[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[RFC PATCH v2 4/5] softmmu/physmem: Introduce flatview_access_allowed()
From: |
Philippe Mathieu-Daudé |
Subject: |
[RFC PATCH v2 4/5] softmmu/physmem: Introduce flatview_access_allowed() to check bus perms |
Date: |
Mon, 23 Aug 2021 18:41:56 +0200 |
Introduce flatview_access_allowed() to check bus permission
before running any bus transaction. For now this is a simple
stub.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
softmmu/physmem.c | 37 +++++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index e534dc69918..0d31a2f4199 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2754,6 +2754,27 @@ static bool prepare_mmio_access(MemoryRegion *mr)
return release_lock;
}
+/**
+ * flatview_access_allowed
+ * @mr: #MemoryRegion to be accessed
+ * @attrs: memory transaction attributes
+ * @addr: address within that memory region
+ * @len: the number of bytes to access
+ * @result: optional pointer to a MemTxResult or NULL
+ *
+ * Check if a memory transaction is allowed. If an error occurs this
+ * method will return false to indicate denial, as well as setting
+ * @result to contain corresponding #MemTxResult.
+ *
+ * Returns: true if transaction is allowed, false if denied.
+ */
+static inline bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs attrs,
+ hwaddr addr, hwaddr len,
+ MemTxResult *result)
+{
+ return true;
+}
+
/* Called within RCU critical section. */
static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
MemTxAttrs attrs,
@@ -2768,7 +2789,9 @@ static MemTxResult flatview_write_continue(FlatView *fv,
hwaddr addr,
const uint8_t *buf = ptr;
for (;;) {
- if (!memory_access_is_direct(mr, true)) {
+ if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) {
+ /* 'result' contains the error, keep going. */
+ } else if (!memory_access_is_direct(mr, true)) {
release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
/* XXX: could force current_cpu to NULL to avoid
@@ -2810,9 +2833,13 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr
addr, MemTxAttrs attrs,
hwaddr l;
hwaddr addr1;
MemoryRegion *mr;
+ MemTxResult result = MEMTX_OK;
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, true, attrs);
+ if (!flatview_access_allowed(mr, attrs, addr, len, &result)) {
+ return result;
+ }
return flatview_write_continue(fv, addr, attrs, buf, len,
addr1, l, mr);
}
@@ -2831,7 +2858,9 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr
addr,
fuzz_dma_read_cb(addr, len, mr);
for (;;) {
- if (!memory_access_is_direct(mr, false)) {
+ if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) {
+ /* 'result' contains the error, keep going. */
+ } else if (!memory_access_is_direct(mr, false)) {
/* I/O case */
release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
@@ -2871,9 +2900,13 @@ static MemTxResult flatview_read(FlatView *fv, hwaddr
addr,
hwaddr l;
hwaddr addr1;
MemoryRegion *mr;
+ MemTxResult result = MEMTX_OK;
l = len;
mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
+ if (!flatview_access_allowed(mr, attrs, addr, len, &result)) {
+ return result;
+ }
return flatview_read_continue(fv, addr, attrs, buf, len,
addr1, l, mr);
}
--
2.31.1