KVM: arm64: vgic-v4: Fall back to software irqbypass if LPI not found

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Continuing with the theme of broken VMMs and guests, irqbypass
registration can fail if the virtual ITS lacks a translation for the
MSI. Either the guest hasn't mapped it or userspace may have forgotten
to restore the ITS.

Exit silently and allow irqbypass configuration to succeed. As a reward
for ingenuity, LPIs are demoted to software injection.

Tested-by: Sudheer Dantuluri <dantuluris@google.com>
Fixes: 196b136498 ("KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass")
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250226183124.82094-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

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Oliver Upton 2025-02-26 10:31:23 -08:00

parent d0b79563fd

commit 5c57533eb8

1 changed files with 10 additions and 5 deletions

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arch/arm64/kvm/vgic/vgic-v4.c

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