From: Cédric Le Goater clg@kaod.org
commit 6f779e1d359b8d5801f677c1d49dcfa10bf95674 upstream.
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: da15c03b047d ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/sysdev/xive/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/powerpc/sysdev/xive/common.c +++ b/arch/powerpc/sysdev/xive/common.c @@ -961,7 +961,8 @@ static int xive_get_irqchip_state(struct * interrupt to be inactive in that case. */ *state = (pq != XIVE_ESB_INVALID) && !xd->stale_p && - (xd->saved_p || !!(pq & XIVE_ESB_VAL_P)); + (xd->saved_p || (!!(pq & XIVE_ESB_VAL_P) && + !irqd_irq_disabled(data))); return 0; default: return -EINVAL;