[Qemu-devel] [PATCH qemu] hmp: Print if memory section is registered in KVM

[Alexey Kardashevskiy]

This adds a "KVM" marker to the "into mtree -f" to tell the user if
a particular memory section is registered as a KVM memory slot; useful
for debugging purposes.

Since it is memory sections which get registered in KVM (rather than
memory regions), this only prints "KVM" for flatviews.

For example:
 Root memory region: system
  0000000000000000-00000003ffffffff (prio 0, ram): ppc_spapr.ram KVM
  0000200000000020-000020000000003f (prio 1, i/o): virtio-pci

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
 include/sysemu/kvm.h |  1 +
 accel/kvm/kvm-all.c  |  7 +++++++
 memory.c             | 10 ++++++++++
 3 files changed, 18 insertions(+)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 97d8d9d0d5..9eab5ac1b1 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -471,6 +471,7 @@ void kvm_set_sigmask_len(KVMState *s, unsigned int 
sigmask_len);
 #if !defined(CONFIG_USER_ONLY)
 int kvm_physical_memory_addr_from_host(KVMState *s, void *ram_addr,
                                        hwaddr *phys_addr);
+bool is_kvm_memory(hwaddr start_addr, hwaddr size);
 #endif
 
 #endif /* NEED_CPU_H */
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 4880a05399..d72808aaa6 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -216,6 +216,13 @@ static KVMSlot *kvm_lookup_matching_slot(KVMMemoryListener 
*kml,
     return NULL;
 }
 
+bool is_kvm_memory(hwaddr start_addr, hwaddr size)
+{
+    KVMMemoryListener *kml = &kvm_state->memory_listener;
+
+    return NULL != kvm_lookup_matching_slot(kml, start_addr, size);
+}
+
 /*
  * Calculate and align the start address and the size of the section.
  * Return the size. If the size is 0, the aligned section is empty.
diff --git a/memory.c b/memory.c
index 51204aa079..56c733c687 100644
--- a/memory.c
+++ b/memory.c
@@ -2916,6 +2916,7 @@ static void mtree_print_flatview(gpointer key, gpointer 
value,
     int n = view->nr;
     int i;
     AddressSpace *as;
+    bool print_kvm = false;
 
     p(f, "FlatView #%d\n", fvi->counter);
     ++fvi->counter;
@@ -2927,6 +2928,9 @@ static void mtree_print_flatview(gpointer key, gpointer 
value,
             p(f, ", alias %s", memory_region_name(as->root->alias));
         }
         p(f, "\n");
+        if (as == &address_space_memory) {
+            print_kvm = true;
+        }
     }
 
     p(f, " Root memory region: %s\n",
@@ -2960,6 +2964,12 @@ static void mtree_print_flatview(gpointer key, gpointer 
value,
         if (fvi->owner) {
             mtree_print_mr_owner(p, f, mr);
         }
+
+        if (kvm_enabled() && print_kvm &&
+            is_kvm_memory(int128_get64(range->addr.start),
+                          MR_SIZE(range->addr.size) + 1)) {
+            p(f, " KVM");
+        }
         p(f, "\n");
         range++;
     }
-- 
2.17.1