[Qemu-devel] [PATCH v3 0/2] ramblock: add hmp command "info ramblock"

[Qemu-devel] [PATCH v3 0/2] ramblock: add hmp command "info ramblock"

[Peter Xu]

v3:
- cast the three PRIx64 addresses using (uint64_t) [Fam]
- add more comment in patch 2 to emphasize that this command is only
  suitable for HMP, not QMP [Markus]

v2:
- replace "lx" with "PRIx64" in three places

Sometimes I would like to know ramblock info for a VM. This command
would help. It provides a way to dump ramblock info. Currently the
list is by default sorted by size, though I think it's good enough.

Please review, thanks.

Peter Xu (2):
  ramblock: add RAMBLOCK_FOREACH()
  ramblock: add new hmp command "info ramblock"

 exec.c                 | 58 ++++++++++++++++++++++++++++++++++++++++----------
 hmp-commands-info.hx   | 14 ++++++++++++
 hmp.c                  |  6 ++++++
 hmp.h                  |  1 +
 include/exec/ramlist.h |  6 ++++++
 migration/ram.c        | 15 +++++++------
 6 files changed, 82 insertions(+), 18 deletions(-)

-- 
2.7.4

[Qemu-devel] [PATCH v3 1/2] ramblock: add RAMBLOCK_FOREACH()

[Peter Xu]

So that it can simplifies the iterators.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 exec.c                 | 22 +++++++++++-----------
 include/exec/ramlist.h |  5 +++++
 migration/ram.c        | 15 ++++++++-------
 3 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/exec.c b/exec.c
index eac6085..50519ae 100644
--- a/exec.c
+++ b/exec.c
@@ -978,7 +978,7 @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr)
     if (block && addr - block->offset < block->max_length) {
         return block;
     }
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         if (addr - block->offset < block->max_length) {
             goto found;
         }
@@ -1578,12 +1578,12 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
         return 0;
     }
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         ram_addr_t end, next = RAM_ADDR_MAX;
 
         end = block->offset + block->max_length;
 
-        QLIST_FOREACH_RCU(next_block, &ram_list.blocks, next) {
+        RAMBLOCK_FOREACH(next_block) {
             if (next_block->offset >= end) {
                 next = MIN(next, next_block->offset);
             }
@@ -1609,7 +1609,7 @@ unsigned long last_ram_page(void)
     ram_addr_t last = 0;
 
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         last = MAX(last, block->offset + block->max_length);
     }
     rcu_read_unlock();
@@ -1659,7 +1659,7 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
     pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
 
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         if (block != new_block &&
             !strcmp(block->idstr, new_block->idstr)) {
             fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
@@ -1693,7 +1693,7 @@ size_t qemu_ram_pagesize_largest(void)
     RAMBlock *block;
     size_t largest = 0;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         largest = MAX(largest, qemu_ram_pagesize(block));
     }
 
@@ -1839,7 +1839,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
      * QLIST (which has an RCU-friendly variant) does not have insertion at
      * tail, so save the last element in last_block.
      */
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         last_block = block;
         if (block->max_length < new_block->max_length) {
             break;
@@ -2021,7 +2021,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
     int flags;
     void *area, *vaddr;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         offset = addr - block->offset;
         if (offset < block->max_length) {
             vaddr = ramblock_ptr(block, offset);
@@ -2167,7 +2167,7 @@ RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
         goto found;
     }
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         /* This case append when the block is not mapped. */
         if (block->host == NULL) {
             continue;
@@ -2200,7 +2200,7 @@ RAMBlock *qemu_ram_block_by_name(const char *name)
 {
     RAMBlock *block;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         if (!strcmp(name, block->idstr)) {
             return block;
         }
@@ -3424,7 +3424,7 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
     int ret = 0;
 
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         ret = func(block->idstr, block->host, block->offset,
                    block->used_length, opaque);
         if (ret) {
diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
index c59880d..f1c6b45 100644
--- a/include/exec/ramlist.h
+++ b/include/exec/ramlist.h
@@ -4,6 +4,7 @@
 #include "qemu/queue.h"
 #include "qemu/thread.h"
 #include "qemu/rcu.h"
+#include "qemu/rcu_queue.h"
 
 typedef struct RAMBlockNotifier RAMBlockNotifier;
 
@@ -54,6 +55,10 @@ typedef struct RAMList {
 } RAMList;
 extern RAMList ram_list;
 
+/* Should be holding either ram_list.mutex, or the RCU lock. */
+#define  RAMBLOCK_FOREACH(block)  \
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
+
 void qemu_mutex_lock_ramlist(void);
 void qemu_mutex_unlock_ramlist(void);
 
diff --git a/migration/ram.c b/migration/ram.c
index f48664e..7ba5d7e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -672,7 +672,7 @@ uint64_t ram_pagesize_summary(void)
     RAMBlock *block;
     uint64_t summary = 0;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         summary |= block->page_size;
     }
 
@@ -700,7 +700,7 @@ static void migration_bitmap_sync(RAMState *rs)
 
     qemu_mutex_lock(&rs->bitmap_mutex);
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         migration_bitmap_sync_range(rs, block, 0, block->used_length);
     }
     rcu_read_unlock();
@@ -1439,8 +1439,9 @@ uint64_t ram_bytes_total(void)
     uint64_t total = 0;
 
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
+    RAMBLOCK_FOREACH(block) {
         total += block->used_length;
+    }
     rcu_read_unlock();
     return total;
 }
@@ -1543,7 +1544,7 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
     struct RAMBlock *block;
     unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         unsigned long first = block->offset >> TARGET_PAGE_BITS;
         unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS);
         unsigned long run_start = find_next_zero_bit(bitmap, range, first);
@@ -1624,7 +1625,7 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
     struct RAMBlock *block;
     int ret;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         unsigned long first = block->offset >> TARGET_PAGE_BITS;
         PostcopyDiscardState *pds = postcopy_discard_send_init(ms,
                                                                first,
@@ -1802,7 +1803,7 @@ static int postcopy_chunk_hostpages(MigrationState *ms)
     rs->last_sent_block = NULL;
     rs->last_page = 0;
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         unsigned long first = block->offset >> TARGET_PAGE_BITS;
 
         PostcopyDiscardState *pds =
@@ -2021,7 +2022,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
 
     qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH(block) {
         qemu_put_byte(f, strlen(block->idstr));
         qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
         qemu_put_be64(f, block->used_length);
-- 
2.7.4

[Qemu-devel] [PATCH v3 2/2] ramblock: add new hmp command "info ramblock"

[Peter Xu]

To dump information about ramblocks. It looks like:

(qemu) info ramblock
              Block Name    PSize              Offset               Used              Total
            /objects/mem       2M  0x0000000000000000 0x0000000080000000 0x0000000080000000
                vga.vram       4K  0x0000000080060000 0x0000000001000000 0x0000000001000000
    /rom@etc/acpi/tables       4K  0x00000000810b0000 0x0000000000020000 0x0000000000200000
                 pc.bios       4K  0x0000000080000000 0x0000000000040000 0x0000000000040000
  0000:00:03.0/e1000.rom       4K  0x0000000081070000 0x0000000000040000 0x0000000000040000
                  pc.rom       4K  0x0000000080040000 0x0000000000020000 0x0000000000020000
    0000:00:02.0/vga.rom       4K  0x0000000081060000 0x0000000000010000 0x0000000000010000
   /rom@etc/table-loader       4K  0x00000000812b0000 0x0000000000001000 0x0000000000001000
      /rom@etc/acpi/rsdp       4K  0x00000000812b1000 0x0000000000001000 0x0000000000001000

Ramblock is something hidden internally in QEMU implementation, and this
command should only be used by mostly QEMU developers on RAM stuff. It
is not a command suitable for QMP interface. So only HMP interface is
provided for it.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 exec.c                 | 36 ++++++++++++++++++++++++++++++++++++
 hmp-commands-info.hx   | 14 ++++++++++++++
 hmp.c                  |  6 ++++++
 hmp.h                  |  1 +
 include/exec/ramlist.h |  1 +
 5 files changed, 58 insertions(+)

diff --git a/exec.c b/exec.c
index 50519ae..9b9d16e 100644
--- a/exec.c
+++ b/exec.c
@@ -71,6 +71,8 @@
 #include "qemu/mmap-alloc.h"
 #endif
 
+#include "monitor/monitor.h"
+
 //#define DEBUG_SUBPAGE
 
 #if !defined(CONFIG_USER_ONLY)
@@ -1333,6 +1335,40 @@ void qemu_mutex_unlock_ramlist(void)
     qemu_mutex_unlock(&ram_list.mutex);
 }
 
+static const char *page_size_to_str(size_t psize)
+{
+    switch (psize) {
+    case 0x1000:
+        return "4K";
+    case 0x10000:
+        return "64K";
+    case 0x200000:
+        return "2M";
+    case 0x40000000:
+        return "1G";
+    default:
+        return "N/A";
+    }
+}
+
+void ram_block_dump(Monitor *mon)
+{
+    RAMBlock *block;
+
+    rcu_read_lock();
+    monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
+                   "Block Name", "PSize", "Offset", "Used", "Total");
+    RAMBLOCK_FOREACH(block) {
+        monitor_printf(mon, "%24s %8s  0x%016" PRIx64 " 0x%016" PRIx64
+                       " 0x%016" PRIx64 "\n", block->idstr,
+                       page_size_to_str(block->page_size),
+                       (uint64_t)block->offset,
+                       (uint64_t)block->used_length,
+                       (uint64_t)block->max_length);
+    }
+    rcu_read_unlock();
+}
+
 #ifdef __linux__
 /*
  * FIXME TOCTTOU: this iterates over memory backends' mem-path, which
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index a53f105..ae16901 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -788,6 +788,20 @@ Display the latest dump status.
 ETEXI
 
     {
+        .name       = "ramblock",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Display system ramblock information",
+        .cmd        = hmp_info_ramblock,
+    },
+
+STEXI
+@item info ramblock
+@findex ramblock
+Dump all the ramblocks of the system.
+ETEXI
+
+    {
         .name       = "hotpluggable-cpus",
         .args_type  = "",
         .params     = "",
diff --git a/hmp.c b/hmp.c
index ab407d6..8369388 100644
--- a/hmp.c
+++ b/hmp.c
@@ -37,6 +37,7 @@
 #include "qemu-io.h"
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
+#include "exec/ramlist.h"
 #include "hw/intc/intc.h"
 
 #ifdef CONFIG_SPICE
@@ -2563,6 +2564,11 @@ void hmp_info_dump(Monitor *mon, const QDict *qdict)
     qapi_free_DumpQueryResult(result);
 }
 
+void hmp_info_ramblock(Monitor *mon, const QDict *qdict)
+{
+    ram_block_dump(mon);
+}
+
 void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
 {
     Error *err = NULL;
diff --git a/hmp.h b/hmp.h
index 799fd37..7353b67 100644
--- a/hmp.h
+++ b/hmp.h
@@ -136,6 +136,7 @@ void hmp_rocker_ports(Monitor *mon, const QDict *qdict);
 void hmp_rocker_of_dpa_flows(Monitor *mon, const QDict *qdict);
 void hmp_rocker_of_dpa_groups(Monitor *mon, const QDict *qdict);
 void hmp_info_dump(Monitor *mon, const QDict *qdict);
+void hmp_info_ramblock(Monitor *mon, const QDict *qdict);
 void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict);
 void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
 
diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
index f1c6b45..2e2ac6c 100644
--- a/include/exec/ramlist.h
+++ b/include/exec/ramlist.h
@@ -73,5 +73,6 @@ void ram_block_notifier_remove(RAMBlockNotifier *n);
 void ram_block_notify_add(void *host, size_t size);
 void ram_block_notify_remove(void *host, size_t size);
 
+void ram_block_dump(Monitor *mon);
 
 #endif /* RAMLIST_H */
-- 
2.7.4

Re: [Qemu-devel] [PATCH v3 1/2] ramblock: add RAMBLOCK_FOREACH()

[Dr. David Alan Gilbert]

* Peter Xu (peterx@redhat.com) wrote:
> So that it can simplifies the iterators.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  exec.c                 | 22 +++++++++++-----------
>  include/exec/ramlist.h |  5 +++++
>  migration/ram.c        | 15 ++++++++-------
>  3 files changed, 24 insertions(+), 18 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index eac6085..50519ae 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -978,7 +978,7 @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr)
>      if (block && addr - block->offset < block->max_length) {
>          return block;
>      }
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          if (addr - block->offset < block->max_length) {
>              goto found;
>          }
> @@ -1578,12 +1578,12 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
>          return 0;
>      }
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          ram_addr_t end, next = RAM_ADDR_MAX;
>  
>          end = block->offset + block->max_length;
>  
> -        QLIST_FOREACH_RCU(next_block, &ram_list.blocks, next) {
> +        RAMBLOCK_FOREACH(next_block) {
>              if (next_block->offset >= end) {
>                  next = MIN(next, next_block->offset);
>              }
> @@ -1609,7 +1609,7 @@ unsigned long last_ram_page(void)
>      ram_addr_t last = 0;
>  
>      rcu_read_lock();
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          last = MAX(last, block->offset + block->max_length);
>      }
>      rcu_read_unlock();
> @@ -1659,7 +1659,7 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
>      pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
>  
>      rcu_read_lock();
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          if (block != new_block &&
>              !strcmp(block->idstr, new_block->idstr)) {
>              fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
> @@ -1693,7 +1693,7 @@ size_t qemu_ram_pagesize_largest(void)
>      RAMBlock *block;
>      size_t largest = 0;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          largest = MAX(largest, qemu_ram_pagesize(block));
>      }
>  
> @@ -1839,7 +1839,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
>       * QLIST (which has an RCU-friendly variant) does not have insertion at
>       * tail, so save the last element in last_block.
>       */
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          last_block = block;
>          if (block->max_length < new_block->max_length) {
>              break;
> @@ -2021,7 +2021,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
>      int flags;
>      void *area, *vaddr;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          offset = addr - block->offset;
>          if (offset < block->max_length) {
>              vaddr = ramblock_ptr(block, offset);
> @@ -2167,7 +2167,7 @@ RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
>          goto found;
>      }
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          /* This case append when the block is not mapped. */
>          if (block->host == NULL) {
>              continue;
> @@ -2200,7 +2200,7 @@ RAMBlock *qemu_ram_block_by_name(const char *name)
>  {
>      RAMBlock *block;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          if (!strcmp(name, block->idstr)) {
>              return block;
>          }
> @@ -3424,7 +3424,7 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
>      int ret = 0;
>  
>      rcu_read_lock();
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          ret = func(block->idstr, block->host, block->offset,
>                     block->used_length, opaque);
>          if (ret) {
> diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
> index c59880d..f1c6b45 100644
> --- a/include/exec/ramlist.h
> +++ b/include/exec/ramlist.h
> @@ -4,6 +4,7 @@
>  #include "qemu/queue.h"
>  #include "qemu/thread.h"
>  #include "qemu/rcu.h"
> +#include "qemu/rcu_queue.h"
>  
>  typedef struct RAMBlockNotifier RAMBlockNotifier;
>  
> @@ -54,6 +55,10 @@ typedef struct RAMList {
>  } RAMList;
>  extern RAMList ram_list;
>  
> +/* Should be holding either ram_list.mutex, or the RCU lock. */
> +#define  RAMBLOCK_FOREACH(block)  \
> +    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
> +
>  void qemu_mutex_lock_ramlist(void);
>  void qemu_mutex_unlock_ramlist(void);
>  
> diff --git a/migration/ram.c b/migration/ram.c
> index f48664e..7ba5d7e 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -672,7 +672,7 @@ uint64_t ram_pagesize_summary(void)
>      RAMBlock *block;
>      uint64_t summary = 0;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          summary |= block->page_size;
>      }
>  
> @@ -700,7 +700,7 @@ static void migration_bitmap_sync(RAMState *rs)
>  
>      qemu_mutex_lock(&rs->bitmap_mutex);
>      rcu_read_lock();
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          migration_bitmap_sync_range(rs, block, 0, block->used_length);
>      }
>      rcu_read_unlock();
> @@ -1439,8 +1439,9 @@ uint64_t ram_bytes_total(void)
>      uint64_t total = 0;
>  
>      rcu_read_lock();
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
> +    RAMBLOCK_FOREACH(block) {
>          total += block->used_length;
> +    }
>      rcu_read_unlock();
>      return total;
>  }
> @@ -1543,7 +1544,7 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
>      struct RAMBlock *block;
>      unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          unsigned long first = block->offset >> TARGET_PAGE_BITS;
>          unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS);
>          unsigned long run_start = find_next_zero_bit(bitmap, range, first);
> @@ -1624,7 +1625,7 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
>      struct RAMBlock *block;
>      int ret;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          unsigned long first = block->offset >> TARGET_PAGE_BITS;
>          PostcopyDiscardState *pds = postcopy_discard_send_init(ms,
>                                                                 first,
> @@ -1802,7 +1803,7 @@ static int postcopy_chunk_hostpages(MigrationState *ms)
>      rs->last_sent_block = NULL;
>      rs->last_page = 0;
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          unsigned long first = block->offset >> TARGET_PAGE_BITS;
>  
>          PostcopyDiscardState *pds =
> @@ -2021,7 +2022,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>  
>      qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
>  
> -    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> +    RAMBLOCK_FOREACH(block) {
>          qemu_put_byte(f, strlen(block->idstr));
>          qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
>          qemu_put_be64(f, block->used_length);
> -- 
> 2.7.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH v3 2/2] ramblock: add new hmp command "info ramblock"

[Dr. David Alan Gilbert]

* Peter Xu (peterx@redhat.com) wrote:
> To dump information about ramblocks. It looks like:
> 
> (qemu) info ramblock
>               Block Name    PSize              Offset               Used              Total
>             /objects/mem       2M  0x0000000000000000 0x0000000080000000 0x0000000080000000
>                 vga.vram       4K  0x0000000080060000 0x0000000001000000 0x0000000001000000
>     /rom@etc/acpi/tables       4K  0x00000000810b0000 0x0000000000020000 0x0000000000200000
>                  pc.bios       4K  0x0000000080000000 0x0000000000040000 0x0000000000040000
>   0000:00:03.0/e1000.rom       4K  0x0000000081070000 0x0000000000040000 0x0000000000040000
>                   pc.rom       4K  0x0000000080040000 0x0000000000020000 0x0000000000020000
>     0000:00:02.0/vga.rom       4K  0x0000000081060000 0x0000000000010000 0x0000000000010000
>    /rom@etc/table-loader       4K  0x00000000812b0000 0x0000000000001000 0x0000000000001000
>       /rom@etc/acpi/rsdp       4K  0x00000000812b1000 0x0000000000001000 0x0000000000001000
> 
> Ramblock is something hidden internally in QEMU implementation, and this
> command should only be used by mostly QEMU developers on RAM stuff. It
> is not a command suitable for QMP interface. So only HMP interface is
> provided for it.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  exec.c                 | 36 ++++++++++++++++++++++++++++++++++++
>  hmp-commands-info.hx   | 14 ++++++++++++++
>  hmp.c                  |  6 ++++++
>  hmp.h                  |  1 +
>  include/exec/ramlist.h |  1 +
>  5 files changed, 58 insertions(+)
> 
> diff --git a/exec.c b/exec.c
> index 50519ae..9b9d16e 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -71,6 +71,8 @@
>  #include "qemu/mmap-alloc.h"
>  #endif
>  
> +#include "monitor/monitor.h"
> +
>  //#define DEBUG_SUBPAGE
>  
>  #if !defined(CONFIG_USER_ONLY)
> @@ -1333,6 +1335,40 @@ void qemu_mutex_unlock_ramlist(void)
>      qemu_mutex_unlock(&ram_list.mutex);
>  }
>  
> +static const char *page_size_to_str(size_t psize)
> +{
> +    switch (psize) {
> +    case 0x1000:
> +        return "4K";
> +    case 0x10000:
> +        return "64K";
> +    case 0x200000:
> +        return "2M";
> +    case 0x40000000:
> +        return "1G";

That's not very portable; other platforms have other sizes, for example
I think ARM has 16kB as one option, and I'm pretty sure the huge-pages
on Power are a different size.
Hmm, we already have
                     qemu-io-cmds.c:cvtstr and
       qapi/string-output-visitor.c:print_type_size

to print sizes nicely; it's a pity we can't use them somehow rather
than having a 3rd similar function.

> +    default:
> +        return "N/A";
> +    }
> +}
> +
> +void ram_block_dump(Monitor *mon)
> +{
> +    RAMBlock *block;
> +
> +    rcu_read_lock();
> +    monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
> +                   "Block Name", "PSize", "Offset", "Used", "Total");
> +    RAMBLOCK_FOREACH(block) {
> +        monitor_printf(mon, "%24s %8s  0x%016" PRIx64 " 0x%016" PRIx64
> +                       " 0x%016" PRIx64 "\n", block->idstr,
> +                       page_size_to_str(block->page_size),
> +                       (uint64_t)block->offset,
> +                       (uint64_t)block->used_length,
> +                       (uint64_t)block->max_length);
> +    }

Yes that should work, I remember there's a RAM_ADDR_FMT macro that's
supposed to be usable for ram_addr_t, but that's fine.

Dave

> +    rcu_read_unlock();
> +}
> +
>  #ifdef __linux__
>  /*
>   * FIXME TOCTTOU: this iterates over memory backends' mem-path, which
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index a53f105..ae16901 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -788,6 +788,20 @@ Display the latest dump status.
>  ETEXI
>  
>      {
> +        .name       = "ramblock",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "Display system ramblock information",
> +        .cmd        = hmp_info_ramblock,
> +    },
> +
> +STEXI
> +@item info ramblock
> +@findex ramblock
> +Dump all the ramblocks of the system.
> +ETEXI
> +
> +    {
>          .name       = "hotpluggable-cpus",
>          .args_type  = "",
>          .params     = "",
> diff --git a/hmp.c b/hmp.c
> index ab407d6..8369388 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -37,6 +37,7 @@
>  #include "qemu-io.h"
>  #include "qemu/cutils.h"
>  #include "qemu/error-report.h"
> +#include "exec/ramlist.h"
>  #include "hw/intc/intc.h"
>  
>  #ifdef CONFIG_SPICE
> @@ -2563,6 +2564,11 @@ void hmp_info_dump(Monitor *mon, const QDict *qdict)
>      qapi_free_DumpQueryResult(result);
>  }
>  
> +void hmp_info_ramblock(Monitor *mon, const QDict *qdict)
> +{
> +    ram_block_dump(mon);
> +}
> +
>  void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
>  {
>      Error *err = NULL;
> diff --git a/hmp.h b/hmp.h
> index 799fd37..7353b67 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -136,6 +136,7 @@ void hmp_rocker_ports(Monitor *mon, const QDict *qdict);
>  void hmp_rocker_of_dpa_flows(Monitor *mon, const QDict *qdict);
>  void hmp_rocker_of_dpa_groups(Monitor *mon, const QDict *qdict);
>  void hmp_info_dump(Monitor *mon, const QDict *qdict);
> +void hmp_info_ramblock(Monitor *mon, const QDict *qdict);
>  void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict);
>  void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
>  
> diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
> index f1c6b45..2e2ac6c 100644
> --- a/include/exec/ramlist.h
> +++ b/include/exec/ramlist.h
> @@ -73,5 +73,6 @@ void ram_block_notifier_remove(RAMBlockNotifier *n);
>  void ram_block_notify_add(void *host, size_t size);
>  void ram_block_notify_remove(void *host, size_t size);
>  
> +void ram_block_dump(Monitor *mon);
>  
>  #endif /* RAMLIST_H */
> -- 
> 2.7.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH v3 2/2] ramblock: add new hmp command "info ramblock"

[Peter Xu]

On Thu, Apr 27, 2017 at 12:23:14PM +0100, Dr. David Alan Gilbert wrote:
> * Peter Xu (peterx@redhat.com) wrote:
> > To dump information about ramblocks. It looks like:
> > 
> > (qemu) info ramblock
> >               Block Name    PSize              Offset               Used              Total
> >             /objects/mem       2M  0x0000000000000000 0x0000000080000000 0x0000000080000000
> >                 vga.vram       4K  0x0000000080060000 0x0000000001000000 0x0000000001000000
> >     /rom@etc/acpi/tables       4K  0x00000000810b0000 0x0000000000020000 0x0000000000200000
> >                  pc.bios       4K  0x0000000080000000 0x0000000000040000 0x0000000000040000
> >   0000:00:03.0/e1000.rom       4K  0x0000000081070000 0x0000000000040000 0x0000000000040000
> >                   pc.rom       4K  0x0000000080040000 0x0000000000020000 0x0000000000020000
> >     0000:00:02.0/vga.rom       4K  0x0000000081060000 0x0000000000010000 0x0000000000010000
> >    /rom@etc/table-loader       4K  0x00000000812b0000 0x0000000000001000 0x0000000000001000
> >       /rom@etc/acpi/rsdp       4K  0x00000000812b1000 0x0000000000001000 0x0000000000001000
> > 
> > Ramblock is something hidden internally in QEMU implementation, and this
> > command should only be used by mostly QEMU developers on RAM stuff. It
> > is not a command suitable for QMP interface. So only HMP interface is
> > provided for it.
> > 
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> >  exec.c                 | 36 ++++++++++++++++++++++++++++++++++++
> >  hmp-commands-info.hx   | 14 ++++++++++++++
> >  hmp.c                  |  6 ++++++
> >  hmp.h                  |  1 +
> >  include/exec/ramlist.h |  1 +
> >  5 files changed, 58 insertions(+)
> > 
> > diff --git a/exec.c b/exec.c
> > index 50519ae..9b9d16e 100644
> > --- a/exec.c
> > +++ b/exec.c
> > @@ -71,6 +71,8 @@
> >  #include "qemu/mmap-alloc.h"
> >  #endif
> >  
> > +#include "monitor/monitor.h"
> > +
> >  //#define DEBUG_SUBPAGE
> >  
> >  #if !defined(CONFIG_USER_ONLY)
> > @@ -1333,6 +1335,40 @@ void qemu_mutex_unlock_ramlist(void)
> >      qemu_mutex_unlock(&ram_list.mutex);
> >  }
> >  
> > +static const char *page_size_to_str(size_t psize)
> > +{
> > +    switch (psize) {
> > +    case 0x1000:
> > +        return "4K";
> > +    case 0x10000:
> > +        return "64K";
> > +    case 0x200000:
> > +        return "2M";
> > +    case 0x40000000:
> > +        return "1G";
> 
> That's not very portable; other platforms have other sizes, for example
> I think ARM has 16kB as one option, and I'm pretty sure the huge-pages
> on Power are a different size.
> Hmm, we already have
>                      qemu-io-cmds.c:cvtstr and
>        qapi/string-output-visitor.c:print_type_size
> 
> to print sizes nicely; it's a pity we can't use them somehow rather
> than having a 3rd similar function.

Indeed. But it's not easy to directly leverage them. Another thing is
that even with these two existing ones, I would still prefer one
function tailored for translating page sizes, since page sizes are
after all static and imho a hash is nice and fast in that case (just
like what the switch does above).

Regarding to the compatibility issue - I considered that, so I had a
"default" below. Since this command is at least currently only for
debugging, if anyone sees "N/A" in the page size field, he/she would
know something wrong, and possibly he/she can add the missed page size
then (if he/she really think this command useful :-).

How about I move this function into util/cutils.c? Would that be a
solution for current series? Also, I can add translations for
4K,8K,16K,... until 1G, if you prefer. That won't be too hard.

> 
> > +    default:
> > +        return "N/A";
> > +    }
> > +}
> > +
> > +void ram_block_dump(Monitor *mon)
> > +{
> > +    RAMBlock *block;
> > +
> > +    rcu_read_lock();
> > +    monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
> > +                   "Block Name", "PSize", "Offset", "Used", "Total");
> > +    RAMBLOCK_FOREACH(block) {
> > +        monitor_printf(mon, "%24s %8s  0x%016" PRIx64 " 0x%016" PRIx64
> > +                       " 0x%016" PRIx64 "\n", block->idstr,
> > +                       page_size_to_str(block->page_size),
> > +                       (uint64_t)block->offset,
> > +                       (uint64_t)block->used_length,
> > +                       (uint64_t)block->max_length);
> > +    }
> 
> Yes that should work, I remember there's a RAM_ADDR_FMT macro that's
> supposed to be usable for ram_addr_t, but that's fine.

That looks better. Will switch to that. Thanks!

-- 
Peter Xu

Re: [Qemu-devel] [PATCH v3 2/2] ramblock: add new hmp command "info ramblock"

[Peter Xu]

On Fri, Apr 28, 2017 at 06:21:30PM +0800, Peter Xu wrote:
> On Thu, Apr 27, 2017 at 12:23:14PM +0100, Dr. David Alan Gilbert wrote:

[...]

> > > +void ram_block_dump(Monitor *mon)
> > > +{
> > > +    RAMBlock *block;
> > > +
> > > +    rcu_read_lock();
> > > +    monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
> > > +                   "Block Name", "PSize", "Offset", "Used", "Total");
> > > +    RAMBLOCK_FOREACH(block) {
> > > +        monitor_printf(mon, "%24s %8s  0x%016" PRIx64 " 0x%016" PRIx64
> > > +                       " 0x%016" PRIx64 "\n", block->idstr,
> > > +                       page_size_to_str(block->page_size),
> > > +                       (uint64_t)block->offset,
> > > +                       (uint64_t)block->used_length,
> > > +                       (uint64_t)block->max_length);
> > > +    }
> > 
> > Yes that should work, I remember there's a RAM_ADDR_FMT macro that's
> > supposed to be usable for ram_addr_t, but that's fine.
> 
> That looks better. Will switch to that. Thanks!

Oh, I found that RAM_ADDR_FMT didn't allow me to do the formatting
with width ("%016..."). So maybe I'll still use current way for now.

-- 
Peter Xu

Re: [Qemu-devel] [PATCH v3 2/2] ramblock: add new hmp command "info ramblock"

[Dr. David Alan Gilbert]

* Peter Xu (peterx@redhat.com) wrote:
> On Fri, Apr 28, 2017 at 06:21:30PM +0800, Peter Xu wrote:
> > On Thu, Apr 27, 2017 at 12:23:14PM +0100, Dr. David Alan Gilbert wrote:
> 
> [...]
> 
> > > > +void ram_block_dump(Monitor *mon)
> > > > +{
> > > > +    RAMBlock *block;
> > > > +
> > > > +    rcu_read_lock();
> > > > +    monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
> > > > +                   "Block Name", "PSize", "Offset", "Used", "Total");
> > > > +    RAMBLOCK_FOREACH(block) {
> > > > +        monitor_printf(mon, "%24s %8s  0x%016" PRIx64 " 0x%016" PRIx64
> > > > +                       " 0x%016" PRIx64 "\n", block->idstr,
> > > > +                       page_size_to_str(block->page_size),
> > > > +                       (uint64_t)block->offset,
> > > > +                       (uint64_t)block->used_length,
> > > > +                       (uint64_t)block->max_length);
> > > > +    }
> > > 
> > > Yes that should work, I remember there's a RAM_ADDR_FMT macro that's
> > > supposed to be usable for ram_addr_t, but that's fine.
> > 
> > That looks better. Will switch to that. Thanks!
> 
> Oh, I found that RAM_ADDR_FMT didn't allow me to do the formatting
> with width ("%016..."). So maybe I'll still use current way for now.

Oh then just stick to the PRIx64 and the case; it's fine.

Dave

> -- 
> Peter Xu
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK