{"id":2215591,"url":"http://patchwork.ozlabs.org/api/patches/2215591/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260324194333.30004-14-farosas@suse.de/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260324194333.30004-14-farosas@suse.de>","list_archive_url":null,"date":"2026-03-24T19:43:28","name":"[RFC,v1,13/17] vmstate: Drop VMS_ARRAY_OF_POINTER_AUTO_ALLOC","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"7142292033fc0801e45b438ac14c2f40e272794a","submitter":{"id":85343,"url":"http://patchwork.ozlabs.org/api/people/85343/?format=json","name":"Fabiano Rosas","email":"farosas@suse.de"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260324194333.30004-14-farosas@suse.de/mbox/","series":[{"id":497339,"url":"http://patchwork.ozlabs.org/api/series/497339/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=497339","date":"2026-03-24T19:43:16","name":"migration: vmstate_save|load changes for peterx","version":1,"mbox":"http://patchwork.ozlabs.org/series/497339/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2215591/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2215591/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256\n header.s=susede2_rsa header.b=SG+MIn1u;\n\tdkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256\n header.s=susede2_ed25519 header.b=nlPayM8p;\n\tdkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de\n header.a=rsa-sha256 header.s=susede2_rsa header.b=SG+MIn1u;\n\tdkim=neutral header.d=suse.de header.i=@suse.de header.a=ed25519-sha256\n header.s=susede2_ed25519 header.b=nlPayM8p;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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t=1774381437;\n h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc:\n mime-version:mime-version:\n content-transfer-encoding:content-transfer-encoding:\n in-reply-to:in-reply-to:references:references;\n bh=CKGmz+lKmXdFvQ91j7EaHfHSLwUO7DpcItY8Bz2/bO0=;\n b=nlPayM8pI51QIJeluhDW03aZYIxWpK6p0GtV0CF6hwYSy9kIH0c6jARU7CoUE05AumlHdh\n hssoq/kQ/yxYoIBw=="],"From":"Fabiano Rosas ","To":"qemu-devel@nongnu.org","Cc":"Peter Xu ,\n Alexander Mikhalitsyn ,\n Juraj Marcin ","Subject":"[RFC PATCH v1 13/17] vmstate: Drop VMS_ARRAY_OF_POINTER_AUTO_ALLOC","Date":"Tue, 24 Mar 2026 16:43:28 -0300","Message-ID":"<20260324194333.30004-14-farosas@suse.de>","X-Mailer":"git-send-email 2.51.0","In-Reply-To":"<20260324194333.30004-1-farosas@suse.de>","References":"<20260324194333.30004-1-farosas@suse.de>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-Spam-Score":"-2.80","X-Spamd-Result":"default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%];\n NEURAL_HAM_LONG(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[];\n R_MISSING_CHARSET(0.50)[]; 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The code is now able to handle such invalid combination,\nso drop the new flag and enable the VMS_ARRAY_OF_POINTER | VMS_ALLOC\ncombo.\n\nNote: I don't quite understand why we cannot allocate the first\nelement of the array with VMS_ARRAY_OF_POINTER_AUTO_ALLOC, so I\navoided that case when using the other flags as well.\n\nSigned-off-by: Fabiano Rosas \n---\n include/migration/vmstate.h | 21 +++++----------------\n migration/savevm.c | 28 ++++++++++++----------------\n migration/vmstate.c | 12 +++++++-----\n 3 files changed, 24 insertions(+), 37 deletions(-)","diff":"diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h\nindex 70bebc60ed..bf12df66e2 100644\n--- a/include/migration/vmstate.h\n+++ b/include/migration/vmstate.h\n@@ -146,8 +146,8 @@ enum VMStateFlags {\n /* When loading serialised VM state, allocate memory for the\n * (entire) field. Only valid in combination with\n * VMS_POINTER. Note: Not all combinations with other flags are\n- * currently supported, e.g. VMS_ALLOC|VMS_ARRAY_OF_POINTER won't\n- * cause the individual entries to be allocated. */\n+ * currently supported.\n+ */\n VMS_ALLOC = 0x2000,\n \n /* Multiply the number of entries given by the integer at opaque +\n@@ -161,19 +161,8 @@ enum VMStateFlags {\n * structure we are referencing to use. */\n VMS_VSTRUCT = 0x8000,\n \n- /*\n- * This is a sub-flag for VMS_ARRAY_OF_POINTER, so VMS_ARRAY_OF_POINTER\n- * must be set altogether. When set, it means array elements can\n- * contain either valid or NULL pointers, vmstate core will sync it\n- * between the two QEMU instances via the stream protocol. When it's a\n- * valid pointer, the vmstate core will be responsible to do the proper\n- * memory allocations. It also means user of this flag must prepare\n- * the array to be all NULLs otherwise memory may leak.\n- */\n- VMS_ARRAY_OF_POINTER_AUTO_ALLOC = 0x10000,\n-\n /* Marker for end of list */\n- VMS_END = 0x20000,\n+ VMS_END = 0x10000,\n };\n \n typedef enum {\n@@ -610,7 +599,7 @@ extern const VMStateInfo vmstate_info_qlist;\n .size = sizeof(_type), \\\n .flags = VMS_POINTER | VMS_VARRAY_UINT8 | \\\n VMS_ARRAY_OF_POINTER | VMS_STRUCT | \\\n- VMS_ARRAY_OF_POINTER_AUTO_ALLOC, \\\n+ VMS_ALLOC, \\\n .offset = vmstate_offset_pointer(_state, _field, _type *), \\\n }\n \n@@ -623,7 +612,7 @@ extern const VMStateInfo vmstate_info_qlist;\n .size = sizeof(_type), \\\n .flags = VMS_POINTER | VMS_VARRAY_UINT32 | \\\n VMS_ARRAY_OF_POINTER | VMS_STRUCT | \\\n- VMS_ARRAY_OF_POINTER_AUTO_ALLOC, \\\n+ VMS_ALLOC, \\\n .offset = vmstate_offset_pointer(_state, _field, _type *), \\\n }\n \ndiff --git a/migration/savevm.c b/migration/savevm.c\nindex db0721996c..5170928d87 100644\n--- a/migration/savevm.c\n+++ b/migration/savevm.c\n@@ -869,7 +869,8 @@ static void vmstate_check(const VMStateDescription *vmsd)\n if (field) {\n while (field->name) {\n if (field->flags & VMS_ARRAY_OF_POINTER) {\n- if (field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC) {\n+ if (field->flags & VMS_ARRAY_OF_POINTER &&\n+ field->flags & VMS_ALLOC) {\n /*\n * Size must be provided because dest QEMU needs that\n * info to know what to allocate\n@@ -882,22 +883,17 @@ static void vmstate_check(const VMStateDescription *vmsd)\n * setup of sizes in this case.\n */\n assert(field->size == 0 && field->size_offset == 0);\n+\n+ /*\n+ * Without VMS_ALLOC, VMS_ARRAY_OF_POINTER must be\n+ * used only together with one of VMS_(V)ARRAY*\n+ * flags.\n+ */\n+ assert(field->flags & (VMS_ARRAY | VMS_VARRAY_INT32 |\n+ VMS_VARRAY_UINT16 |\n+ VMS_VARRAY_UINT8 |\n+ VMS_VARRAY_UINT32));\n }\n- /*\n- * VMS_ARRAY_OF_POINTER must be used only together with one\n- * of VMS_(V)ARRAY* flags.\n- */\n- assert(field->flags & (VMS_ARRAY | VMS_VARRAY_INT32 |\n- VMS_VARRAY_UINT16 | VMS_VARRAY_UINT8 |\n- VMS_VARRAY_UINT32));\n- }\n-\n- /*\n- * When VMS_ARRAY_OF_POINTER_ALLOW_NULL is used, we must have\n- * VMS_ARRAY_OF_POINTER set too.\n- */\n- if (field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC) {\n- assert(field->flags & VMS_ARRAY_OF_POINTER);\n }\n \n if (field->flags & (VMS_STRUCT | VMS_VSTRUCT)) {\ndiff --git a/migration/vmstate.c b/migration/vmstate.c\nindex c1ad0ef9a5..8f0f9383e2 100644\n--- a/migration/vmstate.c\n+++ b/migration/vmstate.c\n@@ -115,7 +115,7 @@ static void *vmstate_first(void *opaque, const VMStateField *field,\n {\n void **first = opaque + field->offset;\n \n- if (alloc) {\n+ if (alloc && field->flags & VMS_ALLOC) {\n return vmstate_handle_alloc(first, size, n);\n }\n \n@@ -142,7 +142,7 @@ static void *vmstate_next(void **first, const VMStateField *field,\n next = *array_elem;\n \n if (alloc) {\n- if (!next || field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC) {\n+ if (!next || field->flags & VMS_ALLOC) {\n /*\n * NOTE: do not use vmstate_size() here, because we\n * need the object size, not entry size of the\n@@ -291,7 +291,7 @@ bool vmstate_load_vmsd(QEMUFile *f, const VMStateDescription *vmsd,\n int size = vmstate_size(opaque, field);\n \n head = vmstate_first(opaque, field, size, n_elems,\n- field->flags & VMS_ALLOC);\n+ !(field->flags & VMS_ARRAY_OF_POINTER));\n \n for (i = 0; i < n_elems; i++) {\n /* If we will process the load of field? */\n@@ -408,7 +408,8 @@ static bool vmsd_can_compress(const VMStateField *field)\n return false;\n }\n \n- if (field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC) {\n+ if (field->flags & VMS_ARRAY_OF_POINTER &&\n+ field->flags & VMS_ALLOC) {\n /*\n * This may involve two VMSD fields to be dumped, one for the\n * marker to show if the pointer is NULL, followed by the real\n@@ -659,7 +660,8 @@ static bool vmstate_save_vmsd_v(QEMUFile *f, const VMStateDescription *vmsd,\n * marker first for each element saying if it's populated.\n */\n use_dynamic_array =\n- field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC;\n+ field->flags & VMS_ARRAY_OF_POINTER &&\n+ field->flags & VMS_ALLOC;\n \n use_marker_field = use_dynamic_array || is_null;\n \n","prefixes":["RFC","v1","13/17"]}