[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
** Also affects: qemu (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
** Description changed: I was able to generate trace dump in Qemu for kvm_run_exit event in both QEMU 2.11.0 and QEMU 4.0.0 From the trace i noticed that the number of KVM_KXIT_MMIO calls has increased alot and is causing delay in testcase execution. I executed same testcase from Qemu 2.11 and Qemu4. Inside Virtual machine when using qemu 2.11 testcase got completed in 11 seconds but the same testcase when executed on Qemu 4.0.0 got executed in 26 seconds. + I did a bit of digging and extracted the kvm_run_exit to figure out + whats going on. - I did a bit of digging and extracted the kvm_run_exit to figure out whats going on. - - Please find + Please find Stats from Qemu2.11: KVM_EXIT_UNKNOWN : 0 KVM_EXIT_EXCEPTION: 0 KVM_EXIT_IO : 182513 KVM_EXIT_HYPERCALL: 0 KVM_EXIT_DEBUG: 0 KVM_EXIT_HLT : 0 KVM_EXIT_MMIO : 216701 KVM_EXIT_IRQ_WINDOW_OPEN : 0 KVM_EXIT_SHUTDOWN : 0 KVM_EXIT_FAIL_ENTRY : 0 KVM_EXIT_INTR : 0 KVM_EXIT_SET_TPR : 0 KVM_EXIT_TPR_ACCESS : 0 KVM_EXIT_S390_SIEIC : 0 KVM_EXIT_S390_RESET : 0 KVM_EXIT_DCR : 0 KVM_EXIT_NMI : 0 KVM_EXIT_INTERNAL_ERROR : 0 KVM_EXIT_OSI : 0 KVM_EXIT_PAPR_HCALL : 0 KVM_EXIT_S390_UCONTROL: 0 KVM_EXIT_WATCHDOG : 0 KVM_EXIT_S390_TSCH: 0 KVM_EXIT_EPR : 0 KVM_EXIT_SYSTEM_EVENT : 0 KVM_EXIT_S390_STSI: 0 KVM_EXIT_IOAPIC_EOI : 0 KVM_EXIT_HYPERV : 0 KVM_RUN_EXIT : 399214 (Total in Qemu 2.11 for a testcase) - Stats For Qemu 4.0.0: - VM_EXIT_UNKNOWN : 0 - KVM_EXIT_EXCEPTION: 0 - KVM_EXIT_IO : 163729 - KVM_EXIT_HYPERCALL: 0 - KVM_EXIT_DEBUG: 0 - KVM_EXIT_HLT : 0 - KVM_EXIT_MMIO : 1094231 - KVM_EXIT_IRQ_WINDOW_OPEN : 46 - KVM_EXIT_SHUTDOWN : 0 - KVM_EXIT_FAIL_ENTRY : 0 - KVM_EXIT_INTR : 0 - KVM_EXIT_SET_TPR : 0 - KVM_EXIT_TPR_ACCESS : 0 - KVM_EXIT_S390_SIEIC : 0 - KVM_EXIT_S390_RESET : 0 - KVM_EXIT_DCR : 0 - KVM_EXIT_NMI : 0 - KVM_EXIT_INTERNAL_ERROR : 0 - KVM_EXIT_OSI : 0 - KVM_EXIT_PAPR_HCALL : 0 - KVM_EXIT_S390_UCONTROL: 0
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
** Changed in: qemu Status: New => Opinion -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
One observation i made was that adding qemu arguments "-nic none" improved the testcase performance. Does "-nic none" reduce KVM_EXIT_MMIO ? Are there any other qemu arguments that can be used to improve qemu overall performance ? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
Could someone update on this? ** Changed in: qemu Status: Incomplete => New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
The testcase is a rather a very basic one. Doing a mmap on a pcie device and triggering a read and write operation on the Virtual Address, which would in-turn trigger transaction requests on the host device. I understand that Qemu v4.0 may be and old one, but the issue is that test case execution has become rather very slow with Qemu4.0.0 and the only thing i could notice from using tracebacks were related with increase in KVM_MMIO_EXIT when compared with Qemu2.11.0 version. Can it be verified as to why the number of KVM_EXIT_MMIO has increased drastically in qemu4 when compared to Qemu2.11.0 ? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
Can you provide a link to the test case that you used? Otherwise, can you try to bisect the problem? Can you please also try with the latest version of QEMU? v4.0 is rather old already. ** Information type changed from Public Security to Public ** Changed in: qemu Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1912777] Re: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0
** Information type changed from Private Security to Public Security ** Also affects: ubuntu Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912777 Title: KVM_EXIT_MMIO has increased in Qemu4.0.0 when compared to Qemu 2.11.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1912777/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
