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Diffstat (limited to 'results/classifier/009/performance/79834768')
| -rw-r--r-- | results/classifier/009/performance/79834768 | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/results/classifier/009/performance/79834768 b/results/classifier/009/performance/79834768 new file mode 100644 index 000000000..95c9f99ec --- /dev/null +++ b/results/classifier/009/performance/79834768 @@ -0,0 +1,419 @@ +performance: 0.952 +debug: 0.943 +other: 0.943 +permissions: 0.939 +graphic: 0.933 +semantic: 0.920 +PID: 0.916 +device: 0.915 +socket: 0.912 +files: 0.904 +vnc: 0.885 +boot: 0.880 +KVM: 0.840 +network: 0.830 + +[Qemu-devel] [BUG] Windows 7 got stuck easily while run PCMark10 application + +Hiï¼ + +We hit a bug in our test while run PCMark 10 in a windows 7 VM, +The VM got stuck and the wallclock was hang after several minutes running +PCMark 10 in it. +It is quite easily to reproduce the bug with the upstream KVM and Qemu. + +We found that KVM can not inject any RTC irq to VM after it was hang, it fails +to +Deliver irq in ioapic_set_irq() because RTC irq is still pending in ioapic->irr. + +static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq, + int irq_level, bool line_status) +{ +⦠⦠+ if (!irq_level) { + ioapic->irr &= ~mask; + ret = 1; + goto out; + } +⦠⦠+ if ((edge && old_irr == ioapic->irr) || + (!edge && entry.fields.remote_irr)) { + ret = 0; + goto out; + } + +According to RTC spec, after RTC injects a High level irq, OS will read CMOSâs +register C to to clear the irq flag, and pull down the irq electric pin. + +For Qemu, we will emulate the reading operation in cmos_ioport_read(), +but Guest OS will fire a write operation before to tell which register will be +read +after this write, where we use s->cmos_index to record the following register +to read. + +But in our test, we found that there is a possible situation that Vcpu fails to +read +RTC_REG_C to clear irq, This could happens while two VCpus are writing/reading +registers at the same time, for example, vcpu 0 is trying to read RTC_REG_C, +so it write RTC_REG_C first, where the s->cmos_index will be RTC_REG_C, +but before it tries to read register C, another vcpu1 is going to read RTC_YEAR, +it changes s->cmos_index to RTC_YEAR by a writing action. +The next operation of vcpu0 will be lead to read RTC_YEAR, In this case, we +will miss +calling qemu_irq_lower(s->irq) to clear the irq. After this, kvm will never +inject RTC irq, +and Windows VM will hang. +static void cmos_ioport_write(void *opaque, hwaddr addr, + uint64_t data, unsigned size) +{ + RTCState *s = opaque; + + if ((addr & 1) == 0) { + s->cmos_index = data & 0x7f; + } +â¦â¦ +static uint64_t cmos_ioport_read(void *opaque, hwaddr addr, + unsigned size) +{ + RTCState *s = opaque; + int ret; + if ((addr & 1) == 0) { + return 0xff; + } else { + switch(s->cmos_index) { + +According to CMOS spec, âany write to PROT 0070h should be followed by an +action to PROT 0071h or the RTC +Will be RTC will be left in an unknown stateâ, but it seems that we can not +ensure this sequence in qemu/kvm. + +Any ideas ? + +Thanks, +Hailiang + +Pls see the trace of kvm_pio: + + CPU 1/KVM-15567 [003] .... 209311.762579: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762582: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x89 + CPU 1/KVM-15567 [003] .... 209311.762590: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x17 + CPU 0/KVM-15566 [005] .... 209311.762611: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0xc + CPU 1/KVM-15567 [003] .... 209311.762615: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762619: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x88 + CPU 1/KVM-15567 [003] .... 209311.762627: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x12 + CPU 0/KVM-15566 [005] .... 209311.762632: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x12 + CPU 1/KVM-15567 [003] .... 209311.762633: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 0/KVM-15566 [005] .... 209311.762634: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0xc <--- Firstly write to 0x70, cmo_index = 0xc & +0x7f = 0xc + CPU 1/KVM-15567 [003] .... 209311.762636: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x86 <-- Secondly write to 0x70, cmo_index = 0x86 & +0x7f = 0x6, cover the cmo_index result of first time + CPU 0/KVM-15566 [005] .... 209311.762641: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x6 <-- vcpu0 read 0x6 because cmo_index is 0x6 now + CPU 1/KVM-15567 [003] .... 209311.762644: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x6 <- vcpu1 read 0x6 + CPU 1/KVM-15567 [003] .... 209311.762649: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762669: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x87 + CPU 1/KVM-15567 [003] .... 209311.762678: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x1 + CPU 1/KVM-15567 [003] .... 209311.762683: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762686: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x84 + CPU 1/KVM-15567 [003] .... 209311.762693: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x10 + CPU 1/KVM-15567 [003] .... 209311.762699: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762702: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x82 + CPU 1/KVM-15567 [003] .... 209311.762709: kvm_pio: pio_read at 0x71 size +1 count 1 val 0x25 + CPU 1/KVM-15567 [003] .... 209311.762714: kvm_pio: pio_read at 0x70 size +1 count 1 val 0xff + CPU 1/KVM-15567 [003] .... 209311.762717: kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x80 + + +Regards, +-Gonglei + +From: Zhanghailiang +Sent: Friday, December 01, 2017 3:03 AM +To: address@hidden; address@hidden; Paolo Bonzini +Cc: Huangweidong (C); Gonglei (Arei); wangxin (U); Xiexiangyou +Subject: [BUG] Windows 7 got stuck easily while run PCMark10 application + +Hiï¼ + +We hit a bug in our test while run PCMark 10 in a windows 7 VM, +The VM got stuck and the wallclock was hang after several minutes running +PCMark 10 in it. +It is quite easily to reproduce the bug with the upstream KVM and Qemu. + +We found that KVM can not inject any RTC irq to VM after it was hang, it fails +to +Deliver irq in ioapic_set_irq() because RTC irq is still pending in ioapic->irr. + +static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq, + int irq_level, bool line_status) +{ +⦠⦠+ if (!irq_level) { + ioapic->irr &= ~mask; + ret = 1; + goto out; + } +⦠⦠+ if ((edge && old_irr == ioapic->irr) || + (!edge && entry.fields.remote_irr)) { + ret = 0; + goto out; + } + +According to RTC spec, after RTC injects a High level irq, OS will read CMOSâs +register C to to clear the irq flag, and pull down the irq electric pin. + +For Qemu, we will emulate the reading operation in cmos_ioport_read(), +but Guest OS will fire a write operation before to tell which register will be +read +after this write, where we use s->cmos_index to record the following register +to read. + +But in our test, we found that there is a possible situation that Vcpu fails to +read +RTC_REG_C to clear irq, This could happens while two VCpus are writing/reading +registers at the same time, for example, vcpu 0 is trying to read RTC_REG_C, +so it write RTC_REG_C first, where the s->cmos_index will be RTC_REG_C, +but before it tries to read register C, another vcpu1 is going to read RTC_YEAR, +it changes s->cmos_index to RTC_YEAR by a writing action. +The next operation of vcpu0 will be lead to read RTC_YEAR, In this case, we +will miss +calling qemu_irq_lower(s->irq) to clear the irq. After this, kvm will never +inject RTC irq, +and Windows VM will hang. +static void cmos_ioport_write(void *opaque, hwaddr addr, + uint64_t data, unsigned size) +{ + RTCState *s = opaque; + + if ((addr & 1) == 0) { + s->cmos_index = data & 0x7f; + } +â¦â¦ +static uint64_t cmos_ioport_read(void *opaque, hwaddr addr, + unsigned size) +{ + RTCState *s = opaque; + int ret; + if ((addr & 1) == 0) { + return 0xff; + } else { + switch(s->cmos_index) { + +According to CMOS spec, âany write to PROT 0070h should be followed by an +action to PROT 0071h or the RTC +Will be RTC will be left in an unknown stateâ, but it seems that we can not +ensure this sequence in qemu/kvm. + +Any ideas ? + +Thanks, +Hailiang + +On 01/12/2017 08:08, Gonglei (Arei) wrote: +> +First write to 0x70, cmos_index = 0xc & 0x7f = 0xc +> +      CPU 0/KVM-15566 kvm_pio: pio_write at 0x70 size 1 count 1 val 0xc> +> +Second write to 0x70, cmos_index = 0x86 & 0x7f = 0x6>       CPU 1/KVM-15567 +> +kvm_pio: pio_write at 0x70 size 1 count 1 val 0x86> vcpu0 read 0x6 because +> +cmos_index is 0x6 now:>       CPU 0/KVM-15566 kvm_pio: pio_read at 0x71 size +> +1 count 1 val 0x6> vcpu1 read 0x6:>       CPU 1/KVM-15567 kvm_pio: pio_read +> +at 0x71 size 1 count 1 val 0x6 +This seems to be a Windows bug. The easiest workaround that I +can think of is to clear the interrupts already when 0xc is written, +without waiting for the read (because REG_C can only be read). + +What do you think? + +Thanks, + +Paolo + +I also think it's windows bug, the problem is that it doesn't occur on xen +platform. And there are some other works need to be done while reading REG_C. +So I wrote that patch. + +Thanks, +Gonglei +å件人ï¼Paolo Bonzini +æ¶ä»¶äººï¼é¾ç£,å¼ æµ·äº®,qemu-devel,Michael S. Tsirkin +æéï¼é»ä¼æ ,ç欣,谢祥æ +æ¶é´ï¼2017-12-02 01:10:08 +主é¢:Re: [BUG] Windows 7 got stuck easily while run PCMark10 application + +On 01/12/2017 08:08, Gonglei (Arei) wrote: +> +First write to 0x70, cmos_index = 0xc & 0x7f = 0xc +> +CPU 0/KVM-15566 kvm_pio: pio_write at 0x70 size 1 count 1 val 0xc> +> +Second write to 0x70, cmos_index = 0x86 & 0x7f = 0x6> CPU 1/KVM-15567 +> +kvm_pio: pio_write at 0x70 size 1 count 1 val 0x86> vcpu0 read 0x6 because +> +cmos_index is 0x6 now:> CPU 0/KVM-15566 kvm_pio: pio_read at 0x71 size +> +1 count 1 val 0x6> vcpu1 read 0x6:> CPU 1/KVM-15567 kvm_pio: pio_read +> +at 0x71 size 1 count 1 val 0x6 +This seems to be a Windows bug. The easiest workaround that I +can think of is to clear the interrupts already when 0xc is written, +without waiting for the read (because REG_C can only be read). + +What do you think? + +Thanks, + +Paolo + +On 01/12/2017 18:45, Gonglei (Arei) wrote: +> +I also think it's windows bug, the problem is that it doesn't occur on +> +xen platform. +It's a race, it may just be that RTC PIO is faster in Xen because it's +implemented in the hypervisor. + +I will try reporting it to Microsoft. + +Thanks, + +Paolo + +> +Thanks, +> +Gonglei +> +*å件人ï¼*Paolo Bonzini +> +*æ¶ä»¶äººï¼*é¾ç£,å¼ æµ·äº®,qemu-devel,Michael S. Tsirkin +> +*æéï¼*é»ä¼æ ,ç欣,谢祥æ +> +*æ¶é´ï¼*2017-12-02 01:10:08 +> +*主é¢:*Re: [BUG] Windows 7 got stuck easily while run PCMark10 application +> +> +On 01/12/2017 08:08, Gonglei (Arei) wrote: +> +> First write to 0x70, cmos_index = 0xc & 0x7f = 0xc +> +>       CPU 0/KVM-15566 kvm_pio: pio_write at 0x70 size 1 count 1 val 0xc> +> +> Second write to 0x70, cmos_index = 0x86 & 0x7f = 0x6>       CPU 1/KVM-15567 +> +> kvm_pio: pio_write at 0x70 size 1 count 1 val 0x86> vcpu0 read 0x6 because +> +> cmos_index is 0x6 now:>       CPU 0/KVM-15566 kvm_pio: pio_read at 0x71 +> +> size 1 count 1 val 0x6> vcpu1 +> +read 0x6:>       CPU 1/KVM-15567 kvm_pio: pio_read at 0x71 size 1 count +> +1 val 0x6 +> +This seems to be a Windows bug. The easiest workaround that I +> +can think of is to clear the interrupts already when 0xc is written, +> +without waiting for the read (because REG_C can only be read). +> +> +What do you think? +> +> +Thanks, +> +> +Paolo + +On 2017/12/2 2:37, Paolo Bonzini wrote: +On 01/12/2017 18:45, Gonglei (Arei) wrote: +I also think it's windows bug, the problem is that it doesn't occur on +xen platform. +It's a race, it may just be that RTC PIO is faster in Xen because it's +implemented in the hypervisor. +No, In Xen, it does not has such problem because it injects the RTC irq without +checking whether its previous irq been cleared or not, which we do has such +checking +in KVM. + +static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq, + int irq_level, bool line_status) +{ + ... ... + if (!irq_level) { + ioapic->irr &= ~mask; -->clear the RTC irq in irr, Or we will can not +inject RTC irq. + ret = 1; + goto out; + } + +I agree that we move the operation of clearing RTC irq from cmos_ioport_read() +to +cmos_ioport_write() to ensure the action been done. + +Thanks, +Hailiang +I will try reporting it to Microsoft. + +Thanks, + +Paolo +Thanks, +Gonglei +*å件人ï¼*Paolo Bonzini +*æ¶ä»¶äººï¼*é¾ç£,å¼ æµ·äº®,qemu-devel,Michael S. Tsirkin +*æéï¼*é»ä¼æ ,ç欣,谢祥æ +*æ¶é´ï¼*2017-12-02 01:10:08 +*主é¢:*Re: [BUG] Windows 7 got stuck easily while run PCMark10 application + +On 01/12/2017 08:08, Gonglei (Arei) wrote: +First write to 0x70, cmos_index = 0xc & 0x7f = 0xc + CPU 0/KVM-15566 kvm_pio: pio_write at 0x70 size 1 count 1 val 0xc> Second write to +0x70, cmos_index = 0x86 & 0x7f = 0x6> CPU 1/KVM-15567 kvm_pio: pio_write at 0x70 +size 1 count 1 val 0x86> vcpu0 read 0x6 because cmos_index is 0x6 now:> CPU +0/KVM-15566 kvm_pio: pio_read at 0x71 size 1 count 1 val 0x6> vcpu1 +read 0x6:> CPU 1/KVM-15567 kvm_pio: pio_read at 0x71 size 1 count +1 val 0x6 +This seems to be a Windows bug. The easiest workaround that I +can think of is to clear the interrupts already when 0xc is written, +without waiting for the read (because REG_C can only be read). + +What do you think? + +Thanks, + +Paolo +. + |