[PATCH v3 4/6] cxl/type3: add an optional mhd validation function for memory accesses

[Gregory Price]

When memory accesses are made, some MHSLD's would validate the address
is within the scope of allocated sections.  To do this, the base device
must call an optional function set by inherited devices.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 hw/mem/cxl_type3.c          | 15 +++++++++++++++
 include/hw/cxl/cxl_device.h |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 6e3309dc11..1fb3ffeca8 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -1034,6 +1034,7 @@ void ct3_realize(PCIDevice *pci_dev, Error **errp)
             goto err_release_cdat;
         }
     }
+
     return;
 
 err_release_cdat:
@@ -1249,6 +1250,7 @@ MemTxResult cxl_type3_read(PCIDevice *d, hwaddr 
host_addr, uint64_t *data,
                            unsigned size, MemTxAttrs attrs)
 {
     CXLType3Dev *ct3d = CXL_TYPE3(d);
+    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
     uint64_t dpa_offset = 0;
     AddressSpace *as = NULL;
     int res;
@@ -1259,6 +1261,11 @@ MemTxResult cxl_type3_read(PCIDevice *d, hwaddr 
host_addr, uint64_t *data,
         return MEMTX_ERROR;
     }
 
+    if (cvc->mhd_access_valid &&
+        !cvc->mhd_access_valid(d, dpa_offset, size)) {
+        return MEMTX_ERROR;
+    }
+
     if (sanitize_running(&ct3d->cci)) {
         qemu_guest_getrandom_nofail(data, size);
         return MEMTX_OK;
@@ -1270,6 +1277,7 @@ MemTxResult cxl_type3_write(PCIDevice *d, hwaddr 
host_addr, uint64_t data,
                             unsigned size, MemTxAttrs attrs)
 {
     CXLType3Dev *ct3d = CXL_TYPE3(d);
+    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
     uint64_t dpa_offset = 0;
     AddressSpace *as = NULL;
     int res;
@@ -1279,6 +1287,12 @@ MemTxResult cxl_type3_write(PCIDevice *d, hwaddr 
host_addr, uint64_t data,
     if (res) {
         return MEMTX_ERROR;
     }
+
+    if (cvc->mhd_access_valid &&
+        !cvc->mhd_access_valid(d, dpa_offset, size)) {
+        return MEMTX_ERROR;
+    }
+
     if (sanitize_running(&ct3d->cci)) {
         return MEMTX_OK;
     }
@@ -2106,6 +2120,7 @@ static void ct3_class_init(ObjectClass *oc, void *data)
     cvc->get_lsa = get_lsa;
     cvc->set_lsa = set_lsa;
     cvc->set_cacheline = set_cacheline;
+    cvc->mhd_access_valid = NULL;
 }
 
 static const TypeInfo ct3d_info = {
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 9c37a54699..37893f8626 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -506,6 +506,9 @@ struct CXLType3Class {
     void (*set_lsa)(CXLType3Dev *ct3d, const void *buf, uint64_t size,
                     uint64_t offset);
     bool (*set_cacheline)(CXLType3Dev *ct3d, uint64_t dpa_offset, uint8_t 
*data);
+
+    /* Multi-headed Device */
+    bool (*mhd_access_valid)(PCIDevice *d, uint64_t addr, unsigned int size);
 };
 
 struct CSWMBCCIDev {
-- 
2.39.1