[Qemu-devel] [PATCH] monitor: Add an "xlate" command for translating a virtual address

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

This is very handy when debugging a guest, especially when it's
stuck on accessing some HW and the only way to figure out what
specific piece of HW is to translate the virtual address to
a hardware address that can then be matched with the mtree

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 hmp-commands.hx | 15 +++++++++++++++
 monitor.c       | 11 +++++++++++
 2 files changed, 26 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 848efee..2d0ce4e 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -569,6 +569,21 @@ Write to I/O port.
 ETEXI
 
     {
+        .name       = "xlate",
+        .args_type  = "addr:l",
+        .params     = "addr",
+        .help       = "Translate virtual address via the MMU",
+        .mhandler.cmd = hmp_mmu_xlate,
+    },
+
+STEXI
+@item xlate @var{addr}
+@findex xlate
+Translate virtual address
+
+ETEXI
+
+    {
         .name       = "sendkey",
         .args_type  = "keys:s,hold-time:i?",
         .params     = "keys [hold_ms]",
diff --git a/monitor.c b/monitor.c
index 5d68a5d..b2b3a6e 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1505,6 +1505,17 @@ static void hmp_ioport_write(Monitor *mon, const QDict *qdict)
     }
 }
 
+static void hmp_mmu_xlate(Monitor *mon, const QDict *qdict)
+{
+    CPUState *cpu = mon_get_cpu();
+    vaddr va = qdict_get_int(qdict, "addr");
+    hwaddr pa;
+
+    pa = cpu_get_phys_page_debug(cpu, va);
+    pa |= (va & ~TARGET_PAGE_MASK);
+    monitor_printf(mon, "0x%#" HWADDR_PRIx "\n", pa);
+}
+
 static void hmp_boot_set(Monitor *mon, const QDict *qdict)
 {
     Error *local_err = NULL;