From: "Daniel P. Berrangé" <berrange@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Harsh Prateek Bora" <harshpb@linux.ibm.com>,
"Peter Maydell" <peter.maydell@linaro.org>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Yanan Wang" <wangyanan55@huawei.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Thomas Huth" <thuth@redhat.com>,
"Cédric Le Goater" <clegoate@redhat.com>,
"Halil Pasic" <pasic@linux.ibm.com>,
"Laurent Vivier" <laurent@vivier.eu>,
qemu-arm@nongnu.org,
"Daniel Henrique Barboza" <danielhb413@gmail.com>,
"Eduardo Habkost" <eduardo@habkost.net>,
qemu-ppc@nongnu.org, "David Gibson" <david@gibson.dropbear.id.au>,
"Ilya Leoshkevich" <iii@linux.ibm.com>,
"Eric Farman" <farman@linux.ibm.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
"David Hildenbrand" <david@redhat.com>,
qemu-s390x@nongnu.org, "Daniel P. Berrangé" <berrange@redhat.com>
Subject: [PATCH 08/14] include/hw: add macros for deprecation & removal of versioned machines
Date: Wed, 1 May 2024 19:27:53 +0100 [thread overview]
Message-ID: <20240501182759.2934195-9-berrange@redhat.com> (raw)
In-Reply-To: <20240501182759.2934195-1-berrange@redhat.com>
Versioned machines live for a long time to provide back compat for
incoming migration and restore of saved images. To guide users away from
usage of old machines, however, we want to deprecate any older than 3
years (equiv of 9 releases), and delete any older than 6 years (equiva
of 18 releases).
To get a standardized deprecation message and avoid having to remember
to manually add it after three years, this introduces two macros to be
used by targets when defining versioned machines.
* MACHINE_VER_DEPRECATION(major, minor)
Automates the task of setting the 'deprecation_reason' field on the
machine, if-and-only-if the major/minor version is older than 3 years.
* MACHINE_VER_DEPRECATION(major, minor)
Simulates the deletion of by skipping registration of the QOM type
for a versioned machine, if-and-only-if the major/minor version is
older than 6 years.
By using these two macros there is no longer any manual work required
per-release to deprecate old machines. By preventing the use of machines
that have reached their deletion date, it is also no neccessary to
manually delete machines per-release. Deletion can be batched up once a
year or whenever makes most sense.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
include/hw/boards.h | 84 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 84 insertions(+)
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 47ca450fca..48b6c98c77 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -427,6 +427,7 @@ struct MachineState {
* MachineClass *mc = MACHINE_CLASS(oc); \
* MACHINE_VER_SYM(options, virt, __VA_ARGS__)(mc); \
* mc->desc = "QEMU " MACHINE_VER_STR(__VA_ARGS__) " Virtual Machine"; \
+ * MACHINE_VER_DEPRECATION(__VA_ARGS__); \
* if (latest) { \
* mc->alias = "virt"; \
* } \
@@ -438,6 +439,7 @@ struct MachineState {
* }; \
* static void MACHINE_VER_SYM(register, virt, __VA_ARGS__)(void) \
* { \
+ * MACHINE_VER_DELETION(__VA_ARGS__); \
* type_register_static(&MACHINE_VER_SYM(info, virt, __VA_ARGS__)); \
* } \
* type_init(MACHINE_VER_SYM(register, virt, __VA_ARGS__));
@@ -580,6 +582,88 @@ struct MachineState {
_MACHINE_VER_SYM2) (sym, prefix, __VA_ARGS__)
+/*
+ * How many years/major releases for each phase
+ * of the life cycle. Assumes use of versioning
+ * scheme where major is bumped each year
+ */
+#define MACHINE_VER_DELETION_MAJOR 6
+#define MACHINE_VER_DEPRECATION_MAJOR 3
+
+/*
+ * Expands to a static string containing a deprecation
+ * message for a versioned machine type
+ */
+#define MACHINE_VER_DEPRECATION_MSG \
+ "machines more than " stringify(MACHINE_VER_DEPRECATION_MAJOR) \
+ " years old are subject to deletion after " \
+ stringify(MACHINE_VER_DELETION_MAJOR) " years"
+
+#define _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor) \
+ (((QEMU_VERSION_MAJOR - major) > cutoff) || \
+ (((QEMU_VERSION_MAJOR - major) == cutoff) && \
+ (QEMU_VERSION_MINOR - minor) >= 0))
+
+#define _MACHINE_VER_IS_EXPIRED2(cutoff, major, minor) \
+ _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor)
+#define _MACHINE_VER_IS_EXPIRED3(cutoff, major, minor, micro) \
+ _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor)
+#define _MACHINE_VER_IS_EXPIRED4(cutoff, major, minor, _unused, tag) \
+ _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor)
+#define _MACHINE_VER_IS_EXPIRED5(cutoff, major, minor, micro, _unused, tag) \
+ _MACHINE_VER_IS_EXPIRED_IMPL(cutoff, major, minor)
+
+#define _MACHINE_IS_EXPIRED(cutoff, ...) \
+ _MACHINE_VER_PICK(__VA_ARGS__, \
+ _MACHINE_VER_IS_EXPIRED5, \
+ _MACHINE_VER_IS_EXPIRED4, \
+ _MACHINE_VER_IS_EXPIRED3, \
+ _MACHINE_VER_IS_EXPIRED2) (cutoff, __VA_ARGS__)
+
+/*
+ * Evaluates true when a machine type with (major, minor)
+ * or (major, minor, micro) version should be considered
+ * deprecated based on the current versioned machine type
+ * lifecycle rules
+ */
+#define MACHINE_VER_IS_DEPRECATED(...) \
+ _MACHINE_IS_EXPIRED(MACHINE_VER_DEPRECATION_MAJOR, __VA_ARGS__)
+
+/*
+ * Evaluates true when a machine type with (major, minor)
+ * or (major, minor, micro) version should be considered
+ * for deletion based on the current versioned machine type
+ * lifecycle rules
+ */
+#define MACHINE_VER_SHOULD_DELETE(...) \
+ _MACHINE_IS_EXPIRED(MACHINE_VER_DELETION_MAJOR, __VA_ARGS__)
+
+/*
+ * Sets the deprecation reason for a versioned machine based
+ * on its lifecycle
+ *
+ * This must be unconditionally used in the _class_init
+ * function for all machine types which support versioning.
+ *
+ * Initially it will be an effective no-op, but after a
+ * suitable period of time has passed, it will set the
+ * 'deprecation_reason' field on the machine, to warn users
+ * about forthcoming removal.
+ */
+#define MACHINE_VER_DEPRECATION(...) \
+ do { \
+ if (MACHINE_VER_IS_DEPRECATED(__VA_ARGS__)) { \
+ mc->deprecation_reason = MACHINE_VER_DEPRECATION_MSG; \
+ } \
+ } while (0)
+
+#define MACHINE_VER_DELETION(...) \
+ do { \
+ if (MACHINE_VER_SHOULD_DELETE(__VA_ARGS__)) { \
+ return; \
+ } \
+ } while (0)
+
#define DEFINE_MACHINE(namestr, machine_initfn) \
static void machine_initfn##_class_init(ObjectClass *oc, void *data) \
{ \
--
2.43.0
next prev parent reply other threads:[~2024-05-01 18:30 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-01 18:27 [PATCH 00/14] hw: define and enforce a standard lifecycle for versioned machines Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 01/14] include/hw: add helpers for defining versioned machine types Daniel P. Berrangé
2024-05-02 10:34 ` Thomas Huth
2024-05-09 14:39 ` Daniel P. Berrangé
2024-05-02 14:57 ` Eric Blake
2024-05-02 16:54 ` Thomas Huth
2024-05-09 14:39 ` Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 02/14] hw/arm: convert 'virt' machine definitions to use new macros Daniel P. Berrangé
2024-05-02 12:11 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 03/14] hw/s390x: convert 'ccw' " Daniel P. Berrangé
2024-05-02 11:12 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 04/14] hw/ppc: convert 'spapr' " Daniel P. Berrangé
2024-05-02 11:57 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 05/14] hw/m68k: convert 'virt' " Daniel P. Berrangé
2024-05-02 12:00 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 06/14] hw/i386: convert 'i440fx' " Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 07/14] hw/i386: convert 'q35' " Daniel P. Berrangé
2024-05-01 18:27 ` Daniel P. Berrangé [this message]
2024-05-02 10:59 ` [PATCH 08/14] include/hw: add macros for deprecation & removal of versioned machines Thomas Huth
2024-05-09 14:42 ` Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 09/14] hw: temporarily disable deletion of versioned machine types Daniel P. Berrangé
2024-05-02 11:05 ` Thomas Huth
2024-05-02 11:13 ` Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 10/14] hw: set deprecation info for all " Daniel P. Berrangé
2024-05-02 11:06 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 11/14] hw: skip registration of outdated " Daniel P. Berrangé
2024-05-02 12:02 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 12/14] hw/ppc: remove obsolete manual deprecation reason string of spapr machines Daniel P. Berrangé
2024-05-02 12:04 ` Thomas Huth
2024-05-01 18:27 ` [PATCH 13/14] hw/i386: remove obsolete manual deprecation reason string of i440fx machines Daniel P. Berrangé
2024-05-02 12:08 ` Thomas Huth
2024-05-02 12:15 ` Daniel P. Berrangé
2024-05-01 18:27 ` [PATCH 14/14] docs: document special exception for machine type deprecation & removal Daniel P. Berrangé
2024-05-02 9:47 ` Thomas Huth
2024-05-02 9:53 ` Daniel P. Berrangé
2024-05-03 11:46 ` [PATCH 00/14] hw: define and enforce a standard lifecycle for versioned machines Cédric Le Goater
2024-05-03 12:14 ` Peter Maydell
2024-05-03 12:34 ` Daniel P. Berrangé
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