Bug 7100 - KVM: x86: Ensure PV TLB flush tracepoint reflects KVM behavior
Summary: KVM: x86: Ensure PV TLB flush tracepoint reflects KVM behavior
Status: NEW
Alias: None
Product: ANCK 5.10 Dev
Classification: ANCK
Component: X86 (show other bugs) X86
Version: unspecified
Hardware: All Linux
: P3-Medium S3-normal
Target Milestone: ---
Assignee: Guanjun
QA Contact: shuming
URL:
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Reported: 2023-10-31 17:34 UTC by jiangxin00
Modified: 2023-11-01 09:25 UTC (History)
2 users (show)

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Description jiangxin00 hygon_group 2023-10-31 17:34:43 UTC 
Description of problem:
In record_steal_time(), st->preempted is read twice, and
trace_kvm_pv_tlb_flush() might output result inconsistent if
kvm_vcpu_flush_tlb_guest() see a different st->preempted later.

It is a very trivial problem and hardly has actual harm and can be
avoided by reseting and reading st->preempted in atomic way via xchg().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>

Message-Id: <20210531174628.10265-1-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Version-Release number of selected component (if applicable):


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Additional info:
Comment 1 小龙 admin 2023-11-01 09:25:06 UTC 
The PR Link: https://gitee.com/anolis/cloud-kernel/pulls/2395