iommu/hyper-v: Remove I/O-APIC ID check from hyperv_irq_remapping_select()
authorDexuan Cui <decui@microsoft.com>
Wed, 2 Dec 2020 00:45:10 +0000 (16:45 -0800)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 2 Dec 2020 10:22:55 +0000 (11:22 +0100)
commit26ab12bb9d96133b7880141d68b5e01a8783de9d
tree04cade33b453c1433dc295c42b9ce0a8a2c20bb8
parentd1adcfbb520c43c10fc22fcdccdd4204e014fb53
iommu/hyper-v: Remove I/O-APIC ID check from hyperv_irq_remapping_select()

commit a491bb19f728 ("iommu/hyper-v: Implement select() method on remapping
irqdomain") restricted the irq_domain_ops::select() callback to match on
I/O-APIC index 0, which was correct until the parameter was changed to
carry the I/O APIC ID in commit f36a74b9345a.

If the ID is not 0 then the match fails. Therefore I/O-APIC init fails to
retrieve the parent irqdomain for the I/O-APIC resulting in a boot panic:

    kernel BUG at arch/x86/kernel/apic/io_apic.c:2408!

Fix it by matching the I/O-APIC independent of the ID as there is only one
I/O APIC emulated by Hyper-V.

[ tglx: Amended changelog ]

Fixes: f36a74b9345a ("x86/ioapic: Use I/O-APIC ID for finding irqdomain, not index")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20201202004510.1818-1-decui@microsoft.com
drivers/iommu/hyperv-iommu.c