We want to inline the case where there is only one iteration, because
then the compiler can also inline the memcpy. As a start, extract
everything after the first address_space_translate call.
Backports commit a203ac702e0720135fac8b1f2061d119814c1798 from qemu
Rather than dispatching on is_write for every iteration, make
address_space_rw call one of the two functions. The amount of
duplicate logic is pretty small, and memory_access_is_direct can
be tweaked so that it inlines better in the callers.
Backports commit eb7eeb88628074207dd611472e712af775985e73 from qemu
Replace qemu_ram_free_from_ptr() with qemu_ram_free().
The only difference between qemu_ram_free_from_ptr() and
qemu_ram_free() is that g_free_rcu() is used instead of
call_rcu(reclaim_ramblock). We can safely replace it because:
* RAM blocks allocated by qemu_ram_alloc_from_ptr() always have
RAM_PREALLOC set;
* reclaim_ramblock(block) will do nothing except g_free(block)
if RAM_PREALLOC is set at block->flags.
Backports commit a29ac16632aec6065c72985b9f7eeb1ca6fbef4a from qemu
memory_region_unref(mr) can free memory.
For example I got:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f43280d4700 (LWP 4462)]
0x00007f43323283c0 in phys_section_destroy (mr=0x7f43259468b0)
at /home/don/xen/tools/qemu-xen-dir/exec.c:1023
1023 if (mr->subpage) {
(gdb) bt
at /home/don/xen/tools/qemu-xen-dir/exec.c:1023
at /home/don/xen/tools/qemu-xen-dir/exec.c:1034
at /home/don/xen/tools/qemu-xen-dir/exec.c:2205
(gdb) p mr
$1 = (MemoryRegion *) 0x7f43259468b0
And this change prevents this.
Backports commit 55b4e80b047300e1512df02887b7448ba3786b62 from qemu
Add a function to find a RAMBlock by name; use it in two
of the places that already open code that loop; we've
got another use later in postcopy.
Backports commit e3dd74934f2d2c8c67083995928ff68e8c1d0030 from qemu
Postcopy sends RAMBlock names and offsets over the wire (since it can't
rely on the order of ramaddr being the same), and it starts out with
HVA fault addresses from the kernel.
qemu_ram_block_from_host translates a HVA into a RAMBlock, an offset
in the RAMBlock and the global ram_addr_t value.
Rewrite qemu_ram_addr_from_host to use qemu_ram_block_from_host.
Provide qemu_ram_get_idstr since its the actual name text sent on the
wire.
Backports commit 422148d3e56c3c9a07c0cf36c1e0a0b76f09c357 from qemu
Whenever the MRU cache hits for the list of RAM blocks, qemu_get_ram_block
does an unnecessary write that causes a processor cache line to bounce
from one core to another. This causes a performance hit.
Backports commit 68851b98e5bf6d397498b74f1776801274ab8d48 from qemu
This makes ROM blocks resizeable. This infrastructure is required for other
functionality we have queued.
Backports commit aaf03019175949eda5087329448b8a0033b89479 from qemu
This ensures that cpu_reload_memory_map() is called as soon as
tcg_cpu_address_space_init() is called, and before cpu->memory_dispatch
is used. qemu-system-s390x never changes the address spaces after
tcg_cpu_address_space_init() is called, and thus tcg_commit() is never
called. This causes a SIGSEGV.
Because memory_map_init() will now call mem_commit(), we have to
initialize io_mem_* before address_space_memory and friends.
Backports commit 680a4783dc13f1059c03d11da58193d76c19ead6 from qemu
Anonymous and file-backed RAM allocation are now almost exactly the same.
Reduce code duplication by moving RAM mmap code out of oslib-posix.c and
exec.c.
Backports commit 794e8f301a17953efa78ab7538019ec43c59e82a from qemu
Change tlb_set_dirty() to accept a CPU instead of an env pointer. This
allows for removal of another CPUArchState usage from prototypes that
need to be QOMified.
Backports commit bcae01e468d961ad9afaf4148329147e4be209ab from qemu
Use pow2floor() to round down to the nearest power of 2,
rather than an inline calculation.
Backports commit 6554f5c03793bb8a3d5dedcebf758a1694fa186c from qemu
The callers (most of them in target-foo/cpu.c) to this function all
have the cpu pointer handy. Just pass it to avoid an ENV_GET_CPU() from
core code (in exec.c).
Backports commit 4bad9e392e788a218967167a38ce2ae7a32a6231 from qemu
All of the core-code usages of this API have the cpu pointer handy so
pass it in. There are only 3 architecture specific usages (2 of which
are commented out) which can just use ENV_GET_CPU() locally to get the
cpu pointer. The reduces core code usage of the CPU env, which brings
us closer to common-obj'ing these core files.
Backports commit bbd77c180d7ff1b04a7661bb878939b2e1d23798 from qemu
QOM objects are already zero-filled when instantiated, there's no need
to explicitly set numa_node to 0.
Backports commit 199fc85acd0571902eeefef6ea861b8ba4c8201f from qemu
Loading the BIOS in the mac99 machine is interesting, because there is a
PROM in the middle of the BIOS region (from 16K to 32K). Before memory
region accesses were clamped, when QEMU was asked to load a BIOS from
0xfff00000 to 0xffffffff it would put even those 16K from the BIOS file
into the region. This is weird because those 16K were not actually
visible between 0xfff04000 and 0xfff07fff. However, it worked.
After clamping was added, this also worked. In this case, the
cpu_physical_memory_write_rom_internal function split the write in
three parts: the first 16K were copied, the PROM area (second 16K) were
ignored, then the rest was copied.
Problems then started with commit 965eb2f (exec: do not clamp accesses
to MMIO regions, 2015-06-17). Clamping accesses is not done for MMIO
regions because they can overlap wildly, and MMIO registers can be
expected to perform full-width accesses based only on their address
(with no respect for adjacent registers that could decode to completely
different MemoryRegions). However, this lack of clamping also applied
to the PROM area! cpu_physical_memory_write_rom_internal thus failed
to copy the third range above, i.e. only copied the first 16K of the BIOS.
In effect, address_space_translate is expecting _something else_ to do
the clamping for MMIO regions if the incoming length is large. This
"something else" is memory_access_size in the case of address_space_rw,
so use the same logic in cpu_physical_memory_write_rom_internal.
Backports commit b242e0e0e2969c044a318e56f7988bbd84de1f63 from qemu
The cpu_physical_memory_reset_dirty() function is sometimes used
together with cpu_physical_memory_get_dirty(). This is not atomic since
two separate accesses to the dirty memory bitmap are made.
Turn cpu_physical_memory_reset_dirty() and
cpu_physical_memory_clear_dirty_range_type() into the atomic
cpu_physical_memory_test_and_clear_dirty().
Backports commit 03eebc9e3246b9b3f5925aa41f7dfd7c1e467875 from qemu
Most of the time, not all bitmaps have to be marked as dirty;
do not do anything if the interesting ones are already dirty.
Previously, any clean bitmap would have cause all the bitmaps to be
marked dirty.
In fact, unless running TCG most of the time bitmap operations need
not be done at all, because memory_region_is_logging returns zero.
In this case, skip the call to cpu_physical_memory_range_includes_clean
altogether as well.
With this patch, cpu_physical_memory_set_dirty_range is called
unconditionally, so there need not be anymore a separate call to
xen_modified_memory.
Backports commit e87f7778b64d4a6a78e16c288c7fdc6c15317d5f from qemu
While it is obvious that cpu_physical_memory_get_dirty returns true even if
a single page is dirty, the same is not true for cpu_physical_memory_get_clean;
one would expect that it returns true only if all the pages are clean, but
it actually looks for even one clean page. (By contrast, the caller of that
function, cpu_physical_memory_range_includes_clean, has a good name).
To clarify, rename the function to cpu_physical_memory_all_dirty and return
true if _all_ the pages are dirty. This is the opposite of the previous
meaning, because "all are 1" is the same as "not (any is 0)", so we have to
modify cpu_physical_memory_range_includes_clean as well
Backports commit 72b47e79cef36ed6ffc718f10e21001d7ec2a66f from qemu
phys_page_set_level is writing zeroes to a struct that has just been
filled in by phys_map_node_alloc. Instead, tell phys_map_node_alloc
whether to fill in the page "as a leaf" or "as a non-leaf".
memcpy is faster than struct assignment, which copies each bitfield
individually. A compiler bug (https://gcc.gnu.org/PR66391), and
small memcpys like this one are special-cased anyway, and optimized
to a register move, so just use the memcpy.
This cuts the cost of phys_page_set_level from 25% to 5% when
booting qboot.
Backports commit db94604b20278c1dc227a04e4c564d80230e6c3f from qemu
address_space_translate_internal will clamp the *plen length argument
based on the size of the memory region being queried. The iommu walker
logic in addresss_space_translate was ignoring this by discarding the
post fn call value of *plen. Fix by just always using *plen as the
length argument throughout the fn, removing the len local variable.
This fixes a bootloader bug when a single elf section spans multiple
QEMU memory regions.
Backports commit 23820dbfc79d1c9dce090b4c555994f2bb6a69b3 from qemu
There could be a race condition when two processes call
address_space_map concurrently and both want to use the bounce buffer.
Add an in_use flag in BounceBuffer to sync it.
Backports commit c2cba0ffe495b60c4cc58080281e99c7a6580d4b from qemu
Add new address_space_ld*/st* functions which allow transaction
attributes and error reporting for basic load and stores. These
are named to be in line with the address_space_read/write/rw
buffer operations.
The existing ld/st*_phys functions are now wrappers around
the new functions.
Backports commit 500131154d677930fce35ec3a6f0b5a26bcd2973 from qemu
Make address_space_rw take transaction attributes, rather
than always using the 'unspecified' attributes.
Backports commit 5c9eb0286c819c1836220a32f2e1a7b5004ac79a from qemu
Convert the subpage memory ops to _with_attrs; this will allow
us to pass the attributes through to the underlying access
functions. (Nothing uses the attributes yet.)
Backports commit f25a49e0057bbfcc2b1111f60785d919b6ddaeea from qemu
Rather than retaining io_mem_read/write as simple wrappers around
the memory_region_dispatch_read/write functions, make the latter
public and change all the callers to use them, since we need to
touch all the callsites anyway to add MemTxAttrs and MemTxResult
support. Delete io_mem_read and io_mem_write entirely.
(All the callers currently pass MEMTXATTRS_UNSPECIFIED
and convert the return value back to bool or ignore it.)
Backports commit 3b6434953934e6d4a776ed426d8c6d6badee176f from qemu
Define an API so that devices can register MemoryRegionOps whose read
and write callback functions are passed an arbitrary pointer to some
transaction attributes and can return a success-or-failure status code.
This will allow us to model devices which:
* behave differently for ARM Secure/NonSecure memory accesses
* behave differently for privileged/unprivileged accesses
* may return a transaction failure (causing a guest exception)
for erroneous accesses
This patch defines the new API and plumbs the attributes parameter through
to the memory.c public level functions io_mem_read() and io_mem_write(),
where it is currently dummied out.
The success/failure response indication is also propagated out to
io_mem_read() and io_mem_write(), which retain the old-style
boolean true-for-error return.
Backports commit cc05c43ad942165ecc6ffd39e41991bee43af044 from qemu
After the previous patch, TLBs will be flushed on every change to
the memory mapping. This patch augments that with synchronization
of the MemoryRegionSections referred to in the iotlb array.
With this change, it is guaranteed that iotlb_to_region will access
the correct memory map, even once the TLB will be accessed outside
the BQL.
Backports commit 9d82b5a792236db31a75b9db5c93af69ac07c7c5 from qemu
This for now is a simple TLB flush. This can change later for two
reasons:
1) an AddressSpaceDispatch will be cached in the CPUState object
2) it will not be possible to do tlb_flush once the TCG-generated code
runs outside the BQL.
Backports commit 76e5c76f2e2e0d20bab2cd5c7a87452f711654fb from qemu
