[PATCH v3 5/7] hw/arm/smmuv3: Enforce invalidation on a power of two range

[Eric Auger]

As of today, the driver can invalidate a number of pages that is
not a power of 2. However IOTLB unmap notifications and internal
IOTLB invalidations work with masks leading to erroneous
invalidations.

In case the range is not a power of 2, split invalidations into
power of 2 invalidations.

When looking for a single page entry in the vSMMU internal IOTLB,
let's make sure that if the entry is not found using a
g_hash_table_remove() we iterate over all the entries to find a
potential range that overlaps it.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/arm/smmu-common.c | 30 ++++++++++++++++++------------
 hw/arm/smmuv3.c      | 24 ++++++++++++++++++++----
 2 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index e9ca3aebb2..84d2c62c26 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -151,22 +151,28 @@ inline void
 smmu_iotlb_inv_iova(SMMUState *s, int asid, dma_addr_t iova,
                     uint8_t tg, uint64_t num_pages, uint8_t ttl)
 {
+    /* if tg is not set we use 4KB range invalidation */
+    uint8_t granule = tg ? tg * 2 + 10 : 12;
+
     if (ttl && (num_pages == 1) && (asid >= 0)) {
         SMMUIOTLBKey key = smmu_get_iotlb_key(asid, iova, tg, ttl);
 
-        g_hash_table_remove(s->iotlb, &key);
-    } else {
-        /* if tg is not set we use 4KB range invalidation */
-        uint8_t granule = tg ? tg * 2 + 10 : 12;
-
-        SMMUIOTLBPageInvInfo info = {
-            .asid = asid, .iova = iova,
-            .mask = (num_pages * 1 << granule) - 1};
-
-        g_hash_table_foreach_remove(s->iotlb,
-                                    smmu_hash_remove_by_asid_iova,
-                                    &info);
+        if (g_hash_table_remove(s->iotlb, &key)) {
+            return;
+        }
+        /*
+         * if the entry is not found, let's see if it does not
+         * belong to a larger IOTLB entry
+         */
     }
+
+    SMMUIOTLBPageInvInfo info = {
+        .asid = asid, .iova = iova,
+        .mask = (num_pages * 1 << granule) - 1};
+
+    g_hash_table_foreach_remove(s->iotlb,
+                                smmu_hash_remove_by_asid_iova,
+                                &info);
 }
 
 inline void smmu_iotlb_inv_asid(SMMUState *s, uint16_t asid)
diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index bd1f97000d..fdd6332ce5 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -861,7 +861,8 @@ static void smmuv3_s1_range_inval(SMMUState *s, Cmd *cmd)
     uint16_t vmid = CMD_VMID(cmd);
     bool leaf = CMD_LEAF(cmd);
     uint8_t tg = CMD_TG(cmd);
-    hwaddr num_pages = 1;
+    uint64_t first_page = 0, last_page;
+    uint64_t num_pages = 1;
     int asid = -1;
 
     if (tg) {
@@ -874,9 +875,24 @@ static void smmuv3_s1_range_inval(SMMUState *s, Cmd *cmd)
     if (type == SMMU_CMD_TLBI_NH_VA) {
         asid = CMD_ASID(cmd);
     }
-    trace_smmuv3_s1_range_inval(vmid, asid, addr, tg, num_pages, ttl, leaf);
-    smmuv3_inv_notifiers_iova(s, asid, addr, tg, num_pages);
-    smmu_iotlb_inv_iova(s, asid, addr, tg, num_pages, ttl);
+
+    /* Split invalidations into ^2 range invalidations */
+    last_page = num_pages - 1;
+    while (num_pages) {
+        uint8_t granule = tg * 2 + 10;
+        uint64_t mask, count;
+
+        mask = dma_aligned_pow2_mask(first_page, last_page, 64 - granule);
+        count = mask + 1;
+
+        trace_smmuv3_s1_range_inval(vmid, asid, addr, tg, count, ttl, leaf);
+        smmuv3_inv_notifiers_iova(s, asid, addr, tg, count);
+        smmu_iotlb_inv_iova(s, asid, addr, tg, count, ttl);
+
+        num_pages -= count;
+        first_page += count;
+        addr += count * BIT_ULL(granule);
+    }
 }
 
 static int smmuv3_cmdq_consume(SMMUv3State *s)
-- 
2.26.2