KVM: arm64: vgic-its: Remove the pending state of a discarded LPI

DISCARD removes the mapping of an event and instructs the Redistributor
to remove the pending state of its LPI (IHI 0069H.b, 5.3.4). KVM only
frees the ITE, so an LPI that is pending when the guest discards it
stays queued on its target vCPU, and the guest still takes it.

Clear the pending state before freeing the ITE. A queued LPI can be
pending in a running vCPU's list register, so halt the guest first when
the LPI is queued, to fold that state back. A forwarded LPI already
loses its pending state in its_free_ite(), whose unmap from the vPE
sends a DISCARD to the host ITS.

[maz: folded-in rework to only pause the involved vcpus]

Fixes: df9f58fbea9bc ("KVM: arm64: vgic-its: Implement ITS command queue command handlers")
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20261013081646.933312-3-fuad.tabba@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>

0 files changed, 0 insertions, 0 deletions