From: bugzilla-daemon@kernel.org
To: kvm@vger.kernel.org
Subject: [Bug 221033] New: Real time clock does not trigger alarm on QEMU
Date: Mon, 02 Feb 2026 07:34:23 +0000 [thread overview]
Message-ID: <bug-221033-28872@https.bugzilla.kernel.org/> (raw)
https://bugzilla.kernel.org/show_bug.cgi?id=221033
Bug ID: 221033
Summary: Real time clock does not trigger alarm on QEMU
Product: Virtualization
Version: unspecified
Hardware: i386
OS: Linux
Status: NEW
Severity: low
Priority: P3
Component: kvm
Assignee: virtualization_kvm@kernel-bugs.osdl.org
Reporter: richard.lyu@suse.com
Regression: No
LTP test rtc01.c [0] attempts to enable alarm via ioctl() RTC_AIE_ON on
/dev/rtc. Following select() timeouts (returns zero) instead of triggering
alarm. I would expect to fail with -1 or pass, timeout is strange:
./rtc01
rtc01 0 TINFO : RTC READ TEST:
rtc01 1 TPASS : RTC READ TEST Passed
rtc01 0 TINFO : Current RTC date/time is 14-11-2025, 01:35:18.
rtc01 0 TINFO : RTC ALARM TEST :
rtc01 0 TINFO : Alarm time set to 01:35:23.
rtc01 0 TINFO : Waiting 5 seconds for the alarm...
rtc01 2 TFAIL : rtc01.c:151: Timed out waiting for the alarm
rtc01 0 TINFO : RTC UPDATE INTERRUPTS TEST :
rtc01 0 TINFO : Waiting for 5 update interrupts...
rtc01 3 TFAIL : rtc01.c:208: Timed out waiting for the update
interrupt
rtc01 0 TINFO : RTC Tests Done!
The bug only triggers in a VM, not on bare metal. I'm not sure yet whether this
is a bug or expected behavior within a VM environment.
[0]
https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/device-drivers/rtc
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next reply other threads:[~2026-02-02 7:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-02 7:34 bugzilla-daemon [this message]
2026-02-02 7:38 ` [Bug 221033] Real time clock does not trigger alarm on QEMU bugzilla-daemon
2026-02-02 8:10 ` bugzilla-daemon
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