Messages in this thread | | | Subject | Re: [PATCH v2 0/3] KVM: Properly account for guest CPU time | From | Christian Borntraeger <> | Date | Tue, 13 Apr 2021 10:32:59 +0200 |
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On 13.04.21 09:16, Wanpeng Li wrote: > The bugzilla https://bugzilla.kernel.org/show_bug.cgi?id=209831 > reported that the guest time remains 0 when running a while true > loop in the guest. > > The commit 87fa7f3e98a131 ("x86/kvm: Move context tracking where it > belongs") moves guest_exit_irqoff() close to vmexit breaks the > tick-based time accouting when the ticks that happen after IRQs are > disabled are incorrectly accounted to the host/system time. This is > because we exit the guest state too early. > > This patchset splits both context tracking logic and the time accounting > logic from guest_enter/exit_irqoff(), keep context tracking around the > actual vmentry/exit code, have the virt time specific helpers which > can be placed at the proper spots in kvm. In addition, it will not > break the world outside of x86. > > v1 -> v2: > * split context_tracking from guest_enter/exit_irqoff > * provide separate vtime accounting functions for consistent > * place the virt time specific helpers at the proper splot > > Suggested-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Michael Tokarev <mjt@tls.msk.ru> > > Wanpeng Li (3): > context_tracking: Split guest_enter/exit_irqoff > context_tracking: Provide separate vtime accounting functions > x86/kvm: Fix vtime accounting > > arch/x86/kvm/svm/svm.c | 6 ++- > arch/x86/kvm/vmx/vmx.c | 6 ++- > arch/x86/kvm/x86.c | 1 + > include/linux/context_tracking.h | 84 +++++++++++++++++++++++++++++++--------- > 4 files changed, 74 insertions(+), 23 deletions(-) >
The non CONFIG_VIRT_CPU_ACCOUNTING_GEN look good.
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