On Mon, Jul 15, 2013 at 7:01 PM, Jan Kiszka <jan.kis...@siemens.com> wrote: > On 2013-07-15 12:52, Stefan Hajnoczi wrote: >> The following qemu.git commit adds a ~2 minute regression in boot time >> to a x86_64 live CD: >> >> commit b40acf99bef69fa8ab0f9092ff162fde945eec12 >> Author: Jan Kiszka <jan.kis...@siemens.com> >> Date: Mon Jun 24 10:45:09 2013 +0200 >> >> ioport: Switch dispatching to memory core layer >> >> After the ISOLINUX menu, the display goes white and sits there for about >> 2 minutes on my laptop before the usual Linux boot screen appears. >> >> $ qemu-system-x86_64 -enable-kvm -cpu host -m 1024 -cdrom ~/iso/livecd.iso >> >> The parent commit immediately goes to the usual boot screen after >> ISOLINUX. Unfortunately I don't have a ISO download link for the live >> CD. > > Can you share it otherwise (before I spend time on recreating something > that does not trigger it)?
I reproduced this now with an installed RHEL 6.4 guest (no ISO). >> >> Any ideas? > > What does perf say during that time? What ftrace regarding the port > numbers and access types? The guest kernel prints the following IPMI initialization output: acpiphp: Slot [31] registered ipmi message handler version 39.2 IPMI System Interface driver. ipmi_si: Adding default-specified kcs state machine ipmi_si: Trying default-specified kcs state machine at i/o address 0xca2, slave address 0x0, irq 0 ipmi_si: There appears to be no BMC at this location ipmi_si: Adding default-specified smic state machine ipmi_si: Trying default-specified smic state machine at i/o address 0xca9, slave address 0x0, irq 0 ipmi_smic_drv: smic hosed: state = SMIC_OP_OK, status != SMIC_SC_SMS_READY ipmi_si: There appears to be no BMC at this location ipmi_si: Adding default-specified bt state machine ipmi_si: Trying default-specified bt state machine at i/o address 0xe4, slave address 0x0, irq 0 Refined TSC clocksource calibration: 2895.094 MHz. [...wait...] IPMI BT: timeout in RD_WAIT [ ] 1 retries left Before this commit the guest boots immediately and does not get stuck in IPMI initialization. kvmstat: kvm_exit 2567180 3007 kvm_entry 2567180 3007 kvm_inj_virq 16226 1002 kvm_emulate_insn 2044389 1001 kvm_userspace_exit 538441 1001 kvm_pio 502055 1001 kvm_msr 16182 1001 kvm_apic 15994 1001 kvm_eoi 15876 1001 kvm_apic_accept_irq 15876 1001 kvm_pv_eoi 15763 1001 kvm_mmio 2006613 0 vcpu_match_mmio 1970359 0 kvm_cr 144706 0 kvm_cpuid 33451 0 kvm_set_irq 1032 0 kvm_pic_set_irq 1024 0 kvm_ioapic_set_irq 1024 0 kvm_page_fault 1020 0 kvm_ack_irq 277 0 kvm_inj_exception 33 0 kvm_fpu 6 0 kvm_track_tsc 2 0 kvm_apic_ipi 2 0 kvm_update_master_clock 2 0 IPMI seems like the smoking gun. perf shows a number of mmio/pio/msr accesses, the longest repeated sequence is: qemu-system-x86 7318 [003] 4188.001381: kvm:kvm_pio: pio_read at 0xe4 size 1 count 1 qemu-system-x86 7318 [003] 4188.002343: kvm:kvm_msr: msr_write 838 = 0xd6ff Stefan
