Commit Graph

102 Commits

Author SHA1 Message Date
James Hogan
c6c0a6637f MIPS: KVM: Remove redundant NULL checks before kfree()
The kfree() function already NULL checks the parameter so remove the
redundant NULL checks before kfree() calls in arch/mips/kvm/.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:46 +02:00
James Hogan
6e95bfd267 MIPS: KVM: Quieten kvm_info() logging
The logging from MIPS KVM is fairly noisy with kvm_info() in places
where it shouldn't be, such as on VM creation and migration to a
different CPU. Replace these kvm_info() calls with kvm_debug().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:37 +02:00
James Hogan
d5c704d525 MIPS: KVM: Remove ifdef DEBUG around kvm_debug
kvm_debug() uses pr_debug() which is already compiled out in the absence
of a DEBUG define, so remove the unnecessary ifdef DEBUG lines around
kvm_debug() calls which are littered around arch/mips/kvm/.

As well as generally cleaning up, this prevents future bit-rot due to
DEBUG not being commonly used.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:28 +02:00
James Hogan
3d65483371 MIPS: KVM: Fix kvm_debug bit-rottage
Fix build errors when DEBUG is defined in arch/mips/kvm/.
 - The DEBUG code in kvm_mips_handle_tlbmod() was missing some variables.
 - The DEBUG code in kvm_mips_host_tlb_write() was conditional on an
   undefined "debug" variable.
 - The DEBUG code in kvm_mips_host_tlb_inv() accessed asid_map directly
   rather than using kvm_mips_get_user_asid(). Also fixed brace
   placement.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:20 +02:00
James Hogan
0fae34f464 MIPS: KVM: Make kvm_mips_comparecount_{func,wakeup} static
The kvm_mips_comparecount_func() and kvm_mips_comparecount_wakeup()
functions are only used within arch/mips/kvm/kvm_mips.c, so make them
static.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:04:59 +02:00
James Hogan
f74a8e224e MIPS: KVM: Add count frequency KVM register
Expose the KVM guest CP0_Count frequency to userland via a new
KVM_REG_MIPS_COUNT_HZ register accessible with the KVM_{GET,SET}_ONE_REG
ioctls.

When the frequency is altered the bias is adjusted such that the guest
CP0_Count doesn't jump discontinuously or lose any timer interrupts.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:02:54 +02:00
James Hogan
f82393426a MIPS: KVM: Add master disable count interface
Expose two new virtual registers to userland via the
KVM_{GET,SET}_ONE_REG ioctls.

KVM_REG_MIPS_COUNT_CTL is for timer configuration fields and just
contains a master disable count bit. This can be used by userland to
freeze the timer in order to read a consistent state from the timer
count value and timer interrupt pending bit. This cannot be done with
the CP0_Cause.DC bit because the timer interrupt pending bit (TI) is
also in CP0_Cause so it would be impossible to stop the timer without
also risking a race with an hrtimer interrupt and having to explicitly
check whether an interrupt should have occurred.

When the timer is re-enabled it resumes without losing time, i.e. the
CP0_Count value jumps to what it would have been had the timer not been
disabled, which would also be impossible to do from userland with
CP0_Cause.DC. The timer interrupt also cannot be lost, i.e. if a timer
interrupt would have occurred had the timer not been disabled it is
queued when the timer is re-enabled.

This works by storing the nanosecond monotonic time when the master
disable is set, and using it for various operations instead of the
current monotonic time (e.g. when recalculating the bias when the
CP0_Count is set), until the master disable is cleared again, i.e. the
timer state is read/written as it would have been at that time. This
state is exposed to userland via the read-only KVM_REG_MIPS_COUNT_RESUME
virtual register so that userland can determine the exact time the
master disable took effect.

This should allow userland to atomically save the state of the timer,
and later restore it.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:02:45 +02:00
James Hogan
e30492bbe9 MIPS: KVM: Rewrite count/compare timer emulation
Previously the emulation of the CPU timer was just enough to get a Linux
guest running but some shortcuts were taken:
 - The guest timer interrupt was hard coded to always happen every 10 ms
   rather than being timed to when CP0_Count would match CP0_Compare.
 - The guest's CP0_Count register was based on the host's CP0_Count
   register. This isn't very portable and fails on cores without a
   CP_Count register implemented such as Ingenic XBurst. It also meant
   that the guest's CP0_Cause.DC bit to disable the CP0_Count register
   took no effect.
 - The guest's CP0_Count register was emulated by just dividing the
   host's CP0_Count register by 4. This resulted in continuity problems
   when used as a clock source, since when the host CP0_Count overflows
   from 0x7fffffff to 0x80000000, the guest CP0_Count transitions
   discontinuously from 0x1fffffff to 0xe0000000.

Therefore rewrite & fix emulation of the guest timer based on the
monotonic kernel time (i.e. ktime_get()). Internally a 32-bit count_bias
value is added to the frequency scaled nanosecond monotonic time to get
the guest's CP0_Count. The frequency of the timer is initialised to
100MHz and cannot yet be changed, but a later patch will allow the
frequency to be configured via the KVM_{GET,SET}_ONE_REG ioctl
interface.

The timer can now be stopped via the CP0_Cause.DC bit (by the guest or
via the KVM_SET_ONE_REG ioctl interface), at which point the current
CP0_Count is stored and can be read directly. When it is restarted the
bias is recalculated such that the CP0_Count value is continuous.

Due to the nature of hrtimer interrupts any read of the guest's
CP0_Count register while it is running triggers a check for whether the
hrtimer has expired, so that the guest/userland cannot observe the
CP0_Count passing CP0_Compare without queuing a timer interrupt. This is
also taken advantage of when stopping the timer to ensure that a pending
timer interrupt is queued.

This replaces the implementation of:
 - Guest read of CP0_Count
 - Guest write of CP0_Count
 - Guest write of CP0_Compare
 - Guest write of CP0_Cause
 - Guest read of HWR 2 (CC) with RDHWR
 - Host read of CP0_Count via KVM_GET_ONE_REG ioctl interface
 - Host write of CP0_Count via KVM_SET_ONE_REG ioctl interface
 - Host write of CP0_Compare via KVM_SET_ONE_REG ioctl interface
 - Host write of CP0_Cause via KVM_SET_ONE_REG ioctl interface

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:48 +02:00
James Hogan
3a0ba77408 MIPS: KVM: Migrate hrtimer to follow VCPU
When a VCPU is scheduled in on a different CPU, refresh the hrtimer used
for emulating count/compare so that it gets migrated to the same CPU.

This should prevent a timer interrupt occurring on a different CPU to
where the guest it relates to is running, which would cause the guest
timer interrupt not to be delivered until after the next guest exit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:33 +02:00
James Hogan
044f0f03ec MIPS: KVM: Deliver guest interrupts after local_irq_disable()
When about to run the guest, deliver guest interrupts after disabling
host interrupts. This should prevent an hrtimer interrupt from being
handled after delivering guest interrupts, and therefore not delivering
the guest timer interrupt until after the next guest exit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:10 +02:00
James Hogan
16fd5c1de4 MIPS: KVM: Add CP0_HWREna KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
HWREna register. This is so that userland can save and restore its
value so that RDHWR instructions don't have to be emulated by the guest.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:03 +02:00
James Hogan
7767b7d2f7 MIPS: KVM: Add CP0_UserLocal KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
UserLocal register. This is so that userland can save and restore its
value.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:57 +02:00
James Hogan
f8be02daca MIPS: KVM: Add CP0_Count/Compare KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
Count and Compare registers. These registers are special in that writing
to them has side effects (adjusting the time until the next timer
interrupt) and reading of Count depends on the time. Therefore add a
couple of callbacks so that different implementations (trap & emulate or
VZ) can implement them differently depending on what the hardware
provides.

The trap & emulate versions mostly duplicate what happens when a T&E
guest reads or writes these registers, so it inherits the same
limitations which can be fixed in later patches.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:44 +02:00
James Hogan
48a3c4e4cd MIPS: KVM: Move KVM_{GET,SET}_ONE_REG definitions into kvm_host.h
Move the KVM_{GET,SET}_ONE_REG MIPS register id definitions out of
kvm_mips.c to kvm_host.h so that they can be shared between multiple
source files. This allows register access to be indirected depending on
the underlying implementation (trap & emulate or VZ).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:35 +02:00
James Hogan
fb6df0cdf0 MIPS: KVM: Add CP0_EPC KVM register access
Contrary to the comment, the guest CP0_EPC register cannot be set via
kvm_regs, since it is distinct from the guest PC. Add the EPC register
to the KVM_{GET,SET}_ONE_REG ioctl interface.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:26 +02:00
James Hogan
b5dfc6c106 MIPS: KVM: Use tlb_write_random
When MIPS KVM needs to write a TLB entry for the guest it reads the
CP0_Random register, uses it to generate the CP_Index, and writes the
TLB entry using the TLBWI instruction (tlb_write_indexed()).

However there's an instruction for that, TLBWR (tlb_write_random()) so
use that instead.

This happens to also fix an issue with Ingenic XBurst cores where the
same TLB entry is replaced each time preventing forward progress on
stores due to alternating between TLB load misses for the instruction
fetch and TLB store misses.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:02 +02:00
James Hogan
facaaec1a7 MIPS: KVM: Use local_flush_icache_range to fix RI on XBurst
MIPS KVM uses mips32_SyncICache to synchronise the icache with the
dcache after dynamically modifying guest instructions or writing guest
exception vector. However this uses rdhwr to get the SYNCI step, which
causes a reserved instruction exception on Ingenic XBurst cores.

It would seem to make more sense to use local_flush_icache_range()
instead which does the same thing but is more portable.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 12:59:54 +02:00
James Hogan
7006e2dfda MIPS: KVM: Allocate at least 16KB for exception handlers
Each MIPS KVM guest has its own copy of the KVM exception vector. This
contains the TLB refill exception handler at offset 0x000, the general
exception handler at offset 0x180, and interrupt exception handlers at
offset 0x200 in case Cause_IV=1. A common handler is copied to offset
0x2000 and offset 0x3000 is used for temporarily storing k1 during entry
from guest.

However the amount of memory allocated for this purpose is calculated as
0x200 rounded up to the next page boundary, which is insufficient if 4KB
pages are in use. This can lead to the common handler at offset 0x2000
being overwritten and infinitely recursive exceptions on the next exit
from the guest.

Increase the minimum size from 0x200 to 0x4000 to cover the full use of
the page.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 12:59:13 +02:00
Deng-Cheng Zhu
356d4c2040 MIPS: KVM: remove the stale memory alias support function unalias_gfn
The memory alias support has been removed since a1f4d39500 (KVM: Remove
memory alias support). So remove unalias_gfn from the MIPS port.

Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-29 21:38:21 +02:00
James Hogan
36c9549460 MIPS: KVM: Remove dead code in CP0 emulation
The code to check whether rd > MIPS_CP0_DESAVE is dead code, since
MIPS_CP0_DESAVE = 31 and rd is already masked with 0x1f. Remove it.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-19 17:01:50 +01:00
James Hogan
26f4f3b578 MIPS: KVM: Consult HWREna before emulating RDHWR
The ability to read hardware registers from userland with the RDHWR
instruction should depend upon the corresponding bit of the HWREna
register being set, otherwise a reserved instruction exception should be
generated.

However KVM's current emulation ignores the guest's HWREna and always
emulates RDHWR instructions even if the guest OS has disallowed them.

Therefore rework the RDHWR emulation code to check for privilege or the
corresponding bit in the guest HWREna bit. Also remove the #if 0 case
for the UserLocal register. I presume it was there for debug purposes
but it seems unnecessary now that the guest can control whether it
causes a guest exception.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-19 17:01:43 +01:00
James Hogan
1550567936 MIPS: KVM: Pass reserved instruction exceptions to guest
Previously a reserved instruction exception while in guest code would
cause a KVM internal error if kvm_mips_handle_ri() didn't recognise the
instruction (including a RDHWR from an unrecognised hardware register).

However the guest OS should really have the opportunity to catch the
exception so that it can take the appropriate actions such as sending a
SIGILL to the guest user process or emulating the instruction itself.

Therefore in these cases emulate a guest RI exception and only return
EMULATE_FAIL if that fails, being careful to revert the PC first in case
the exception occurred in a branch delay slot in which case the PC will
already point to the branch target.

Also turn the printk messages relating to these cases into kvm_debug
messages so that they aren't usually visible.

This allows crashme to run in the guest without killing the entire VM.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-03-19 17:01:34 +01:00
Paul Gortmaker
3b2663ca84 mips: delete non-required instances of include <linux/init.h>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6320/
2014-01-24 22:39:56 +01:00
James Hogan
08596b0a75 MIPS: KVM: remove shadow_tlb code
The kvm_mips_init_shadow_tlb() function is called from
kvm_arch_vcpu_init() and initialises entries 0 to
current_cpu_data.tlbsize-1 of the virtual cpu's shadow_tlb[64] array.

However newer cores with FTLBs can have a tlbsize > 64, for example the
ProAptiv I'm testing on has a total tlbsize of 576. This causes
kvm_mips_init_shadow_tlb() to overflow the shadow_tlb[64] array and
overwrite the comparecount_timer among other things, causing a lock up
when starting a KVM guest.

Aside from kvm_mips_init_shadow_tlb() which only initialises it, the
shadow_tlb[64] array is only actually used by the following functions:
 - kvm_shadow_tlb_put() & kvm_shadow_tlb_load()
     These are never called. The only call sites are #if 0'd out.
 - kvm_mips_dump_shadow_tlbs()
     This is never called.

It was originally added for trap & emulate, but turned out to be
unnecessary so it was disabled.

So instead of fixing the shadow_tlb initialisation code, lets just
remove the shadow_tlb[64] array and the above functions entirely. The
only functional change here is the removal of broken shadow_tlb
initialisation. The rest just deletes dead code.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6384/
2014-01-24 22:39:56 +01:00
James Hogan
e36059e508 MIPS: KVM: use common EHINV aware UNIQUE_ENTRYHI
When KVM is enabled and TLB invalidation is supported,
kvm_mips_flush_host_tlb() can cause a machine check exception due to
multiple matching TLB entries. This can occur on shutdown even when KVM
hasn't been actively used.

Commit adb78de9eae8 (MIPS: mm: Move UNIQUE_ENTRYHI macro to a header
file) created a common UNIQUE_ENTRYHI in asm/tlb.h but it didn't update
the copy of UNIQUE_ENTRYHI in kvm_tlb.c to use it.

Commit 36b175451399 (MIPS: tlb: Set the EHINV bit for TLBINVF cores when
invalidating the TLB) later added TLB invalidation (EHINV) support to
the common UNIQUE_ENTRYHI.

Therefore make kvm_tlb.c use the EHINV aware UNIQUE_ENTRYHI
implementation in asm/tlb.h too.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6383/
2014-01-24 22:39:56 +01:00
Aneesh Kumar K.V
5587027ce9 kvm: Add struct kvm arg to memslot APIs
We will use that in the later patch to find the kvm ops handler

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-17 15:49:23 +02:00
Linus Torvalds
ae7a835cc5 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Gleb Natapov:
 "The highlights of the release are nested EPT and pv-ticketlocks
  support (hypervisor part, guest part, which is most of the code, goes
  through tip tree).  Apart of that there are many fixes for all arches"

Fix up semantic conflicts as discussed in the pull request thread..

* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (88 commits)
  ARM: KVM: Add newlines to panic strings
  ARM: KVM: Work around older compiler bug
  ARM: KVM: Simplify tracepoint text
  ARM: KVM: Fix kvm_set_pte assignment
  ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256
  ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs
  ARM: KVM: vgic: fix GICD_ICFGRn access
  ARM: KVM: vgic: simplify vgic_get_target_reg
  KVM: MMU: remove unused parameter
  KVM: PPC: Book3S PR: Rework kvmppc_mmu_book3s_64_xlate()
  KVM: PPC: Book3S PR: Make instruction fetch fallback work for system calls
  KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX
  KVM: x86: update masterclock when kvmclock_offset is calculated (v2)
  KVM: PPC: Book3S: Fix compile error in XICS emulation
  KVM: PPC: Book3S PR: return appropriate error when allocation fails
  arch: powerpc: kvm: add signed type cast for comparation
  KVM: x86: add comments where MMIO does not return to the emulator
  KVM: vmx: count exits to userspace during invalid guest emulation
  KVM: rename __kvm_io_bus_sort_cmp to kvm_io_bus_cmp
  kvm: optimize away THP checks in kvm_is_mmio_pfn()
  ...
2013-09-04 18:15:06 -07:00
David Daney
ea69f28ddf mips/kvm: Make kvm_locore.S 64-bit buildable/safe.
We need to use more of the Macros in asm.h to allow kvm_locore.S to
build in a 64-bit kernel.

For 32-bit there is no change in the generated object code.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-26 12:30:49 +03:00
David Daney
bb48c2fc64 mips/kvm: Cleanup .push/.pop directives in kvm_locore.S
There are:
	.set	push
	.set	noreorder
	.set	noat
	 .
	 .
	 .
	.set	pop

Sequences all over the place in this file, but in some places the
final ".set pop" is erroneously converted to ".set push", so none of
these really do what they appear to.

Clean up the whole mess by moving ".set noreorder", ".set noat" to the
top, and get rid of everything else.

Generated object code is unchanged.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-26 12:30:39 +03:00
David Daney
2c07ebbd2c mips/kvm: Improve code formatting in arch/mips/kvm/kvm_locore.S
No code changes, just reflowing some comments and consistently using
tabs and spaces.  Object code is verified to be unchanged.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-26 12:30:24 +03:00
Markos Chandras
f1b7001903 MIPS: kvm: Kconfig: Drop HAVE_KVM dependency from VIRTUALIZATION
Virtualization does not always need KVM capabilities so drop the
dependency. The KVM symbol already depends on HAVE_KVM.

Fixes the following problem on a randconfig:
warning: (REMOTEPROC && RPMSG) selects VIRTUALIZATION which has unmet direct
dependencies (HAVE_KVM)
warning: (REMOTEPROC && RPMSG) selects VIRTUALIZATION which has unmet
direct dependencies (HAVE_KVM)

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5443/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-07-19 12:45:57 +02:00
Takuya Yoshikawa
e59dbe09f8 KVM: Introduce kvm_arch_memslots_updated()
This is called right after the memslots is updated, i.e. when the result
of update_memslots() gets installed in install_new_memslots().  Since
the memslots needs to be updated twice when we delete or move a memslot,
kvm_arch_commit_memory_region() does not correspond to this exactly.

In the following patch, x86 will use this new API to check if the mmio
generation has reached its maximum value, in which case mmio sptes need
to be flushed out.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Acked-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-18 12:29:25 +02:00
David Daney
681865d48e mips/kvm: Use KVM_REG_MIPS and proper size indicators for *_ONE_REG
The API requires that the GET_ONE_REG and SET_ONE_REG ioctls have this
extra information encoded in the register identifiers.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-11 11:07:38 +03:00
David Daney
ed829857b3 mips/kvm: Use ENOIOCTLCMD to indicate unimplemented ioctls.
The Linux Way is to return -ENOIOCTLCMD to the vfs when an
unimplemented ioctl is requested.  Do this in kvm_mips instead of a
random mixture of -ENOTSUPP and -EINVAL.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03 10:58:55 +03:00
David Daney
4c73fb2b05 mips/kvm: Fix ABI by moving manipulation of CP0 registers to KVM_{G,S}ET_ONE_REG
Because not all 256 CP0 registers are ever implemented, we need a
different method of manipulating them.  Use the
KVM_SET_ONE_REG/KVM_GET_ONE_REG mechanism.

Now unused code and definitions are removed.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03 10:58:54 +03:00
David Daney
8d17dd041a mips/kvm: Use ARRAY_SIZE() instead of hardcoded constants in kvm_arch_vcpu_ioctl_{s,g}et_regs
Also we cannot set special zero register, so force it to zero.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03 10:58:53 +03:00
David Daney
bf32ebf66d mips/kvm: Fix name of gpr field in struct kvm_regs.
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03 10:58:53 +03:00
Linus Torvalds
72dd4e7980 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm bugfixes from Gleb Natapov.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()
  KVM/MIPS32: Move include/asm/kvm.h => include/uapi/asm/kvm.h since it is a user visible API.
  KVM: take over co-maintainership from Marcelo, fix MAINTAINERS entry
2013-05-23 09:18:08 -07:00
Sanjay Lal
6d17c0d1e8 KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()
- As suggested by Gleb, wrap calls to gfn_to_pfn() with srcu_read_lock/unlock().
  Memory slots should be acccessed from a SRCU read section.
- kvm_mips_map_page() now returns an error code to it's callers, instead of
  calling panic() if it cannot find a mapping for a particular gfn.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-22 11:44:09 +03:00
David Daney
48c4ac976a Revert "MIPS: Allow ASID size to be determined at boot time."
This reverts commit d532f3d267.

The original commit has several problems:

1) Doesn't work with 64-bit kernels.

2) Calls TLBMISS_HANDLER_SETUP() before the code is generated.

3) Calls TLBMISS_HANDLER_SETUP() twice in per_cpu_trap_init() when
   only one call is needed.

[ralf@linux-mips.org: Also revert the bits of the ASID patch which were
hidden in the KVM merge.]

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: "Steven J. Hill" <Steven.Hill@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5242/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-16 20:35:42 +02:00
Linus Torvalds
daf799cca8 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:

 - More work on DT support for various platforms

 - Various fixes that were to late to make it straight into 3.9

 - Improved platform support, in particular the Netlogic XLR and
   BCM63xx, and the SEAD3 and Malta eval boards.

 - Support for several Ralink SOC families.

 - Complete support for the microMIPS ASE which basically reencodes the
   existing MIPS32/MIPS64 ISA to use non-constant size instructions.

 - Some fallout from LTO work which remove old cruft and will generally
   make the MIPS kernel easier to maintain and resistant to compiler
   optimization, even in absence of LTO.

 - KVM support.  While MIPS has announced hardware virtualization
   extensions this KVM extension uses trap and emulate mode for
   virtualization of MIPS32.  More KVM work to add support for VZ
   hardware virtualizaiton extensions and MIPS64 will probably already
   be merged for 3.11.

Most of this has been sitting in -next for a long time.  All defconfigs
have been build or run time tested except three for which fixes are being
sent by other maintainers.

Semantic conflict with kvm updates done as per Ralf

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (118 commits)
  MIPS: Add new GIC clockevent driver.
  MIPS: Formatting clean-ups for clocksources.
  MIPS: Refactor GIC clocksource code.
  MIPS: Move 'gic_frequency' to common location.
  MIPS: Move 'gic_present' to common location.
  MIPS: MIPS16e: Add unaligned access support.
  MIPS: MIPS16e: Support handling of delay slots.
  MIPS: MIPS16e: Add instruction formats.
  MIPS: microMIPS: Optimise 'strnlen' core library function.
  MIPS: microMIPS: Optimise 'strlen' core library function.
  MIPS: microMIPS: Optimise 'strncpy' core library function.
  MIPS: microMIPS: Optimise 'memset' core library function.
  MIPS: microMIPS: Add configuration option for microMIPS kernel.
  MIPS: microMIPS: Disable LL/SC and fix linker bug.
  MIPS: microMIPS: Add vdso support.
  MIPS: microMIPS: Add unaligned access support.
  MIPS: microMIPS: Support handling of delay slots.
  MIPS: microMIPS: Add support for exception handling.
  MIPS: microMIPS: Floating point support.
  MIPS: microMIPS: Fix macro naming in micro-assembler.
  ...
2013-05-10 07:48:05 -07:00
Ralf Baechle
b22d1b6a91 Merge branch 'mti-next' of git://git.linux-mips.org/pub/scm/sjhill/linux-sjhill into mips-for-linux-next 2013-05-09 17:57:30 +02:00
Sanjay Lal
50c8308538 KVM/MIPS32: Binary patching of select privileged instructions.
Currently, the following instructions are translated:
- CACHE (indexed)
- CACHE (va based): translated to a SYNCI, overkill on D-CACHE operations,
  but still much faster than a trap.
- mfc0/mtc0: the virtual COP0 registers for the guest are implemented as
  2-D array.
  [COP#][SEL] and this is mapped into the guest kernel address space @ VA 0x0.
  mfc0/mtc0 operations are transformed to load/stores.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-09 17:48:22 +02:00
Sanjay Lal
f5c236dd0a KVM/MIPS32: Routines to handle specific traps/exceptions while executing the guest.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:36 +02:00
Sanjay Lal
06d1838db0 KVM/MIPS32: Guest interrupt delivery.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:36 +02:00
Sanjay Lal
3c20ef5262 KVM/MIPS32: COP0 accesses profiling.
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:36 +02:00
Sanjay Lal
03a0331c8c KVM/MIPS32: Release notes and KVM module Makefile
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:35 +02:00
Sanjay Lal
858dd5d457 KVM/MIPS32: MMU/TLB operations for the Guest.
- Note that this file is statically linked with the rest of the host kernel (KSEG0). This is because kernel modules are
loaded into mapped space on MIPS and we want to make sure that we don't get any host kernel TLB faults while
manipulating TLBs.
- Virtual Guest TLBs are implemented as 64 entry array regardless of the number of host TLB entries.
- Shadow TLBs map Guest virtual addresses to Host physical addresses.

    - TLB miss handling details:
        Guest KSEG0 TLBMISS (0x40000000 – 0x60000000): Transparent to the Guest.
        Guest KSEG2/3 (0x60000000 – 0x80000000) & Guest UM TLBMISS (0x00000000 – 0x40000000)
            Lookup in Guest/Virtual TLB
            If an entry doesn’t match
                deliver appropriate TLBMISS LD/ST exception to the guest
            If entry does exist in the Guest TLB and is NOT Valid
                Deliver TLB invalid exception to the guest
            If entry does exist in the Guest TLB and is VALID
                Inject the TLB entry into the Shadow TLB

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:35 +02:00
Sanjay Lal
e685c689f3 KVM/MIPS32: Privileged instruction/target branch emulation.
- The Guest kernel is run in UM and privileged instructions cause a trap.
- If the instruction causing the trap is in a branch delay slot, the branch
  needs to be emulated to figure out the PC @ which the guest will resume
  execution.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:35 +02:00
Sanjay Lal
669e846e6c KVM/MIPS32: MIPS arch specific APIs for KVM
- Implements the arch specific APIs for KVM, some are stubs for MIPS
- kvm_mips_handle_exit(): Main 'C' distpatch routine for handling exceptions while in "Guest" mode.
- Also implements in-kernel timer interrupt support for the guest.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:35 +02:00
Sanjay Lal
b680f70fc1 KVM/MIPS32: Entry point for trampolining to the guest and trap handlers.
- __kvm_mips_vcpu_run: main entry point to enter guest, we save kernel context, load
  up guest context from and ERET to guest context.
- mips32_exception: L1 exception handler(s), save k0/k1 and jump to main handlers.
- mips32_GuestException: Generic exception handlers for exceptions/interrupts while in
  guest context.  Save guest context, restore some kernel context and jump to
  main 'C' handler: kvm_mips_handle_exit()

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:34 +02:00
Sanjay Lal
2235a54dea KVM/MIPS32: Infrastructure/build files.
- Add the KVM option to MIPS build files.
- Add default config files for KVM host/guest kernels.
- Change the link address for the Malta KVM Guest kernel to UM (0x40100000).
- Add KVM Kconfig file with KVM/MIPS specific options

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08 03:55:34 +02:00