[RFC,v1,08/10] Introduce debug version of physical memory read/write API

Commit Message

Yuan Yao May 6, 2021, 1:40 a.m. UTC

From: Yuan Yao <[e-mail]>

Add below APIs for reading/writing the physical memory, subsequent
patch will use them in monitor commands and gdbstub to support
encrypted guest debugging.

uint32_t x86_ldl_phys_debug(CPUState *cs, hwaddr addr);
uint64_t x86_ldq_phys_debug(CPUState *cs, hwaddr addr);
void cpu_physical_memory_rw_debug(hwaddr addr, void *buf,
                                  hwaddr len, bool is_write);
void cpu_physical_memory_read_debug(hwaddr addr,
                                    void *buf,
                                    hwaddr len);
void cpu_physical_memory_write_debug(hwaddr addr,
                                     const void *buf,
                                     hwaddr len);

Signed-off-by: Yuan Yao <[e-mail]>

Patch

diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 5a0a2d93e0..f77a9ecb60 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -69,6 +69,8 @@  size_t qemu_ram_pagesize_largest(void);
 
 void cpu_physical_memory_rw(hwaddr addr, void *buf,
                             hwaddr len, bool is_write);
+void cpu_physical_memory_rw_debug(hwaddr addr, void *buf,
+                                  hwaddr len, bool is_write);
 static inline void cpu_physical_memory_read(hwaddr addr,
                                             void *buf, hwaddr len)
 {
@@ -79,6 +81,18 @@  static inline void cpu_physical_memory_write(hwaddr addr,
 {
     cpu_physical_memory_rw(addr, (void *)buf, len, true);
 }
+
+static inline void cpu_physical_memory_read_debug(hwaddr addr,
+                                                  void *buf, hwaddr len)
+{
+    cpu_physical_memory_rw_debug(addr, buf, len, false);
+}
+static inline void cpu_physical_memory_write_debug(hwaddr addr,
+                                                   const void *buf, hwaddr len)
+{
+    cpu_physical_memory_rw_debug(addr, (void *)buf, len, true);
+}
+
 void *cpu_physical_memory_map(hwaddr addr,
                               hwaddr *plen,
                               bool is_write);
diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h
index c8b56389d6..6d223ea196 100644
--- a/include/exec/memattrs.h
+++ b/include/exec/memattrs.h
@@ -60,6 +60,9 @@  typedef struct MemTxAttrs {
  */
 #define MEMTXATTRS_UNSPECIFIED ((MemTxAttrs) { .unspecified = 1 })
 
+// Same as MEMTXATTRS_UNSPECIFIED but enable debug
+#define MEMTXATTRS_UNSPECIFIED_DEBUG ((MemTxAttrs) { .unspecified = 1, .debug = 1 })
+
 /* New-style MMIO accessors can indicate that the transaction failed.
  * A zero (MEMTX_OK) response means success; anything else is a failure
  * of some kind. The memory subsystem will bitwise-OR together results
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 0fde02d325..ff6e215a3a 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2910,6 +2910,19 @@  void cpu_physical_memory_rw(hwaddr addr, void *buf,
                      buf, len, is_write);
 }
 
+void cpu_physical_memory_rw_debug(hwaddr addr, void *buf,
+                            hwaddr len, bool is_write)
+{
+    if (is_write)
+        physical_memory_debug_ops->write(&address_space_memory,
+                                         addr, MEMTXATTRS_UNSPECIFIED_DEBUG,
+                                         buf, len);
+    else
+        physical_memory_debug_ops->read(&address_space_memory,
+                                        addr, MEMTXATTRS_UNSPECIFIED_DEBUG,
+                                        buf, len);
+}
+
 enum write_rom_type {
     WRITE_DATA,
     FLUSH_CACHE,
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e5dbe84d3a..7a8a1386fb 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1960,6 +1960,8 @@  void x86_stl_phys_notdirty(CPUState *cs, hwaddr addr, uint32_t val);
 void x86_stw_phys(CPUState *cs, hwaddr addr, uint32_t val);
 void x86_stl_phys(CPUState *cs, hwaddr addr, uint32_t val);
 void x86_stq_phys(CPUState *cs, hwaddr addr, uint64_t val);
+uint32_t x86_ldl_phys_debug(CPUState *cs, hwaddr addr);
+uint64_t x86_ldq_phys_debug(CPUState *cs, hwaddr addr);
 #endif
 
 /* will be suppressed */
diff --git a/target/i386/helper.c b/target/i386/helper.c
index 618ad1c409..21edcb9204 100644
--- a/target/i386/helper.c
+++ b/target/i386/helper.c
@@ -663,4 +663,30 @@  void x86_stq_phys(CPUState *cs, hwaddr addr, uint64_t val)
 
     address_space_stq(as, addr, val, attrs, NULL);
 }
+
+uint32_t x86_ldl_phys_debug(CPUState *cs, hwaddr addr)
+{
+    uint32_t ret;
+    MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED_DEBUG;
+    int as_id = cpu_asidx_from_attrs(cs, attrs);
+    struct AddressSpace *as = cpu_get_address_space(cs, as_id);
+
+    physical_memory_debug_ops->read(as, addr, attrs,
+                                    &ret, sizeof(ret));
+
+    return tswap32(ret);
+}
+
+uint64_t x86_ldq_phys_debug(CPUState *cs, hwaddr addr)
+{
+    uint64_t ret;
+    MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED_DEBUG;
+    int as_id = cpu_asidx_from_attrs(cs, attrs);
+    struct AddressSpace *as = cpu_get_address_space(cs, as_id);
+
+    physical_memory_debug_ops->read(as, addr, attrs,
+                                    &ret, sizeof(ret));
+
+    return tswap64(ret);
+}
 #endif