The external interrupt interception can only occur in rare cases, e.g.
when the PSW of the interrupt handler has a bad value. The old handler
for this interception simply ignored these events (except for increasing
the exit_external_interrupt counter), but for proper operation we either
have to inject the interrupts manually or we should drop to userspace in
case of errors.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Add an interface to inject clock comparator and CPU timer interrupts
into the guest. This is needed for handling the external interrupt
interception.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When copy_from_user() fails, this code returns the number of bytes
remaining instead of a negative error code.  The positive number is
returned to the user but otherwise it is harmless.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch enables the IBS facility when a single VCPU is running.
The facility is dynamically turned on/off as soon as other VCPUs
enter/leave the stopped state.

When this facility is operating, some instructions can be executed
faster for single-cpu guests.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NDominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch introduces two new functions to set/clear the CPUSTAT_STOPPED bit and
makes use of it at all applicable places. These functions prepare the additional
execution of code when starting/stopping a vcpu.

The CPUSTAT_STOPPED bit should not be touched outside of these functions.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

TEST BLOCK is also subject to the low-address protection, so we need
to check the destination address in our handler.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Add a check for low-address protection to the PFMF handler and
convert real-addresses to absolute if necessary, as it is defined
in the Principles of Operations specification.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The s390 architecture has a special protection mechanism that can
be used to prevent write access to the vital data in the low-core
memory area. This patch adds a new helper function that can be used
to check for such write accesses and in case of protection, it also
sets up the exception data accordingly.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When the guest executes the MVPG instruction with DAT disabled,
and the source or destination page is not mapped in the host,
the so-called partial execution interception occurs. We need to
handle this event by setting up a mapping for the corresponding
user pages.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Factor out the new function handle_itdb(), which copies the ITDB into
guest lowcore to fully handle a TX abort.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The generically assembled low core labels already contain the
address for the TDB.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

On hard exits (abort, sigkill) we have have some kvm_s390_interrupt_info
structures hanging around. Delete those on exit to avoid memory leaks.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>

When a guest is single-stepped, we want to disable timer interrupts. Otherwise,
the guest will continuously execute the external interrupt handler and make
debugging of code where timer interrupts are enabled almost impossible.

The delivery of timer interrupts can be enforced in such sections by setting a
breakpoint and continuing execution.

In order to disable timer interrupts, they are disabled in the control register
of the guest just before SIE entry and are suppressed in the interrupt
check/delivery methods.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch moves the checks for enabled timer (clock-comparator) interrupts and pending
timer interrupts into own functions, making the code better readable and easier to
maintain.

The method kvm_cpu_has_pending_timer is filled with life.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch adds support to debug the guest using the PER facility on s390.
Single-stepping, hardware breakpoints and hardware watchpoints are supported. In
order to use the PER facility of the guest without it noticing it, the control
registers of the guest have to be patched and access to them has to be
intercepted(stctl, stctg, lctl, lctlg).

All PER program interrupts have to be intercepted and only the relevant PER
interrupts for the guest have to be given back. Special care has to be taken
about repeated exits on the same hardware breakpoint. The intervention of the
host in the guests PER configuration is not fully transparent. PER instruction
nullification can not be used by the guest and too many storage alteration
events may be reported to the guest (if it is activated for special address
ranges only) when the host concurrently debugging it.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Introduce the methods to emulate the stctl and stctg instruction. Added tracing
code.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When a program interrupt was to be delivered until now, no program interrupt
parameters were stored in the low-core of the target vcpu.

This patch enables the delivery of those program interrupt parameters, takes
care of concurrent PER events which can be injected in addition to any program
interrupt and uses the correct instruction length code (depending on the
interception code) for the injection of program interrupts.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Whenever a program interrupt is intercepted, some parameters are stored in the
sie control block. These parameters have to be extracted in order to be
reinjected correctly. This patch also takes care of intercepted PER events which
can occurr in addition to any program interrupt.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Add kerneldoc comment to kvm_s390_real_to_abs() and change the code
so it matches the coding style of the rest of gaccess.h.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_stsi() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle lctl[g]() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_stidp() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_lpsw[e]() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The tpi instruction should be suppressed on addressing and protection
exceptions, so we need to re-inject the dequeued io interrupt in that
case.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_tpi() to new guest access functions.

The code now sets up a structure which is copied with a single call to
guest space instead of issuing several separate guest access calls.
This is necessary since the to be copied data may cross a page boundary.
If a protection exception happens while accessing any of the pages, the
instruction is suppressed and may not have modified any memory contents.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_test_block() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_store_cpu_address() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_store_prefix() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_set_clock() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert __sigp_set_prefix() and handle_set_prefix() to new guest
access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert kvm_s390_store_status_unloaded() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_prog() to new guest access functions.
Also make the code a bit more readable and look at the return code
of write_guest_lc() which was missing before.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert pfault code to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NDominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert handle_stfl() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert local irqs in __do_deliver_interrupt() to new guest
access functions.
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Convert __do_deliver_interrupt() to new guest access functions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Check if siif is available before setting.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The new guest memory access function write_guest() and read_guest() can be
used to access guest memory in an architecture compliant way.
These functions will look at the vcpu's PSW and select the correct address
space for memory access and also perform correct address wrap around.
In case DAT is turned on, page tables will be walked otherwise access will
happen to real or absolute memory.

Any access exception will be recognized and exception data will be stored
in the vcpu's kvm_vcpu_arch.pgm member. Subsequently an exception can be
injected if necessary.

Missing are:
- key protection checks
- access register mode support
- program event recording support

This patch also adds write_guest_real(), read_guest_real(),
write_guest_absolute() and read_guest_absolute() guest functions which can
be used to access real and absolute storage. These functions currently do
not perform any access checks, since there is no use case (yet?).
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>