From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34530) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UvSwk-0002YS-Pp for qemu-devel@nongnu.org; Sat, 06 Jul 2013 09:54:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UvSwj-0001rw-MJ for qemu-devel@nongnu.org; Sat, 06 Jul 2013 09:54:42 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:35976) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UvSwj-0001rm-HD for qemu-devel@nongnu.org; Sat, 06 Jul 2013 09:54:41 -0400 Received: by mail-pd0-f174.google.com with SMTP id 10so2755570pdc.33 for ; Sat, 06 Jul 2013 06:54:40 -0700 (PDT) From: Alexey Kardashevskiy Date: Sat, 6 Jul 2013 23:54:00 +1000 Message-Id: <1373118856-30171-4-git-send-email-aik@ozlabs.ru> In-Reply-To: <1373118856-30171-1-git-send-email-aik@ozlabs.ru> References: <1373118856-30171-1-git-send-email-aik@ozlabs.ru> Subject: [Qemu-devel] [PATCH 03/19] savevm: Implement VMS_DIVIDE flag List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Anthony Liguori , aik@ozlabs.ru, Alexander Graf , qemu-ppc@nongnu.org, Paul Mackerras , David Gibson From: David Gibson The vmstate infrastructure includes a VMS_MULTIPY flag, and associated VMSTATE_VBUFFER_MULTIPLY helper macro. These can be used to save a variably sized buffer where the size in bytes of the buffer isn't directly accessible as a structure field, but an element count from which the size can be derived is. This patch adds an analogous VMS_DIVIDE option, which handles a variably sized buffer whose size is a submultiple of a field, rather than a multiple. For example a buffer containing per-page structures whose size is derived from a field storing the total address space described by the structures could use this construct. Signed-off-by: David Gibson Signed-off-by: Alexey Kardashevskiy --- include/migration/vmstate.h | 13 +++++++++++++ savevm.c | 8 ++++++++ 2 files changed, 21 insertions(+) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index 1c31b5d..672b0a7 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -100,6 +100,7 @@ enum VMStateFlags { VMS_MULTIPLY = 0x200, /* multiply "size" field by field_size */ VMS_VARRAY_UINT8 = 0x400, /* Array with size in uint8_t field*/ VMS_VARRAY_UINT32 = 0x800, /* Array with size in uint32_t field*/ + VMS_DIVIDE = 0x1000, /* divide "size" field by field_size */ }; typedef struct { @@ -422,6 +423,18 @@ extern const VMStateInfo vmstate_info_bitmap; .start = (_start), \ } +#define VMSTATE_VBUFFER_DIVIDE(_field, _state, _version, _test, _start, _field_size, _divide) { \ + .name = (stringify(_field)), \ + .version_id = (_version), \ + .field_exists = (_test), \ + .size_offset = vmstate_offset_value(_state, _field_size, uint32_t),\ + .size = (_divide), \ + .info = &vmstate_info_buffer, \ + .flags = VMS_VBUFFER|VMS_POINTER|VMS_DIVIDE, \ + .offset = offsetof(_state, _field), \ + .start = (_start), \ +} + #define VMSTATE_VBUFFER(_field, _state, _version, _test, _start, _field_size) { \ .name = (stringify(_field)), \ .version_id = (_version), \ diff --git a/savevm.c b/savevm.c index e0491e7..788af85 100644 --- a/savevm.c +++ b/savevm.c @@ -1700,6 +1700,10 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, if (field->flags & VMS_MULTIPLY) { size *= field->size; } + if (field->flags & VMS_DIVIDE) { + assert((size % field->size) == 0); + size /= field->size; + } } if (field->flags & VMS_ARRAY) { n_elems = field->num; @@ -1764,6 +1768,10 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, if (field->flags & VMS_MULTIPLY) { size *= field->size; } + if (field->flags & VMS_DIVIDE) { + assert((size % field->size) == 0); + size /= field->size; + } } if (field->flags & VMS_ARRAY) { n_elems = field->num; -- 1.8.3.2