Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <e6dd0429cafe84ca603179c298a8703bddca2904.1594396418.git.berto@igalia.com>
[mreitz: Use env in shebang line]
Signed-off-by: Max Reitz <mreitz@redhat.com>
This function is only used by qcow2_expand_zero_clusters() to
downgrade a qcow2 image to a previous version. This would require
transforming all extended L2 entries into normal L2 entries but this
is not a simple task and there are no plans to implement this at the
moment.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <15e65112b4144381b4d8c0bdf8fb76b0d813e3d1.1594396418.git.berto@igalia.com>
[mreitz: Fixed comment style]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Traditional qcow2 images don't allow preallocation if a backing file
is set. This is because once a cluster is allocated there is no way to
tell that its data should be read from the backing file.
Extended L2 entries have individual allocation bits for each
subcluster, and therefore it is perfectly possible to have an
allocated cluster with all its subclusters unallocated.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6d5b0f38e7dc5f2f31d8cab1cb92044e9909aece.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that the implementation of subclusters is complete we can finally
add the necessary options to create and read images with this feature,
which we call "extended L2 entries".
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6476caaa73216bd05b7bb2d504a20415e1665176.1594396418.git.berto@igalia.com>
[mreitz: %s/5\.1/5.2/; fixed 302's and 303's reference output]
Signed-off-by: Max Reitz <mreitz@redhat.com>
This field allows us to indicate that the L2 metadata update does not
come from a write request with actual data but from a preallocation
request.
For traditional images this does not make any difference, but for
images with extended L2 entries this means that the clusters are
allocated normally in the L2 table but individual subclusters are
marked as unallocated.
This will allow preallocating images that have a backing file.
There is one special case: when we resize an existing image we can
also request that the new clusters are preallocated. If the image
already had a backing file then we have to hide any possible stale
data and zero out the new clusters (see commit 955c7d6687 for more
details).
In this case the subclusters cannot be left as unallocated so the L2
bitmap must be updated.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <960d4c444a4f5a870e2b47e5da322a73cd9a2f5a.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Extended L2 entries are bigger than normal L2 entries so this has an
impact on the amount of metadata needed for a qcow2 file.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <7efae2efd5e36b42d2570743a12576d68ce53685.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This works now at the subcluster level and pwrite_zeroes_alignment is
updated accordingly.
qcow2_cluster_zeroize() is turned into qcow2_subcluster_zeroize() with
the following changes:
- The request can now be subcluster-aligned.
- The cluster-aligned body of the request is still zeroized using
zero_in_l2_slice() as before.
- The subcluster-aligned head and tail of the request are zeroized
with the new zero_l2_subclusters() function.
There is just one thing to take into account for a possible future
improvement: compressed clusters cannot be partially zeroized so
zero_l2_subclusters() on the head or the tail can return -ENOTSUP.
This makes the caller repeat the *complete* request and write actual
zeroes to disk. This is sub-optimal because
1) if the head area was compressed we would still be able to use
the fast path for the body and possibly the tail.
2) if the tail area was compressed we are writing zeroes to the
head and the body areas, which are already zeroized.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <17e05e2ee7e12f10dcf012da81e83ebe27eb3bef.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The bdrv_co_pwrite_zeroes() call here fills complete clusters with
zeroes, but it can happen that some subclusters are not part of the
write request or the copy-on-write. This patch makes sure that only
the affected subclusters are overwritten.
A potential improvement would be to also fill with zeroes the other
subclusters if we can guarantee that we are not overwriting existing
data. However this would waste more disk space, so we should first
evaluate if it's really worth doing.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <b3dc97e8e2240ddb5191a4f930e8fc9653f94621.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Compressed clusters always have the bitmap part of the extended L2
entry set to 0.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <04455b3de5dfeb9d1cfe1fc7b02d7060a6e09710.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The L2 bitmap needs to be updated after each write to indicate what
new subclusters are now allocated. This needs to happen even if the
cluster was already allocated and the L2 entry was otherwise valid.
In some cases however a write operation doesn't need change the L2
bitmap (because all affected subclusters were already allocated). This
is detected in calculate_l2_meta(), and qcow2_alloc_cluster_link_l2()
is never called in those cases.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <0875620d49f44320334b6a91c73b3f301f975f38.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The offset field of an uncompressed cluster's L2 entry must be aligned
to the cluster size, otherwise it is invalid. If the cluster has no
data then it means that the offset points to a preallocation, so we
can clear the offset field without affecting the guest-visible data.
This is what 'qemu-img check' does when run in repair mode.
On traditional qcow2 images this can only happen when QCOW_OFLAG_ZERO
is set, and repairing such entries turns the clusters from ZERO_ALLOC
into ZERO_PLAIN.
Extended L2 entries have no ZERO_ALLOC clusters and no QCOW_OFLAG_ZERO
but the idea is the same: if none of the subclusters are allocated
then we can clear the offset field and leave the bitmap untouched.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <9f4ed1d0a34b0a545b032c31ecd8c14734065342.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Two things need to be taken into account here:
1) With full_discard == true the L2 entry must be cleared completely.
This also includes the L2 bitmap if the image has extended L2
entries.
2) With full_discard == false we have to make the discarded cluster
read back as zeroes. With normal L2 entries this is done with the
QCOW_OFLAG_ZERO bit, whereas with extended L2 entries this is done
with the individual 'all zeroes' bits for each subcluster.
Note however that QCOW_OFLAG_ZERO is not supported in v2 qcow2
images so, if there is a backing file, discard cannot guarantee
that the image will read back as zeroes. If this is important for
the caller it should forbid it as qcow2_co_pdiscard() does (see
80f5c01183 for more details).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <5ef8274e628aa3ab559bfac467abf488534f2b76.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The QCOW_OFLAG_ZERO bit that indicates that a cluster reads as
zeroes is only used in standard L2 entries. Extended L2 entries use
individual 'all zeroes' bits for each subcluster.
This must be taken into account when updating the L2 entry and also
when deciding that an existing entry does not need to be updated.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <b61d61606d8c9b367bd641ab37351ddb9172799a.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The logic of this function remains pretty much the same, except that
it uses count_contiguous_subclusters(), which combines the logic of
count_contiguous_clusters() / count_contiguous_clusters_unallocated()
and checks individual subclusters.
qcow2_cluster_to_subcluster_type() is not necessary as a separate
function anymore so it's inlined into its caller.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <d2193fd48653a350d80f0eca1c67b1d9053fb2f3.1594396418.git.berto@igalia.com>
[mreitz: Initialize expected_type to anything]
Signed-off-by: Max Reitz <mreitz@redhat.com>
If an image has subclusters then there are more copy-on-write
scenarios that we need to consider. Let's say we have a write request
from the middle of subcluster #3 until the end of the cluster:
1) If we are writing to a newly allocated cluster then we need
copy-on-write. The previous contents of subclusters #0 to #3 must
be copied to the new cluster. We can optimize this process by
skipping all leading unallocated or zero subclusters (the status of
those skipped subclusters will be reflected in the new L2 bitmap).
2) If we are overwriting an existing cluster:
2.1) If subcluster #3 is unallocated or has the all-zeroes bit set
then we need copy-on-write (on subcluster #3 only).
2.2) If subcluster #3 was already allocated then there is no need
for any copy-on-write. However we still need to update the L2
bitmap to reflect possible changes in the allocation status of
subclusters #4 to #31. Because of this, this function checks
if all the overwritten subclusters are already allocated and
in this case it returns without creating a new QCowL2Meta
structure.
After all these changes l2meta_cow_start() and l2meta_cow_end()
are not necessarily cluster-aligned anymore. We need to update the
calculation of old_start and old_end in handle_dependencies() to
guarantee that no two requests try to write on the same cluster.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <4292dd56e4446d386a2fe307311737a711c00708.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When dealing with subcluster types there is a new value called
QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC that has no equivalent in
QCow2ClusterType.
This patch handles that value in all places where subcluster types
are processed.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <bf09e2e2439a468a901bb96ace411eed9ee50295.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
In order to support extended L2 entries some functions of the qcow2
driver need to start dealing with subclusters instead of clusters.
qcow2_get_host_offset() is modified to return the subcluster type
instead of the cluster type, and all callers are updated to replace
all values of QCow2ClusterType with their QCow2SubclusterType
equivalents.
This patch only changes the data types, there are no semantic changes.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <f6c29737c295f32cbee74c903c30b01820363b34.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This function returns an integer that can be either an error code or a
cluster type (a value from the QCow2ClusterType enum).
We are going to start using subcluster types instead of cluster types
in some functions so it's better to use the exact data types instead
of integers for clarity and in order to detect errors more easily.
This patch makes qcow2_get_host_offset() return 0 on success and
puts the returned cluster type in a separate parameter. There are no
semantic changes.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <396b6eab1859a271551dcd7dcba77f8934aa3c3f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This helper function tells us if a cluster is allocated (that is,
there is an associated host offset for it).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6d8771c5c79cbdc6c519875a5078e1cc85856d63.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
There are situations in which we want to know how many contiguous
subclusters of the same type there are in a given cluster. This can be
done by simply iterating over the subclusters and repeatedly calling
qcow2_get_subcluster_type() for each one of them.
However once we determined the type of a subcluster we can check the
rest efficiently by counting the number of adjacent ones (or zeroes)
in the bitmap. This is what this function does.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <db917263d568ec6ffb4a41cac3c9100f96bf6c18.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch adds QCow2SubclusterType, which is the subcluster-level
version of QCow2ClusterType. All QCOW2_SUBCLUSTER_* values have the
the same meaning as their QCOW2_CLUSTER_* equivalents (when they
exist). See below for details and caveats.
In images without extended L2 entries clusters are treated as having
exactly one subcluster so it is possible to replace one data type with
the other while keeping the exact same semantics.
With extended L2 entries there are new possible values, and every
subcluster in the same cluster can obviously have a different
QCow2SubclusterType so functions need to be adapted to work on the
subcluster level.
There are several things that have to be taken into account:
a) QCOW2_SUBCLUSTER_COMPRESSED means that the whole cluster is
compressed. We do not support compression at the subcluster
level.
b) There are two different values for unallocated subclusters:
QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN which means that the whole
cluster is unallocated, and QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC
which means that the cluster is allocated but the subcluster is
not. The latter can only happen in images with extended L2
entries.
c) QCOW2_SUBCLUSTER_INVALID is used to detect the cases where an L2
entry has a value that violates the specification. The caller is
responsible for handling these situations.
To prevent compatibility problems with images that have invalid
values but are currently being read by QEMU without causing side
effects, QCOW2_SUBCLUSTER_INVALID is only returned for images
with extended L2 entries.
qcow2_cluster_to_subcluster_type() is added as a separate function
from qcow2_get_subcluster_type(), but this is only temporary and both
will be merged in a subsequent patch.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <26ef38e270f25851c98b51278852b4c4a7f97e69.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Extended L2 entries are 128-bit wide: 64 bits for the entry itself and
64 bits for the subcluster allocation bitmap.
In order to support them correctly get/set_l2_entry() need to be
updated so they take the entry width into account in order to
calculate the correct offset.
This patch also adds the get/set_l2_bitmap() functions that are
used to access the bitmaps. For convenience we allow calling
get_l2_bitmap() on images without subclusters. In this case the
returned value is always 0 and has no meaning.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6ee0f81ae3329c991de125618b3675e1e46acdbb.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2 images with subclusters have 128-bit L2 entries. The first 64
bits contain the same information as traditional images and the last
64 bits form a bitmap with the status of each individual subcluster.
Because of that we cannot assume that L2 entries are sizeof(uint64_t)
anymore. This function returns the proper value for the image.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <d34d578bd0380e739e2dde3e8dd6187d3d249fa9.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Like offset_into_cluster() and size_to_clusters(), but for
subclusters.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <3cc2390dcdef3d234d47c741b708bd8734490862.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
For a given offset, return the subcluster number within its cluster
(i.e. with 32 subclusters per cluster it returns a number between 0
and 31).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <56e3e4ac0d827c6a2f5f259106c5ddb7c4ca2653.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch adds the following new fields to BDRVQcow2State:
- subclusters_per_cluster: Number of subclusters in a cluster
- subcluster_size: The size of each subcluster, in bytes
- subcluster_bits: No. of bits so 1 << subcluster_bits = subcluster_size
Images without subclusters are treated as if they had exactly one
subcluster per cluster (i.e. subcluster_size = cluster_size).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <55bfeac86b092fa2c9d182a95cbeb479ff7eca4f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This function will be used by the qcow2 code to check if an image has
subclusters or not.
At the moment this simply returns false. Once all patches needed for
subcluster support are ready then QEMU will be able to create and
read images with subclusters and this function will return the actual
value.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <905526221083581a1b7057bca1585487661c5c13.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Subcluster allocation in qcow2 is implemented by extending the
existing L2 table entries and adding additional information to
indicate the allocation status of each subcluster.
This patch documents the changes to the qcow2 format and how they
affect the calculation of the L2 cache size.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <5199f2e1c717bcaa58b48142c9062b803145ff7f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The size of an L2 entry is 64 bits, but if we want to have subclusters
we need extended L2 entries. This means that we have to access L2
tables and slices differently depending on whether an image has
extended L2 entries or not.
This patch replaces all l2_slice[] accesses with calls to
get_l2_entry() and set_l2_entry().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <9586363531fec125ba1386e561762d3e4224e9fc.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When writing to a qcow2 file there are two functions that take a
virtual offset and return a host offset, possibly allocating new
clusters if necessary:
- handle_copied() looks for normal data clusters that are already
allocated and have a reference count of 1. In those clusters we
can simply write the data and there is no need to perform any
copy-on-write.
- handle_alloc() looks for clusters that do need copy-on-write,
either because they haven't been allocated yet, because their
reference count is != 1 or because they are ZERO_ALLOC clusters.
The ZERO_ALLOC case is a bit special because those are clusters that
are already allocated and they could perfectly be dealt with in
handle_copied() (as long as copy-on-write is performed when required).
In fact, there is extra code specifically for them in handle_alloc()
that tries to reuse the existing allocation if possible and frees them
otherwise.
This patch changes the handling of ZERO_ALLOC clusters so the
semantics of these two functions are now like this:
- handle_copied() looks for clusters that are already allocated and
which we can overwrite (NORMAL and ZERO_ALLOC clusters with a
reference count of 1).
- handle_alloc() looks for clusters for which we need a new
allocation (all other cases).
One important difference after this change is that clusters found
in handle_copied() may now require copy-on-write, but this will be
necessary anyway once we add support for subclusters.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <eb17fc938f6be7be2e8d8ff42763d2c19241f866.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We are going to need it in other places.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <65e5d9627ca2ebe7e62deaeddf60949c33067d9d.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
handle_alloc() creates a QCowL2Meta structure in order to update the
image metadata and perform the necessary copy-on-write operations.
This patch moves that code to a separate function so it can be used
from other places.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <e5bc4a648dac31972bfa7a0e554be8064be78799.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2_get_cluster_offset() takes an (unaligned) guest offset and
returns the (aligned) offset of the corresponding cluster in the qcow2
image.
In practice none of the callers need to know where the cluster starts
so this patch makes the function calculate and return the final host
offset directly. The function is also renamed accordingly.
There is a pre-existing exception with compressed clusters: in this
case the function returns the complete cluster descriptor (containing
the offset and size of the compressed data). This does not change with
this patch but it is now documented.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <ffae6cdc5ca8950e8280ac0f696dcc376cb07095.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The file_cluster_offset field of Qcow2AioTask stores a cluster-aligned
host offset. In practice this is not very useful because all users(*)
of this structure need the final host offset into the cluster, which
they calculate using
host_offset = file_cluster_offset + offset_into_cluster(s, offset)
There is no reason why Qcow2AioTask cannot store host_offset directly
and that is what this patch does.
(*) compressed clusters are the exception: in this case what
file_cluster_offset was storing was the full compressed cluster
descriptor (offset + size). This does not change with this patch
but it is documented now.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <07c4b15c644dcf06c9459f98846ac1c4ea96e26f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
* hw/cpu/a9mpcore: Verify the machine use Cortex-A9 cores
* hw/arm/smmuv3: Implement SMMUv3.2 range-invalidation
* docs/system/arm: Document the Xilinx Versal Virt board
* target/arm: Make M-profile NOCP take precedence over UNDEF
* target/arm: Use correct FPST for VCMLA, VCADD on fp16
* target/arm: Various cleanups preparing for fp16 support
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Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20200824' into staging
target-arm queue:
* hw/cpu/a9mpcore: Verify the machine use Cortex-A9 cores
* hw/arm/smmuv3: Implement SMMUv3.2 range-invalidation
* docs/system/arm: Document the Xilinx Versal Virt board
* target/arm: Make M-profile NOCP take precedence over UNDEF
* target/arm: Use correct FPST for VCMLA, VCADD on fp16
* target/arm: Various cleanups preparing for fp16 support
# gpg: Signature made Mon 24 Aug 2020 10:47:14 BST
# gpg: using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg: issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg: aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE
* remotes/pmaydell/tags/pull-target-arm-20200824: (27 commits)
target/arm: Use correct FPST for VCMLA, VCADD on fp16
target/arm: Implement FPST_STD_F16 fpstatus
target/arm: Make A32/T32 use new fpstatus_ptr() API
target/arm: Replace A64 get_fpstatus_ptr() with generic fpstatus_ptr()
target/arm: Delete unused ARM_FEATURE_CRC
target/arm/translate.c: Delete/amend incorrect comments
target/arm: Delete unused VFP_DREG macros
target/arm: Remove ARCH macro
target/arm: Convert T32 coprocessor insns to decodetree
target/arm: Do M-profile NOCP checks early and via decodetree
target/arm: Tidy up disas_arm_insn()
target/arm: Convert A32 coprocessor insns to decodetree
target/arm: Separate decode from handling of coproc insns
target/arm: Pull handling of XScale insns out of disas_coproc_insn()
docs/system/arm: Document the Xilinx Versal Virt board
hw/arm/smmuv3: Advertise SMMUv3.2 range invalidation
hw/arm/smmuv3: Support HAD and advertise SMMUv3.1 support
hw/arm/smmuv3: Let AIDR advertise SMMUv3.0 support
hw/arm/smmuv3: Fix IIDR offset
hw/arm/smmuv3: Get prepared for range invalidation
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When we implemented the VCMLA and VCADD insns we put in the
code to handle fp16, but left it using the standard fp status
flags. Correct them to use FPST_STD_F16 for fp16 operations.
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: 20200806104453.30393-5-peter.maydell@linaro.org
Architecturally, Neon FP16 operations use the "standard FPSCR" like
all other Neon operations. However, this is defined in the Arm ARM
pseudocode as "a fixed value, except that FZ16 (and AHP) follow the
FPSCR bits". In QEMU, the softfloat float_status doesn't include
separate flush-to-zero for FP16 operations, so we must keep separate
fp_status for "Neon non-FP16" and "Neon fp16" operations, in the
same way we do already for the non-Neon "fp_status" vs "fp_status_f16".
Add the extra float_status field to the CPU state structure,
ensure it is correctly initialized and updated on FPSCR writes,
and make fpstatus_ptr(FPST_STD_F16) return a pointer to it.
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: 20200806104453.30393-4-peter.maydell@linaro.org
Make A32/T32 code use the new fpstatus_ptr() API:
get_fpstatus_ptr(0) -> fpstatus_ptr(FPST_FPCR)
get_fpstatus_ptr(1) -> fpstatus_ptr(FPST_STD)
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: 20200806104453.30393-3-peter.maydell@linaro.org
We currently have two versions of get_fpstatus_ptr(), which both take
an effectively boolean argument:
* the one for A64 takes "bool is_f16" to distinguish fp16 from other ops
* the one for A32/T32 takes "int neon" to distinguish Neon from other ops
This is confusing, and to implement ARMv8.2-FP16 the A32/T32 one will
need to make a four-way distinction between "non-Neon, FP16",
"non-Neon, single/double", "Neon, FP16" and "Neon, single/double".
The A64 version will then be a strict subset of the A32/T32 version.
To clean this all up, we want to go to a single implementation which
takes an enum argument with values FPST_FPCR, FPST_STD,
FPST_FPCR_F16, and FPST_STD_F16. We rename the function to
fpstatus_ptr() so that unconverted code gets a compilation error
rather than silently passing the wrong thing to the new function.
This commit implements that new API, and converts A64 to use it:
get_fpstatus_ptr(false) -> fpstatus_ptr(FPST_FPCR)
get_fpstatus_ptr(true) -> fpstatus_ptr(FPST_FPCR_F16)
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: 20200806104453.30393-2-peter.maydell@linaro.org
In commit 962fcbf2ef we converted the uses of the
ARM_FEATURE_CRC bit to use the aa32_crc32 isar_feature test
instead. However we forgot to remove the now-unused definition
of the feature name in the enum. Delete it now.
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>
Message-id: 20200805210848.6688-1-peter.maydell@linaro.org
In arm_tr_init_disas_context() we have a FIXME comment that suggests
"cpu_M0 can probably be the same as cpu_V0". This isn't in fact
possible: cpu_V0 is used as a temporary inside gen_iwmmxt_shift(),
and that function is called in various places where cpu_M0 contains a
live value (i.e. between gen_op_iwmmxt_movq_M0_wRn() and
gen_op_iwmmxt_movq_wRn_M0() calls). Remove the comment.
We also have a comment on the declarations of cpu_V0/V1/M0 which
claims they're "for efficiency". This isn't true with modern TCG, so
replace this comment with one which notes that they're only used with
the iwmmxt decode.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803132815.3861-1-peter.maydell@linaro.org
As part of the Neon decodetree conversion we removed all
the uses of the VFP_DREG macros, but forgot to remove the
macro definitions. Do so now.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200803124848.18295-1-peter.maydell@linaro.org
The ARCH() macro was used a lot in the legacy decoder, but
there are now just two uses of it left. Since a macro which
expands out to a goto is liable to be confusing when reading
code, replace the last two uses with a simple open-coded
qeuivalent.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-8-peter.maydell@linaro.org
Convert the T32 coprocessor instructions to decodetree.
As with the A32 conversion, this corrects an underdecoding
where we did not check that MRRC/MCRR [24:21] were 0b0010
and so treated some kinds of LDC/STC and MRRC/MCRR rather
than UNDEFing them.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-7-peter.maydell@linaro.org
For M-profile CPUs, the architecture specifies that the NOCP
exception when a coprocessor is not present or disabled should cover
the entire wide range of coprocessor-space encodings, and should take
precedence over UNDEF exceptions. (This is the opposite of
A-profile, where checking for a disabled FPU has to happen last.)
Implement this with decodetree patterns that cover the specified
ranges of the encoding space. There are a few instructions (VLLDM,
VLSTM, and in v8.1 also VSCCLRM) which are in copro-space but must
not be NOCP'd: these must be handled also in the new m-nocp.decode so
they take precedence.
This is a minor behaviour change: for unallocated insn patterns in
the VFP area (cp=10,11) we will now NOCP rather than UNDEF when the
FPU is disabled.
As well as giving us the correct architectural behaviour for v8.1M
and the recommended behaviour for v8.0M, this refactoring also
removes the old NOCP handling from the remains of the 'legacy
decoder' in disas_thumb2_insn(), paving the way for cleaning that up.
Since we don't currently have a v8.1M feature bit or any v8.1M CPUs,
the minor changes to this logic that we'll need for v8.1M are marked
up with TODO comments.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-6-peter.maydell@linaro.org
The only thing left in the "legacy decoder" is the handling
of disas_xscale_insn(), and we can simplify the code.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-5-peter.maydell@linaro.org
Convert the A32 coprocessor instructions to decodetree.
Note that this corrects an underdecoding: for the 64-bit access case
(MRRC/MCRR) we did not check that bits [24:21] were 0b0010, so we
would incorrectly treat LDC/STC as MRRC/MCRR rather than UNDEFing
them.
The decodetree versions of these insns assume the coprocessor
is in the range 0..7 or 14..15. This is architecturally sensible
(as per the comments) and OK in practice for QEMU because the only
uses of the ARMCPRegInfo infrastructure we have that aren't
for coprocessors 14 or 15 are the pxa2xx use of coprocessor 6.
We add an assertion to the define_one_arm_cp_reg_with_opaque()
function to catch any accidental future attempts to use it to
define coprocessor registers for invalid coprocessors.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-4-peter.maydell@linaro.org
As a prelude to making coproc insns use decodetree, split out the
part of disas_coproc_insn() which does instruction decoding from the
part which does the actual work, and make do_coproc_insn() handle the
UNDEF-on-bad-permissions and similar cases itself rather than
returning 1 to eventually percolate up to a callsite that calls
unallocated_encoding() for it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200803111849.13368-3-peter.maydell@linaro.org