diff options
| author | Marc Zyngier <maz@kernel.org> | 2024-10-27 13:22:20 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-10-27 19:30:16 +0300 |
| commit | e6c24e2d05bb05de96ffb9bdb0ee62d20ad526f8 (patch) | |
| tree | 36e92d418bf236b4fd00e2c889532bff8861eb5e /drivers/irqchip | |
| parent | 5f994f534120f47432092fb36f5cb0c7a80ed2bf (diff) | |
| download | linux-e6c24e2d05bb05de96ffb9bdb0ee62d20ad526f8.tar.xz | |
irqchip/gic-v4: Correctly deal with set_affinity on lazily-mapped VPEs
Zenghui points out that a recent change to the way set_affinity is
handled for VPEs has the potential to return an error if the VPE
hasn't been mapped yet (because the guest hasn't emited a MAPTI
command yet), affecting GICv4.0 implementations that rely on the
ITSList feature.
Fix this by making the set_affinity succeed in this case, and
return early, without trying to touch the HW.
Fixes: 1442ee0011983 ("irqchip/gic-v4: Don't allow a VMOVP on a dying VPE")
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/all/20241027102220.1858558-1-maz@kernel.org
Link: https://lore.kernel.org/r/aab45cd3-e5ca-58cf-e081-e32a17f5b4e7@huawei.com
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index ab597e74ba08..52f625e07658 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3810,8 +3810,18 @@ static int its_vpe_set_affinity(struct irq_data *d, * Check if we're racing against a VPE being destroyed, for * which we don't want to allow a VMOVP. */ - if (!atomic_read(&vpe->vmapp_count)) - return -EINVAL; + if (!atomic_read(&vpe->vmapp_count)) { + if (gic_requires_eager_mapping()) + return -EINVAL; + + /* + * If we lazily map the VPEs, this isn't an error and + * we can exit cleanly. + */ + cpu = cpumask_first(mask_val); + irq_data_update_effective_affinity(d, cpumask_of(cpu)); + return IRQ_SET_MASK_OK_DONE; + } /* * Changing affinity is mega expensive, so let's be as lazy as |