ppc/pnv: Add a PNOR address and size sanity checks

The BMC HIOMAP PNOR access protocol has certain limits on PNOR addresses
and sizes. Add some sanity checks for these so we don't get strange
behaviour.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

diff --git a/hw/ppc/pnv_bmc.c b/hw/ppc/pnv_bmc.c
index 0c1274df21a941d05b8a07bc50b1501b6ab82cb9..811ba3d7a499aa678596eb8ce893c4230f3420c7 100644 (file)
--- a/hw/ppc/pnv_bmc.c
+++ b/hw/ppc/pnv_bmc.c
@@ -251,10 +251,38 @@ static const IPMINetfn hiomap_netfn = {
 
 void pnv_bmc_set_pnor(IPMIBmc *bmc, PnvPnor *pnor)
 {
+    uint32_t pnor_size = pnor->size;
+    uint32_t pnor_addr = PNOR_SPI_OFFSET;
+
     if (!pnv_bmc_is_simulator(bmc)) {
         return;
     }
 
+    /*
+     * The HIOMAP protocol uses block units and 16-bit addressing.
+     * Prevent overflow or misalign.
+     */
+    if (pnor_addr >= 1U << (BLOCK_SHIFT + 16)) {
+        warn_report("PNOR address is larger than 2^%d, disabling PNOR",
+                    BLOCK_SHIFT + 16);
+        return;
+    }
+    if (pnor_addr & ((1U << BLOCK_SHIFT) - 1)) {
+        warn_report("PNOR address is not aligned to 2^%d, disabling PNOR",
+                    BLOCK_SHIFT);
+        return;
+    }
+    if (pnor_size > 1U << (BLOCK_SHIFT + 16)) {
+        warn_report("PNOR size is larger than 2^%d, disabling PNOR",
+                    BLOCK_SHIFT + 16);
+        return;
+    }
+    if (pnor_size & ((1U << BLOCK_SHIFT) - 1)) {
+        warn_report("PNOR size is not aligned to 2^%d, disabling PNOR",
+                    BLOCK_SHIFT);
+        return;
+    }
+
     object_ref(OBJECT(pnor));
     object_property_add_const_link(OBJECT(bmc), "pnor", OBJECT(pnor));