Allow the memory region to have different behaviors for read and fetch
operations.
For example RISCV IOPMP will raise interrupt when cpu try to fetch a
non-excutable region.
If fetch operation of a memory region is not implemented, it still uses the
read operation for fetch.
Signed-off-by: Ethan Chen
---
accel/tcg/cputlb.c| 9 +++-
include/exec/memory.h | 30
system/memory.c | 104 ++
3 files changed, 141 insertions(+), 2 deletions(-)
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index 117b516739..edb3715017 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -1942,8 +1942,13 @@ static uint64_t int_ld_mmio_beN(CPUState *cpu,
CPUTLBEntryFull *full,
this_size = 1 << this_mop;
this_mop |= MO_BE;
-r = memory_region_dispatch_read(mr, mr_offset, &val,
-this_mop, full->attrs);
+if (type == MMU_INST_FETCH) {
+r = memory_region_dispatch_fetch(mr, mr_offset, &val,
+ this_mop, full->attrs);
+} else {
+r = memory_region_dispatch_read(mr, mr_offset, &val,
+this_mop, full->attrs);
+}
if (unlikely(r != MEMTX_OK)) {
io_failed(cpu, full, addr, this_size, type, mmu_idx, r, ra);
}
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 1be58f694c..6d61ec443e 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -274,6 +274,13 @@ struct MemoryRegionOps {
uint64_t data,
unsigned size);
+/* Fetch to the memory region. @addr is relative to @mr; @size is
+ * in bytes. */
+uint64_t (*fetch)(void *opaque,
+ hwaddr addr,
+ unsigned size);
+
+
MemTxResult (*read_with_attrs)(void *opaque,
hwaddr addr,
uint64_t *data,
@@ -284,6 +291,12 @@ struct MemoryRegionOps {
uint64_t data,
unsigned size,
MemTxAttrs attrs);
+MemTxResult (*fetch_with_attrs)(void *opaque,
+hwaddr addr,
+uint64_t *data,
+unsigned size,
+MemTxAttrs attrs);
+
enum device_endian endianness;
/* Guest-visible constraints: */
@@ -2672,6 +2685,23 @@ MemTxResult memory_region_dispatch_write(MemoryRegion
*mr,
MemOp op,
MemTxAttrs attrs);
+
+/**
+ * memory_region_dispatch_fetch: perform a fetch directly to the specified
+ * MemoryRegion.
+ *
+ * @mr: #MemoryRegion to access
+ * @addr: address within that region
+ * @pval: pointer to uint64_t which the data is written to
+ * @op: size, sign, and endianness of the memory operation
+ * @attrs: memory transaction attributes to use for the access
+ */
+MemTxResult memory_region_dispatch_fetch(MemoryRegion *mr,
+ hwaddr addr,
+ uint64_t *pval,
+ MemOp op,
+ MemTxAttrs attrs);
+
/**
* address_space_init: initializes an address space
*
diff --git a/system/memory.c b/system/memory.c
index 74cd73ebc7..ecd3020b1c 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -477,6 +477,51 @@ static MemTxResult
memory_region_read_with_attrs_accessor(MemoryRegion *mr,
return r;
}
+static MemTxResult memory_region_fetch_accessor(MemoryRegion *mr,
+hwaddr addr,
+uint64_t *value,
+unsigned size,
+signed shift,
+uint64_t mask,
+MemTxAttrs attrs)
+{
+uint64_t tmp;
+
+tmp = mr->ops->fetch(mr->opaque, addr, size);
+if (mr->subpage) {
+trace_memory_region_subpage_fetch(get_cpu_index(), mr, addr, tmp,
size);
+} else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_FETCH)) {
+hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
+trace_memory_region_ops_fetch(get_cpu_index(), mr, abs_addr, tmp, size,
+ memory_region_name(mr));
+}
+memory_region_shift_read_access(value, shift, mask, tmp);
+return MEMTX_OK;
+}
+
+static MemTxResult memory_region_fetch_with_attrs_accessor(MemoryRegion *mr,
+ hwaddr addr,
+ uint64_t *value,
+
