From: Zenghui Yu Date: Thu, 30 Jan 2020 16:02:05 +0000 Subject: hw/intc/arm_gicv3_kvm: Stop wrongly programming GICR_PENDBASER.PTZ bit Git-commit: 618bacabd3c8c3360be795cd8763bacdf5bec101 If LPIs are disabled, KVM will just ignore the GICR_PENDBASER.PTZ bit when restoring GICR_CTLR. Setting PTZ here makes littlt sense in "reduce GIC initialization time". And what's worse, PTZ is generally programmed by guest to indicate to the Redistributor whether the LPI Pending table is zero when enabling LPIs. If migration is triggered when the PTZ has just been cleared by guest (and before enabling LPIs), we will see PTZ==1 on the destination side, which is not as expected. Let's just drop this hackish userspace behavior. Also take this chance to refine the comment a bit. Fixes: 367b9f527bec ("hw/intc/arm_gicv3_kvm: Implement get/put functions") Signed-off-by: Zenghui Yu Message-id: 20200119133051.642-1-yuzenghui@huawei.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell Signed-off-by: Bruce Rogers --- hw/intc/arm_gicv3_kvm.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c index 9c7f4ab8711cd7ba780727089a1c..49304ca589d1f016cdfb217bf719 100644 --- a/hw/intc/arm_gicv3_kvm.c +++ b/hw/intc/arm_gicv3_kvm.c @@ -336,7 +336,10 @@ static void kvm_arm_gicv3_put(GICv3State *s) kvm_gicd_access(s, GICD_CTLR, ®, true); if (redist_typer & GICR_TYPER_PLPIS) { - /* Set base addresses before LPIs are enabled by GICR_CTLR write */ + /* + * Restore base addresses before LPIs are potentially enabled by + * GICR_CTLR write + */ for (ncpu = 0; ncpu < s->num_cpu; ncpu++) { GICv3CPUState *c = &s->cpu[ncpu]; @@ -347,12 +350,6 @@ static void kvm_arm_gicv3_put(GICv3State *s) kvm_gicr_access(s, GICR_PROPBASER + 4, ncpu, ®h, true); reg64 = c->gicr_pendbaser; - if (!(c->gicr_ctlr & GICR_CTLR_ENABLE_LPIS)) { - /* Setting PTZ is advised if LPIs are disabled, to reduce - * GIC initialization time. - */ - reg64 |= GICR_PENDBASER_PTZ; - } regl = (uint32_t)reg64; kvm_gicr_access(s, GICR_PENDBASER, ncpu, ®l, true); regh = (uint32_t)(reg64 >> 32);