On 2025/9/1 17:03, Duan, Zhenzhong wrote:
}
+/*
+ * This function walks over PASID range within [start, end) in a single
+ * PASID table for entries matching @info type/did, then retrieve/create
+ * vtd_as and fill associated pasid entry cache.
+ */
+static void vtd_sm_pasid_table_walk_one(IntelIOMMUState *s,
+ dma_addr_t pt_base,
+ int start,
+ int end,
+ VTDPASIDCacheInfo
*info)
+{
+ VTDPASIDEntry pe;
+ int pasid = start;
+
+ while (pasid < end) {
+ if (!vtd_get_pe_in_pasid_leaf_table(s, pasid, pt_base, &pe)
+ && vtd_pe_present(&pe)) {
+ int bus_n = pci_bus_num(info->bus), devfn = info->devfn;
+ uint16_t sid = PCI_BUILD_BDF(bus_n, devfn);
+ VTDPASIDCacheEntry *pc_entry;
+ VTDAddressSpace *vtd_as;
+
+ vtd_iommu_lock(s);
+ /*
+ * When indexed by rid2pasid, vtd_as should have been
created,
+ * e.g., by PCI subsystem. For other iommu pasid, we need
to
+ * create vtd_as dynamically. Other iommu pasid is same
value
since you don't support somthing else than rid2pasid, I would drop that
and simplify the code. See below.
+ * as PCI's pasid, so it's used as input of vtd_find_add_as().
+ */
+ vtd_as = vtd_as_from_iommu_pasid_locked(s, sid, pasid);
+ vtd_iommu_unlock(s);
+ if (!vtd_as) {
+ vtd_as = vtd_find_add_as(s, info->bus, devfn, pasid);
you could check the vtd_as already exists here per the rid2pasid support
limitation
In this series, I do include some basic codes for non-rid2pasid because they
share some common code with rid2pasid and we already have emulated rid2pasid
support in vIOMMU for a long time, it's not bad to accumulate some supporting
code for non-rid2pasid for passthrough device. But I can do the factor out if
you insist to have only rid_pasid code.
I think it's a reasonable ask. :)
+ }
+
+ if ((info->type == VTD_PASID_CACHE_DOMSI ||
+ info->type == VTD_PASID_CACHE_PASIDSI) &&
+ (info->did != VTD_SM_PASID_ENTRY_DID(&pe))) {
+ /*
+ * VTD_PASID_CACHE_DOMSI and
VTD_PASID_CACHE_PASIDSI
+ * requires domain id check. If domain id check fail,
fails
+ * go to next pasid.
+ */
+ pasid++;
+ continue;
+ }
+
+ pc_entry = &vtd_as->pasid_cache_entry;
+ /*
+ * pasid cache update and clear are handled in
+ * vtd_flush_pasid_locked(), only care new pasid entry
here.
+ */
+ if (!pc_entry->valid) {
+ pc_entry->pasid_entry = pe;
+ pc_entry->valid = true;
+ }
+ }
+ pasid++;
+ }
+}
+
+/*
+ * In VT-d scalable mode translation, PASID dir + PASID table is used.
+ * This function aims at looping over a range of PASIDs in the given
+ * two level table to identify the pasid config in guest.
+ */
+static void vtd_sm_pasid_table_walk(IntelIOMMUState *s,
+ dma_addr_t pdt_base,
+ int start, int end,
+ VTDPASIDCacheInfo *info)
+{
+ VTDPASIDDirEntry pdire;
+ int pasid = start;
+ int pasid_next;
+ dma_addr_t pt_base;
+
+ while (pasid < end) {
+ pasid_next =
+ (pasid + VTD_PASID_TBL_ENTRY_NUM) &
~(VTD_PASID_TBL_ENTRY_NUM - 1);
+ pasid_next = pasid_next < end ? pasid_next : end;
+
+ if (!vtd_get_pdire_from_pdir_table(pdt_base, pasid, &pdire)
+ && vtd_pdire_present(&pdire)) {
+ pt_base = pdire.val &
VTD_PASID_TABLE_BASE_ADDR_MASK;
+ vtd_sm_pasid_table_walk_one(s, pt_base, pasid,
pasid_next, info);
+ }
+ pasid = pasid_next;
+ }
+}
+
+static void vtd_replay_pasid_bind_for_dev(IntelIOMMUState *s,
+ int start, int end,
+ VTDPASIDCacheInfo
*info)
+{
+ VTDContextEntry ce;
+
+ if (!vtd_dev_to_context_entry(s, pci_bus_num(info->bus),
info->devfn,
+ &ce)) {
+ uint32_t max_pasid;
+
+ max_pasid = vtd_sm_ce_get_pdt_entry_num(&ce) *
VTD_PASID_TBL_ENTRY_NUM;
+ if (end > max_pasid) {
+ end = max_pasid;
+ }
+ vtd_sm_pasid_table_walk(s,
+
VTD_CE_GET_PASID_DIR_TABLE(&ce),
+ start,
+ end,
+ info);
+ }
+}
+
+/*
+ * This function replays the guest pasid bindings by walking the two level
+ * guest PASID table. For each valid pasid entry, it finds or creates a
+ * vtd_as and caches pasid entry in vtd_as.
+ */
+static void vtd_replay_guest_pasid_bindings(IntelIOMMUState *s,
+ VTDPASIDCacheInfo
*pc_info)
+{
+ /*
+ * Currently only Requests-without-PASID is supported, as vIOMMU
doesn't
+ * support RPS(RID-PASID Support), pasid scope is fixed to [0, 1).
+ */
+ int start = 0, end = 1;
+ VTDHostIOMMUDevice *vtd_hiod;
+ VTDPASIDCacheInfo walk_info;
+ GHashTableIter as_it;
+
+ switch (pc_info->type) {
+ case VTD_PASID_CACHE_PASIDSI:
+ start = pc_info->pasid;
+ end = pc_info->pasid + 1;
if you never replay a range, you could simplify the code for now because
some code paths are not properly tested
OK. Instead of assignment of start and end variable, maybe just an
assert(!pc_info->pasid).
I think there are two reasons for this range replay.
1) as a preparation for patch 16 of this series.
2) support domain selective or global pasid cache invalidation
+ /* fall through */
+ case VTD_PASID_CACHE_DOMSI:
Why can't we have other invalidation types along with request without
PASID? It is not obvious to me at least why it couldn't be used by the
guest. Would deserve a comment in the commit desc I think.
Other invalidation types are indeed used, just in pasid scope [0, 1), because
[start, end) are already initialized to [0, 1), nothing more here, so just
break.
hmmm. The fixed scope makes the range replay a fake one. It's better
holding the range replay logic for now and add it when there is
non-rid_pasid support for passthrough devices.
Regards,
Yi Liu
