On 2022/5/3 05:36, Jacob Pan wrote:
Hi BaoLu,
On Sun, 1 May 2022 19:24:33 +0800, Lu Baolu <baolu...@linux.intel.com>
wrote:
The IOMMU force snooping capability is not required to be consistent
among all the IOMMUs anymore. Remove force snooping capability check
in the IOMMU hot-add path and domain_update_iommu_snooping() becomes
a dead code now.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 34 +---------------------------------
1 file changed, 1 insertion(+), 33 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 3c1c228f9031..d5808495eb64 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -533,33 +533,6 @@ static void domain_update_iommu_coherency(struct
dmar_domain *domain) rcu_read_unlock();
}
-static bool domain_update_iommu_snooping(struct intel_iommu *skip)
-{
- struct dmar_drhd_unit *drhd;
- struct intel_iommu *iommu;
- bool ret = true;
-
- rcu_read_lock();
- for_each_active_iommu(iommu, drhd) {
- if (iommu != skip) {
- /*
- * If the hardware is operating in the scalable
mode,
- * the snooping control is always supported
since we
- * always set PASID-table-entry.PGSNP bit if the
domain
- * is managed outside (UNMANAGED).
- */
- if (!sm_supported(iommu) &&
- !ecap_sc_support(iommu->ecap)) {
- ret = false;
- break;
- }
- }
- }
- rcu_read_unlock();
-
- return ret;
-}
-
static int domain_update_iommu_superpage(struct dmar_domain *domain,
struct intel_iommu *skip)
{
@@ -3593,12 +3566,7 @@ static int intel_iommu_add(struct dmar_drhd_unit
*dmaru) iommu->name);
return -ENXIO;
}
- if (!ecap_sc_support(iommu->ecap) &&
- domain_update_iommu_snooping(iommu)) {
- pr_warn("%s: Doesn't support snooping.\n",
- iommu->name);
- return -ENXIO;
- }
+
Maybe I missed earlier patches, so this bit can also be deleted?
struct dmar_domain {
u8 iommu_snooping: 1; /* indicate snooping control
feature */
It has been cleaned up by below commit:
71cfafda9c9b vfio: Move the Intel no-snoop control off of IOMMU_CACHE
sp = domain_update_iommu_superpage(NULL, iommu) - 1;
if (sp >= 0 && !(cap_super_page_val(iommu->cap) & (1 << sp))) {
pr_warn("%s: Doesn't support large page.\n",
Thanks,
Jacob
Best regards,
baolu
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