@@ -794,8 +794,16 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
its_encode_alloc(cmd, alloc);
- /* We can only signal PTZ when alloc==1. Why do we have two bits? */
- its_encode_ptz(cmd, alloc);
+ /*
+ * We can only signal PTZ when alloc==1. Why do we have two bits?
+ * GICv4.1 gives a way to get the VLPI state, which needs the vPE
+ * to be unmapped first, and in this case, we may remap the vPE
+ * back while the VPT is not empty. So we can't assume that the
+ * VPT is empty at the first map. Besides, the optimization of PTZ
+ * is probably limited since the HW should be fairly efficient to
+ * parse the empty VPT. Let's drop the setting of PTZ altogether.
+ */
+ its_encode_ptz(cmd, false);
its_encode_vconf_addr(cmd, vconf_addr);
its_encode_vmapp_default_db(cmd, desc->its_vmapp_cmd.vpe->vpe_db_lpi);
GICv4.1 gives a way to get the VLPI state, which needs to map the vPE first, and after the state read, we may remap the vPE back while the VPT is not empty. So we can't assume that the VPT is empty at the first map. Besides, the optimization of PTZ is probably limited since the HW should be fairly efficient to parse the empty VPT. Let's drop the setting of PTZ altogether. Signed-off-by: Shenming Lu <lushenming@huawei.com> --- drivers/irqchip/irq-gic-v3-its.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)