Commit Graph

28 Commits

Author SHA1 Message Date
Christoffer Dall b856a59141 arm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu
When userspace resets the vcpu using KVM_ARM_VCPU_INIT, we should also
reset the HCR, because we now modify the HCR dynamically to
enable/disable trapping of guest accesses to the VM registers.

This is crucial for reboot of VMs working since otherwise we will not be
doing the necessary cache maintenance operations when faulting in pages
with the guest MMU off.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-13 14:15:26 +01:00
Christoffer Dall 0496daa5cf arm/arm64: KVM: Report correct FSC for unsupported fault types
When we catch something that's not a permission fault or a translation
fault, we log the unsupported FSC in the kernel log, but we were masking
off the bottom bits of the FSC which was not very helpful.

Also correctly report the FSC for data and instruction faults rather
than telling people it was a DFCS, which doesn't exist in the ARM ARM.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-09-26 14:39:45 +02:00
Victor Kamensky 27f194fd36 ARM: KVM: MMIO support BE host running LE code
In case of status register E bit is not set (LE mode) and host runs in
BE mode we need byteswap data, so read/write is emulated correctly.

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11 04:57:40 -07:00
Paolo Bonzini ede5822242 A handful of fixes for KVM/arm64:
- A couple a basic fixes for running BE guests on a LE host
 - A performance improvement for overcommitted VMs (same as the equivalent
   patch for ARM)
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Merge tag 'kvm-arm64/for-3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into kvm-next

A handful of fixes for KVM/arm64:

- A couple a basic fixes for running BE guests on a LE host
- A performance improvement for overcommitted VMs (same as the equivalent
  patch for ARM)

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Conflicts:
	arch/arm/include/asm/kvm_emulate.h
	arch/arm64/include/asm/kvm_emulate.h
2013-11-11 12:05:20 +01:00
Marc Zyngier ce94fe93d5 arm/arm64: KVM: PSCI: propagate caller endianness to the incoming vcpu
When booting a vcpu using PSCI, make sure we start it with the
endianness of the caller. Otherwise, secondaries can be pretty
unhappy to execute a BE kernel in LE mode...

This conforms to PSCI spec Rev B, 5.13.3.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-11-07 19:09:08 +00:00
Marc Zyngier 6d89d2d9b5 arm/arm64: KVM: MMIO support for BE guest
Do the necessary byteswap when host and guest have different
views of the universe. Actually, the only case we need to take
care of is when the guest is BE. All the other cases are naturally
handled.

Also be careful about endianness when the data is being memcopy-ed
from/to the run buffer.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-11-07 19:09:04 +00:00
Marc Zyngier 79c648806f arm/arm64: KVM: PSCI: use MPIDR to identify a target CPU
The KVM PSCI code blindly assumes that vcpu_id and MPIDR are
the same thing. This is true when vcpus are organized as a flat
topology, but is wrong when trying to emulate any other topology
(such as A15 clusters).

Change the KVM PSCI CPU_ON code to look at the MPIDR instead
of the vcpu_id to pick a target CPU.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-22 08:00:06 -07:00
Marc Zyngier 8734f16fb2 ARM: KVM: don't special case PC when doing an MMIO
Admitedly, reading a MMIO register to load PC is very weird.
Writing PC to a MMIO register is probably even worse. But
the architecture doesn't forbid any of these, and injecting
a Prefetch Abort is the wrong thing to do anyway.

Remove this check altogether, and let the adventurous guest
wander into LaLaLand if they feel compelled to do so.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-06-26 10:50:03 -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 c599756329 ARM: KVM: move kvm_condition_valid to emulate.c
This is really hardware emulation, and as such it better be with
its little friends.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:43 -08:00
Marc Zyngier 52d1dba933 ARM: KVM: abstract HSR_EC_IABT away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:43 -08:00
Marc Zyngier 1cc287dd08 ARM: KVM: abstract fault decoding away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:43 -08:00
Marc Zyngier 4926d445eb ARM: KVM: abstract exception class decoding away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:43 -08:00
Marc Zyngier 23b415d61a ARM: KVM: abstract IL decoding away
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
Marc Zyngier a7123377e7 ARM: KVM: abstract SAS decoding away
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
Marc Zyngier b37670b0f3 ARM: KVM: abstract S1TW abort detection away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:42 -08:00
Marc Zyngier 78abfcde49 ARM: KVM: abstract (and fix) external abort detection away
Bit 8 is cache maintenance, bit 9 is external abort.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:42 -08:00
Marc Zyngier d0adf747c9 ARM: KVM: abstract HSR_SRT_{MASK,SHIFT} away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:42 -08:00
Marc Zyngier 7c511b881f ARM: KVM: abstract HSR_SSE away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:42 -08:00
Marc Zyngier 023cc96406 ARM: KVM: abstract HSR_WNR away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:42 -08:00
Marc Zyngier 4a1df28ac0 ARM: KVM: abstract HSR_ISV away
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06 15:48:42 -08:00
Marc Zyngier 7393b59917 ARM: KVM: abstract fault register accesses
Instead of directly accessing the fault registers, use proper accessors
so the core code can be shared.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:42 -08:00
Marc Zyngier db730d8d62 ARM: KVM: convert GP registers from u32 to unsigned long
On 32bit ARM, unsigned long is guaranteed to be a 32bit quantity.
On 64bit ARM, it is a 64bit quantity.

In order to be able to share code between the two architectures,
convert the registers to be unsigned long, so the core code can
be oblivious of the change.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06 15:48:42 -08:00
Marc Zyngier aa024c2f35 KVM: ARM: Power State Coordination Interface implementation
Implement the PSCI specification (ARM DEN 0022A) to control
virtual CPUs being "powered" on or off.

PSCI/KVM is detected using the KVM_CAP_ARM_PSCI capability.

A virtual CPU can now be initialized in a "powered off" state,
using the KVM_ARM_VCPU_POWER_OFF feature flag.

The guest can use either SMC or HVC to execute a PSCI function.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:18 -05:00
Christoffer Dall 45e96ea6b3 KVM: ARM: Handle I/O aborts
When the guest accesses I/O memory this will create data abort
exceptions and they are handled by decoding the HSR information
(physical address, read/write, length, register) and forwarding reads
and writes to QEMU which performs the device emulation.

Certain classes of load/store operations do not support the syndrome
information provided in the HSR.  We don't support decoding these (patches
are available elsewhere), so we report an error to user space in this case.

This requires changing the general flow somewhat since new calls to run
the VCPU must check if there's a pending MMIO load and perform the write
after userspace has made the data available.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:17 -05:00
Christoffer Dall 5b3e5e5bf2 KVM: ARM: Emulation framework and CP15 emulation
Adds a new important function in the main KVM/ARM code called
handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns
from guest execution. This function examines the Hyp-Syndrome-Register
(HSR), which contains information telling KVM what caused the exit from
the guest.

Some of the reasons for an exit are CP15 accesses, which are
not allowed from the guest and this commit handles these exits by
emulating the intended operation in software and skipping the guest
instruction.

Minor notes about the coproc register reset:
1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our
   table, at cost of 4 bytes per vcpu.

2) Added comments on the table indicating how we handle each register, for
   simplicity of understanding.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:13 -05:00
Christoffer Dall 749cf76c5a KVM: ARM: Initial skeleton to compile KVM support
Targets KVM support for Cortex A-15 processors.

Contains all the framework components, make files, header files, some
tracing functionality, and basic user space API.

Only supported core is Cortex-A15 for now.

Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23 13:29:10 -05:00