We were having static IOTLB size as 1024. Let it be a tunable. We can
also turns IOTLB off if we want, by specify the size as zero.
The tunable is named as "x-iotlb-size" since that should not really be
something used by user yet, but mostly for debugging purpose now.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
hw/i386/intel_iommu.c | 11 ++++++++++-
hw/i386/intel_iommu_internal.h | 1 -
include/hw/i386/intel_iommu.h | 1 +
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 392da45..9c36866 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -222,6 +222,10 @@ static VTDIOTLBEntry *vtd_lookup_iotlb(IntelIOMMUState *s,
uint16_t source_id,
uint64_t key;
int level;
+ if (s->iotlb_size == 0) {
+ return NULL;
+ }
+
for (level = VTD_SL_PT_LEVEL; level < VTD_SL_PML4_LEVEL; level++) {
key = vtd_get_iotlb_key(vtd_get_iotlb_gfn(addr, level),
source_id, level);
@@ -244,8 +248,12 @@ static void vtd_update_iotlb(IntelIOMMUState *s, uint16_t
source_id,
uint64_t *key = g_malloc(sizeof(*key));
uint64_t gfn = vtd_get_iotlb_gfn(addr, level);
+ if (s->iotlb_size == 0) {
+ return;
+ }
+
trace_vtd_iotlb_page_update(source_id, addr, slpte, domain_id);
- if (g_hash_table_size(s->iotlb) >= VTD_IOTLB_MAX_SIZE) {
+ if (g_hash_table_size(s->iotlb) >= s->iotlb_size) {
trace_vtd_iotlb_reset("iotlb exceeds size limit");
vtd_reset_iotlb(s);
}
@@ -2397,6 +2405,7 @@ static Property vtd_properties[] = {
ON_OFF_AUTO_AUTO),
DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false),
DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE),
+ DEFINE_PROP_UINT16("x-iotlb-size", IntelIOMMUState, iotlb_size, 1024),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index 754cf8a..2d77249 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -116,7 +116,6 @@
/* The shift of source_id in the key of IOTLB hash table */
#define VTD_IOTLB_SID_SHIFT 36
#define VTD_IOTLB_LVL_SHIFT 52
-#define VTD_IOTLB_MAX_SIZE 1024 /* Max size of the hash table */
/* IOTLB_REG */
#define VTD_TLB_GLOBAL_FLUSH (1ULL << 60) /* Global invalidation */
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 3e51876..a57f419 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -288,6 +288,7 @@ struct IntelIOMMUState {
uint32_t context_cache_gen; /* Should be in [1,MAX] */
GHashTable *iotlb; /* IOTLB */
+ uint16_t iotlb_size; /* IOTLB max cache entries */
MemoryRegionIOMMUOps iommu_ops;
GHashTable *vtd_as_by_busptr; /* VTDBus objects indexed by PCIBus*
reference */
--
2.7.4
