From 876853fa76071968337010b8a78c25fb2ec2062f Mon Sep 17 00:00:00 2001 From: Shenming Lu Date: Wed, 14 Jul 2021 10:14:57 +0800 Subject: [PATCH] irqchip/gic-v3-its: Drop the setting of PTZ altogether virt inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZSU3 CVE: NA --------------------------- 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 Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210322060158.1584-3-lushenming@huawei.com Reviewed-by: Keqian Zhu Signed-off-by: Zheng Zengkai --- drivers/irqchip/irq-gic-v3-its.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 8c248687f4b4..b7e6149ba067 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -794,8 +794,13 @@ 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); + /* + * GICv4.1 provides 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 on map. This is why we never advertise PTZ. + */ + 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); -- GitLab