On 30.08.2019 10:29, Paul Durrant wrote: > This patch introduces a common domain creation flag to determine whether > the domain is permitted to make use of the IOMMU. Currently the flag is > always set (for both dom0 and domU) if the IOMMU is globally enabled > (i.e. iommu_enabled == 1). sanitise_domain_config() is modified to reject > the flag if !iommu_enabled. > > A new helper function, is_iommu_enabled(), is added to test the flag and > iommu_domain_init() will return immediately if !is_iommu_enabled(). This is > slightly different to the previous behaviour based on !iommu_enabled where > the call to arch_iommu_domain_init() was made regardless, however it appears > that this call was only necessary to initialize the dt_devices list for ARM > such that iommu_release_dt_devices() can be called unconditionally by > domain_relinquish_resources(). Adding a simple check of is_iommu_enabled() > into iommu_release_dt_devices() keeps this unconditional call working. > > No functional change should be observed with this patch applied. > > Subsequent patches will allow the toolstack to control whether use of the > IOMMU is enabled for a domain. > > NOTE: The introduction of the is_iommu_enabled() helper function might > seem excessive but its use is expected to increase with subsequent > patches. Also, having iommu_domain_init() bail before calling > arch_iommu_domain_init() is not strictly necessary, but I think the > consequent addition of the call to is_iommu_enabled() in > iommu_release_dt_devices() makes the code clearer. > > Signed-off-by: Paul Durrant <paul.durr...@citrix.com> > Reviewed-by: "Roger Pau Monné" <roger....@citrix.com>
Hypervisor parts (non-Arm) Acked-by: Jan Beulich <jbeul...@suse.com> Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
