Messages in this thread Patch in this message |  | | Subject | Re: [PATCH v3 0/5] x86/apic: Fix restoring boot irq mode in reboot and kexec/kdump | From | Dou Liyang <> | Date | Mon, 12 Feb 2018 12:06:10 +0800 |
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Hi all,
One thing confused me.
The disconnect_bsp_APIC() may restore the interrupt delivery mode into virtual wire mode. it uses the vector F as the spurious interrput, But, IMO, using the vector 0xFF(SPURIOUS_APIC_VECTOR) may more suitable and will give us more detail. Why the disconnect_bsp_APIC() use vector F here?
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 25ddf02598d2..550deaad6a9a 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2130,7 +2130,7 @@ void disconnect_bsp_APIC(int virt_wire_setup) value = apic_read(APIC_SPIV); value &= ~APIC_VECTOR_MASK; value |= APIC_SPIV_APIC_ENABLED; - value |= 0xf; + value |= SPURIOUS_APIC_VECTOR; apic_write(APIC_SPIV, value);
if (!virt_wire_setup) { Thanks, dou
At 02/09/2018 08:10 PM, Baoquan He wrote: > A regression bug was introduced in below commit. > commit 522e66464467 ("x86/apic: Disable I/O APIC before shutdown of the local APIC") > > It caused the action to fail which we try to restore boot irq mode > in reboot and kexec/kdump. Details can be seen in patch 0002. > > Warning can always be seen during kdump kernel boot on qemu/kvm > platform. Our customer even saw casual kdump kernel hang once in > ~30 attempts during stress testing of kdump on KVM machine. > > This is v3 post, patches are rearranged and changed according to > Eric's suggestions. > > Baoquan He (5): > x86/apic: Split out restore_boot_irq_mode from disable_IO_APIC > x86/apic: Fix restoring boot irq mode in reboot and kexec/kdump > x86/apic: Remove useless disable_IO_APIC > x86/apic: Rename variable/function related to x86_io_apic_ops > x86/apic: Set up through-local-APIC on boot CPU if 'noapic' specified > > arch/x86/include/asm/io_apic.h | 9 +++++---- > arch/x86/include/asm/x86_init.h | 8 ++++---- > arch/x86/kernel/apic/apic.c | 2 +- > arch/x86/kernel/apic/io_apic.c | 16 ++++------------ > arch/x86/kernel/crash.c | 3 ++- > arch/x86/kernel/machine_kexec_32.c | 7 +++---- > arch/x86/kernel/machine_kexec_64.c | 7 +++---- > arch/x86/kernel/reboot.c | 3 ++- > arch/x86/kernel/x86_init.c | 6 +++--- > arch/x86/xen/apic.c | 2 +- > drivers/iommu/irq_remapping.c | 4 ++-- > 11 files changed, 30 insertions(+), 37 deletions(-) >
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