[tip: irq/core] irqchip/gic-v4: Always configure affinity on VPE activation

[tip-bot2 for Marc Zyngier]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     7d2c2048a86477461f7bc75d064579ed349472bc
Gitweb:        https://git.kernel.org/tip/7d2c2048a86477461f7bc75d064579ed349472bc
Author:        Marc Zyngier <maz@xxxxxxxxxx>
AuthorDate:    Fri, 05 Jul 2024 10:31:53 +01:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Mon, 15 Jul 2024 15:13:55 +02:00

irqchip/gic-v4: Always configure affinity on VPE activation

There are currently two paths to set the initial affinity of a VPE:

 - at activation time on GICv4 without the stupid VMOVP list, and
   on GICv4.1

 - at map time for GICv4 with VMOVP list

The latter location may end-up modifying the affinity of VPE that is
currently running, making the results unpredictible.

Instead, unify the two paths, making sure to set the initial affinity only
at activation time.

Reported-by: Nianyao Tang <tangnianyao@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Nianyao Tang <tangnianyao@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240705093155.871070-2-maz@xxxxxxxxxx

---
 drivers/irqchip/irq-gic-v3-its.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index af5297e..387ac5a 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1809,13 +1809,9 @@ static void its_map_vm(struct its_node *its, struct its_vm *vm)
 
 		for (i = 0; i < vm->nr_vpes; i++) {
 			struct its_vpe *vpe = vm->vpes[i];
-			struct irq_data *d = irq_get_irq_data(vpe->irq);
 
-			/* Map the VPE to the first possible CPU */
-			vpe->col_idx = cpumask_first(cpu_online_mask);
 			its_send_vmapp(its, vpe, true);
 			its_send_vinvall(its, vpe);
-			irq_data_update_effective_affinity(d, cpumask_of(vpe->col_idx));
 		}
 	}
 
@@ -4582,6 +4578,10 @@ static int its_vpe_irq_domain_activate(struct irq_domain *domain,
 	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
 	struct its_node *its;
 
+	/* Map the VPE to the first possible CPU */
+	vpe->col_idx = cpumask_first(cpu_online_mask);
+	irq_data_update_effective_affinity(d, cpumask_of(vpe->col_idx));
+
 	/*
 	 * If we use the list map, we issue VMAPP on demand... Unless
 	 * we're on a GICv4.1 and we eagerly map the VPE on all ITSs
@@ -4590,9 +4590,6 @@ static int its_vpe_irq_domain_activate(struct irq_domain *domain,
 	if (!gic_requires_eager_mapping())
 		return 0;
 
-	/* Map the VPE to the first possible CPU */
-	vpe->col_idx = cpumask_first(cpu_online_mask);
-
 	list_for_each_entry(its, &its_nodes, entry) {
 		if (!is_v4(its))
 			continue;
@@ -4601,8 +4598,6 @@ static int its_vpe_irq_domain_activate(struct irq_domain *domain,
 		its_send_vinvall(its, vpe);
 	}
 
-	irq_data_update_effective_affinity(d, cpumask_of(vpe->col_idx));
-
 	return 0;
 }