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| author | Tao Cui <cuitao@kylinos.cn> | 2026-08-10 12:21:50 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2026-08-10 12:21:50 +0800 |
| commit | fe41c0759b11b982f945633b7abb4b49dfaf8ce4 (patch) | |
| tree | 153d1704426430d09184f904d494245b496d0326 | |
| parent | a5518ad7ef7dc1837258d37ba0a11dcb5d7ecaba (diff) | |
| download | linux-stable-fe41c0759b11b982f945633b7abb4b49dfaf8ce4.tar.gz linux-stable-fe41c0759b11b982f945633b7abb4b49dfaf8ce4.zip | |
LoongArch: KVM: Reload one-shot TVAL on migration destination
kvm_restore_timer() rebuilds the remaining timer countdown value from
vcpu->arch.expire, which is host-internal and is not part of the
migrated vCPU state. On the migration destination it is still 0, so for
a one-shot timer that has not expired yet the computed delta is 0 and
write_gcsr_timertick(0) injects the timer interrupt immediately instead
of after the remaining time.
The expired one-shot case (TVAL = -1) is already handled earlier. When
expire has not been set (i.e. on the migration destination), reload the
remaining countdown value from the migrated TVAL. This covers both one-
shot and periodic timers. The regular preempt/resume path on the source,
where expire is valid, is unchanged.
Fixes: a5857b9ff6e0 ("LoongArch: KVM: Implement vcpu timer operations")
Suggested-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/kvm/timer.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/loongarch/kvm/timer.c b/arch/loongarch/kvm/timer.c index 3829f35a4070..96f33e34855a 100644 --- a/arch/loongarch/kvm/timer.c +++ b/arch/loongarch/kvm/timer.c @@ -119,6 +119,18 @@ void kvm_restore_timer(struct kvm_vcpu *vcpu) delta = 0; now = ktime_get(); expire = vcpu->arch.expire; + if (!expire) { + /* + * vcpu->arch.expire is host-internal and is not migrated, + * so it is 0 after migration. Reload the remaining countdown + * from the migrated TVAL. This covers both one-shot and + * periodic timers. + */ + if (ticks < cfg) + delta = tick_to_ns(vcpu, ticks); + expire = ktime_add_ns(now, delta); + } + if (ktime_before(now, expire)) delta = ktime_to_tick(vcpu, ktime_sub(expire, now)); else if (cfg & CSR_TCFG_PERIOD) { |