Commit Graph

17 Commits

Author SHA1 Message Date
Marc Zyngier e656a1f91e arm: KVM: Drop unreachable HYP abort handlers
Both data and prefetch aborts occuring in HYP lead to a well
deserved panic. Let's get rid of these silly handlers.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00
Marc Zyngier 5d7bcf7d64 arm: KVM: Inject a Virtual Abort if it was pending
If we have caught an Abort whilst exiting, we've tagged the
exit code with the pending information. In that case, let's
re-inject the error into the guest, after having adjusted
the PC if required.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00
Marc Zyngier cc325cfc37 arm: KVM: Add HYP async abort handler
If we've exited the guest because it has triggered an asynchronous
abort, a possible course of action is to let it know it screwed up
by giving it a Virtual Abort to chew on.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00
Marc Zyngier f9e515eeb1 ARM: KVM: Remove handling of ARM_EXCEPTION_DATA/PREF_ABORT
These are now handled as a panic, so there is little point in
keeping them around.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:15 +00:00
Marc Zyngier 311b5b363c ARM: KVM: Remove unused hyp_pc field
This field was never populated, and the panic code already
does something similar. Delete the related code.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:15 +00:00
Amit Tomar b19e6892a9 KVM: arm/arm64: Count guest exit due to various reasons
It would add guest exit statistics to debugfs, this can be helpful
while measuring KVM performance.

  [ Renamed some of the field names - Christoffer ]

Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:00 +00:00
Andre Przywara 924de80db9 ARM: KVM: extend WFI tracepoint to differentiate between wfi and wfe
Currently the trace printk talks about "wfi" only, though the trace
point triggers both on wfi and wfe traps.
Add a parameter to differentiate between the two.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-15 13:12:27 +01:00
Christoffer Dall 05e0127f9e arm/arm64: KVM: Complete WFI/WFE instructions
The architecture specifies that when the processor wakes up from a WFE
or WFI instruction, the instruction is considered complete, however we
currrently return to EL1 (or EL0) at the WFI/WFE instruction itself.

While most guests may not be affected by this because their local
exception handler performs an exception returning setting the event bit
or with an interrupt pending, some guests like UEFI will get wedged due
this little mishap.

Simply skip the instruction when we have completed the emulation.

Cc: <stable@vger.kernel.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-08-29 11:53:53 +02:00
Anup Patel e8e7fcc5e2 ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible
Currently, the kvm_psci_call() returns 'true' or 'false' based on whether
the PSCI function call was handled successfully or not. This does not help
us emulate system-level PSCI functions where the actual emulation work will
be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI
functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET.

This patch updates kvm_psci_call() to return three types of values:
1) > 0 (success)
2) = 0 (success but exit to user space)
3) < 0 (errors)

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-04-30 04:18:57 -07:00
Sachin Kamat 61466710de KVM: ARM: Remove duplicate include
trace.h was included twice. Remove duplicate inclusion.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-01-08 13:54:00 -08:00
Christoffer Dall 86ed81aa2e KVM: ARM: Update comments for kvm_handle_wfi
Update comments to reflect what is really going on and add the TWE bit
to the comments in kvm_arm.h.

Also renames the function to kvm_handle_wfx like is done on arm64 for
consistency and uber-correctness.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-17 15:26:50 -07:00
Marc Zyngier 58d5ec8f8e ARM: KVM: Yield CPU when vcpu executes a WFE
On an (even slightly) oversubscribed system, spinlocks are quickly
becoming a bottleneck, as some vcpus are spinning, waiting for a
lock to be released, while the vcpu holding the lock may not be
running at all.

This creates contention, and the observed slowdown is 40x for
hackbench. No, this isn't a typo.

The solution is to trap blocking WFEs and tell KVM that we're
now spinning. This ensures that other vpus will get a scheduling
boost, allowing the lock to be released more quickly. Also, using
CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance
when the VM is severely overcommited.

Quick test to estimate the performance: hackbench 1 process 1000

2xA15 host (baseline):	1.843s

2xA15 guest w/o patch:	2.083s
4xA15 guest w/o patch:	80.212s
8xA15 guest w/o patch:	Could not be bothered to find out

2xA15 guest w/ patch:	2.102s
4xA15 guest w/ patch:	3.205s
8xA15 guest w/ patch:	6.887s

So we go from a 40x degradation to 1.5x in the 2x overcommit case,
which is vaguely more acceptable.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-17 15:26:50 -07:00
Dave P Martin 24a7f67575 ARM: KVM: Don't handle PSCI calls via SMC
Currently, kvmtool unconditionally declares that HVC should be used
to call PSCI, so the function numbers in the DT tell the guest
nothing about the function ID namespace or calling convention for
SMC.

We already assume that the guest will examine and honour the DT,
since there is no way it could possibly guess the KVM-specific PSCI
function IDs otherwise.  So let's not encourage guests to violate
what's specified in the DT by using SMC to make the call.

[ Modified to apply to top of kvm/arm tree - Christoffer ]

Signed-off-by: Dave P Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-06-26 10:50:02 -07:00
Linus Torvalds 8546dc1d4b Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
 "The major items included in here are:

   - MCPM, multi-cluster power management, part of the infrastructure
     required for ARMs big.LITTLE support.

   - A rework of the ARM KVM code to allow re-use by ARM64.

   - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes
     of that stuff for arch/arm

   - Preparatory patches for Cortex-M3 support from Uwe Kleine-König.

  There is also a set of three patches in here from Hugh/Catalin to
  address freeing of inappropriate page tables on LPAE.  You already
  have these from akpm, but they were already part of my tree at the
  time he sent them, so unfortunately they'll end up with duplicate
  commits"

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits)
  ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE()
  ARM: IMX: remove unnecessary use of IS_ERR_VALUE()
  ARM: OMAP: use consistent error checking
  ARM: cleanup: OMAP hwmod error checking
  ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels
  ARM: 7700/2: Make cpu_init() notrace
  ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE
  ARM: 7701/1: mm: Allow arch code to control the user page table ceiling
  ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum()
  ARM: mcpm: provide an interface to set the SMP ops at run time
  ARM: mcpm: generic SMP secondary bringup and hotplug support
  ARM: mcpm_head.S: vlock-based first man election
  ARM: mcpm: Add baremetal voting mutexes
  ARM: mcpm: introduce helpers for platform coherency exit/setup
  ARM: mcpm: introduce the CPU/cluster power API
  ARM: multi-cluster PM: secondary kernel entry code
  ARM: cacheflush: add synchronization helpers for mixed cache state accesses
  ARM: cpu hotplug: remove majority of cache flushing from platforms
  ARM: smp: flush L1 cache in cpu_die()
  ARM: tegra: remove tegra specific cpu_disable()
  ...
2013-05-03 09:13:19 -07:00
Marc Zyngier 6190920a35 ARM: KVM: move kvm_handle_wfi to handle_exit.c
It has little to do in emulate.c these days...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:45 -08:00
Christoffer Dall c088f8f008 KVM: ARM: Reintroduce trace_kvm_hvc
This one got lost in the move to handle_exit, so let's reintroduce it
using an accessor to the immediate value field like the other ones.

Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:43 -08:00
Marc Zyngier 3414bbfff9 ARM: KVM: move exit handler selection to a separate file
The exit handler selection code cannot be shared with arm64
(two different modes, more exception classes...).

Move it to a separate file (handle_exit.c).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:43 -08:00