Messages in this thread | | | Date | Thu, 20 Jan 2022 12:20:20 +0100 | Subject | Re: [PATCH v2 7/7] kvm/x86: rework guest entry logic | From | Paolo Bonzini <> |
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On 1/19/22 11:58, Mark Rutland wrote: > > To minimize duplication and to more clearly balance entry and exit, both > entry and exit of guest timing are placed in vcpu_enter_guest(), using > the new guest_timing_{enter,exit}_irqoff() helpers. When context > tracking is used a small amount of additional time will be accounted > towards guests; tick-based accounting is unnaffected as IRQs are > disabled at this point and not enabled until after the return from the > guest. > > This also corrects (benign) mis-balanced context tracking accounting > introduced in commits: > > ae95f566b3d22ade ("KVM: X86: TSCDEADLINE MSR emulation fastpath") > 26efe2fd92e50822 ("KVM: VMX: Handle preemption timer fastpath") > > Where KVM can enter a guest multiple times, calling vtime_guest_enter() > without a corresponding call to vtime_account_guest_exit(), and with > vtime_account_system() called when vtime_account_guest() should be used. > As account_system_time() checks PF_VCPU and calls account_guest_time(), > this doesn't result in any functional problem, but is unnecessarily > confusing.
Yes, I agree.
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo
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