When XIVE is supported, the device tree should be populated
accordingly and the XIVE memory regions mapped to activate MMIOs.

Depending on the design we choose, we could also allocate different
ICS and ICP objects, or switch between objects. This needs to be
discussed.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

On POWER9, the Client Architecture Support (CAS) negotiation process
determines whether the guest operates in XIVE Legacy compatibility
(the former POWER8 interrupt model) or in XIVE exploitation mode (the
newer POWER9 interrupt model).

Bit 7 of Byte 23 of vector 5 is used for this purpose.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

When running KVM on POWER, we allow the user to pass "-cpu POWERx" instead
of "-cpu host". This is achieved by patching the ppc_cpu_aliases[] array
so that "POWERx" points to the CPU class with the same PVR as the host CPU.
This causes CPUs to be instantiated from this CPU class instead of the
TYPE_HOST_POWERPC_CPU class which is used with "-cpu host". These CPUs thus
miss all the KVM specific tuning from kvmppc_host_cpu_class_init().

This currently causes QEMU with "-cpu POWER9" to fail when running KVM on a
POWER9 DD1 host:

qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only
 "-cpu host" is possible
kvm_init_vcpu failed: Invalid argument

Let's have the "POWERx" alias to point to TYPE_HOST_POWERPC_CPU directly,
so that "-cpu POWERx" instantiates CPUs from the same class as "-cpu host".
Signed-off-by: NGreg Kurz <groug@kaod.org>
Tested-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We print a warning if the spapr IOMMU isn't configured to support a page
size matching the host page size backing RAM.  When that's the case we need
more complex logic to translate VFIO mappings, which is slower.

But, it's not so slow that it would be at all noticeable against the
general slowness of TCG.  So, only warn when using KVM.  This removes some
noisy and unhelpful warnings from make check on hosts with page sizes
which typically differ from those on POWER (e.g. Sparc).
Reported-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NThomas Huth <thuth@redhat.com>

QEMU shouldn't abort if spapr_add_lmbs()->spapr_drc_attach() fails.
Let's propagate the error instead, like it is done everywhere else
where spapr_drc_attach() is called.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NDaniel Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

In target/ppc/mmu-hash64.c there already exists the function
ppc_hash64_get_phys_page_debug() to get the physical (real) address for
a given effective address in hash mode.

Implement the function ppc_radix64_get_phys_page_debug() to allow a real
address to be obtained for a given effective address in radix mode.
This is used when a debugger is attached to qemu.

Previously we just had a comment saying this is unimplemented which then
fell through to the default case and caused an abort due to
unrecognised mmu model as the default had no case for the V3 mmu, which
was misleading at best.

We reuse ppc_radix64_walk_tree() which is used by the radix fault
handler since the process of walking the radix tree is identical.
Reported-by: NBalbir Singh <bsingharora@gmail.com>
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The mmu-radix64.c file implements functions to enable the radix mmu
emulation in tcg mode. There is a function ppc_radix64_walk_tree() which
performs the radix tree walk and also implicitly checks the pte
protection.

Move the protection checking of the pte from the ppc_radix64_walk_tree()
function into the caller. This means the ppc_radix64_walk_tree() function
can be used without protection checking which is useful for debugging.

ppc_radix64_walk_tree() no longer needs to take the rwx and prot variables.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

AIUI, ->unplug_request in the HotplugHandler is used for "soft"
unplug, where acknowledgement from the guest is required before
completing the unplug, whereas ->unplug is used for "hard" unplug
where qemu unilaterally removes the device, and the guest just has to
cope with its sudden absence.  For spapr we (correctly) use
->unplug_request for CPU and memory hot unplug but we use ->unplug for
PCI.

While I think it might be possible to support "hard" PCI unplug within
the PAPR model, that's not how it actually works now.  Although it's
called from ->unplug, the PCI unplug path will usually just mark the
device for removal, with completion of the unplug delayed until
userspace responds to the unplug notification. If the guest doesn't
respond as expected, that could delay the unplug completion arbitrarily
long.

To reflect that, change the PCI unplug path to be called from
->unplug_request.  We also rename spapr_phb_hot_plug_child() and
spapr_phb_hot_unplug_child() to spapr_pci_plug() and
spapr_pci_unplug_request() to more obviously reflect the callbacks they're
implementing.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

spapr_drc_attach() has a 'coldplug' parameter which sets the DRC into
configured state initially, instead of the usual ISOLATED/UNUSABLE state.
It turns out this is unnecessary: although coldplugged devices do need to
be in CONFIGURED state once the guest starts, that will already be
accomplished by the reset code which will move DRCs for already plugged
devices into a coldplug equivalent state.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

At the moment, spapr_drc_release() has an ugly switch on the DRC type to
call the right, device-specific release function.  This cleans it up by
doing that via a proper QOM method.

It's still arguably an abstraction violation for the DRC code to call into
the specific device code, but one mess at a time.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

DRC objects have a regular device reset method.  However, it only gets
called in the usual way for PCI DRCs.  Because of where CPU and LMB DRCs
are in the QOM tree, their device reset method isn't automatically called.
So, the machine manually registers reset handlers to call device_reset().

This patch removes the device reset method, and instead always explicitly
registers the reset handler from realize().  This means the callers don't
have to worry about the two cases, and we always get proper resets.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>

The DR-indicator is essentially a "virtual LED" attached to a hotpluggable
device, which the guest can set to various states for the attention of
the operator or management layers.

It's mostly guest managed, except that we once-off set it to
ACTIVE/INACTIVE in the attach/detach path.  While that makes certain sense,
there's no indication in PAPR that the hypervisor should do this, and the
drmgr code on the guest side doesn't appear to need it (it will already set
the indicator to ACTIVE on hotplug, and INACTIVE on remove).

So, leave the DR-indicator entirely to the guest; the only thing we need
to do is ensure it's in a sane state on reset.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>

Properly set the book E exception syndrome register when a floating
point exception occurs.

Currently on a book E processor, the POWERPC_EXCP_FP exception handler
fails to set "env->spr[SPR_BOOKE_ESR] = ESR_FP;" as required by the
book E specification.
Signed-off-by: NAaron Larson <alarson@ddci.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

since commit 5c4537bd ("spapr: Fix 2.7<->2.8 migration of PCI host bridge"),
some migration fields are forged from the new ones in spapr_pci_pre_save().

It works well, except when the number of MSI devices is 0,
because in this case the function exits immediately.

This fix moves the migration code before the exit code.

The problem can be reproduced with these commands:

source qemu-2.9:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults -S

destination qemu-2.6:

    qemu-system-ppc64 -monitor stdio -M pseries-2.6 -nodefaults \
                      -incoming tcp:0:4444

on the source:

    migrate tcp:localhost:4444

Destination fails with the following error:

    qemu-system-ppc64: error while loading state for
                       instance 0x0 of device 'spapr_pci'
    qemu-system-ppc64: load of migration failed: Invalid argument
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

$ git grep spapr_ppc_reset
hw/ppc/spapr.c: * as part of spapr_ppc_reset().

$ git grep ppc_spapr_reset
hw/ppc/spapr.c:static void ppc_spapr_reset(void)
hw/ppc/spapr.c:    mc->reset = ppc_spapr_reset;
hw/ppc/spapr_hcall.c:        /* If ppc_spapr_reset() did not set up a HPT
 but one is necessary
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We have more of these since the addition of KVMPPC_H_LOGICAL_MEMOP in 2012.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Since commit ff9006dd ("spapr: move spapr_core_[foo]plug() callbacks
close to machine code in spapr.c"), this function doesn't need to be extern
anymore.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

nbd patches for 2017-07-10

- Eric Blake: MAINTAINERS: Promote NBD to supported, with new maintainer
- Vladimir Sementsov-Ogievskiy: [00/10] nbd refactoring part 2

# gpg: Signature made Mon 10 Jul 2017 15:59:18 BST
# gpg:                using RSA key 0xA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2017-07-10-v2:
  nbd: use generic trace subsystem instead of TRACE macro
  nbd: refactor tracing
  nbd/server: rename clientflags var in nbd_negotiate_options
  nbd/server: fix TRACE in nbd_negotiate_send_rep_len
  nbd/client: refactor TRACE of NBD_MAGIC
  nbd/common: nbd_tls_handshake: remove extra TRACE
  nbd/server: add errp to nbd_send_reply()
  nbd/server: use errp instead of LOG
  nbd/server: refactor nbd_negotiate
  nbd/server: nbd_negotiate: return 1 on NBD_OPT_ABORT
  MAINTAINERS: Promote NBD to supported, with new maintainer
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Let NBD use the trace mechanisms already present in qemu. Now you can
use the -trace optino of qemu, or the -T/--trace option of qemu-img,
qemu-io, and qemu-nbd, to select nbd traces. For qemu, the QMP commands
trace-event-{get,set}-state can also toggle tracing on the fly.

Example:
   qemu-nbd --trace 'nbd_*' <image file> # enables all nbd traces

Recompilation with CFLAGS=-DDEBUG_NBD is no more needed, furthermore,
DEBUG_NBD macro is removed from the code.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-11-vsementsov@virtuozzo.com>
[eblake: minor tweaks to a couple of traces]
Signed-off-by: NEric Blake <eblake@redhat.com>

Reorganize traces: move, reword, add information, drop extra ones.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-10-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Rename 'clientflags' to just 'option'. This variable has nothing to do
with flags, but is a single integer representing the option requested
by the client.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-9-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Fix wrong order of TRACE arguments.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-8-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

We are going to switch from TRACE macro to trace points,
this TRACE complicates things, this patch simplifies it.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-7-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Error is propagated to the caller, TRACE is not needed.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707152918.23086-6-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707152918.23086-5-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Move to modern errp scheme from just LOGging errors.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-4-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Combine two successive "if (oldStyle) {...} else {...}" into one.

Block "if (client->tlscreds)" under "if (oldStyle)" is unreachable,
as we have "oldStyle = client->exp != NULL && !client->tlscreds;".
So, delete this block.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170707152918.23086-3-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Separate the case when a client sends NBD_OPT_ABORT from all other
errors. It will be needed for the following patch, where errors will be
reported.
This particular case is not actually an error - it honestly follows the
NBD protocol. Therefore it should not be reported like an error.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707152918.23086-2-vsementsov@virtuozzo.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

We are promising more than just odd fixes, and Paolo is hoping
to offload the pull requests to me.  Also, enough of NBD is related
to the block layer that it is worth including qemu-block on patches.

While at it, include blockdev-nbd.c and qemu-nbd.texi in the set
of maintained files.
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <20170707182151.29872-1-eblake@redhat.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>

Block layer patches

# gpg: Signature made Mon 10 Jul 2017 12:26:44 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (40 commits)
  block: Make bdrv_is_allocated_above() byte-based
  block: Minimize raw use of bds->total_sectors
  block: Make bdrv_is_allocated() byte-based
  backup: Switch backup_run() to byte-based
  backup: Switch backup_do_cow() to byte-based
  backup: Switch block_backup.h to byte-based
  backup: Switch BackupBlockJob to byte-based
  block: Drop unused bdrv_round_sectors_to_clusters()
  mirror: Switch mirror_iteration() to byte-based
  mirror: Switch mirror_do_read() to byte-based
  mirror: Switch mirror_cow_align() to byte-based
  mirror: Update signature of mirror_clip_sectors()
  mirror: Switch mirror_do_zero_or_discard() to byte-based
  mirror: Switch MirrorBlockJob to byte-based
  commit: Switch commit_run() to byte-based
  commit: Switch commit_populate() to byte-based
  stream: Switch stream_run() to byte-based
  stream: Drop reached_end for stream_complete()
  stream: Switch stream_populate() to byte-based
  trace: Show blockjob actions via bytes, not sectors
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, for the most part this patch is just the
addition of scaling at the callers followed by inverse scaling at
bdrv_is_allocated().  But some code, particularly stream_run(),
gets a lot simpler because it no longer has to mess with sectors.
Leave comments where we can further simplify by switching to
byte-based iterations, once later patches eliminate the need for
sector-aligned operations.

For ease of review, bdrv_is_allocated() was tackled separately.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_is_allocated_above() was relying on intermediate->total_sectors,
which is a field that can have stale contents depending on the value
of intermediate->has_variable_length.  An audit shows that we are safe
(we were first calling through bdrv_co_get_block_status() which in
turn calls bdrv_nb_sectors() and therefore just refreshed the current
length), but it's nicer to favor our accessor functions to avoid having
to repeat such an audit, even if it means refresh_total_sectors() is
called more frequently.
Suggested-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NManos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned
on input and that *pnum is sector-aligned on return to the caller,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, this code adds usages like
DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned
values, where the call might reasonbly give non-aligned results
in the future; on the other hand, no rounding is needed for callers
that should just continue to work with byte alignment.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_is_allocated().  But
some code, particularly bdrv_commit(), gets a lot simpler because it
no longer has to mess with sectors; also, it is now possible to pass
NULL if the caller does not care how much of the image is allocated
beyond the initial offset.  Leave comments where we can further
simplify once a later patch eliminates the need for sector-aligned
requests through bdrv_is_allocated().

For ease of review, bdrv_is_allocated_above() will be tackled
separately.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Change the internal
loop iteration of backups to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are cluster-aligned).
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Convert another internal
function (no semantic change).
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Continue by converting
the public interface to backup jobs (no semantic change), including
a change to CowRequest to track by bytes instead of cluster indices.

Note that this does not change the difference between the public
interface (starting point, and size of the subsequent range) and
the internal interface (starting and end points).
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NXie Changlong <xiechanglong@cmss.chinamobile.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Continue by converting an
internal structure (no semantic change), and all references to
tracking progress.  Drop a redundant local variable bytes_per_cluster.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Now that the last user [mirror_iteration()] has converted to using
bytes, we no longer need a function to round sectors to clusters.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Change the internal
loop iteration of mirroring to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are both sector-aligned and multiples of the granularity).  Drop
the now-unused mirror_clip_sectors().
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Convert another internal
function, preserving all existing semantics, and adding one more
assertion that things are still sector-aligned (so that conversions
to sectors in mirror_read_complete don't need to round).
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>