There are many call sites referencing context entry by calling
vtd_as_to_context_entry() which will traverse the DMAR table.
In most cases we can use cached context entry in vtd_as->context_cache_entry
except it's stale. Currently only global and domain context invalidation
stales it.
So introduce a helper function vtd_as_to_context_entry() to fetch from cache
before trying with vtd_dev_to_context_entry().
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
hw/i386/intel_iommu.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index df5fb30bc8..7709f55be5 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1597,6 +1597,22 @@ static int vtd_dev_to_context_entry(IntelIOMMUState *s,
uint8_t bus_num,
return 0;
}
+static int vtd_as_to_context_entry(VTDAddressSpace *vtd_as, VTDContextEntry
*ce)
+{
+ IntelIOMMUState *s = vtd_as->iommu_state;
+ uint8_t bus_num = pci_bus_num(vtd_as->bus);
+ uint8_t devfn = vtd_as->devfn;
+ VTDContextCacheEntry *cc_entry = &vtd_as->context_cache_entry;
+
+ /* Try to fetch context-entry from cache first */
+ if (cc_entry->context_cache_gen == s->context_cache_gen) {
+ *ce = cc_entry->context_entry;
+ return 0;
+ } else {
+ return vtd_dev_to_context_entry(s, bus_num, devfn, ce);
+ }
+}
+
static int vtd_sync_shadow_page_hook(const IOMMUTLBEvent *event,
void *private)
{
@@ -1649,9 +1665,7 @@ static int vtd_address_space_sync(VTDAddressSpace *vtd_as)
return 0;
}
- ret = vtd_dev_to_context_entry(vtd_as->iommu_state,
- pci_bus_num(vtd_as->bus),
- vtd_as->devfn, &ce);
+ ret = vtd_as_to_context_entry(vtd_as, &ce);
if (ret) {
if (ret == -VTD_FR_CONTEXT_ENTRY_P) {
/*
@@ -1710,8 +1724,7 @@ static bool vtd_as_pt_enabled(VTDAddressSpace *as)
assert(as);
s = as->iommu_state;
- if (vtd_dev_to_context_entry(s, pci_bus_num(as->bus), as->devfn,
- &ce)) {
+ if (vtd_as_to_context_entry(as, &ce)) {
/*
* Possibly failed to parse the context entry for some reason
* (e.g., during init, or any guest configuration errors on
@@ -2443,8 +2456,7 @@ static void vtd_iotlb_domain_invalidate(IntelIOMMUState
*s, uint16_t domain_id)
vtd_iommu_unlock(s);
QLIST_FOREACH(vtd_as, &s->vtd_as_with_notifiers, next) {
- if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
- vtd_as->devfn, &ce) &&
+ if (!vtd_as_to_context_entry(vtd_as, &ce) &&
domain_id == vtd_get_domain_id(s, &ce, vtd_as->pasid)) {
vtd_address_space_sync(vtd_as);
}
@@ -2466,8 +2478,7 @@ static void
vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s,
hwaddr size = (1 << am) * VTD_PAGE_SIZE;
QLIST_FOREACH(vtd_as, &(s->vtd_as_with_notifiers), next) {
- ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
- vtd_as->devfn, &ce);
+ ret = vtd_as_to_context_entry(vtd_as, &ce);
if (!ret && domain_id == vtd_get_domain_id(s, &ce, vtd_as->pasid)) {
uint32_t rid2pasid = PCI_NO_PASID;
@@ -2974,8 +2985,7 @@ static void vtd_piotlb_pasid_invalidate(IntelIOMMUState
*s,
vtd_iommu_unlock(s);
QLIST_FOREACH(vtd_as, &s->vtd_as_with_notifiers, next) {
- if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
- vtd_as->devfn, &ce) &&
+ if (!vtd_as_to_context_entry(vtd_as, &ce) &&
domain_id == vtd_get_domain_id(s, &ce, vtd_as->pasid)) {
uint32_t rid2pasid = VTD_CE_GET_RID2PASID(&ce);
@@ -4154,7 +4164,7 @@ static void vtd_report_ir_illegal_access(VTDAddressSpace
*vtd_as,
assert(vtd_as->pasid != PCI_NO_PASID);
/* Try out best to fetch FPD, we can't do anything more */
- if (vtd_dev_to_context_entry(s, bus_n, vtd_as->devfn, &ce) == 0) {
+ if (vtd_as_to_context_entry(vtd_as, &ce) == 0) {
is_fpd_set = ce.lo & VTD_CONTEXT_ENTRY_FPD;
if (!is_fpd_set && s->root_scalable) {
vtd_ce_get_pasid_fpd(s, &ce, &is_fpd_set, vtd_as->pasid);
@@ -4491,7 +4501,7 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iommu_mr,
IOMMUNotifier *n)
/* replay is protected by BQL, page walk will re-setup it safely */
iova_tree_remove(vtd_as->iova_tree, map);
- if (vtd_dev_to_context_entry(s, bus_n, vtd_as->devfn, &ce) == 0) {
+ if (vtd_as_to_context_entry(vtd_as, &ce) == 0) {
trace_vtd_replay_ce_valid(s->root_scalable ? "scalable mode" :
"legacy mode",
bus_n, PCI_SLOT(vtd_as->devfn),
--
2.34.1
