Commit Graph

102229 Commits

Author SHA1 Message Date
Alex Bennée 379b42e8b7 gdbstub: don't use target_ulong while handling registers
This is a hangover from the original code. addr is misleading as it is
only really a register id. While len will never exceed
MAX_PACKET_LENGTH I've used size_t as that is what strlen returns.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-20-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-20-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée b428ad1234 gdbstub: fix address type of gdb_set_cpu_pc
The underlying call uses vaddr and the comms API uses unsigned long
long which will always fit. We don't need to deal in target_ulong
here.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-19-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-19-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée 505601d580 gdbstub: specialise stub_can_reverse
Currently we only support replay for softmmu mode so it is a constant
false for user-mode.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-18-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-18-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée 7ea0c33def gdbstub: introduce gdb_get_max_cpus
This is needed for handling vcont packets as the way of calculating
max cpus vhanges between user and softmmu mode.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-17-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-17-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée 589a58672e gdbstub: specialise target_memory_rw_debug
The two implementations are different enough to encourage having a
specialisation and we can move some of the softmmu only stuff out of
gdbstub.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-16-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-16-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée 8a2025b36b gdbstub: specialise handle_query_attached
In both user and softmmu cases we are just replying with a constant.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-15-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-15-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée a7e0f9bd2a gdbstub: abstract target specific details from gdb_put_packet_binary
We unfortunately handle the checking of packet acknowledgement
differently for user and softmmu modes. Abstract the user mode stuff
behind gdb_got_immediate_ack with a stub for softmmu.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-14-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-14-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée ccd4c7c24a gdbstub: rationalise signal mapping in softmmu
We don't really need a table for mapping two symbols.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-13-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-13-richard.henderson@linaro.org>
2023-03-07 20:44:08 +00:00
Alex Bennée d96bf49ba8 gdbstub: move chunks of user code into own files
The process was pretty similar to the softmmu move except we take the
time to split stuff between user.c and user-target.c to avoid as much
target specific compilation as possible. We also start to make use of
our shiny new header scheme so the user-only helpers can be included
without the rest of the exec/gsbstub.h cruft.

As before we split some functions into user and softmmu versions

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-12-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-12-richard.henderson@linaro.org>
2023-03-07 20:44:04 +00:00
Cédric Le Goater 969dae5448 vfio: Fix vfio_get_dev_region() trace event
Simply transpose 'x8' to fix the typo and remove the ending '8'

Fixes: e61a424f05 ("vfio: Create device specific region info helper")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1526
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230303074330.2609377-1-clg@kaod.org
[aw: commit log s/revert/transpose/]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 11:19:07 -07:00
Alex Williamson 8249cffc62 vfio/migration: Rename entry points
Pick names that align with the section drivers should use them from,
avoiding the confusion of calling a _finalize() function from _exit()
and generalizing the actual _finalize() to handle removing the viommu
blocker.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/167820912978.606734.12740287349119694623.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 11:19:07 -07:00
Avihai Horon 333f988d19 docs/devel: Document VFIO device dirty page tracking
Adjust the VFIO dirty page tracking documentation and add a section to
describe device dirty page tracking.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20230307125450.62409-16-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:22 -07:00
Joao Martins 95b29658b6 vfio/migration: Query device dirty page tracking support
Now that everything has been set up for device dirty page tracking,
query the device for device dirty page tracking support.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20230307125450.62409-15-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:22 -07:00
Joao Martins e46883204c vfio/migration: Block migration with vIOMMU
Migrating with vIOMMU will require either tracking maximum
IOMMU supported address space (e.g. 39/48 address width on Intel)
or range-track current mappings and dirty track the new ones
post starting dirty tracking. This will be done as a separate
series, so add a live migration blocker until that is fixed.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20230307125450.62409-14-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:22 -07:00
Joao Martins b153402a89 vfio/common: Add device dirty page bitmap sync
Add device dirty page bitmap sync functionality. This uses the device
DMA logging uAPI to sync dirty page bitmap from the device.

Device dirty page bitmap sync is used only if all devices within a
container support device dirty page tracking.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20230307125450.62409-13-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:22 -07:00
Avihai Horon 6607109f05 vfio/common: Extract code from vfio_get_dirty_bitmap() to new function
Extract the VFIO_IOMMU_DIRTY_PAGES ioctl code in vfio_get_dirty_bitmap()
to its own function.

This will help the code to be more readable after next patch will add
device dirty page bitmap sync functionality.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20230307125450.62409-12-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:22 -07:00
Joao Martins 5255bbf4ec vfio/common: Add device dirty page tracking start/stop
Add device dirty page tracking start/stop functionality. This uses the
device DMA logging uAPI to start and stop dirty page tracking by device.

Device dirty page tracking is used only if all devices within a
container support device dirty page tracking.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20230307125450.62409-11-joao.m.martins@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-07 10:21:11 -07:00
Marcin Nowakowski 9055ffd76e target/mips: Fix JALS32/J32 instruction handling for microMIPS
microMIPS J & JAL instructions perform a jump in a 128MB region and 5
top bits of the address need to be preserved. This is different behavior
compared to standard mips systems, where the jump is executed within a
256MB region.
Note that microMIPS32 instruction set documentation appears to have
inconsistent information regarding JALX32 instruction - it is written in
the doc that:

"To execute a procedure call within the current 256 MB-aligned region
(...)
The low 26 bits of the target address is the target field shifted left
2 bits."

But the target address is already 26 bits. Moreover, the operation
description indicates that 28 bits are copied, so the statement about
use of 26 bits is _most likely_ incorrect and the corresponding code
remains the same as for standard mips instruction set.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@fungible.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230216051717.3911212-2-marcin.nowakowski@fungible.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-03-07 18:09:13 +01:00
Philippe Mathieu-Daudé a43972e176 target/mips: Replace [g_]assert(0) -> g_assert_not_reached()
In order to avoid warnings such commit c0a6665c3c ("target/i386:
Remove compilation errors when -Werror=maybe-uninitialized"),
replace all assert(0) and g_assert(0) by g_assert_not_reached().

Remove any code following g_assert_not_reached().

See previous commit for rationale.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230221232520.14480-4-philmd@linaro.org>
2023-03-07 18:08:12 +01:00
Jiaxun Yang abe45a859b docs/system: Remove "mips" board from target-mips.rst
This board had been removed long ago in commit f169413c27
("hw/mips: Remove the 'r4k' machine")

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230202132138.30945-2-jiaxun.yang@flygoat.com>
[PMD: Mention commit f169413c27]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-03-07 18:08:12 +01:00
Alex Bennée b6fa2ec238 gdbstub: move chunk of softmmu functionality to own file
This is mostly code motion but a number of things needed to be done
for this minimal patch set:

  - move shared structures to internals.h
  - splitting some functions into user and softmmu versions
  - fixing a few casting issues to keep softmmu common

More CONFIG_USER_ONLY stuff will be handled in a following patches.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-11-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-11-richard.henderson@linaro.org>
2023-03-07 17:06:41 +00:00
Alex Bennée 36e067b2f2 gdbstub: make various helpers visible to the rest of the module
We will be needing to use these helpers between the user and softmmu
files so declare them in the headers, add a system prefix and remove
static from the implementations.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-10-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-10-richard.henderson@linaro.org>
2023-03-07 17:06:38 +00:00
Alex Bennée 1678ea040e gdbstub: move fromhex/tohex routines to internals
These will be needed from multiple places in the code. They are
declared as inline so move to the header and fix up to modern coding
style.

The only other place that messes with hex stuff at the moment is the
URI handling in utils but that would be more code churn so leave for
now.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-9-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-9-richard.henderson@linaro.org>
2023-03-07 17:06:36 +00:00
Alex Bennée 548c96095d includes: move tb_flush into its own header
This aids subsystems (like gdbstub) that want to trigger a flush
without pulling target specific headers.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-8-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-8-richard.henderson@linaro.org>
2023-03-07 17:06:33 +00:00
Alex Bennée 9f56787c12 gdbstub: move GDBState to shared internals header
We are about to split softmmu and user mode helpers into different
files. To facilitate this we will need to share access to the GDBState
between those files.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-7-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-7-richard.henderson@linaro.org>
2023-03-07 17:06:31 +00:00
Alex Bennée 8e70c6f947 gdbstub: define separate user/system structures
In preparation for moving user/softmmu specific bits from the main
gdbstub file we need to separate the connection details into a
user/softmmu state. As these will eventually be defined in their own
files we move them out of the common GDBState structure.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-6-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-6-richard.henderson@linaro.org>
2023-03-07 17:06:28 +00:00
Alex Bennée ad9e4585b3 gdbstub: clean-up indent on gdb_exit
Otherwise checkpatch will throw a hissy fit on the later patches that
split this function up.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230302190846.2593720-5-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-5-richard.henderson@linaro.org>
2023-03-07 17:06:26 +00:00
Philippe Mathieu-Daudé 1c4517b8b6 gdbstub: Make syscall_complete/[gs]et_reg target-agnostic typedefs
Prototypes using gdb_syscall_complete_cb() or gdb_?et_reg_cb()
don't depend on "cpu.h", thus are not target-specific.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221214143659.62133-1-philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-4-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-4-richard.henderson@linaro.org>
2023-03-07 17:06:23 +00:00
Alex Bennée 9455762f58 gdbstub: fix-up copyright and license files
When I started splitting gdbstub apart I was a little too boilerplate
with my file headers. Fix up to carry over Fabrice's copyright and the
LGPL license header.

Fixes: ae7467b1ac (gdbstub: move breakpoint logic to accel ops)
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-3-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-3-richard.henderson@linaro.org>
2023-03-07 17:06:20 +00:00
Alex Bennée 9774855842 gdbstub/internals.h: clean up include guard
Use something more specific to avoid name clashes.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230302190846.2593720-2-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-2-richard.henderson@linaro.org>
2023-03-07 17:06:15 +00:00
David Woodhouse 154eac3719 docs: Update Xen-on-KVM documentation for PV disk support
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 438bec498b MAINTAINERS: Add entry for Xen on KVM emulation
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse a78c54c4f9 i386/xen: Initialize Xen backends from pc_basic_device_init() for emulation
Now that all the work is done to enable the PV backends to work without
actual Xen, instantiate the bus from pc_basic_device_init() for emulated
mode.

This allows us finally to launch an emulated Xen guest with PV disk.

   qemu-system-x86_64 -serial mon:stdio -M q35 -cpu host -display none \
     -m 1G -smp 2 -accel kvm,xen-version=0x4000a,kernel-irqchip=split \
     -kernel bzImage -append "console=ttyS0 root=/dev/xvda1" \
     -drive file=/var/lib/libvirt/images/fedora28.qcow2,if=none,id=disk \
     -device xen-disk,drive=disk,vdev=xvda

If we use -M pc instead of q35, we can even add an IDE disk and boot a
guest image normally through grub. But q35 gives us AHCI and that isn't
unplugged by the Xen magic, so the guests ends up seeing "both" disks.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse de26b26197 hw/xen: Implement soft reset for emulated gnttab
This is only part of it; we will also need to get the PV back end drivers
to tear down their own mappings (or do it for them, but they kind of need
to stop using the pointers too).

Some more work on the actual PV back ends and xen-bus code is going to be
needed to really make soft reset and migration fully functional, and this
part is the basis for that.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse d05864d23b hw/xen: Map guest XENSTORE_PFN grant in emulated Xenstore
We don't actually access the guest's page through the grant, because
this isn't real Xen, and we can just use the page we gave it in the
first place. Map the grant anyway, mostly for cosmetic purposes so it
*looks* like it's in use in the guest-visible grant table.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 0324751272 hw/xen: Add emulated implementation of XenStore operations
Now that we have an internal implementation of XenStore, we can populate
the xenstore_backend_ops to allow PV backends to talk to it.

Watches can't be processed with immediate callbacks because that would
call back into XenBus code recursively. Defer them to a QEMUBH to be run
as appropriate from the main loop. We use a QEMUBH per XS handle, and it
walks all the watches (there shouldn't be many per handle) to fire any
which have pending events. We *could* have done it differently but this
allows us to use the same struct watch_event as we have for the guest
side, and keeps things relatively simple.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse b08d88e30f hw/xen: Add emulated implementation of grant table operations
This is limited to mapping a single grant at a time, because under Xen the
pages are mapped *contiguously* into qemu's address space, and that's very
hard to do when those pages actually come from anonymous mappings in qemu
in the first place.

Eventually perhaps we can look at using shared mappings of actual objects
for system RAM, and then we can make new mappings of the same backing
store (be it deleted files, shmem, whatever). But for now let's stick to
a page at a time.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 4dfd5fb178 hw/xen: Hook up emulated implementation for event channel operations
We provided the backend-facing evtchn functions very early on as part of
the core Xen platform support, since things like timers and xenstore need
to use them.

By what may or may not be an astonishing coincidence, those functions
just *happen* all to have exactly the right function prototypes to slot
into the evtchn_backend_ops table and be called by the PV backends.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 072519037d hw/xen: Only advertise ring-page-order for xen-block if gnttab supports it
Whem emulating Xen, multi-page grants are distinctly non-trivial and we
have elected not to support them for the time being. Don't advertise
them to the guest.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
Paul Durrant 240cc11369 hw/xen: Avoid crash when backend watch fires too early
The xen-block code ends up calling aio_poll() through blkconf_geometry(),
which means we see watch events during the indirect call to
xendev_class->realize() in xen_device_realize(). Unfortunately this call
is made before populating the initial frontend and backend device nodes
in xenstore and hence xen_block_frontend_changed() (which is called from
a watch event) fails to read the frontend's 'state' node, and hence
believes the device is being torn down. This in-turn sets the backend
state to XenbusStateClosed and causes the device to be deleted before it
is fully set up, leading to the crash.
By simply moving the call to xendev_class->realize() after the initial
xenstore nodes are populated, this sorry state of affairs is avoided.

Reported-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 4ca8cf092d hw/xen: Build PV backend drivers for CONFIG_XEN_BUS
Now that we have the redirectable Xen backend operations we can build the
PV backends even without the Xen libraries.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse e2abfe5ec6 hw/xen: Rename xen_common.h to xen_native.h
This header is now only for native Xen code, not PV backends that may be
used in Xen emulation. Since the toolstack libraries may depend on the
specific version of Xen headers that they pull in (and will set the
__XEN_TOOLS__ macro to enable internal definitions that they depend on),
the rule is that xen_native.h (and thus the toolstack library headers)
must be included *before* any of the headers in include/hw/xen/interface.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse a9ae1418b3 hw/xen: Use XEN_PAGE_SIZE in PV backend drivers
XC_PAGE_SIZE comes from the actual Xen libraries, while XEN_PAGE_SIZE is
provided by QEMU itself in xen_backend_ops.h. For backends which may be
built for emulation mode, use the latter.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 7a8a749da7 hw/xen: Move xenstore_store_pv_console_info to xen_console.c
There's no need for this to be in the Xen accel code, and as we want to
use the Xen console support with KVM-emulated Xen we'll want to have a
platform-agnostic version of it. Make it use GString to build up the
path while we're at it.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
Paul Durrant ba2a92db1f hw/xen: Add xenstore operations to allow redirection to internal emulation
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse 15e283c5b6 hw/xen: Add foreignmem operations to allow redirection to internal emulation
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse f80fad16af hw/xen: Pass grant ref to gnttab unmap operation
The previous commit introduced redirectable gnttab operations fairly
much like-for-like, with the exception of the extra arguments to the
->open() call which were always NULL/0 anyway.

This *changes* the arguments to the ->unmap() operation to include the
original ref# that was mapped. Under real Xen it isn't necessary; all we
need to do from QEMU is munmap(), then the kernel will release the grant,
and Xen does the tracking/refcounting for the guest.

When we have emulated grant tables though, we need to do all that for
ourselves. So let's have the back ends keep track of what they mapped
and pass it in to the ->unmap() method for us.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse c412ba47b2 hw/xen: Add gnttab operations to allow redirection to internal emulation
Move the existing code using libxengnttab to xen-operations.c and allow
the operations to be redirected so that we can add emulation of grant
table mapping for backend drivers.

In emulation, mapping more than one grant ref to be virtually contiguous
would be fairly difficult. The best way to do it might be to make the
ram_block mappings actually backed by a file (shmem or a deleted file,
perhaps) so that we can have multiple *shared* mappings of it. But that
would be fairly intrusive.

Making the backend drivers cope with page *lists* instead of expecting
the mapping to be contiguous is also non-trivial, since some structures
would actually *cross* page boundaries (e.g. the 32-bit blkif responses
which are 12 bytes).

So for now, we'll support only single-page mappings in emulation. Add a
XEN_GNTTAB_OP_FEATURE_MAP_MULTIPLE flag to indicate that the native Xen
implementation *does* support multi-page maps, and a helper function to
query it.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
David Woodhouse b6cacfea0b hw/xen: Add evtchn operations to allow redirection to internal emulation
The existing implementation calling into the real libxenevtchn moves to
a new file hw/xen/xen-operations.c, and is called via a function table
which in a subsequent commit will also be able to invoke the emulated
event channel support.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00
Paul Durrant 831b0db8ab hw/xen: Create initial XenStore nodes
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07 17:04:30 +00:00