[Qemu-devel] [PATCH 3/3] pflash_cfi01: add secure property

[Paolo Bonzini <pbonzini@redhat.com>]

When this property is set, MMIO accesses are only allowed with the
MEMTXATTRS_SECURE attribute.  This is used for secure access to UEFI
variables stored in flash.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/block/pflash_cfi01.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 0b3667a..df3b0b0 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -65,6 +65,7 @@ do {                                                        \
 #define CFI_PFLASH01(obj) OBJECT_CHECK(pflash_t, (obj), TYPE_CFI_PFLASH01)
 
 #define PFLASH_BE		0
+#define PFLASH_SECURE		1
 
 struct pflash_t {
     /*< private >*/
@@ -650,25 +651,37 @@ static void pflash_write(pflash_t *pfl, hwaddr offset,
 }
 
 
-static uint64_t pflash_mem_read(void *opaque, hwaddr addr, unsigned len)
+static MemTxResult pflash_mem_read_with_attrs(void *opaque, hwaddr addr, uint64_t *value,
+                                              unsigned len, MemTxAttrs attrs)
 {
     pflash_t *pfl = opaque;
     bool be = !!(pfl->features & (1 << PFLASH_BE));
 
-    return pflash_read(pfl, addr, len, be);
+    if ((pfl->features & (1 << PFLASH_SECURE)) && !(attrs & MEMTXATTRS_SECURE)) {
+        return MEMTX_ERROR;
+    }
+
+    *value = pflash_read(opaque, addr, len, be);
+    return MEMTX_OK;
 }
 
-static void pflash_mem_write(void *opaque, hwaddr addr, uint64_t value, unsigned len)
+static MemTxResult pflash_mem_write_with_attrs(void *opaque, hwaddr addr, uint64_t value,
+                                               unsigned len, MemTxAttrs attrs)
 {
     pflash_t *pfl = opaque;
     bool be = !!(pfl->features & (1 << PFLASH_BE));
 
-    pflash_write(pfl, addr, value, len, be);
+    if ((pfl->features & (1 << PFLASH_SECURE)) && !(attrs & MEMTXATTRS_SECURE)) {
+        return MEMTX_ERROR;
+    }
+
+    pflash_write(opaque, addr, value, len, be);
+    return MEMTX_OK;
 }
 
 static const MemoryRegionOps pflash_cfi01_ops = {
-    .read = pflash_mem_read,
-    .write = pflash_mem_write,
+    .read_with_attrs = pflash_mem_read_with_attrs,
+    .write_with_attrs = pflash_mem_write_with_attrs,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
@@ -853,6 +866,7 @@ static Property pflash_cfi01_properties[] = {
     DEFINE_PROP_UINT8("device-width", struct pflash_t, device_width, 0),
     DEFINE_PROP_UINT8("max-device-width", struct pflash_t, max_device_width, 0),
     DEFINE_PROP_BIT("big-endian", struct pflash_t, features, PFLASH_BE, 0),
+    DEFINE_PROP_BIT("secure", struct pflash_t, features, PFLASH_SECURE, 0),
     DEFINE_PROP_UINT16("id0", struct pflash_t, ident0, 0),
     DEFINE_PROP_UINT16("id1", struct pflash_t, ident1, 0),
     DEFINE_PROP_UINT16("id2", struct pflash_t, ident2, 0),
-- 
2.3.5