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| author | Baoquan He <bhe@redhat.com> | 2018-02-14 06:46:53 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-17 11:47:45 +0100 |
| commit | 339b2ae0cd5d4a58f9efe06e4ee36adbeca59228 (patch) | |
| tree | c629f2ed6224a140624e3a7cfef0790064b6efd2 /arch/x86/kernel/reboot.c | |
| parent | x86/apic: Split disable_IO_APIC() into two functions to fix CONFIG_KEXEC_JUMP=y (diff) | |
| download | linux-339b2ae0cd5d4a58f9efe06e4ee36adbeca59228.tar.xz linux-339b2ae0cd5d4a58f9efe06e4ee36adbeca59228.zip | |
x86/apic: Fix restoring boot IRQ mode in reboot and kexec/kdump
This is a regression fix.
Before, to fix erratum AVR31, the following commit:
522e66464467 ("x86/apic: Disable I/O APIC before shutdown of the local APIC")
... moved the lapic_shutdown() call to after disable_IO_APIC() in the reboot
and kexec/kdump code paths.
This introduced the following regression: disable_IO_APIC() not only clears
the IO-APIC, but it also restores boot IRQ mode by setting the
LAPIC/APIC/IMCR, calling lapic_shutdown() after disable_IO_APIC() will
disable LAPIC and ruin the possible virtual wire mode setting which
the code has been trying to do all along.
The consequence is that a KVM guest kernel always prints the warning below
during kexec/kdump as the kernel boots up:
[ 0.001000] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/apic/apic.c:1467 setup_local_APIC+0x228/0x330
[ ........]
[ 0.001000] Call Trace:
[ 0.001000] apic_bsp_setup+0x56/0x74
[ 0.001000] x86_late_time_init+0x11/0x16
[ 0.001000] start_kernel+0x3c9/0x486
[ 0.001000] secondary_startup_64+0xa5/0xb0
[ ........]
[ 0.001000] masked ExtINT on CPU#0
To fix this, just call clear_IO_APIC() to stop the IO-APIC where
disable_IO_APIC() was called, and call restore_boot_irq_mode() to
restore boot IRQ mode before a reboot or a kexec/kdump jump.
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: douly.fnst@cn.fujitsu.com
Cc: joro@8bytes.org
Cc: prarit@redhat.com
Cc: stable@vger.kernel.org
Cc: uobergfe@redhat.com
Fixes: commit 522e66464467 ("x86/apic: Disable I/O APIC before shutdown of the local APIC")
Link: http://lkml.kernel.org/r/20180214054656.3780-4-bhe@redhat.com
[ Rewrote the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/reboot.c')
| -rw-r--r-- | arch/x86/kernel/reboot.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 2126b9d27c34..725624b6c0c0 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -666,7 +666,7 @@ void native_machine_shutdown(void) * Even without the erratum, it still makes sense to quiet IO APIC * before disabling Local APIC. */ - disable_IO_APIC(); + clear_IO_APIC(); #endif #ifdef CONFIG_SMP @@ -680,6 +680,7 @@ void native_machine_shutdown(void) #endif lapic_shutdown(); + restore_boot_irq_mode(); #ifdef CONFIG_HPET_TIMER hpet_disable(); |