The dirty bit is DIRTY_MEMORY_MIGRATION. Correct the comment.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190426020927.25470-1-richardw.yang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
mtree_info() takes an fprintf()-like callback and a FILE * to pass to
it, and so do its helper functions. Passing around callback and
argument is rather tiresome.
Its only caller hmp_info_mtree() passes monitor_printf() cast to
fprintf_function and the current monitor cast to FILE *.
The type-punning is technically undefined behaviour, but works in
practice. Clean up: drop the callback, and call qemu_printf()
instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-9-armbru@redhat.com>
Currently, a callback registered through the RAMBlock notifier
is not able to get the memory region type (i.e callback is not
able to use memory_region_is_ram_device function). This is
because mr->ram assignment happens _after_ the memory is allocated
whereas the callback is executed during allocation.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1667249
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Message-Id: <20190204222322.26766-2-brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not add/del coalesced IO ranges in the case where the
same FlatRanges are present in both old and new FlatViews
Fixes: 3ac7d43a6f ("memory: update coalesced_range on transaction_commit")
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Message-Id: <59572a7353830be4b7aa57d79ccb7ad6b72f0dda.1549406119.git.jag.raman@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Most list head structs need not be given a name. In most cases the
name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV
or reverse iteration, but this does not apply to lists of other kinds,
and even for QTAILQ in practice this is only rarely needed. In addition,
we will soon reimplement those macros completely so that they do not
need a name for the head struct. So clean up everything, not giving a
name except in the rare case where it is necessary.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The e1000 driver calls memory_region_add_coalescing but
kvm_coalesce_mmio_region is never called for those regions. The bug
dates back to the introduction of the memory region API; to fix it,
delete and re-add coalesced MMIO ranges when building the FlatViews.
Because coalesced MMIO regions apply to all address spaces, the
has_coalesced_range flag has to be changed into an int.
Fixes: 093bc2cd88 ("Hierarchical memory region API")
Reported-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Store whether the FlatRange has had any coalesced I/O ranges applied,
and if not avoid calling coalesced_io_del. This is useful in preparation
for the next patch, which will call coalesced_io_del when rendering
memory regions.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Extract two new functions from memory_region_update_coalesced_range_as.
To avoid duplication in the creation of the MemoryRegionSection, use
MEMORY_LISTENER_UPDATE_REGION instead of MEMORY_LISTENER_CALL
to invoke the listener callback.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a new flag to mark memory region that are used as non-volatile, by
NVDIMM for example. That bit is propagated down to the flat view, and
reflected in HMP info mtree with a "nv-" prefix on the memory type.
This way, guest_phys_blocks_region_add() can skip the NV memory
regions for dumps and TCG memory clear in a following patch.
Cc: dgilbert@redhat.com
Cc: imammedo@redhat.com
Cc: pbonzini@redhat.com
Cc: guangrong.xiao@linux.intel.com
Cc: mst@redhat.com
Cc: xiaoguangrong.eric@gmail.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181003114454.5662-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that all the users of old_mmio MemoryRegion accessors
have been converted, we can remove the core code support.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180824170422.5783-2-peter.maydell@linaro.org>
Based-on: <20180802174042.29234-1-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Memory regions configured as DEVICE_BIG_ENDIAN (or DEVICE_NATIVE_ENDIAN on
big-endian guest) behave incorrectly when the memory access 'size' is smaller
than the implementation 'access_size'.
In the following code segment from access_with_adjusted_size():
if (memory_region_big_endian(mr)) {
for (i = 0; i < size; i += access_size) {
r |= access_fn(mr, addr + i, value, access_size,
(size - access_size - i) * 8, access_mask, attrs);
}
(size - access_size - i) * 8 is the number of bits that will arithmetic
shift the current value.
Currently we can only 'left' shift a read() access, and 'right' shift a write().
When the access 'size' is smaller than the implementation, we get a negative
number of bits to shift.
For the read() case, a negative 'left' shift is a 'right' shift :)
However since the 'shift' type is unsigned, there is currently no way to
right shift.
Fix this by changing the access_fn() prototype to handle signed shift values,
and modify the memory_region_shift_read|write_access() helpers to correctly
arithmetic shift the opposite direction when the 'shift' value is negative.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180927002416.1781-4-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180927002416.1781-3-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180927002416.1781-2-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Before this change, memory-backend-file object is valid for Linux hosts
only because hostmem-file.c is compiled only on Linux hosts.
However, other POSIX-based hosts (such as macOS) can support
memory-backend-file object in the same way as on Linux hosts.
This patch makes hostmem-file.c and related functions to be compiled on
all POSIX-based hosts to make available memory-backend-file on them.
Signed-off-by: Hikaru Nishida <hikarupsp@gmail.com>
Message-Id: <20180924123205.29651-1-hikarupsp@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
if MemoryRegion intialization fails it's left in semi-initialized state,
where it's size is not 0 and attached as child to owner object.
And this leds to crash in following use-case:
(monitor) object_add memory-backend-file,id=mem1,size=99999G,mem-path=/tmp/foo,discard-data=yes
memory.c:2083: memory_region_get_ram_ptr: Assertion `mr->ram_block' failed
Aborted (core dumped)
it happens due to assumption that memory region is intialized when
memory_region_size() != 0
and therefore it's ok to access it in
file_backend_unparent()
if (memory_region_size() != 0)
memory_region_get_ram_ptr()
which happens when object_add fails and unparents failed backend making
file_backend_unparent() access invalid memory region.
Fix it by making sure that memory_region_init_foo() APIs cleanup externally
visible side effects on failure (like set size to 0 and unparenting object)
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1536064777-42312-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This includes nvdimm persistence fixes queued before the release.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
pc: fixes
This includes nvdimm persistence fixes queued before the release.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Mon 20 Aug 2018 11:38:11 BST
# gpg: using RSA key 281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg: aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17 0970 C350 3912 AFBE 8E67
# Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA 8A0D 281F 0DB8 D28D 5469
* remotes/mst/tags/for_upstream:
migration/ram: ensure write persistence on loading all data to PMEM.
migration/ram: Add check and info message to nvdimm post copy.
mem/nvdimm: ensure write persistence to PMEM in label emulation
hostmem-file: add the 'pmem' option
configure: add libpmem support
memory, exec: switch file ram allocation functions to 'flags' parameters
memory, exec: Expose all memory block related flags.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove the obsolete MMIO request_ptr APIs; they have no
users now.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: KONRAD Frederic <frederic.konrad@adacore.com>
Message-id: 20180817114619.22354-3-peter.maydell@linaro.org
The io_readx() function needs to know whether the load it is
doing is an MMU_DATA_LOAD or an MMU_INST_FETCH, so that it
can pass the right value to the cpu_transaction_failed()
function. Plumb this information through from the softmmu
code.
This is currently not often going to give the wrong answer,
because usually instruction fetches go via get_page_addr_code().
However once we switch over to handling execution from non-RAM by
creating single-insn TBs, the path for an insn fetch to generate
a bus error will be through cpu_ld*_code() and io_readx(),
so without this change we will generate a d-side fault when we
should generate an i-side fault.
We also have to pass the access type via a CPU struct global
down to unassigned_mem_read(), for the benefit of the targets
which still use the cpu_unassigned_access() hook (m68k, mips,
sparc, xtensa).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180710160013.26559-2-peter.maydell@linaro.org
As more flag parameters besides the existing 'share' are going to be
added to following functions
memory_region_init_ram_from_file
qemu_ram_alloc_from_fd
qemu_ram_alloc_from_file
let's switch them to use the 'flags' parameters so as to ease future
flag additions.
The existing 'share' flag is converted to the RAM_SHARED bit in ram_flags,
and other flag bits are ignored by above functions right now.
Signed-off-by: Junyan He <junyan.he@intel.com>
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This adds owners/parents (which are the same, just occasionally
owner==NULL) printing for memory regions; a new '-o' flag
enabled new output.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20180604032511.6980-1-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add an IOMMU index argument to the translate method of
IOMMUs. Since all of our current IOMMU implementations
support only a single IOMMU index, this has no effect
on the behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-4-peter.maydell@linaro.org
Add support for multiple IOMMU indexes to the IOMMU notifier APIs.
When initializing a notifier with iommu_notifier_init(), the caller
must pass the IOMMU index that it is interested in. When a change
happens, the IOMMU implementation must pass
memory_region_notify_iommu() the IOMMU index that has changed and
that notifiers must be called for.
IOMMUs which support only a single index don't need to change.
Callers which only really support working with IOMMUs with a single
index can use the result of passing MEMTXATTRS_UNSPECIFIED to
memory_region_iommu_attrs_to_index().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-3-peter.maydell@linaro.org
If an IOMMU supports mappings that care about the memory
transaction attributes, then it no longer has a unique
address -> output mapping, but more than one. We can
represent these using an IOMMU index, analogous to TCG's
mmu indexes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-2-peter.maydell@linaro.org
This changes the functions memory_region_ioeventfd_equal, memory_region_ioeventfd_before, and their callers,
to pass the MemoryRegionIoeventfd struct via pointer, instead of directly passing the struct. This saves on stack space
and is considered safe practice.
Signed-off-by: Tristan Burgess <tburgessdev@gmail.com>
Message-Id: <20180529030445.177867-1-tburgessdev@gmail.com>
Fixes: Launchpad bug 1720969
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since struct AddressSpaceOps isn't used anywhere else,
so just delete it.
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Message-Id: <1526384108-49348-1-git-send-email-jianjay.zhou@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As part of plumbing MemTxAttrs down to the IOMMU translate method,
add MemTxAttrs as an argument to the MemoryRegion valid.accepts
callback. We'll need this for subpage_accepts().
We could take the approach we used with the read and write
callbacks and add new a new _with_attrs version, but since there
are so few implementations of the accepts hook we just change
them all.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180521140402.23318-9-peter.maydell@linaro.org
As part of plumbing MemTxAttrs down to the IOMMU translate method,
add MemTxAttrs as an argument to memory_region_access_valid().
Its callers either have an attrs value to hand, or don't care
and can use MEMTXATTRS_UNSPECIFIED.
The callsite in flatview_access_valid() is part of a recursive
loop flatview_access_valid() -> memory_region_access_valid() ->
subpage_accepts() -> flatview_access_valid(); we make it pass
MEMTXATTRS_UNSPECIFIED for now, until the next several commits
have plumbed an attrs parameter through the rest of the loop
and we can add an attrs parameter to flatview_access_valid().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180521140402.23318-8-peter.maydell@linaro.org
MemoryRegionCache was reverted to "normal" address_space_* operations
for 2.9, due to lack of support for IOMMUs. Reinstate the
optimizations, caching only the IOMMU translation at address_cache_init
but not the IOMMU lookup and target AddressSpace translation are not
cached; now that MemoryRegionCache supports IOMMUs, it becomes more widely
applicable too.
The inlined fast path is defined in memory_ldst_cached.inc.h, while the
slow path uses memory_ldst.inc.c as before. The smaller fast path causes
a little code size reduction in MemoryRegionCache users:
hw/virtio/virtio.o text size before: 32373
hw/virtio/virtio.o text size after: 31941
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These accessors are called from inlined functions, and the call sequence
is much more expensive than just inlining the access. Move the
struct declaration to memory-internal.h so that exec.c and memory.c
can both use an inline function.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently only file backed memory backend can
be created with a "share" flag in order to allow
sharing guest RAM with other processes in the host.
Add the "share" flag also to RAM Memory Backend
in order to allow remapping parts of the guest RAM
to different host virtual addresses. This is needed
by the RDMA devices in order to remap non-contiguous
QEMU virtual addresses to a contiguous virtual address range.
Moved the "share" flag to the Host Memory base class,
modified phys_mem_alloc to include the new parameter
and a new interface memory_region_init_ram_shared_nomigrate.
There are no functional changes if the new flag is not used.
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Now that memory_region_sync_dirty_bitmap is NULL, we can unify its
loop with memory_global_dirty_log_sync's. The only difference is
that memory_region_sync_dirty_bitmap will no longer call log_sync on
FlatRanges that do have a zero dirty_log_mask, but this is okay because
video memory is always registered with the dirty page logging mechanism.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Simplify the users of memory_region_snapshot_and_clear_dirty, so
that they do not have to call memory_region_sync_dirty_bitmap
explicitly.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When unregister memory listeners, we should call, e.g.,
region_del() (and possibly other undo operations) on every existing
memory region sections there, otherwise we may leak resources that are
held during the region_add(). This patch undo the stuff for the
listeners, which emulates the case when the address space is set from
current to an empty state.
I found this problem when debugging a refcount leak issue that leads to
a device unplug event lost (please see the "Bug:" line below). In that
case, the leakage of resource is the PCI BAR memory region refcount.
And since memory regions are not keeping their own refcount but onto
their owners, so the vfio-pci device's (who is the owner of the PCI BAR
memory regions) refcount is leaked, and event missing.
We had encountered similar issues before and fixed in other
way (ee4c112846, "vhost: Release memory references on cleanup"). This
patch can be seen as a more high-level fix of similar problems that are
caused by the resource leaks from memory listeners. So now we can remove
the explicit unref of memory regions since that'll be done altogether
during unregistering of listeners now.
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1531393
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180122060244.29368-5-peterx@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This adds get_attr() to IOMMUMemoryRegionClass, like
iommu_ops::domain_get_attr in the Linux kernel.
This defines the first attribute - IOMMU_ATTR_SPAPR_TCE_FD - which
will be used between the pSeries machine and VFIO-PCI.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We should set ioeventfd_update_pending same as memory_region_update_pending.
Signed-off-by: linzhecheng <linzc@zju.edu.cn>
Message-Id: <1515934519-16158-1-git-send-email-linzc@zju.edu.cn>
Cc: qemu-stable@nongnu.org
Fixes: ade9c1aac5
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When mmap(2) the backend files, QEMU uses the host page size
(getpagesize(2)) by default as the alignment of mapping address.
However, some backends may require alignments different than the page
size. For example, mmap a device DAX (e.g., /dev/dax0.0) on Linux
kernel 4.13 to an address, which is 4K-aligned but not 2M-aligned,
fails with a kernel message like
[617494.969768] dax dax0.0: qemu-system-x86: dax_mmap: fail, unaligned vma (0x7fa37c579000 - 0x7fa43c579000, 0x1fffff)
Because there is no common approach to get such alignment requirement,
we add the 'align' option to 'memory-backend-file', so that users or
management utils, which have enough knowledge about the backend, can
specify a proper alignment via this option.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Message-Id: <20171211072806.2812-2-haozhong.zhang@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[ehabkost: fixed typo, fixed error_setg() format string]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This was never used since its introduction in commit
196ea13104 ("memory: Add global-locking property to memory
regions").
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
We can use section_from_flat_range() instead of manually initializing.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171016144302.24284-8-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It might be confusing for some listener implementations that implement
both, region_add and log_start (e.g. KVM) if we call log_start before an
actual region was added using region_add.
This makes current KVM code trigger an assertion
("kvm_section_update_flags: error finding slot"). So let's just reverse
the order instead of tolerating log_start on yet unknown regions.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171016144302.24284-2-david@redhat.com>
Tested-by: Joe Clifford <joeclifford@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch fixes an off-by-one error that could lead to the
notifyee to receive notifications for ranges it is not
registered to.
The bug has been spotted by code review.
Fixes: bd2bfa4c52 ("memory: introduce memory_region_notify_one()")
Cc: qemu-stable@nongnu.org
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-Id: <20171010094247.10173-4-maxime.coquelin@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This shares an cached empty FlatView among address spaces. The empty
FV is used every time when a root MR renders into a FV without memory
sections which happens when MR or its children are not enabled or
zero-sized. The empty_view is not NULL to keep the rest of memory
API intact; it also has a dispatch tree for the same reason.
On POWER8 with 255 CPUs, 255 virtio-net, 40 PCI bridges guest this halves
the amount of FlatView's in use (557 -> 260) and dispatch tables
(~800000 -> ~370000). In an unrelated experiment with 112 non-virtio
devices on x86 ("-M pc"), only 4 FlatViews are alive, and about ~2000
are created at startup.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-16-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A container can be used instead of an alias to allow switching between
multiple subregions. In this case we cannot directly share the
subregions (since they only belong to a single parent), but if the
subregions are aliases we can in turn walk those.
This is not enough to remove all source of quadratic FlatView creation,
but it enables sharing of the PCI bus master FlatViews (and their
AddressSpaceDispatch structures) across all PCI devices. For 112
virtio-net-pci devices, boot time is reduced from 25 to 10 seconds and
memory consumption from 1.4 to 1 G.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This avoids usual memory_region_transaction_commit() which rebuilds
all FVs.
On POWER8 with 255 CPUs, 255 virtio-net, 40 PCI bridges guest this brings
down the boot time from 25s to 20s and reduces the amount of temporary FVs
allocated during machine constructon (~800000 -> ~640000) and amount of
temporary dispatch trees (~370000 -> ~300000), the total memory footprint
goes down (18G -> 17G).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-18-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
