[PATCH 3/3] irqchip/gic-v4: Make sure a VPE is locked when VMAPP is issued

From: Marc Zyngier
Date: Fri Jul 05 2024 - 05:32:28 EST


In order to make sure that vpe->col_idx is correctly sampled
when a VMAPP command is issued, we must hold the lock for the
VPE. This is now possible since the introduction of the per-VM
vmapp_lock, which can be taken before vpe_lock in the locking
order.

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index b52d60097cad5..951ec140bcea2 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1810,7 +1810,9 @@ 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];

- its_send_vmapp(its, vpe, true);
+ scoped_guard(raw_spinlock, &vpe->vpe_lock)
+ its_send_vmapp(its, vpe, true);
+
its_send_vinvall(its, vpe);
}
}
@@ -1827,8 +1829,10 @@ static void its_unmap_vm(struct its_node *its, struct its_vm *vm)
if (!--vm->vlpi_count[its->list_nr]) {
int i;

- for (i = 0; i < vm->nr_vpes; i++)
+ for (i = 0; i < vm->nr_vpes; i++) {
+ guard(raw_spinlock)(&vm->vpes[i]->vpe_lock);
its_send_vmapp(its, vm->vpes[i], false);
+ }
}
}

--
2.39.2