Re: [PATCH v6 12/14] iommu/arm-smmu-v3: Introduce struct arm_smmu_vmaster

[Nicolin Chen]

On Tue, Feb 18, 2025 at 01:08:24PM -0400, Jason Gunthorpe wrote:
> On Fri, Jan 24, 2025 at 04:30:41PM -0800, Nicolin Chen wrote:
> > +	int ret;
> >  	struct arm_smmu_ste ste;
> >  	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
> > +	struct arm_smmu_attach_state state = {
> > +		.master = master,
> > +	};
> > +
> > +	ret = arm_smmu_attach_prepare_vmaster(&state, domain);
> > +	if (ret)
> > +		return ret;
> > +	arm_smmu_attach_commit_vmaster(&state);
> 
> I think you should make this into just a arm_smmu_clear_vmaster()
> with less complication..

Ack:

+void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master)
+{
+       mutex_lock(&master->smmu->streams_mutex);
+       kfree(master->vmaster);
+       master->vmaster = NULL;
+       mutex_unlock(&master->smmu->streams_mutex);
+}
[...]
@@ -3162,6 +3172,7 @@ static int arm_smmu_attach_dev_identity(struct iommu_domain *domain,
        struct arm_smmu_ste ste;
        struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 
+       arm_smmu_master_clear_vmaster(master);
        arm_smmu_make_bypass_ste(master->smmu, &ste);
        arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS);
        return 0;
@@ -3180,7 +3191,9 @@ static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain,
                                        struct device *dev)
 {
        struct arm_smmu_ste ste;
+       struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 
+       arm_smmu_master_clear_vmaster(master);
        arm_smmu_make_abort_ste(&ste);
        arm_smmu_attach_dev_ste(domain, dev, &ste,
                                STRTAB_STE_1_S1DSS_TERMINATE);

Thanks
Nicolin