On 08/02/2024 10:31, Joao Martins wrote:
On 08/02/2024 09:14, Yi Liu wrote:
Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the pasid entry when attaching a device to a nested domain if its parent has already enabled dirty tracking.
Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation") Signed-off-by: Yi Liu yi.l.liu@intel.com
Reviewed-by: Joao Martins joao.m.martins@oracle.com
On a second thought, while the patch looks fine if this is what we wanna do, just a quick clarification on the why (that's also applicable to the last patch of your other series[0]). I am sure I am missing something :)
Shouldn't the nested domain be subdued to whatever features guest idea of ecap/cap instead of host's view? Or is this because guest first-stage page table on Intel is supposed to be always-enabled dirty tracking (per SDM) ? If it's the latter, it probably should be sprinkled in the commit message(s).
[0] https://lore.kernel.org/linux-iommu/20240208082307.15759-9-yi.l.liu@intel.co...
base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
drivers/iommu/intel/pasid.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index 3239cefa4c33..9be24bb762cf 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev, pasid_set_domain_id(pte, did); pasid_set_address_width(pte, s2_domain->agaw); pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
- if (s2_domain->dirty_tracking)
pasid_set_ssade(pte);