MISRA-C requires that there should be no unused parameters in
functions.
This patch removes the unused parameters that is not being used
unconditionally.
Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
MISRA-C requires that there should be no unused parameters in
functions.
In some cases, we will keep the unused parameters.
vmexit handler is one example. It is used as function pointer.
Some of the vmexit handlers use the input parameter 'vcpu', some of
them don't. We still need to keep the unused parameters 'vcpu' for
those handlers don't use 'vcpu'.
This patch removes the unused parameters that is not being used
unconditionally.
v1 -> v2:
* remove the non-implemented API 'vlapic_id_write_handler'
Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Now the DM has adopted the new VHM request state transitions and
REQ_STATE_FAILED is obsolete since neither VHM nor kernel mediators will set the
state to FAILED.
This patch drops the definition to REQ_STATE_FAILED in the hypervisor, makes
''processed'' unsigned to make the compiler happy about typing and simplifies
error handling in the following ways.
* (dm_)emulate_(pio|mmio)_post no longer returns an error code, by introducing a
constraint that these functions must be called after an I/O request
completes (which is the case in the current design) and assuming
handlers/VHM/DM will always give a value for reads (typically all 1's if the
requested address is invalid).
* emulate_io() now returns a positive value IOREQ_PENDING to indicate that the
request is sent to VHM. This mitigates a potential race between
dm_emulate_pio() and pio_instr_vmexit_handler() which can cause
emulate_pio_post() being called twice for the same request.
* Remove the ''processed'' member in io_request. Previously this mirrors the
state of the VHM request which terminates at either COMPLETE or FAILED. After
the FAILED state is removed, the terminal state will always be constantly
COMPLETE. Thus the mirrored ''processed'' member is no longer useful.
Note that emulate_instruction() will always succeed after a reshuffle, and this
patch takes that assumption in advance. This does not hurt as that returned
value is not currently handled.
This patch makes it explicit that I/O emulation is not expected to fail. One
issue remains, though, which occurs when a non-aligned cross-boundary access
happens. Currently the hypervisor, VHM and DM adopts different policy:
* Hypervisor: inject #GP if it detects that the access crossed boundary
* VHM: deliver to DM if the access does not complete falls in the range of a
client
* DM: a handler covering part of the to-be-accessed region is picked and
assertion failure can be triggered.
A high-level design covering all these components (in addition to instruction
emulation) is needed for this. Thus this patch does not yet cover the issue.
Tracked-On: #875
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Fix the parameter name mismatch between API declaration and definition.
v2 -> v3:
* Fix two more violations which are missed in previous report.
shell_puts and console_write
v1 -> v2:
* Replace 'ret_desc' with 'desc'
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
Add the parameter identifier for typedef function pointer.
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
There are some functions for the post work of I/O emulation. This patch moves
these functions to io.c for clarity. No functional change introduced.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This is the counterpart to the PIO emulation side.
1. ept_violation_vmexit_handler (entry point for handling vmexit on EPT instruction):
Extract mmio address, size, direction and value (for write only), fill in an
I/O request, invoke do_io to handle that and emulate_pio_post for
post-processing.
2. emulate_io
Handle the given I/O request, either completed by registered MMIO handlers
or sent to VHM.
3. emulate_mmio_post:
Update guest registers after the emulation is done.
v2 -> v3:
* Rename: emulate_mmio_by_handler -> hv_emulate_mmio.
* Inline the original hv_emulate_mmio.
* No longer check alignment. The handlers are responsible for handling
unaligned accesses.
v1 -> v2:
* Rename: do_io -> emulate_io.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This patch refactors how I/O instructions are emulated, in order for a unify the
I/O emulation path. The major control flow includes:
1. pio_instr_vmexit_handler (entry point for handling vmexit on I/O instruction):
Extract port address, register size, direction and value (for write only),
fill in an I/O request (of type io_request), invokes do_io to handle that
and update the guest registers if the request has been successfully handled
when do_io returns.
2. emulate_io:
Handle the given I/O request. The request is handled or sent to VHM if it
returns 0 (the actual status can be found in io_req->processed). On errors a
negative error code is returned.
3. emulate_pio_by_handler:
Look for the PIO handler for the given request and invoke that
handler. Return 0 if a proper handler is found and invoked (the status of
the emulation can be found in io_req->processed), -EIO when the request
spans across devices, and -ENODEV when no handler is found.
4. emulate_pio_post:
Update guest registers after the emulation is done. Currently this can
happen either right after do_io() or after the vcpu is resumed. Status check
on the I/O request and follow-up actions on failure will also go here.
Note:
Currently do_io can return 0 with io_req->processed being REQ_STATE_PENDING if
the request is sent to VHM for further processing. In this case the current vcpu
will be paused after handling this vm_exit, and dm_emulate_pio_post will be
invoked to do the rest after this vcpu is resumed. When vcpus are scheduled back
to exactly where they are scheduled out later, do_io should be responsible for
the post_work and the processing of do_io results shall be mostly the same.
v2 -> v3:
* Rename: emulate_pio_by_handler -> hv_emulate_pio.
* Properly mask the value passed to port I/O handler.
v1 -> v2:
* Rename: do_io -> emulate_io.
* Rename io_instr_vmexit_handler -> pio_instr_vmexit_handler to reflect the
fact that it handles port I/O only.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Misra c required parameter should not changed in the scope
of function,use local variable to replace it.
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
The current struct vcpu has two members, namely 'struct vhm_request req' and
'struct mem_io mmio', that hold similar info, including the address, direction, size,
value and status of mmio reqeusts.
As a step towards a unified framework for both MMIO/PIO, this patch unifies
these two members by a tailored version of vhm_reqeust, mostly with the reserved
fields dropped. The definitions to request types, directions and process status
are reused.
Handling errors during emulations will be revisited after the I/O emulation
paths are unified. Thus for this patch the mmio.mmio_status in inherited by
io_req.processed which is not yet properly processed.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Currently the I/O emulation structures and interfaces are scattered among mmu.h,
io.h and guest.h, and tangled with other interfaces there. This patch moves the
former to a separate header ioreq.h.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
