On 2025/8/22 14:40, Zhenzhong Duan wrote:
PCI device supports two request types, Requests-without-PASID and
Requests-with-PASID. Requests-without-PASID doesn't include a PASID TLP
prefix, IOMMU fetches rid_pasid from context entry and use it as IOMMU's
pasid to index pasid table.
So we need to translate between PCI's pasid and IOMMU's pasid specially
for Requests-without-PASID, e.g., PCI_NO_PASID(-1) <-> rid_pasid.
For Requests-with-PASID, PCI's pasid and IOMMU's pasid are same value.
vtd_as_from_iommu_pasid_locked() translates from BDF+iommu_pasid to vtd_as
which contains PCI's pasid vtd_as->pasid.
vtd_as_to_iommu_pasid_locked() translates from BDF+vtd_as->pasid to iommu_pasid.
translate is somehow strange. convert or get might be better? Same to
the translate terms in the patch.
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
---
hw/i386/intel_iommu.c | 58 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 6edd91d94e..1801f1cdf6 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1602,6 +1602,64 @@ static int vtd_dev_to_context_entry(IntelIOMMUState *s,
uint8_t bus_num,
return 0;
}
+static int vtd_as_to_iommu_pasid_locked(VTDAddressSpace *vtd_as,
+ uint32_t *pasid)
+{
+ VTDContextCacheEntry *cc_entry = &vtd_as->context_cache_entry;
+ IntelIOMMUState *s = vtd_as->iommu_state;
+ uint8_t bus_num = pci_bus_num(vtd_as->bus);
+ uint8_t devfn = vtd_as->devfn;
+ VTDContextEntry ce;
+ int ret;
+
+ /* For Requests-with-PASID, its pasid value is used by vIOMMU directly */
+ if (vtd_as->pasid != PCI_NO_PASID) {
+ *pasid = vtd_as->pasid;
+ return 0;
+ }
+
+ if (cc_entry->context_cache_gen == s->context_cache_gen) {
+ ce = cc_entry->context_entry;
+ } else {
+ ret = vtd_dev_to_context_entry(s, bus_num, devfn, &ce);
+ if (ret) {
+ return ret;
+ }
+ }
+ *pasid = VTD_CE_GET_RID2PASID(&ce);
looks like we have quite a few code get rid_pasid from the context
entry. I think we may simplify it by using PASID #0 since vIOMMU does
not report ECAP.RPS bit at all. It could be done as a separate cleanup.
+ return 0;
+}
+
+static gboolean vtd_find_as_by_sid_and_iommu_pasid(gpointer key, gpointer
value,
+ gpointer user_data)
+{
+ VTDAddressSpace *vtd_as = (VTDAddressSpace *)value;
+ struct vtd_as_raw_key *target = (struct vtd_as_raw_key *)user_data;
+ uint16_t sid = PCI_BUILD_BDF(pci_bus_num(vtd_as->bus), vtd_as->devfn);
+ uint32_t pasid;
+
+ if (vtd_as_to_iommu_pasid_locked(vtd_as, &pasid)) {
+ return false;
+ }
+
+ return (pasid == target->pasid) && (sid == target->sid);
+}
+
+/* Translate iommu pasid to vtd_as */
+static inline
+VTDAddressSpace *vtd_as_from_iommu_pasid_locked(IntelIOMMUState *s,
+ uint16_t sid, uint32_t pasid)
+{
+ struct vtd_as_raw_key key = {
+ .sid = sid,
+ .pasid = pasid
+ };
+
+ return g_hash_table_find(s->vtd_address_spaces,
+ vtd_find_as_by_sid_and_iommu_pasid, &key);
+}
+
static int vtd_sync_shadow_page_hook(const IOMMUTLBEvent *event,
void *private)
{
the code looks good to me.
Reviewed-by: Yi Liu <yi.l....@intel.com>
