Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

* scripts: dump stdin on meson-buildoptions error
* rust: introduce qemu_api::cell::Opaque<>
* rust: express pinning requirements for timers
* rust: hpet: decode HPET registers into enums
* rust: cell: add full example of declaring a SysBusDevice
* rust: qom: remove operations on &mut

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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (25 commits)
  rust: pl011: Allow NULL chardev argument to pl011_create()
  meson.build: default to -gsplit-dwarf for debug info
  rust: qom: remove operations on &mut
  rust: cell: add full example of declaring a SysBusDevice
  rust: hpet: decode HPET registers into enums
  rust: pl011: pass around registers::Data
  rust: pl011: switch to safe chardev operation
  rust: pl011: clean up visibilities of callbacks
  rust: pl011: move register definitions out of lib.rs
  rust: chardev: provide basic bindings to character devices
  rust: bindings: remove more unnecessary Send/Sync impls
  rust: chardev: wrap Chardev with Opaque<>
  rust: memory: wrap MemoryRegion with Opaque<>
  rust: sysbus: wrap SysBusDevice with Opaque<>
  rust: hpet: do not access fields of SysBusDevice
  rust: qdev: wrap Clock and DeviceState with Opaque<>
  rust: qom: wrap Object with Opaque<>
  rust: irq: wrap IRQState with Opaque<>
  rust: timer: wrap QEMUTimer with Opaque<> and express pinning requirements
  rust: hpet: embed Timer without the Option and Box indirection
  ...

Signed-off-by: Stefan Hajnoczi <[email protected]>

Author: stefanhaRH

docs/devel/rust.rst

@@ -296,15 +296,35 @@ of ``&mut self``; access to internal fields must use *interior mutability*
 to go from a shared reference to a ``&mut``.
 
 Whenever C code provides you with an opaque ``void *``, avoid converting it
-to a Rust mutable reference, and use a shared reference instead.  Rust code
-will then have to use QEMU's ``BqlRefCell`` and ``BqlCell`` type, which
-enforce that locking rules for the "Big QEMU Lock" are respected.  These cell
-types are also known to the ``vmstate`` crate, which is able to "look inside"
-them when building an in-memory representation of a ``struct``'s layout.
-Note that the same is not true of a ``RefCell`` or ``Mutex``.
-
-In the future, similar cell types might also be provided for ``AioContext``-based
-locking as well.
+to a Rust mutable reference, and use a shared reference instead.  The
+``qemu_api::cell`` module provides wrappers that can be used to tell the
+Rust compiler about interior mutability, and optionally to enforce locking
+rules for the "Big QEMU Lock".  In the future, similar cell types might
+also be provided for ``AioContext``-based locking as well.
+
+In particular, device code will usually rely on the ``BqlRefCell`` and
+``BqlCell`` type to ensure that data is accessed correctly under the
+"Big QEMU Lock".  These cell types are also known to the ``vmstate``
+crate, which is able to "look inside" them when building an in-memory
+representation of a ``struct``'s layout.  Note that the same is not true
+of a ``RefCell`` or ``Mutex``.
+
+Bindings code instead will usually use the ``Opaque`` type, which hides
+the contents of the underlying struct and can be easily converted to
+a raw pointer, for use in calls to C functions.  It can be used for
+example as follows::
+
+    #[repr(transparent)]
+    #[derive(Debug, qemu_api_macros::Wrapper)]
+    pub struct Object(Opaque<bindings::Object>);
+
+where the special ``derive`` macro provides useful methods such as
+``from_raw``, ``as_ptr`, ``as_mut_ptr`` and ``raw_get``.  The bindings will
+then manually check for the big QEMU lock with assertions, which allows
+the wrapper to be declared thread-safe::
+
+    unsafe impl Send for Object {}
+    unsafe impl Sync for Object {}
 
 Writing bindings to C code
 ''''''''''''''''''''''''''

meson.build

@@ -601,6 +601,10 @@ if get_option('tsan')
   qemu_ldflags = ['-fsanitize=thread'] + qemu_ldflags
 endif
 
+if get_option('debug') and get_option('split_debug')
+  qemu_cflags += '-gsplit-dwarf'
+endif
+
 # Detect support for PT_GNU_RELRO + DT_BIND_NOW.
 # The combination is known as "full relro", because .got.plt is read-only too.
 qemu_ldflags += cc.get_supported_link_arguments('-Wl,-z,relro', '-Wl,-z,now')
@@ -4015,7 +4019,7 @@ libchardev = static_library('chardev', chardev_ss.sources() + genh,
                             build_by_default: false)
 
 chardev = declare_dependency(objects: libchardev.extract_all_objects(recursive: false),
-                             dependencies: chardev_ss.dependencies())
+                             dependencies: [chardev_ss.dependencies(), io])
 
 hwcore_ss = hwcore_ss.apply({})
 libhwcore = static_library('hwcore', sources: hwcore_ss.sources() + genh,
@@ -4100,13 +4104,6 @@ if have_rust
   foreach enum : c_bitfields
     bindgen_args += ['--bitfield-enum', enum]
   endforeach
-  c_nocopy = [
-    'QEMUTimer',
-  ]
-  # Used to customize Drop trait
-  foreach struct : c_nocopy
-    bindgen_args += ['--no-copy', struct]
-  endforeach
 
   # TODO: Remove this comment when the clang/libclang mismatch issue is solved.
   #
@@ -4590,6 +4587,8 @@ if have_rust
   summary_info += {'bindgen':         bindgen.full_path()}
   summary_info += {'bindgen version': bindgen.version()}
 endif
+# option_cflags is purely for the summary display, meson will pass
+# -g/-O options directly
 option_cflags = (get_option('debug') ? ['-g'] : [])
 if get_option('optimization') != 'plain'
   option_cflags += ['-O' + get_option('optimization')]

meson_options.txt

@@ -362,6 +362,8 @@ option('debug_mutex', type: 'boolean', value: false,
        description: 'mutex debugging support')
 option('debug_stack_usage', type: 'boolean', value: false,
        description: 'measure coroutine stack usage')
+option('split_debug', type: 'boolean', value: true,
+       description: 'split debug info from object files')
 option('qom_cast_debug', type: 'boolean', value: true,
        description: 'cast debugging support')
 option('slirp_smbd', type : 'feature', value : 'auto',

rust/Cargo.toml

@@ -37,6 +37,8 @@ result_unit_err = "allow"
 should_implement_trait = "deny"
 # can be for a reason, e.g. in callbacks
 unused_self = "allow"
+# common in device crates
+upper_case_acronyms = "allow"
 
 # default-allow lints
 as_ptr_cast_mut = "deny"