[PATCH 2/4] KVM: arm64: Reset last_steal on vCPU pid change
Dongli Zhang <[email protected]>
| Newsgroups | org.kernel.vger.kvm,dev.linux.lists.kvmarm,org.kernel.vger.linux-kselftest |
|---|---|
| Message-ID | <[email protected]> |
The previous commit resets x86 steal time accounting when the vCPU PID is changed. Do the same for arm64. KVM keeps a vCPU fd alive when userspace hot-unplugs a vCPU. If the fd is later reused from a new vCPU thread, vcpu->arch.steal.last_steal still reflects the old task's run_delay, while current->sched_info.run_delay belongs to the new task. Reset vcpu->arch.steal.last_steal from kvm_arch_vcpu_run_pid_change() unconditionally so the next stolen time update computes its delta against the new task's run_delay. Assisted-by: Codex:GPT-5.5 Signed-off-by: Dongli Zhang <[email protected]> --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 2 ++ arch/arm64/kvm/pvtime.c | 5 +++++ 3 files changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index bae2c4f92ef5..4607f956e787 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1339,6 +1339,7 @@ static inline bool kvm_arch_pmi_in_guest(struct kvm_vcpu *vcpu) long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); void kvm_update_stolen_time(struct kvm_vcpu *vcpu); +void kvm_reset_stolen_time(struct kvm_vcpu *vcpu); bool kvm_arm_pvtime_supported(void); int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9a6c72a18672..0f6e63eace21 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -929,6 +929,8 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) if (!kvm_arm_vcpu_is_finalized(vcpu)) return -EPERM; + kvm_reset_stolen_time(vcpu); + if (likely(vcpu_has_run_once(vcpu))) return 0; diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 4ceabaa4c30b..000bf49cc0fd 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -32,6 +32,11 @@ void kvm_update_stolen_time(struct kvm_vcpu *vcpu) srcu_read_unlock(&kvm->srcu, idx); } +void kvm_reset_stolen_time(struct kvm_vcpu *vcpu) +{ + vcpu->arch.steal.last_steal = current->sched_info.run_delay; +} + long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu) { u32 feature = smccc_get_arg1(vcpu); -- 2.43.5