Commit Graph

23 Commits

Author SHA1 Message Date
Marc Zyngier 5b560525ad ARM: hyp-stub: Fix Thumb-2 compilation
The assembler defaults to emiting the short form of ADR, leading
to an out-of-range immediate. Using the wide version solves this
issue.

Fixes: bc845e4fbb ("ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-20 12:58:53 +02:00
Marc Zyngier d9118c87d2 ARM: hyp-stub: Zero r0 on successful stub handling
We now return HVC_STUB_ERR when a stub hypercall fails, but we
leave whatever was in r0 on success. Zeroing it on return seems
like a good idea.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:36 -07:00
Marc Zyngier ecb5d61daa ARM: hyp-stub/KVM: Kill __hyp_get_vectors
Nobody is using __hyp_get_vectors anymore, so let's remove both
implementations (hyp-stub and KVM).

Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:34 -07:00
Marc Zyngier bc845e4fbb ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code
In order to restore HYP mode to its original condition, KVM currently
implements __kvm_hyp_reset(). As we're moving towards a hyp-stub
defined API, it becomes necessary to implement HVC_RESET_VECTORS.

This patch adds the HVC_RESET_VECTORS hypercall to the KVM init
code, which so far lacked any form of hypercall support.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:28 -07:00
Marc Zyngier 7d1bf4e057 ARM: hyp-stub: Implement HVC_RESET_VECTORS stub hypercall
Let's define a new stub hypercall that resets the HYP configuration
to its default: hyp-stub vectors, and MMU disabled.

Of course, for the hyp-stub itself, this is a trivial no-op.
Hypervisors will have a bit more work to do.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:27 -07:00
Marc Zyngier 4c70cf07ce ARM: hyp-stub: Define a return value for failed stub calls
Define a standard return value to be returned when a hyp stub
call fails.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:27 -07:00
Marc Zyngier 6b52f7bdb8 ARM: hyp-stub: Use r1 for the soft-restart address
It is not really obvious why the restart address should be in r3
when communicated to the hyp-stub. r1 should be perfectly adequate,
and consistent with the rest of the code.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:25 -07:00
Marc Zyngier 467f97b72b ARM: KVM: Convert KVM to use HVC_GET_VECTORS
The conversion of the HYP stub ABI to something similar to arm64
left the KVM code broken, as it doesn't know about the new
stub numbering. Let's move the various #defines to virt.h, and
let KVM use HVC_GET_VECTORS.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:24 -07:00
Russell King 9da5ac236d ARM: soft-reboot into same mode that we entered the kernel
When we soft-reboot (eg, kexec) from one kernel into the next, we need
to ensure that we enter the new kernel in the same processor mode as
when we were entered, so that (eg) the new kernel can install its own
hypervisor - the old kernel's hypervisor will have been overwritten.

In order to do this, we need to pass a flag to cpu_reset() so it knows
what to do, and we need to modify the kernel's own hypervisor stub to
allow it to handle a soft-reboot.

As we are always guaranteed to install our own hypervisor if we're
entered in HYP32 mode, and KVM will have moved itself out of the way
on kexec/normal reboot, we can assume that our hypervisor is in place
when we want to kexec, so changing our hypervisor API should not be a
problem.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:24 -07:00
Russell King 1342337bc8 ARM: hyp-stub: improve ABI
Improve the hyp-stub ABI to allow it to do more than just get/set the
vectors.  We follow the example in ARM64, where r0 is used as an opcode
with the other registers as an argument.

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:49:23 -07:00
Robin Murphy 1527eda3ab ARM: 8600/1: Enforce some NS-SVC initialisation
Since the non-secure copies of banked registers lack architecturally
defined reset values, there is no actual guarantee when entering in Hyp
from secure-only firmware that the Non-Secure PL1 state will look the
way that kernel entry (in particular the decompressor stub) expects.
So far, we've been getting away with it thanks to implementation details
of ARMv7 cores and/or bootloader behaviour, but for the sake of forwards
compatibility let's try to ensure that we have a minimally sane state
before dropping down into it.

Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-08-23 10:08:33 +01:00
Jean-Philippe Brucker e59941b9b3 ARM: 8527/1: virt: enable GICv3 system registers
ARMv8 introduces system registers for the Generic Interrupt Controllers
CPU and virtual interfaces.  When GICv3 is implemented, EL2 needs to
allow the kernel to use those registers, by changing the value of
ICC_HSRE.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-16 16:33:02 +00:00
Linus Torvalds 66bb0aa077 Here are the PPC and ARM changes for KVM, which I separated because
they had small conflicts (respectively within KVM documentation,
 and with 3.16-rc changes).  Since they were all within the subsystem,
 I took care of them.
 
 Stephen Rothwell reported some snags in PPC builds, but they are all
 fixed now; the latest linux-next report was clean.
 
 New features for ARM include:
 - KVM VGIC v2 emulation on GICv3 hardware
 - Big-Endian support for arm/arm64 (guest and host)
 - Debug Architecture support for arm64 (arm32 is on Christoffer's todo list)
 
 And for PPC:
 - Book3S: Good number of LE host fixes, enable HV on LE
 - Book3S HV: Add in-guest debug support
 
 This release drops support for KVM on the PPC440.  As a result, the
 PPC merge removes more lines than it adds. :)
 
 I also included an x86 change, since Davidlohr tied it to an independent
 bug report and the reporter quickly provided a Tested-by; there was no
 reason to wait for -rc2.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull second round of KVM changes from Paolo Bonzini:
 "Here are the PPC and ARM changes for KVM, which I separated because
  they had small conflicts (respectively within KVM documentation, and
  with 3.16-rc changes).  Since they were all within the subsystem, I
  took care of them.

  Stephen Rothwell reported some snags in PPC builds, but they are all
  fixed now; the latest linux-next report was clean.

  New features for ARM include:
   - KVM VGIC v2 emulation on GICv3 hardware
   - Big-Endian support for arm/arm64 (guest and host)
   - Debug Architecture support for arm64 (arm32 is on Christoffer's todo list)

  And for PPC:
   - Book3S: Good number of LE host fixes, enable HV on LE
   - Book3S HV: Add in-guest debug support

  This release drops support for KVM on the PPC440.  As a result, the
  PPC merge removes more lines than it adds.  :)

  I also included an x86 change, since Davidlohr tied it to an
  independent bug report and the reporter quickly provided a Tested-by;
  there was no reason to wait for -rc2"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (122 commits)
  KVM: Move more code under CONFIG_HAVE_KVM_IRQFD
  KVM: nVMX: fix "acknowledge interrupt on exit" when APICv is in use
  KVM: nVMX: Fix nested vmexit ack intr before load vmcs01
  KVM: PPC: Enable IRQFD support for the XICS interrupt controller
  KVM: Give IRQFD its own separate enabling Kconfig option
  KVM: Move irq notifier implementation into eventfd.c
  KVM: Move all accesses to kvm::irq_routing into irqchip.c
  KVM: irqchip: Provide and use accessors for irq routing table
  KVM: Don't keep reference to irq routing table in irqfd struct
  KVM: PPC: drop duplicate tracepoint
  arm64: KVM: fix 64bit CP15 VM access for 32bit guests
  KVM: arm64: GICv3: mandate page-aligned GICV region
  arm64: KVM: GICv3: move system register access to msr_s/mrs_s
  KVM: PPC: PR: Handle FSCR feature deselects
  KVM: PPC: HV: Remove generic instruction emulation
  KVM: PPC: BOOKEHV: rename e500hv_spr to bookehv_spr
  KVM: PPC: Remove DCR handling
  KVM: PPC: Expose helper functions for data/inst faults
  KVM: PPC: Separate loadstore emulation from priv emulation
  KVM: PPC: Handle magic page in kvmppc_ld/st
  ...
2014-08-07 11:35:30 -07:00
Russell King 6ebbf2ce43 ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+
ARMv6 and greater introduced a new instruction ("bx") which can be used
to return from function calls.  Recent CPUs perform better when the
"bx lr" instruction is used rather than the "mov pc, lr" instruction,
and this sequence is strongly recommended to be used by the ARM
architecture manual (section A.4.1.1).

We provide a new macro "ret" with all its variants for the condition
code which will resolve to the appropriate instruction.

Rather than doing this piecemeal, and miss some instances, change all
the "mov pc" instances to use the new macro, with the exception of
the "movs" instruction and the kprobes code.  This allows us to detect
the "mov pc, lr" case and fix it up - and also gives us the possibility
of deploying this for other registers depending on the CPU selection.

Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S
Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385
Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M
Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18 12:29:04 +01:00
Li Liu af92394efc ARM: virt: fix wrong HSCTLR.EE bit setting
HSCTLR.EE is defined as bit[25] referring to arm manual
DDI0606C.b(p1590).

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Li Liu <john.liuli@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11 04:57:38 -07:00
Mark Rutland b60d5db690 ARM: 7786/1: hyp: fix macro parameterisation
Currently, compare_cpu_mode_with_primary uses a mixture of macro
arguments and hardcoded registers, and does so incorrectly, as it
stores (__boot_cpu_mode_offset | BOOT_CPU_MODE_MISMATCH) to
(__boot_cpu_mode + &__boot_cpu_mode_offset), which could corrupt an
arbitrary portion of memory.

This patch fixes up compare_cpu_mode_with_primary to use the macro
arguments, correctly updating __boot_cpu_mode.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-22 14:30:34 +01:00
Marc Zyngier 3f71be237c ARM: arch_timer: stop virtual timer when booted in HYP mode
When booting the kernel, a bootloader could have left the virtual
timer ticking away, potentially generating interrupts. This could
be troublesome if the user of the virtual timer is not careful
when enabling the interrupt.

In order to avoid any surprise, stop the virtual timer from
interrupting us when booted in HYP mode, as we'll use the physical
timer in this case.

Reported-by: Giridhar Maruthy <giridhar.m@samsung.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Martin <dave.martin@linaro.org>
2013-06-07 10:20:29 +01:00
Marc Zyngier 0af0b189ab ARM: hyp: initialize CNTVOFF to zero
In order to be able to use the virtual counter in a safe way,
make sure it is initialized to zero before dropping to SVC.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Martin <dave.martin@linaro.org>
2013-06-07 10:20:27 +01:00
Marc Zyngier d01723479e ARM: virt: simplify __hyp_stub_install epilog
__hyp_stub_install duplicates quite a bit of safe_svcmode_maskall
by forcing the CPU back to SVC. This is unnecessary, as
safe_svcmode_maskall is called just after.

Furthermore, the way we build SPSR_hyp is buggy as we fail to mask
the interrupts, leading to interesting behaviours on TC2 + UEFI.

The fix is to simply remove this code and rely on safe_svcmode_maskall
to do the right thing.

Cc: <stable@vger.kernel.org>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Reported-by: Harry Liebel <harry.liebel@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-01-10 21:08:55 +00:00
Dave Martin a4a12e008e ARM: virt: Avoid bx instruction for compatibility with <=ARMv4
Non-T variants of ARMv4 do not support the bx instruction.

However, __hyp_stub_install is always called from the same
instruction set used to build the bulk of the kernel, so bx should
not be necessary.

This patch uses the traditional "mov pc" instead of bx.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
[will: fixed up remaining bx instruction]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-01-10 21:08:22 +00:00
Marc Zyngier 8ec58be9f3 ARM: virt: arch_timers: enable access to physical timers
If booting in HYP mode, it makes sense to enable the use of the
physical timers, so the kernel can use them directly.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-09-19 08:32:54 +01:00
Dave Martin 424e5994e6 ARM: zImage/virt: hyp mode entry support for the zImage loader
The zImage loader needs to turn on the MMU in order to take
advantage of caching while decompressing the zImage.  Running this
in hyp mode would require the LPAE pagetable format to be
supported; to avoid this complexity, this patch switches out of hyp
mode, and returns back to hyp mode just before booting the kernel.

This implementation assumes that the Hyp mode view of memory and the
PL1 view of memory are coherent, providing that the MMU and caches
are off in both, as required by the boot protocol.  The zImage
decompression code must drain the write buffer on completion anyway, and
entry into Hyp mode should flush any prefetch buffer, avoiding hazards
associated with local write buffers and the pipeline.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-09-19 08:32:50 +01:00
Dave Martin 80c59dafb1 ARM: virt: allow the kernel to be entered in HYP mode
This patch does two things:

  * Ensure that asynchronous aborts are masked at kernel entry.
    The bootloader should be masking these anyway, but this reduces
    the damage window just in case it doesn't.

  * Enter svc mode via exception return to ensure that CPU state is
    properly serialised.  This does not matter when switching from
    an ordinary privileged mode ("PL1" modes in ARMv7-AR rev C
    parlance), but it potentially does matter when switching from a
    another privileged mode such as hyp mode.

This should allow the kernel to boot safely either from svc mode or
hyp mode, even if no support for use of the ARM Virtualization
Extensions is built into the kernel.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-09-19 08:32:50 +01:00