hostmem: Wire up RAM_NORESERVE via "reserve" property

Let's provide a way to control the use of RAM_NORESERVE via memory
backends using the "reserve" property which defaults to true (old
behavior).

hostmem: Wire up RAM_NORESERVE via "reserve" property

Let's provide a way to control the use of RAM_NORESERVE via memory
backends using the "reserve" property which defaults to true (old
behavior).

Only Linux currently supports clearing the flag (and support is checked at
runtime, depending on the setting of "/proc/sys/vm/overcommit_memory").
Windows and other POSIX systems will bail out with "reserve=false".

The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM. This essentially allows
avoiding to set "/proc/sys/vm/overcommit_memory == 0") when using
virtio-mem and also supporting hugetlbfs in the future.

As really only Linux implements RAM_NORESERVE right now, let's expose
the property only with CONFIG_LINUX. Setting the property to "false"
will then only fail in corner cases -- for example on very old kernels
or when memory overcommit was completely disabled by the admin.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-11-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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softmmu/memory: Pass ram_flags to memory_region_init_ram_shared_nomigrate()

Let's forward ram_flags instead, renaming
memory_region_init_ram_shared_nomigrate() into
memory_region_init_ram_flags_nomi

softmmu/memory: Pass ram_flags to memory_region_init_ram_shared_nomigrate()

Let's forward ram_flags instead, renaming
memory_region_init_ram_shared_nomigrate() into
memory_region_init_ram_flags_nomigrate().

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-6-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd()

Let's pass in ram flags just like we do with qemu_ram_alloc_from_file(),
to clean up and prepare for more flags.

Simplify the documentatio

softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd()

Let's pass in ram flags just like we do with qemu_ram_alloc_from_file(),
to clean up and prepare for more flags.

Simplify the documentation of passed ram flags: Looking at our
documentation of RAM_SHARED and RAM_PMEM is sufficient, no need to be
repetitive.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-5-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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docs: fix references to docs/devel/tracing.rst

Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.

We still have several referenc

docs: fix references to docs/devel/tracing.rst

Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.

We still have several references to the old file, so let's fix them
with the following command:

sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

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backends/tpm: Replace qemu_mutex_lock calls with QEMU_LOCK_GUARD

Simplify the tpm_emulator_ctrlcmd() handler by replacing a pair of
qemu_mutex_lock/qemu_mutex_unlock calls by the WITH_QEMU_LOCK_GUAR

backends/tpm: Replace qemu_mutex_lock calls with QEMU_LOCK_GUARD

Simplify the tpm_emulator_ctrlcmd() handler by replacing a pair of
qemu_mutex_lock/qemu_mutex_unlock calls by the WITH_QEMU_LOCK_GUARD
macro.

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Christophe de Dinechin <dinechin@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210512070713.3286188-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

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Do not include sysemu/sysemu.h if it's not really necessary

Stop including sysemu/sysemu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.207

Do not include sysemu/sysemu.h if it's not really necessary

Stop including sysemu/sysemu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

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dbus-vmstate: Increase the size of input stream buffer used during load

This commit fixes an issue where migration is failing in the load phase
because of a false alarm about data unavailability.

F

dbus-vmstate: Increase the size of input stream buffer used during load

This commit fixes an issue where migration is failing in the load phase
because of a false alarm about data unavailability.

Following is the error received when the amount of data to be transferred
exceeds the default buffer size setup by G_BUFFERED_INPUT_STREAM(4KiB),
even when the maximum data size supported by this backend is 1MiB
(DBUS_VMSTATE_SIZE_LIMIT):

dbus_vmstate_post_load: Invalid vmstate size: 4364
qemu-kvm: error while loading state for instance 0x0 of device 'dbus-vmstate/dbus-vmstate'

This commit sets the size of the input stream buffer used during load to
DBUS_VMSTATE_SIZE_LIMIT which is the maximum amount of data a helper can
send during save phase.
Secondly, this commit makes sure that the input stream buffer is loaded before
checking the size of the data available in it, rectifying the false alarm about
data unavailability.

Fixes: 5010cec2bc87 ("Add dbus-vmstate object")
Signed-off-by: Priyankar Jain <priyankar.jain@nutanix.com>
Message-Id: <cdaad4718e62bf22fd5e93ef3e252de20da5c17c.1612273156.git.priyankar.jain@nutanix.com>
[ Modified printf format for gsize ]
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

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backends/dbus-vmstate: Fix short read error handling

When dbus_vmstate_post_load() fails, it complains to stderr. Except
on short read, where it checks with g_return_val_if_fail(). This
fails sile

backends/dbus-vmstate: Fix short read error handling

When dbus_vmstate_post_load() fails, it complains to stderr. Except
on short read, where it checks with g_return_val_if_fail(). This
fails silently if G_DISABLE_CHECKS is undefined (it should be), or
else pads the short read with uninitialized bytes.

Replace g_return_val_if_fail() by a proper error check.

Fixes: 5010cec2bc87dafab39b3913c8ca91f88df9c540
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210126124240.2081959-2-armbru@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

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hostmem: Don't report pmem attribute if unsupported

When management applications (like Libvirt) want to check whether
memory-backend-file.pmem is supported they can list object
properties using 'qom

hostmem: Don't report pmem attribute if unsupported

When management applications (like Libvirt) want to check whether
memory-backend-file.pmem is supported they can list object
properties using 'qom-list-properties'. However, 'pmem' is
declared always (and thus reported always) and only at runtime
QEMU errors out if it was built without libpmem (and thus can not
guarantee write persistence). This is suboptimal since we have
ability to declare attributes at compile time.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1915216
Message-Id: <dfcc5dc7e2efc0283bc38e3036da2c0323621cdb.1611647111.git.mprivozn@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

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memory: alloc RAM from file at offset

Allow RAM MemoryRegion to be created from an offset in a file, instead
of allocating at offset of 0 by default. This is needed to synchronize
RAM between QEMU &

memory: alloc RAM from file at offset

Allow RAM MemoryRegion to be created from an offset in a file, instead
of allocating at offset of 0 by default. This is needed to synchronize
RAM between QEMU & remote process.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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replay: rng-builtin support

This patch enables using rng-builtin with record/replay
by making the callbacks deterministic.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <16

replay: rng-builtin support

This patch enables using rng-builtin with record/replay
by making the callbacks deterministic.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <161233201286.170686.7858208964037376305.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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machine: add missing doc for memory-backend option

Add documentation for '-machine memory-backend' CLI option and
how to use it.

And document that x-use-canonical-path-for-ramblock-id,
is considere

machine: add missing doc for memory-backend option

Add documentation for '-machine memory-backend' CLI option and
how to use it.

And document that x-use-canonical-path-for-ramblock-id,
is considered to be stable to make sure it won't go away by accident.

x- was intended for unstable/iternal properties, and not supposed to
be stable option. However it's too late to rename (drop x-)
it as it would mean that users will have to mantain both
x-use-canonical-path-for-ramblock-id (for QEMU 5.0-5.2) versions
and prefix-less for later versions.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20210121161504.1007247-1-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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