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>
Flushing TB cache is required because TBs key in the cache may match
different code which existed in the previous state.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Signed-off-by: Maria Klimushenkova <maria.klimushenkova@ispras.ru>
Message-Id: <20180110134846.12940.99993.stgit@pasha-VirtualBox>
[Add comment suggested by Peter Maydell. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
The dirty bitmaps are built from 'long's and there is fast-path code
for synchronising the case where the RAMBlock is aligned to the start
of a long boundary. Align the allocation to this boundary
to cause the fast path to be used.
Offsets before change:
11398@1515169675.018566:find_ram_offset size: 0x1e0000 @ 0x8000000
11398@1515169675.020064:find_ram_offset size: 0x20000 @ 0x81e0000
11398@1515169675.020244:find_ram_offset size: 0x20000 @ 0x8200000
11398@1515169675.024343:find_ram_offset size: 0x1000000 @ 0x8220000
11398@1515169675.025154:find_ram_offset size: 0x10000 @ 0x9220000
11398@1515169675.027682:find_ram_offset size: 0x40000 @ 0x9230000
11398@1515169675.032921:find_ram_offset size: 0x200000 @ 0x9270000
11398@1515169675.033307:find_ram_offset size: 0x1000 @ 0x9470000
11398@1515169675.033601:find_ram_offset size: 0x1000 @ 0x9471000
after change:
10923@1515169108.818245:find_ram_offset size: 0x1e0000 @ 0x8000000
10923@1515169108.819410:find_ram_offset size: 0x20000 @ 0x8200000
10923@1515169108.819587:find_ram_offset size: 0x20000 @ 0x8240000
10923@1515169108.823708:find_ram_offset size: 0x1000000 @ 0x8280000
10923@1515169108.824503:find_ram_offset size: 0x10000 @ 0x9280000
10923@1515169108.827093:find_ram_offset size: 0x40000 @ 0x92c0000
10923@1515169108.833045:find_ram_offset size: 0x200000 @ 0x9300000
10923@1515169108.833504:find_ram_offset size: 0x1000 @ 0x9500000
10923@1515169108.833787:find_ram_offset size: 0x1000 @ 0x9540000
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20180105170138.23357-3-dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add some comments so I can understand the various nested loops.
Add some tracing so I can see what they're doing.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20180105170138.23357-2-dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We set up the io_mem_rom special memory region using the
unassigned_mem_ops structure; this is then used when a guest tries to
write to ROM. This is incorrect, because the behaviour of unassigned
memory may be different from that of ROM for writes. In particular,
on some architectures writing to unassigned memory generates a guest
exception, whereas writing to ROM is generally ignored. Use a
special readonly_mem_ops for this purpose instead, so writes to
ROM are ignored for all guest CPUs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1513187549-2435-2-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Renaming cpu address space names so that they won't be the same when
there are more than one.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20171123092333.16085-4-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Normally we create an address space for that CPU and pass that address
space into the function. Let's just do it inside to unify address space
creations. It'll simplify my next patch to rename those address spaces.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20171123092333.16085-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
exec: housekeeping (funny since 02d0e09503)
applied using ./scripts/clean-includes
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
The function notdirty_mem_write() has a sequence of actions
it has to do before and after the actual business of writing
data to host RAM to ensure that dirty flags are correctly
updated and we flush any TCG translations for the region.
We need to do this also in other places that write directly
to host RAM, most notably the TCG atomic helper functions.
Pull out the before and after pieces into their own functions.
We use an API where the prepare function stashes the various
bits of information about the write into a struct for the
complete function to use, because in the calls for the atomic
helpers the place where the complete function will be called
doesn't have the information to hand.
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1511201308-23580-2-git-send-email-peter.maydell@linaro.org
This fixes a crash caused by picking the wrong memory region in
address_space_lookup_region seen with client code accessing a device
model that uses alias memory regions. The expensive part of
address_space_lookup_region anyway is phys_page_find; performance-wise
it is okay to repeat the subsequent subpage lookup.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-Id: <20171114225941.072707456B5@zero.eik.bme.hu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
55c3cee ("qom: Introduce CPUClass.tcg_initialize", 2017-10-24)
introduces a per-CPUClass bool that we check so that the target CPU
is initialized for TCG only once. This works well except when
we end up creating more than one CPUClass, in which case we end
up incorrectly initializing TCG more than once, i.e. once for
each CPUClass.
This can be replicated with:
$ aarch64-softmmu/qemu-system-aarch64 -machine xlnx-zcu102 -smp 6 \
-global driver=xlnx,,zynqmp,property=has_rpu,value=on
In this case the class name of the "RPUs" is prefixed by "cortex-r5-",
whereas the "regular" CPUs are prefixed by "cortex-a53-". This
results in two CPUClass instances being created.
Fix it by introducing a static variable, so that only the first
target CPU being initialized will initialize the target-dependent
part of TCG, regardless of CPUClass instances.
Fixes: 55c3ceef61
Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 1510343626-25861-2-git-send-email-cota@braap.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We were generating code during tb_invalidate_phys_page_range,
check_watchpoint, cpu_io_recompile, and (seemingly) discarding
the TB, assuming that it would magically be picked up during
the next iteration through the cpu_exec loop.
Instead, record the desired cflags in CPUState so that we request
the proper TB so that there is no more magic.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will enable us to decouple code translation from the value
of parallel_cpus at any given time. It will also help us minimize
TB flushes when generating code via EXCP_ATOMIC.
Note that the declaration of parallel_cpus is brought to exec-all.h
to be able to define there the "curr_cflags" inline.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move target cpu tcg initialization to common code,
called from cpu_exec_realizefn.
Acked-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Aligned 8-byte memory writes by a 64-bit target on a 64-bit host should
always turn into atomic 8-byte writes on the host, however a write
write watchpoint would end up tearing the 8-byte write into two 4-byte
writes in access_with_adjusted_size().
Reported-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Aligned 8-byte memory writes by a 64-bit target on a 64-bit host should
always turn into atomic 8-byte writes on the host, however if we missed
in the softmmu, and the TLB line was marked as not dirty, then we
would end up tearing the 8-byte write into two 4-byte writes in
access_with_adjusted_size().
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Message-Id: <20171013181913.7556-1-Andrew.Baumann@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch let address_space_get_iotlb_entry() to use the newly
introduced page_mask parameter in flatview_do_translate(). Then we
will be sure the IOTLB can be aligned to page mask, also we should
nicely support huge pages now when introducing a764040.
Fixes: a764040 ("exec: abstract address_space_do_translate()")
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20171010094247.10173-3-maxime.coquelin@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function is originally used for flatview_space_translate() and what
we care about most is (xlat, plen) range. However for iotlb requests, we
don't really care about "plen", but the size of the page that "xlat" is
located on. While, plen cannot really contain this information.
A simple example to show why "plen" is not good for IOTLB translations:
E.g., for huge pages, it is possible that guest mapped 1G huge page on
device side that used this GPA range:
0x100000000 - 0x13fffffff
Then let's say we want to translate one IOVA that finally mapped to GPA
0x13ffffe00 (which is located on this 1G huge page). Then here we'll
get:
(xlat, plen) = (0x13fffe00, 0x200)
So the IOTLB would be only covering a very small range since from
"plen" (which is 0x200 bytes) we cannot tell the size of the page.
Actually we can really know that this is a huge page - we just throw the
information away in flatview_do_translate().
This patch introduced "page_mask" optional parameter to capture that
page mask info. Also, I made "plen" an optional parameter as well, with
some comments for the whole function.
No functional change yet.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-Id: <20171010094247.10173-2-maxime.coquelin@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These only depend on the host and therefore belong in the common
osdep, not in a target-dependent object.
While at it, query the host during an init constructor, which guarantees
the page size will be well-defined throughout the execution of the program.
Suggested-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This adds a new "-d" switch to "info mtree" to print dispatch tree
internals.
This changes the way "-f" is handled - it prints now flat views and
associated address spaces.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-15-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This renames some helpers to reflect better what they do.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-9-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We store AddressSpaceDispatch* in FlatView anyway so there is no need
to carry it from mem_add() to register_subpage/register_multipage.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-8-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AS in ASD is only used to pass AS from mem_begin() to register_subpage()
to store it in MemoryRegionSection, we can do this directly now.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-6-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As we are going to share FlatView's between AddressSpace's,
and AddressSpaceDispatch is a structure to perform quick lookup
in FlatView, this moves ASD to FlatView.
After previosly open coded ASD rendering, we can also remove
as->next_dispatch as the new FlatView pointer is stored
on a stack and set to an AS atomically.
flatview_destroy() is executed under RCU instead of
address_space_dispatch_free() now.
This makes mem_begin/mem_commit to work with ASD and mem_add with FV
as later on mem_add will be taking FV as an argument anyway.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-5-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We are going to share FlatView's between AddressSpace's and per-AS
memory listeners won't suit the purpose anymore so open code
the dispatch tree rendering.
Since there is a good chance that dispatch_listener was the only
listener, this avoids address_space_update_topology_pass() if there is
no registered listeners; this should improve starting time.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-3-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This adds an AS** parameter to address_space_do_translate()
to make it easier for the next patch to share FlatViews.
This should cause no behavioural change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-2-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All but a handful of files include exec/cpu-all.h via cpu.h only.
As these files already include cpu.h, let's just drop the additional
include.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-2-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Commit 04bf2526ce (exec: use
qemu_ram_ptr_length to access guest ram) start using qemu_ram_ptr_length
instead of qemu_map_ram_ptr, but when used with Xen, the behavior of
both function is different. They both call xen_map_cache, but one with
"lock", meaning the mapping of guest memory is never released
implicitly, and the second one without, which means, mapping can be
release later, when needed.
In the context of address_space_{read,write}_continue, the ptr to those
mapping should not be locked because it is used immediatly and never
used again.
The lock parameter make it explicit in which context qemu_ram_ptr_length
is called.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20170726165326.10327-1-anthony.perard@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This finishes QOM'fication of IOMMUMemoryRegion by introducing
a IOMMUMemoryRegionClass. This also provides a fastpath analog for
IOMMU_MEMORY_REGION_GET_CLASS().
This makes IOMMUMemoryRegion an abstract class.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170711035620.4232-3-aik@ozlabs.ru>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This defines new QOM object - IOMMUMemoryRegion - with MemoryRegion
as a parent.
This moves IOMMU-related fields from MR to IOMMU MR. However to avoid
dymanic QOM casting in fast path (address_space_translate, etc),
this adds an @is_iommu boolean flag to MR and provides new helper to
do simple cast to IOMMU MR - memory_region_get_iommu. The flag
is set in the instance init callback. This defines
memory_region_is_iommu as memory_region_get_iommu()!=NULL.
This switches MemoryRegion to IOMMUMemoryRegion in most places except
the ones where MemoryRegion may be an alias.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20170711035620.4232-2-aik@ozlabs.ru>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When accessing guest's ram block during DMA operation, use
'qemu_ram_ptr_length' to get ram block pointer. It ensures
that DMA operation of given length is possible; And avoids
any OOB memory access situations.
Reported-by: Alex <broscutamaker@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20170712123840.29328-1-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
translate-all.c will be disabled if tcg is disabled in the build,
so page_size_init() function and related variables will be moved
to exec.c file.
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@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>
Move file opening part in a seperate function, file_ram_open(). This
allows for reuse of file_ram_alloc() with a given fd.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170602141229.15326-3-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move kvm mmu notifiers check before calling file_ram_alloc(), with the
other xen precondition. (file_ram_alloc() will be reused in other cases
than -mem-path).
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170602141229.15326-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It really only plays with the dispatchers, so the parameter list does
not need that complexity. This helps for readability at least.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1494838260-30439-2-git-send-email-peterx@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch converts the old "is_write" bool into IOMMUAccessFlags. The
difference is that "is_write" can only express either read/write, but
sometimes what we really want is "none" here (neither read nor write).
Replay is an good example - during replay, we should not check any RW
permission bits since thats not an actual IO at all.
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
It only needed TARGET_PAGE_SIZE/BITS/BITS_MIN values, so just export
them from exec.h
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
That is the only function that we need from exec.c, and having to
include the whole sysemu.h for this.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
/me leans to be less sloppy with copyright notices
thanks Dave
This function is an abstraction helper for address_space_translate() and
address_space_get_iotlb_entry(). It does the lookup of address into
memory region section, then does proper IOMMU translation if necessary.
Refactor the two existing functions to use it.
This fixes vhost when IOMMU is disabled by guest.
Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
To dump information about ramblocks. It looks like:
(qemu) info ramblock
Block Name PSize Offset Used Total
/objects/mem 2 MiB 0x0000000000000000 0x0000000080000000 0x0000000080000000
vga.vram 4 KiB 0x0000000080060000 0x0000000001000000 0x0000000001000000
/rom@etc/acpi/tables 4 KiB 0x00000000810b0000 0x0000000000020000 0x0000000000200000
pc.bios 4 KiB 0x0000000080000000 0x0000000000040000 0x0000000000040000
0000:00:03.0/e1000.rom 4 KiB 0x0000000081070000 0x0000000000040000 0x0000000000040000
pc.rom 4 KiB 0x0000000080040000 0x0000000000020000 0x0000000000020000
0000:00:02.0/vga.rom 4 KiB 0x0000000081060000 0x0000000000010000 0x0000000000010000
/rom@etc/table-loader 4 KiB 0x00000000812b0000 0x0000000000001000 0x0000000000001000
/rom@etc/acpi/rsdp 4 KiB 0x00000000812b1000 0x0000000000001000 0x0000000000001000
Ramblock is something hidden internally in QEMU implementation, and this
command should only be used by mostly QEMU developers on RAM stuff. It
is not a command suitable for QMP interface. So only HMP interface is
provided for it.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1494562661-9063-4-git-send-email-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
So that it can simplifies the iterators.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1494562661-9063-2-git-send-email-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The Xen mapcache is able to create long term mappings, they are called
"locked" mappings. The third parameter of the xen_map_cache call
specifies if a mapping is a "locked" mapping.
>From the QEMU point of view there are two kinds of long term mappings:
[a] device memory mappings, such as option roms and video memory
[b] dma mappings, created by dma_memory_map & friends
After certain operations, ballooning a VM in particular, Xen asks QEMU
kindly to destroy all mappings. However, certainly [a] mappings are
present and cannot be removed. That's not a problem as they are not
affected by balloonning. The *real* problem is that if there are any
mappings of type [b], any outstanding dma operations could fail. This is
a known shortcoming. In other words, when Xen asks QEMU to destroy all
mappings, it is an error if any [b] mappings exist.
However today we have no way of distinguishing [a] from [b]. Because of
that, we cannot even print a decent warning.
This patch introduces a new "dma" bool field to MapCacheRev entires, to
remember if a given mapping is for dma or is a long term device memory
mapping. When xen_invalidate_map_cache is called, we print a warning if
any [b] mappings exist. We ignore [a] mappings.
Mappings created by qemu_map_ram_ptr are assumed to be [a], while
mappings created by address_space_map->qemu_ram_ptr_length are assumed
to be [b].
The goal of the patch is to make debugging and system understanding
easier.
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
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>
Haozhong Zhang
Pavel Dovgalyuk
Dr. David Alan Gilbert
Peter Maydell
Peter Xu
Philippe Mathieu-Daudé
Paolo Bonzini
Emilio G. Cota
Richard Henderson
Andrew Baumann
Alexey Kardashevskiy
David Hildenbrand
Anthony PERARD
Fam Zheng
Pranith Kumar
Prasad J Pandit
Yang Zhong
Marc-André Lureau
Juan Quintela
Stefano Stabellini
Gerd Hoffmann