From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Michael Tokarev <mjt@tls.msk.ru>
Subject: [PATCH v2 0/3] KVM: Properly account for guest CPU time
Date: Tue, 13 Apr 2021 15:16:06 +0800 [thread overview]
Message-ID: <1618298169-3831-1-git-send-email-wanpengli@tencent.com> (raw)
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(-)
--
2.7.4
next reply other threads:[~2021-04-13 7:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 7:16 Wanpeng Li [this message]
2021-04-13 7:16 ` [PATCH v2 1/3] context_tracking: Split guest_enter/exit_irqoff Wanpeng Li
2021-04-13 7:35 ` Christian Borntraeger
2021-04-13 7:38 ` Wanpeng Li
2021-04-13 7:48 ` Christian Borntraeger
2021-04-13 7:52 ` Wanpeng Li
2021-04-13 8:07 ` Christian Borntraeger
2021-04-13 7:16 ` [PATCH v2 2/3] context_tracking: Provide separate vtime accounting functions Wanpeng Li
2021-04-13 7:16 ` [PATCH v2 3/3] x86/kvm: Fix vtime accounting Wanpeng Li
2021-04-13 8:32 ` [PATCH v2 0/3] KVM: Properly account for guest CPU time Christian Borntraeger
2021-04-13 17:25 ` Sean Christopherson
2021-04-14 9:36 ` Wanpeng Li
2021-04-15 0:49 ` Sean Christopherson
2021-04-15 1:23 ` Wanpeng Li
2021-04-15 19:02 ` Sean Christopherson
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