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>
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>
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
...
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>
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>
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>
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>
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>
__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>
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>
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>
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>
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>
Robin Murphy