Add an option for hostmem-file to start the memory object at an offset
into the target file. This is useful if multiple memory objects reside
inside the same target file, such as a device node.
In particular, it's useful to map guest memory directly into /dev/mem
for experimentation.
To make this work consistently, also fix up all places in QEMU that
expect fd offsets to be 0.
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20230403221421.60877-1-graf@amazon.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Since we already have bitmap_mutex to protect either the dirty bitmap or
the clear log bitmap, we don't need atomic operations to set/clear/test on
the clear log bitmap. Switching all ops from atomic to non-atomic
versions, meanwhile touch up the comments to show which lock is in charge.
Introduced non-atomic version of bitmap_test_and_clear_atomic(), mostly the
same as the atomic version but simplified a few places, e.g. dropped the
"old_bits" variable, and also the explicit memory barriers.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We missed this function when we introduced tb_page_addr_t.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.
This avoids the need for a constructor initialization too.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
introduce global var total_dirty_pages to stat dirty pages
along with memory_global_dirty_log_sync.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
since dirty ring has been introduced, there are two methods
to track dirty pages of vm. it seems that "logging" has
a hint on the method, so rename the global_dirty_log to
global_dirty_tracking would make description more accurate.
dirty rate measurement may start or stop dirty tracking during
calculation. this conflict with migration because stop dirty
tracking make migration leave dirty pages out then that'll be
a problem.
make global_dirty_tracking a bitmask can let both migration and
dirty rate measurement work fine. introduce GLOBAL_DIRTY_MIGRATION
and GLOBAL_DIRTY_DIRTY_RATE to distinguish what current dirty
tracking aims for, migration or dirty rate.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <9c9388657cfa0301bd2c1cfa36e7cf6da4aeca19.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Let's introduce RAM_NORESERVE, allowing mmap'ing with MAP_NORESERVE. The
new flag has the following semantics:
"
RAM is mmap-ed with MAP_NORESERVE. When set, reserving swap space (or huge
pages if applicable) is skipped: will bail out if not supported. When not
set, the OS will do the reservation, if supported for the memory type.
"
Allow passing it into:
- memory_region_init_ram_nomigrate()
- memory_region_init_resizeable_ram()
- memory_region_init_ram_from_file()
... and teach qemu_ram_mmap() and qemu_anon_ram_alloc() about the flag.
Bail out if the flag is not supported, which is the case right now for
both, POSIX and win32. We will add Linux support next and allow specifying
RAM_NORESERVE via memory backends.
The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM.
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: <20210510114328.21835-9-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's pass ram_flags to qemu_ram_alloc() and qemu_ram_alloc_internal(),
preparing for passing additional flags.
Reviewed-by: Philippe Mathieu-Daudé <philmd@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: <20210510114328.21835-7-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
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>
There is currently no way to open(O_RDONLY) and mmap(PROT_READ) when
creating a memory region from a file. This functionality is needed since
the underlying host file may not allow writing.
Add a bool readonly argument to memory_region_init_ram_from_file() and
the APIs it calls.
Extend memory_region_init_ram_from_file() rather than introducing a
memory_region_init_rom_from_file() API so that callers can easily make a
choice between read/write and read-only at runtime without calling
different APIs.
No new RAMBlock flag is introduced for read-only because it's unclear
whether RAMBlocks need to know that they are read-only. Pass a bool
readonly argument instead.
Both of these design decisions can be changed in the future. It just
seemed like the simplest approach to me.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210104171320.575838-2-stefanha@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:
$ CC=clang CXX=clang++ ./configure ... && make
../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.
This patch was generated using:
$ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
sort -u >/tmp/changed_identifiers
$ for identifier in $(</tmp/changed_identifiers); do
sed -i "s%\<$identifier\>%q$identifier%g" \
$(git grep -I -l "\<$identifier\>")
done
I manually fixed line-wrap issues and misaligned rST tables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
real_dirty_pages becomes equal to total ram size after dirty log sync
in ram_init_bitmaps, the reason is that the bitmap of ramblock is
initialized to be all set, so old path counts them as "real dirty" at
beginning.
This causes wrong dirty rate and false positive throttling.
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Message-Id: <20200622032037.31112-1-zhukeqian1@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This code is not related to hardware emulation.
Move it under accel/ with the other hypervisors.
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200508100222.7112-1-philmd@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rename qemu_ram_writeback() as qemu_ram_msync() to better
match what it does.
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20200508062456.23344-5-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
We need some of the fields without having to poison everything else.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add an option to trigger memory writeback to sync given memory region
with the corresponding backing store, case one is available.
This extends the support for persistent memory, allowing syncing on-demand.
Signed-off-by: Beata Michalska <beata.michalska@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191121000843.24844-3-beata.michalska@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
There are three page size in qemu:
real host page size
host page size
target page size
All of them have dedicate variable to represent. For the last two, we
use the same form in the whole qemu project, while for the first one we
use two forms: qemu_real_host_page_size and getpagesize().
qemu_real_host_page_size is defined to be a replacement of
getpagesize(), so let it serve the role.
[Note] Not fully tested for some arch or device.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191013021145.16011-3-richardw.yang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-6-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Commit f3f491fcd6 ('Postcopy: Maintain unsentmap') introduced
unsentmap to track not yet sent pages.
This is not necessary since:
* unsentmap is a sub-set of bmap before postcopy start
* unsentmap is the summation of bmap and unsentmap after canonicalizing
This patch just removes it.
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190819061843.28642-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Back in 2016, we discussed[1] rules for headers, and these were
generally liked:
1. Have a carefully curated header that's included everywhere first. We
got that already thanks to Peter: osdep.h.
2. Headers should normally include everything they need beyond osdep.h.
If exceptions are needed for some reason, they must be documented in
the header. If all that's needed from a header is typedefs, put
those into qemu/typedefs.h instead of including the header.
3. Cyclic inclusion is forbidden.
This patch gets include/ closer to obeying 2.
It's actually extracted from my "[RFC] Baby steps towards saner
headers" series[2], which demonstrates a possible path towards
checking 2 automatically. It passes the RFC test there.
[1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org>
https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html
[2] Message-Id: <20190711122827.18970-1-armbru@redhat.com>
https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-2-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Currently we are doing log_clear() right after log_sync() which mostly
keeps the old behavior when log_clear() was still part of log_sync().
This patch tries to further optimize the migration log_clear() code
path to split huge log_clear()s into smaller chunks.
We do this by spliting the whole guest memory region into memory
chunks, whose size is decided by MigrationState.clear_bitmap_shift (an
example will be given below). With that, we don't do the dirty bitmap
clear operation on the remote node (e.g., KVM) when we fetch the dirty
bitmap, instead we explicitly clear the dirty bitmap for the memory
chunk for each of the first time we send a page in that chunk.
Here comes an example.
Assuming the guest has 64G memory, then before this patch the KVM
ioctl KVM_CLEAR_DIRTY_LOG will be a single one covering 64G memory.
If after the patch, let's assume when the clear bitmap shift is 18,
then the memory chunk size on x86_64 will be 1UL<<18 * 4K = 1GB. Then
instead of sending a big 64G ioctl, we'll send 64 small ioctls, each
of the ioctl will cover 1G of the guest memory. For each of the 64
small ioctls, we'll only send if any of the page in that small chunk
was going to be sent right away.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190603065056.25211-12-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Introduce a new memory region listener hook log_clear() to allow the
listeners to hook onto the points where the dirty bitmap is cleared by
the bitmap users.
Previously log_sync() contains two operations:
- dirty bitmap collection, and,
- dirty bitmap clear on remote site.
Let's take KVM as example - log_sync() for KVM will first copy the
kernel dirty bitmap to userspace, and at the same time we'll clear the
dirty bitmap there along with re-protecting all the guest pages again.
We add this new log_clear() interface only to split the old log_sync()
into two separated procedures:
- use log_sync() to collect the collection only, and,
- use log_clear() to clear the remote dirty bitmap.
With the new interface, the memory listener users will still be able
to decide how to implement the log synchronization procedure, e.g.,
they can still only provide log_sync() method only and put all the two
procedures within log_sync() (that's how the old KVM works before
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is introduced). However with this
new interface the memory listener users will start to have a chance to
postpone the log clear operation explicitly if the module supports.
That can really benefit users like KVM at least for host kernels that
support KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2.
There are three places that can clear dirty bits in any one of the
dirty bitmap in the ram_list.dirty_memory[3] array:
cpu_physical_memory_snapshot_and_clear_dirty
cpu_physical_memory_test_and_clear_dirty
cpu_physical_memory_sync_dirty_bitmap
Currently we hook directly into each of the functions to notify about
the log_clear().
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190603065056.25211-7-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Also we change the 2nd parameter of it to be the relative offset
within the memory region. This is to be used in follow up patches.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20190603065056.25211-6-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Similar to 9460dee4b2 ("memory: do not touch code dirty bitmap unless
TCG is enabled", 2015-06-05) but for the migration bitmap - we can
skip the MIGRATION bitmap update if migration not enabled.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190603065056.25211-4-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
cpu_physical_memory_sync_dirty_bitmap() has one RAMBlock* as
parameter, which means that it must be with RCU read lock held
already. Taking it again inside seems redundant. Removing it.
Instead comment on the functions about the RCU read lock.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190603065056.25211-2-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Other accelerators have their own headers: sysemu/hax.h, sysemu/hvf.h,
sysemu/kvm.h, sysemu/whpx.h. Only tcg_enabled() & friends sit in
qemu-common.h. This necessitates inclusion of qemu-common.h into
headers, which is against the rules spelled out in qemu-common.h's
file comment.
Move tcg_enabled() & friends into their own header sysemu/tcg.h, and
adjust #include directives.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-2-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[Rebased with conflicts resolved automatically, except for
accel/tcg/tcg-all.c]
Rename qemu_getrampagesize() to qemu_minrampagesize(). While at it,
properly rename find_max_supported_pagesize() to
find_min_backend_pagesize().
s390x is actually interested into the maximum ram pagesize, so
introduce and use qemu_maxrampagesize().
Add a TODO, indicating that looking at any mapped memory backends is not
100% correct in some cases.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190417113143.5551-3-david@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
We should not load PVM's state directly into SVM, because there maybe some
errors happen when SVM is receving data, which will break SVM.
We need to ensure receving all data before load the state into SVM. We use
an extra memory to cache these data (PVM's ram). The ram cache in secondary side
is initially the same as SVM/PVM's memory. And in the process of checkpoint,
we cache the dirty pages of PVM into this ram cache firstly, so this ram cache
always the same as PVM's memory at every checkpoint, then we flush this cached ram
to SVM after we receive all PVM's state.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Zhang Chen <zhangckid@gmail.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
When QEMU emulates vNVDIMM labels and migrates vNVDIMM devices, it
needs to know whether the backend storage is a real persistent memory,
in order to decide whether special operations should be performed to
ensure the data persistence.
This boolean option 'pmem' allows users to specify whether the backend
storage of memory-backend-file is a real persistent memory. If
'pmem=on', QEMU will set the flag RAM_PMEM in the RAM block of the
corresponding memory region. If 'pmem' is set while lack of libpmem
support, a error is generated.
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: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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>
Place them in exec.c, exec-all.h and ram_addr.h. This removes
knowledge of translate-all.h (which is an internal header) from
several files outside accel/tcg and removes knowledge of
AddressSpace from translate-all.c (as it only operates on ram_addr_t).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Not needed. Don't expose last_ram_page().
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180620202736.21399-1-david@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@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>
This code has an optimised, word aligned version, and a boring
unaligned version. My commit f70d345 fixed one alignment issue, but
there's another.
The optimised version operates on 'longs' dealing with (typically) 64
pages at a time, replacing the whole long by a 0 and counting the bits.
If the Ramblock is less than 64bits in length that long can contain bits
representing two different RAMBlocks, but the code will update the
bmap belinging to the 1st RAMBlock only while having updated the total
dirty page count for both.
This probably didn't matter prior to 6b6712ef which split the dirty
bitmap by RAMBlock, but now they're separate RAMBlocks we end up
with a count that doesn't match the state in the bitmaps.
Symptom:
Migration showing a few dirty pages left to be sent constantly
Seen on aarch64 and x86 with x86+ovmf
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reported-by: Wei Huang <wei@redhat.com>
Fixes: 6b6712efcc
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds ability to track down already received
pages, it's necessary for calculation vCPU block time in
postcopy migration feature, and for recovery after
postcopy migration failure.
Also it's necessary to solve shared memory issue in
postcopy livemigration. Information about received pages
will be transferred to the software virtual bridge
(e.g. OVS-VSWITCHD), to avoid fallocate (unmap) for
already received pages. fallocate syscall is required for
remmaped shared memory, due to remmaping itself blocks
ioctl(UFFDIO_COPY, ioctl in this case will end with EEXIT
error (struct page is exists after remmap).
Bitmap is placed into RAMBlock as another postcopy/precopy
related bitmaps.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
In cpu_physical_memory_sync_dirty_bitmap(rb, start, ...), the 2nd
argument 'start' is relative to the start of the ramblock 'rb'. When
it's used to access the dirty memory bitmap of ram_list (i.e.
ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION]->blocks[]), an offset to
the start of all RAM (i.e. rb->offset) should be added to it, which has
however been missed since c/s 6b6712efcc. For a ramblock of host memory
backend whose offset is not zero, cpu_physical_memory_sync_dirty_bitmap()
synchronizes the incorrect part of the dirty memory bitmap of ram_list
to the per ramblock dirty bitmap. As a result, a guest with host
memory backend may crash after migration.
Fix it by adding the offset of ramblock when accessing the dirty memory
bitmap of ram_list in cpu_physical_memory_sync_dirty_bitmap().
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Message-Id: <20170628083704.24997-1-haozhong.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Juan Quintela <quintela@redhat.com>
Tested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Add qemu_ram_alloc_from_fd(), which can be use to allocate ramblock from
fd only.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170602141229.15326-4-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Both the ram bitmap and the unsent bitmap are split by RAMBlock.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Fix compilation when DEBUG_POSTCOPY is enabled (thanks Hailiang)
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Merge remote-tracking branch 'remotes/sstabellini/tags/xen-20170421-v2-tag' into staging
Xen 2017/04/21 + fix
# gpg: Signature made Tue 25 Apr 2017 19:10:37 BST
# gpg: using RSA key 0x894F8F4870E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
# gpg: aka "Stefano Stabellini <sstabellini@kernel.org>"
# Primary key fingerprint: D04E 33AB A51F 67BA 07D3 0AEA 894F 8F48 70E1 AE90
* remotes/sstabellini/tags/xen-20170421-v2-tag: (21 commits)
move xen-mapcache.c to hw/i386/xen/
move xen-hvm.c to hw/i386/xen/
move xen-common.c to hw/xen/
add xen-9p-backend to MAINTAINERS under Xen
xen/9pfs: build and register Xen 9pfs backend
xen/9pfs: send responses back to the frontend
xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal
xen/9pfs: receive requests from the frontend
xen/9pfs: connect to the frontend
xen/9pfs: introduce Xen 9pfs backend
9p: introduce a type for the 9p header
xen: import ring.h from xen
configure: use pkg-config for obtaining xen version
xen: additionally restrict xenforeignmemory operations
xen: use libxendevice model to restrict operations
xen: use 5 digit xen versions
xen: use libxendevicemodel when available
configure: detect presence of libxendevicemodel
xen: create wrappers for all other uses of xc_hvm_XXX() functions
xen: rename xen_modified_memory() to xen_hvm_modified_memory()
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch adds support for getting and using a local copy of the dirty
bitmap.
memory_region_snapshot_and_clear_dirty() will create a snapshot of the
dirty bitmap for the specified range, clear the dirty bitmap and return
the copy. The returned bitmap can be a bit larger than requested, the
range is expanded so the code can copy unsigned longs from the bitmap
and avoid atomic bit update operations.
memory_region_snapshot_get_dirty() will return the dirty status of
pages, pretty much like memory_region_get_dirty(), but using the copy
returned by memory_region_copy_and_clear_dirty().
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20170421091632.30900-3-kraxel@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We have disabled memory hotplug, so we don't need to handle
migration_bitamp there.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
We change the meaning of start to be the offset from the beggining of
the block.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This patch is a purely cosmetic change that avoids a name collision in
a subsequent patch.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
In function cpu_physical_memory_sync_dirty_bitmap, file
include/exec/ram_addr.h:
if (src[idx][offset]) {
unsigned long bits = atomic_xchg(&src[idx][offset], 0);
unsigned long new_dirty;
new_dirty = ~dest[k];
dest[k] |= bits;
new_dirty &= bits;
num_dirty += ctpopl(new_dirty);
}
After these codes executed, only the pages not dirtied in bitmap(dest),
but dirtied in dirty_memory[DIRTY_MEMORY_MIGRATION] will be calculated.
For example:
When ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION] = 0b00001111,
and atomic_rcu_read(&migration_bitmap_rcu)->bmap = 0b00000011,
the new_dirty will be 0b00001100, and this function will return 2 but not
4 which is expected.
the dirty pages in dirty_memory[DIRTY_MEMORY_MIGRATION] are all new,
so these should be calculated also.
Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
getrampagesize() returns the largest supported page size and mainly
used to know if huge pages are enabled.
However is implemented in target-ppc/kvm.c and not available
in TCG or other architectures.
This renames and moves gethugepagesize() to mmap-alloc.c where
fd-based analog of it is already implemented. This renames and moves
getrampagesize() to exec.c as it seems to be the common place for
helpers like this.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
