linux/arch/powerpc/sysdev/xive
Cédric Le Goater 6f779e1d35 powerpc/xive: Discard disabled interrupts in get_irqchip_state()
When an interrupt is passed through, the KVM XIVE device calls the
set_vcpu_affinity() handler which raises the P bit to mask the
interrupt and to catch any in-flight interrupts while routing the
interrupt to the guest.

On the guest side, drivers (like some Intels) can request at probe
time some MSIs and call synchronize_irq() to check that there are no
in flight interrupts. This will call the XIVE get_irqchip_state()
handler which will always return true as the interrupt P bit has been
set on the host side and lock the CPU in an infinite loop.

Fix that by discarding disabled interrupts in get_irqchip_state().

Fixes: da15c03b04 ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race")
Cc: stable@vger.kernel.org #v5.4+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: seeteena <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211011070203.99726-1-clg@kaod.org
2021-10-13 16:38:55 +11:00
..
common.c powerpc/xive: Discard disabled interrupts in get_irqchip_state() 2021-10-13 16:38:55 +11:00
Kconfig powerpc: Move the use of irq_domain_add_nomap() behind a config option 2021-06-10 13:09:17 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
native.c KVM: PPC: Book3S HV: XIVE: Add support for automatic save-restore 2021-08-10 23:15:02 +10:00
spapr.c powerpc/xive: use true and false for bool variable 2021-03-29 13:22:13 +11:00
xive-internal.h powerpc/xive: Use the "ibm, chip-id" property only under PowerNV 2021-04-17 10:40:51 +10:00