From c9b51bb60d944067f36f67750e19c18c3cc2697c Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 26 Oct 2017 17:23:05 +0200 Subject: [PATCH] KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS The spec says it is UNPREDICTABLE to enable the ITS if any of the following conditions are true: - GITS_CBASER.Valid == 0. - GITS_BASER.Valid == 0, for any GITS_BASER register where the Type field indicates Device. - GITS_BASER.Valid == 0, for any GITS_BASER register where the Type field indicates Interrupt Collection and GITS_TYPER.HCC == 0. In that case, let's keep the ITS disabled. Signed-off-by: Eric Auger Reported-by: Andre Przywara Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic-its.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 6a715a6ec64e..e69ef7d27fde 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -1466,6 +1466,16 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its, { mutex_lock(&its->cmd_lock); + /* + * It is UNPREDICTABLE to enable the ITS if any of the CBASER or + * device/collection BASER are invalid + */ + if (!its->enabled && (val & GITS_CTLR_ENABLE) && + (!(its->baser_device_table & GITS_BASER_VALID) || + !(its->baser_coll_table & GITS_BASER_VALID) || + !(its->cbaser & GITS_CBASER_VALID))) + goto out; + its->enabled = !!(val & GITS_CTLR_ENABLE); /* @@ -1474,6 +1484,7 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its, */ vgic_its_process_commands(kvm, its); +out: mutex_unlock(&its->cmd_lock); } -- 2.20.1