5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kunkun Jiang <jiangkunkun@xxxxxxxxxx> commit 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143 upstream. When DISCARD frees an ITE, it does not invalidate the corresponding ITE. In the scenario of continuous saves and restores, there may be a situation where an ITE is not saved but is restored. This is unreasonable and may cause restore to fail. This patch clears the corresponding ITE when DISCARD frees an ITE. Cc: stable@xxxxxxxxxxxxxxx Fixes: eff484e0298d ("KVM: arm64: vgic-its: ITT save and restore") Signed-off-by: Kunkun Jiang <jiangkunkun@xxxxxxxxxx> [Jing: Update with entry write helper] Signed-off-by: Jing Zhang <jingzhangos@xxxxxxxxxx> Link: https://lore.kernel.org/r/20241107214137.428439-6-jingzhangos@xxxxxxxxxx Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/arm/vgic/vgic-its.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -854,6 +854,9 @@ static int vgic_its_cmd_handle_discard(s ite = find_ite(its, device_id, event_id); if (ite && ite->collection) { + struct its_device *device = find_its_device(its, device_id); + int ite_esz = vgic_its_get_abi(its)->ite_esz; + gpa_t gpa = device->itt_addr + ite->event_id * ite_esz; /* * Though the spec talks about removing the pending state, we * don't bother here since we clear the ITTE anyway and the @@ -862,7 +865,8 @@ static int vgic_its_cmd_handle_discard(s vgic_its_invalidate_cache(kvm); its_free_ite(kvm, ite); - return 0; + + return vgic_its_write_entry_lock(its, gpa, 0, ite_esz); } return E_ITS_DISCARD_UNMAPPED_INTERRUPT;