[PATCH -v3] Monitor command: x-gpa2hva, translate guest physical address to host virtual address

[Huang Ying <ying.huang@intel.com>]

Author: Max Asbock <masbock@linux.vnet.ibm.com>

Add command x-gpa2hva to translate guest physical address to host
virtual address. Because gpa to hva translation is not consistent, so
this command is only used for debugging.

The x-gpa2hva command provides one step in a chain of translations from
guest virtual to guest physical to host virtual to host physical. Host
physical is then used to inject a machine check error. As a
consequence the HWPOISON code on the host and the MCE injection code
in qemu-kvm are exercised.

v3:

- Rename to x-gpa2hva
- Remove QMP support, because gpa2hva is not consistent

v2:

- Add QMP support

Signed-off-by: Max Asbock <masbock@linux.vnet.ibm.com>
Signed-off-by: Jiajia Zheng <jiajia.zheng@intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
---
 hmp-commands.hx |   15 +++++++++++++++
 monitor.c       |   22 ++++++++++++++++++++++
 2 files changed, 37 insertions(+)

--- a/monitor.c
+++ b/monitor.c
@@ -2272,6 +2272,28 @@ static void do_inject_mce(Monitor *mon,
 }
 #endif
 
+static void do_gpa2hva_print(Monitor *mon, const QObject *data)
+{
+    QInt *qint;
+
+    qint = qobject_to_qint(data);
+    monitor_printf(mon, "0x%lx\n", (unsigned long)qint->value);
+}
+
+static int do_gpa2hva(Monitor *mon, const QDict *qdict, QObject **ret_data)
+{
+    target_phys_addr_t paddr;
+    target_phys_addr_t size = TARGET_PAGE_SIZE;
+    void *vaddr;
+
+    paddr = qdict_get_int(qdict, "addr");
+    vaddr = cpu_physical_memory_map(paddr, &size, 0);
+    cpu_physical_memory_unmap(vaddr, size, 0, 0);
+    *ret_data = qobject_from_jsonf("%ld", (unsigned long)vaddr);
+
+    return 0;
+}
+
 static int do_getfd(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     const char *fdname = qdict_get_str(qdict, "fdname");
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -293,6 +293,21 @@ Start gdbserver session (default @var{po
 ETEXI
 
     {
+        .name       = "x-gpa2hva",
+        .args_type  = "fmt:/,addr:l",
+        .params     = "/fmt addr",
+        .help       = "translate guest physical 'addr' to host virtual address, only for debugging",
+        .user_print = do_gpa2hva_print,
+        .mhandler.cmd_new = do_gpa2hva,
+    },
+
+STEXI
+@item x-gpa2hva @var{addr}
+@findex x-gpa2hva
+Translate guest physical @var{addr} to host virtual address, only for debugging.
+ETEXI
+
+    {
         .name       = "x",
         .args_type  = "fmt:/,addr:l",
         .params     = "/fmt addr",