07H:EBX.rdseed [bit 18] warning: TCG doesn't support requested feature: CPUID.80000001H:ECX.3dnowprefetch (Among possible other uses, the lack of the MONITOR feature bit causes NetBSD to fall-back on a check-and-pause loop while an application CPU is waiting to be told to proceed by the boot CPU.) Can you still reproduce this issue with the latest version of QEMU? Looking at https://git.qemu.org/?p=qemu.git;a=commitdiff;h=0723cc8a5558c94388 for example, it might have been fixed since QEMU v4.2... This bug seems not to be a problem, and may reflect an issue with NetBSD. Even though the decode of the features1 register does not include MONITOR/MWAIT, that capability is separately reported on a separate line, further down (apologies in advance for any confusing line-wrap): # cpuctl identify 0 cpu0: highest basic info 0000000d cpu0: highest hypervisor info 40000001 cpu0: highest extended info 80000008 cpu0: Running on hypervisor: QEMU(TCG) cpu0: "Intel Core Processor (Broadwell)" cpu0: Intel Core M-5xxx, 5th gen Core (Broadwell) (686-class), 3198.24 MHz cpu0: family 0x6 model 0x3d stepping 0x2 (id 0x306d2) cpu0: features 0x78bfbfd cpu0: features 0x78bfbfd cpu0: features1 0xced82203 cpu0: features1 0xced82203 cpu0: features2 0x28100800 cpu0: features3 0x21 cpu0: features5 0x180389 cpu0: xsave features 0x7 cpu0: xsave instructions 0x1 cpu0: xsave area size: current 832, maximum 832, xgetbv enabled cpu0: enabled xsave 0x7 cpu0: I-cache 32KB 64B/line 8-way, D-cache 32KB 64B/line 8-way cpu0: L2 cache 4MB 64B/line 16-way cpu0: L3 cache 16MB 64B/line 16-way cpu0: Initial APIC ID 0 cpu0: Cluster/Package ID 0 cpu0: Core ID 0 cpu0: SMT ID 0 cpu0: MONITOR/MWAIT extensions 0x3 cpu0: monitor-line size 0 cpu0: DSPM-eax 0x4 cpu0: SEF highest subleaf 00000000 cpu0: Power Management features: 0 cpu0: microcode version 0x0, platform ID 0 # On Fri, 22 May 2020, Thomas Huth wrote: > Can you still reproduce this issue with the latest version of QEMU? > Looking at > https://git.qemu.org/?p=qemu.git;a=commitdiff;h=0723cc8a5558c94388 for > example, it might have been fixed since QEMU v4.2... > > ** Changed in: qemu > Status: New => Incomplete > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/1693667 > > Title: > -cpu haswell / broadwell have no MONITOR in features1 > > Status in QEMU: > Incomplete > > Bug description: > In qemu 2.9.0 if you run > > qemu-system-x86_64 -cpu Broadwell (or Haswell) > > then the CPU features1 flag include the SSE3 bit, but do NOT include > the MONITOR/MWAIT bit. This is so even when the host includes the > features. > > > Additionally, running qemu in this manner results in several error messages: > > warning: TCG doesn't support requested feature: CPUID.01H:ECX.fma [bit 12] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.pcid [bit 17] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.x2apic [bit 21] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.tsc-deadline [bit 24] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.avx [bit 28] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.f16c [bit 29] > warning: TCG doesn't support requested feature: CPUID.01H:ECX.rdrand [bit 30] > warning: TCG doesn't support requested feature: CPUID.07H:EBX.hle [bit 4] > warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx2 [bit 5] > warning: TCG doesn't support requested feature: CPUID.07H:EBX.invpcid [bit 10] > warning: TCG doesn't support requested feature: CPUID.07H:EBX.rtm [bit 11] > warning: TCG doesn't support requested feature: CPUID.07H:EBX.rdseed [bit 18] > warning: TCG doesn't support requested feature: CPUID.80000001H:ECX.3dnowprefetch > > > (Among possible other uses, the lack of the MONITOR feature bit causes NetBSD to fall-back on a > check-and-pause loop while an application CPU is waiting to be told to proceed by the boot CPU.) > > To manage notifications about this bug go to: > https://bugs.launchpad.net/qemu/+bug/1693667/+subscriptions > > !DSPAM:5ec76256254551748016490! > > +--------------------+--------------------------+-----------------------+ | Paul Goyette | PGP Key fingerprint: | E-mail addresses: | | (Retired) | FA29 0E3B 35AF E8AE 6651 |