Until KVM has full SVE support, guests must not be allowed to
execute SVE instructions.
This patch enables the necessary traps, and also ensures that the
traps are disabled again on exit from the guest so that the host
can still use SVE if it wants to.
On guest exit, high bits of the SVE Zn registers may have been
clobbered as a side-effect the execution of FPSIMD instructions in
the guest. The existing KVM host FPSIMD restore code is not
sufficient to restore these bits, so this patch explicitly marks
the CPU as not containing cached vector state for any task, thus
forcing a reload on the next return to userspace. This is an
interim measure, in advance of adding full SVE awareness to KVM.
This marking of cached vector state in the CPU as invalid is done
using __this_cpu_write(fpsimd_last_state, NULL) in fpsimd.c. Due
to the repeated use of this rather obscure operation, it makes
sense to factor it out as a separate helper with a clearer name.
This patch factors it out as fpsimd_flush_cpu_state(), and ports
all callers to use it.
As a side effect of this refactoring, a this_cpu_write() in
fpsimd_cpu_pm_notifier() is changed to __this_cpu_write(). This
should be fine, since cpu_pm_enter() is supposed to be called only
with interrupts disabled.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, a guest kernel sees the true CPU feature registers
(ID_*_EL1) when it reads them using MRS instructions. This means
that the guest may observe features that are present in the
hardware but the host doesn't understand or doesn't provide support
for. A guest may legimitately try to use such a feature as per the
architecture, but use of the feature may trap instead of working
normally, triggering undef injection into the guest.
This is not a problem for the host, but the guest may go wrong when
running on newer hardware than the host knows about.
This patch hides from guest VMs any AArch64-specific CPU features
that the host doesn't support, by exposing to the guest the
sanitised versions of the registers computed by the cpufeatures
framework, instead of the true hardware registers. To achieve
this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation
code is added to KVM to report the sanitised versions of the
affected registers in response to MRS and register reads from
userspace.
The affected registers are removed from invariant_sys_regs[] (since
the invariant_sys_regs handling is no longer quite correct for
them) and added to sys_reg_desgs[], with appropriate access(),
get_user() and set_user() methods. No runtime vcpu storage is
allocated for the registers: instead, they are read on demand from
the cpufeatures framework. This may need modification in the
future if there is a need for userspace to customise the features
visible to the guest.
Attempts by userspace to write the registers are handled similarly
to the current invariant_sys_regs handling: writes are permitted,
but only if they don't attempt to change the value. This is
sufficient to support VM snapshot/restore from userspace.
Because of the additional registers, restoring a VM on an older
kernel may not work unless userspace knows how to handle the extra
VM registers exposed to the KVM user ABI by this patch.
Under the principle of least damage, this patch makes no attempt to
handle any of the other registers currently in
invariant_sys_regs[], or to emulate registers for AArch32: however,
these could be handled in a similar way in future, as necessary.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
SPE is part of the v8.2 architecture, so move its system register and
field definitions into sysreg.h and the new PSB barrier into barrier.h
Finally, move KVM over to using the generic definitions so that it
doesn't have to open-code its own versions.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Since the pte handling for hardware AF/DBM works even when the hardware
feature is not present, make the pte accessors implementation permanent
and remove the corresponding #ifdefs. The Kconfig option is kept as it
can still be used to disable the feature at the hardware level.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In order to start handling guest access to GICv3 system registers,
let's add a hook that will get called when we trap a system register
access. This is gated by a new static key (vgic_v3_cpuif_trap).
Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
When KVM panics, it hurridly restores the host context and parachutes
into the host's panic() code. At some point panic() touches the physical
timer/counter. Unless we are an arm64 system with VHE, this traps back
to EL2. If we're lucky, we panic again.
Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the
guest registers and disables the traps for the host.
Fixes: 53fd5b6487 ("arm64: KVM: Add panic handling")
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
We like living dangerously. Nothing explicitely forbids stack-protector
to be used in the EL2 code, while distributions routinely compile their
kernel with it. We're just lucky that no code actually triggers the
instrumentation.
Let's not try our luck for much longer, and disable stack-protector
for code living at EL2.
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
support; virtual interrupt controller performance improvements; support
for userspace virtual interrupt controller (slower, but necessary for
KVM on the weird Broadcom SoCs used by the Raspberry Pi 3)
* MIPS: basic support for hardware virtualization (ImgTec
P5600/P6600/I6400 and Cavium Octeon III)
* PPC: in-kernel acceleration for VFIO
* s390: support for guests without storage keys; adapter interruption
suppression
* x86: usual range of nVMX improvements, notably nested EPT support for
accessed and dirty bits; emulation of CPL3 CPUID faulting
* generic: first part of VCPU thread request API; kvm_stat improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- HYP mode stub supports kexec/kdump on 32-bit
- improved PMU support
- virtual interrupt controller performance improvements
- support for userspace virtual interrupt controller (slower, but
necessary for KVM on the weird Broadcom SoCs used by the Raspberry
Pi 3)
MIPS:
- basic support for hardware virtualization (ImgTec P5600/P6600/I6400
and Cavium Octeon III)
PPC:
- in-kernel acceleration for VFIO
s390:
- support for guests without storage keys
- adapter interruption suppression
x86:
- usual range of nVMX improvements, notably nested EPT support for
accessed and dirty bits
- emulation of CPL3 CPUID faulting
generic:
- first part of VCPU thread request API
- kvm_stat improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
kvm: nVMX: Don't validate disabled secondary controls
KVM: put back #ifndef CONFIG_S390 around kvm_vcpu_kick
Revert "KVM: Support vCPU-based gfn->hva cache"
tools/kvm: fix top level makefile
KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
KVM: Documentation: remove VM mmap documentation
kvm: nVMX: Remove superfluous VMX instruction fault checks
KVM: x86: fix emulation of RSM and IRET instructions
KVM: mark requests that need synchronization
KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
KVM: add explicit barrier to kvm_vcpu_kick
KVM: perform a wake_up in kvm_make_all_cpus_request
KVM: mark requests that do not need a wakeup
KVM: remove #ifndef CONFIG_S390 around kvm_vcpu_wake_up
KVM: x86: always use kvm_make_request instead of set_bit
KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
s390: kvm: Cpu model support for msa6, msa7 and msa8
KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
kvm: better MWAIT emulation for guests
KVM: x86: virtualize cpuid faulting
...
We are now able to use the hyp stub to reset HYP mode. Time to
kiss __kvm_hyp_reset goodbye, and use __hyp_reset_vectors.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
We now have a full hyp-stub implementation in the KVM init code,
but the main KVM code only supports HVC_GET_VECTORS, which is not
enough.
Instead of reinventing the wheel, let's reuse the init implementation
by branching to the idmap page when called with a hyp-stub hypercall.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
At the moment, we only save/restore lr if on VHE, as we rely only
the EL1 code to have preserved it in the non-VHE case.
As we're about to get rid of the latter, let's move the save/restore
code to the do_el2_call macro, unifying both code paths.
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>
A VPIPT I-cache has two main properties:
1. Lines allocated into the cache are tagged by VMID and a lookup can
only hit lines that were allocated with the current VMID.
2. I-cache invalidation from EL1/0 only invalidates lines that match the
current VMID of the CPU doing the invalidation.
This can cause issues with non-VHE configurations, where the host runs
at EL1 and wants to invalidate I-cache entries for a guest running with
a different VMID. VHE is not affected, because the host runs at EL2 and
I-cache invalidation applies as expected.
This patch solves the problem by invalidating the I-cache when unmapping
a page at stage 2 on a system with a VPIPT I-cache but not running with
VHE enabled. Hopefully this is an obscure enough configuration that the
overhead isn't anything to worry about, although it does mean that the
by-range I-cache invalidation currently performed when mapping at stage
2 can be elided on such systems, because the I-cache will be clean for
the guest VMID following a rollover event.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When invalidating guest TLBs, special care must be taken to
actually shoot the guest TLBs and not the host ones if we're
running on a VHE system. This is controlled by the HCR_EL2.TGE
bit, which we forget to clear before invalidating TLBs.
Address the issue by introducing two wrappers (__tlb_switch_to_guest
and __tlb_switch_to_host) that take care of both the VTTBR_EL2
and HCR_EL2.TGE switching.
Reported-by: Tomasz Nowicki <tnowicki@caviumnetworks.com>
Tested-by: Tomasz Nowicki <tnowicki@caviumnetworks.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The SPE buffer is virtually addressed, using the page tables of the CPU
MMU. Unusually, this means that the EL0/1 page table may be live whilst
we're executing at EL2 on non-VHE configurations. When VHE is in use,
we can use the same property to profile the guest behind its back.
This patch adds the relevant disabling and flushing code to KVM so that
the host can make use of SPE without corrupting guest memory, and any
attempts by a guest to use SPE will result in a trap.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Refactor the KVM code to use the __tlbi macros, which will allow an errata
workaround that repeats tlbi dsb sequences to only change one location.
This is not intended to change the generated assembly and comparing before
and after vmlinux objdump shows no functional changes.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
- struct thread_info moved off-stack (also touching
include/linux/thread_info.h and include/linux/restart_block.h)
- cpus_have_cap() reworked to avoid __builtin_constant_p() for static
key use (also touching drivers/irqchip/irq-gic-v3.c)
- Uprobes support (currently only for native 64-bit tasks)
- Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1
switching to a reserved page table
- CPU capacity information passing via DT or sysfs (used by the
scheduler)
- Support for systems without FP/SIMD (IOW, kernel avoids touching these
registers; there is no soft-float ABI, nor kernel emulation for
AArch64 FP/SIMD)
- Handling of hardware watchpoint with unaligned addresses, varied
lengths and offsets from base
- Use of the page table contiguous hint for kernel mappings
- Hugetlb fixes for sizes involving the contiguous hint
- Remove unnecessary I-cache invalidation in flush_cache_range()
- CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1)
- Boot-time checks for writable+executable kernel mappings
- Simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart
and make the arm64 kernel headers self-consistent (Xen headers patch
merged separately)
- Workaround for broken .inst support in certain binutils versions
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- struct thread_info moved off-stack (also touching
include/linux/thread_info.h and include/linux/restart_block.h)
- cpus_have_cap() reworked to avoid __builtin_constant_p() for static
key use (also touching drivers/irqchip/irq-gic-v3.c)
- uprobes support (currently only for native 64-bit tasks)
- Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1
switching to a reserved page table
- CPU capacity information passing via DT or sysfs (used by the
scheduler)
- support for systems without FP/SIMD (IOW, kernel avoids touching
these registers; there is no soft-float ABI, nor kernel emulation for
AArch64 FP/SIMD)
- handling of hardware watchpoint with unaligned addresses, varied
lengths and offsets from base
- use of the page table contiguous hint for kernel mappings
- hugetlb fixes for sizes involving the contiguous hint
- remove unnecessary I-cache invalidation in flush_cache_range()
- CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1)
- boot-time checks for writable+executable kernel mappings
- simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart
and make the arm64 kernel headers self-consistent (Xen headers patch
merged separately)
- Workaround for broken .inst support in certain binutils versions
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (60 commits)
arm64: Disable PAN on uaccess_enable()
arm64: Work around broken .inst when defective gas is detected
arm64: Add detection code for broken .inst support in binutils
arm64: Remove reference to asm/opcodes.h
arm64: Get rid of asm/opcodes.h
arm64: smp: Prevent raw_smp_processor_id() recursion
arm64: head.S: Fix CNTHCTL_EL2 access on VHE system
arm64: Remove I-cache invalidation from flush_cache_range()
arm64: Enable HIBERNATION in defconfig
arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN
arm64: xen: Enable user access before a privcmd hvc call
arm64: Handle faults caused by inadvertent user access with PAN enabled
arm64: Disable TTBR0_EL1 during normal kernel execution
arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1
arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro
arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
arm64: Update the synchronous external abort fault description
selftests: arm64: add test for unaligned/inexact watchpoint handling
arm64: Allow hw watchpoint of length 3,5,6 and 7
arm64: hw_breakpoint: Handle inexact watchpoint addresses
...
The ARMv8 architecture allows the cycle counter to be configured
by setting PMSELR_EL0.SEL==0x1f and then accessing PMXEVTYPER_EL0,
hence accessing PMCCFILTR_EL0. But it disallows the use of
PMSELR_EL0.SEL==0x1f to access the cycle counter itself through
PMXEVCNTR_EL0.
Linux itself doesn't violate this rule, but we may end up with
PMSELR_EL0.SEL being set to 0x1f when we enter a guest. If that
guest accesses PMXEVCNTR_EL0, the access may UNDEF at EL1,
despite the guest not having done anything wrong.
In order to avoid this unfortunate course of events (haha!), let's
sanitize PMSELR_EL0 on guest entry. This ensures that the guest
won't explode unexpectedly.
Cc: stable@vger.kernel.org #4.6+
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The arm64 kernel assumes that FP/ASIMD units are always present
and accesses the FP/ASIMD specific registers unconditionally. This
could cause problems when they are absent. This patch adds the
support for kernel handling systems without FP/ASIMD by skipping the
register access within the kernel. For kvm, we trap the accesses
to FP/ASIMD and inject an undefined instruction exception to the VM.
The callers of the exported kernel_neon_begin_partial() should
make sure that the FP/ASIMD is supported.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: add comment on the ARM64_HAS_NO_FPSIMD conflict and the new location]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Architecturally, TLBs are private to the (physical) CPU they're
associated with. But when multiple vcpus from the same VM are
being multiplexed on the same CPU, the TLBs are not private
to the vcpus (and are actually shared across the VMID).
Let's consider the following scenario:
- vcpu-0 maps PA to VA
- vcpu-1 maps PA' to VA
If run on the same physical CPU, vcpu-1 can hit TLB entries generated
by vcpu-0 accesses, and access the wrong physical page.
The solution to this is to keep a per-VM map of which vcpu ran last
on each given physical CPU, and invalidate local TLBs when switching
to a different vcpu from the same VM.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
So we can reuse the code under arch/arm
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Since we are going to share vgic-v3 save/restore code with ARM keep
arch specific accessors separately.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Currently GIC backend is selected via alternative framework and this
is fine. We are going to introduce vgic-v3 to 32-bit world and there
we don't have patching framework in hand, so we can either check
support for GICv3 every time we need to choose which backend to use or
try to optimise it by using static keys. The later looks quite
promising because we can share logic involved in selecting GIC backend
between architectures if both uses static keys.
This patch moves arm64 from alternative to static keys framework for
selecting GIC backend. For that we embed static key into vgic_global
and enable the key during vgic initialisation based on what has
already been exposed by the host GIC driver.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
If, when proxying a GICV access at EL2, we detect that the guest is
doing something silly, report an EL1 SError instead ofgnoring the
access.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
If EL1 generates an asynchronous abort and then traps into EL2
before the abort has been delivered, we may end-up with the
abort firing at the worse possible place: on the host.
In order to avoid this, it is necessary to take the abort at EL2,
by clearing the PSTATE.A bit. In order to survive this abort,
we do it at a point where we're in a known state with respect
to the world switch, and handle the resulting exception,
overloading the exit code in the process.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
As we now have some basic handling to EL1-triggered aborts, we can
actually report them to KVM.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The HCR_EL2.VSE bit is used to signal an SError to a guest, and has
the peculiar feature of getting cleared when the guest has taken
the abort (this is the only bit that behaves as such in this register).
This means that if we signal such an abort, we must leave it
in the guest context until it disappears from HCR_EL2, and at which
point it must be cleared from the context. This is achieved by
reading back from HCR_EL2 until the guest takes the fault.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
In order to efficiently perform the GICV access on behalf of the
guest, we need to be able to avoid going back all the way to
the host kernel.
For this, we introduce a new hook in the world switch code,
conveniently placed just after populating the fault info.
At that point, we only have saved/restored the GP registers,
and we can quickly perform all the required checks (data abort,
translation fault, valid faulting syndrome, not an external
abort, not a PTW).
Coming back from the emulation code, we need to skip the emulated
instruction. This involves an additional bit of save/restore in
order to be able to access the guest's PC (and possibly CPSR if
this is a 32bit guest).
At this stage, no emulation code is provided.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
SCTLR_EL2.SPAN bit controls what happens with the PSTATE.PAN bit on an
exception. However, this bit has no effect on the PSTATE.PAN when
HCR_EL2.E2H or HCR_EL2.TGE is unset. Thus when VHE is used and
exception taken from a guest PSTATE.PAN bit left unchanged and we
continue with a value guest has set.
To address that always reset PSTATE.PAN on entry from EL1.
Fixes: 1f364c8c48 ("arm64: VHE: Add support for running Linux in EL2 mode")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When rewriting the assembly code to C code, it was useful to have
exported aliases or static functions so that we could keep the existing
common C code unmodified and at the same time rewrite arm64 from
assembly to C code, and later do the arm part.
Now when both are done, we really don't need this level of indirection
anymore, and it's time to save a few lines and brain cells.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We are doing an unnecessary stack push/pop operation when restoring
the guest registers x0-x18 in __guest_enter(). This patch saves the
two instructions by using x18 as a base register. No need to store
the vcpu context pointer in stack because it is redundant, the same
information is available in tpidr_el2. The function __guest_exit()
calling convention is slightly modified, caller only pushes the regs
x0-x1 to stack instead of regs x0-x3.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We already have a workaround for Cortex-A57 erratum #852523,
but Cortex-A72 r0p0 to r0p2 do suffer from the same issue
(known as erratum #853709).
Let's document the fact that we already handle this.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
VGIC implementation.
- s390: support for trapping software breakpoints, nested virtualization
(vSIE), the STHYI opcode, initial extensions for CPU model support.
- MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups,
preliminary to this and the upcoming support for hardware virtualization
extensions.
- x86: support for execute-only mappings in nested EPT; reduced vmexit
latency for TSC deadline timer (by about 30%) on Intel hosts; support for
more than 255 vCPUs.
- PPC: bugfixes.
The ugly bit is the conflicts. A couple of them are simple conflicts due
to 4.7 fixes, but most of them are with other trees. There was definitely
too much reliance on Acked-by here. Some conflicts are for KVM patches
where _I_ gave my Acked-by, but the worst are for this pull request's
patches that touch files outside arch/*/kvm. KVM submaintainers should
probably learn to synchronize better with arch maintainers, with the
latter providing topic branches whenever possible instead of Acked-by.
This is what we do with arch/x86. And I should learn to refuse pull
requests when linux-next sends scary signals, even if that means that
submaintainers have to rebase their branches.
Anyhow, here's the list:
- arch/x86/kvm/vmx.c: handle_pcommit and EXIT_REASON_PCOMMIT was removed
by the nvdimm tree. This tree adds handle_preemption_timer and
EXIT_REASON_PREEMPTION_TIMER at the same place. In general all mentions
of pcommit have to go.
There is also a conflict between a stable fix and this patch, where the
stable fix removed the vmx_create_pml_buffer function and its call.
- virt/kvm/kvm_main.c: kvm_cpu_notifier was removed by the hotplug tree.
This tree adds kvm_io_bus_get_dev at the same place.
- virt/kvm/arm/vgic.c: a few final bugfixes went into 4.7 before the
file was completely removed for 4.8.
- include/linux/irqchip/arm-gic-v3.h: this one is entirely our fault;
this is a change that should have gone in through the irqchip tree and
pulled by kvm-arm. I think I would have rejected this kvm-arm pull
request. The KVM version is the right one, except that it lacks
GITS_BASER_PAGES_SHIFT.
- arch/powerpc: what a mess. For the idle_book3s.S conflict, the KVM
tree is the right one; everything else is trivial. In this case I am
not quite sure what went wrong. The commit that is causing the mess
(fd7bacbca4, "KVM: PPC: Book3S HV: Fix TB corruption in guest exit
path on HMI interrupt", 2016-05-15) touches both arch/powerpc/kernel/
and arch/powerpc/kvm/. It's large, but at 396 insertions/5 deletions
I guessed that it wasn't really possible to split it and that the 5
deletions wouldn't conflict. That wasn't the case.
- arch/s390: also messy. First is hypfs_diag.c where the KVM tree
moved some code and the s390 tree patched it. You have to reapply the
relevant part of commits 6c22c98637, plus all of e030c1125e, to
arch/s390/kernel/diag.c. Or pick the linux-next conflict
resolution from http://marc.info/?l=kvm&m=146717549531603&w=2.
Second, there is a conflict in gmap.c between a stable fix and 4.8.
The KVM version here is the correct one.
I have pushed my resolution at refs/heads/merge-20160802 (commit
3d1f53419842) at git://git.kernel.org/pub/scm/virt/kvm/kvm.git.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
- ARM: GICv3 ITS emulation and various fixes. Removal of the
old VGIC implementation.
- s390: support for trapping software breakpoints, nested
virtualization (vSIE), the STHYI opcode, initial extensions
for CPU model support.
- MIPS: support for MIPS64 hosts (32-bit guests only) and lots
of cleanups, preliminary to this and the upcoming support for
hardware virtualization extensions.
- x86: support for execute-only mappings in nested EPT; reduced
vmexit latency for TSC deadline timer (by about 30%) on Intel
hosts; support for more than 255 vCPUs.
- PPC: bugfixes.
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits)
KVM: PPC: Introduce KVM_CAP_PPC_HTM
MIPS: Select HAVE_KVM for MIPS64_R{2,6}
MIPS: KVM: Reset CP0_PageMask during host TLB flush
MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()
MIPS: KVM: Sign extend MFC0/RDHWR results
MIPS: KVM: Fix 64-bit big endian dynamic translation
MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
MIPS: KVM: Use 64-bit CP0_EBase when appropriate
MIPS: KVM: Set CP0_Status.KX on MIPS64
MIPS: KVM: Make entry code MIPS64 friendly
MIPS: KVM: Use kmap instead of CKSEG0ADDR()
MIPS: KVM: Use virt_to_phys() to get commpage PFN
MIPS: Fix definition of KSEGX() for 64-bit
KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD
kvm: x86: nVMX: maintain internal copy of current VMCS
KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE
KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures
KVM: arm64: vgic-its: Simplify MAPI error handling
KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers
KVM: arm64: vgic-its: Turn device_id validation into generic ID validation
...
- Kexec support for arm64
- Kprobes support
- Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs
- Trapping of user space cache maintenance operations and emulation in
the kernel (CPU errata workaround)
- Clean-up of the early page tables creation (kernel linear mapping, EFI
run-time maps) to avoid splitting larger blocks (e.g. pmds) into
smaller ones (e.g. ptes)
- VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()
- ARCH_HAS_KCOV enabled for arm64
- Optimise IP checksum helpers
- SWIOTLB optimisation to only allocate/initialise the buffer if the
available RAM is beyond the 32-bit mask
- Properly handle the "nosmp" command line argument
- Fix for the initialisation of the CPU debug state during early boot
- vdso-offsets.h build dependency workaround
- Build fix when RANDOMIZE_BASE is enabled with MODULES off
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Kexec support for arm64
- Kprobes support
- Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs
- Trapping of user space cache maintenance operations and emulation in
the kernel (CPU errata workaround)
- Clean-up of the early page tables creation (kernel linear mapping,
EFI run-time maps) to avoid splitting larger blocks (e.g. pmds) into
smaller ones (e.g. ptes)
- VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime()
- ARCH_HAS_KCOV enabled for arm64
- Optimise IP checksum helpers
- SWIOTLB optimisation to only allocate/initialise the buffer if the
available RAM is beyond the 32-bit mask
- Properly handle the "nosmp" command line argument
- Fix for the initialisation of the CPU debug state during early boot
- vdso-offsets.h build dependency workaround
- Build fix when RANDOMIZE_BASE is enabled with MODULES off
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype
arm64: Only select ARM64_MODULE_PLTS if MODULES=y
arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages
arm64: mm: make create_mapping_late() non-allocating
arm64: Honor nosmp kernel command line option
arm64: Fix incorrect per-cpu usage for boot CPU
arm64: kprobes: Add KASAN instrumentation around stack accesses
arm64: kprobes: Cleanup jprobe_return
arm64: kprobes: Fix overflow when saving stack
arm64: kprobes: WARN if attempting to step with PSTATE.D=1
arm64: debug: remove unused local_dbg_{enable, disable} macros
arm64: debug: remove redundant spsr manipulation
arm64: debug: unmask PSTATE.D earlier
arm64: localise Image objcopy flags
arm64: ptrace: remove extra define for CPSR's E bit
kprobes: Add arm64 case in kprobe example module
arm64: Add kernel return probes support (kretprobes)
arm64: Add trampoline code for kretprobes
arm64: kprobes instruction simulation support
arm64: Treat all entry code as non-kprobe-able
...
The kprobe enablement work has uncovered that changes made by
a guest to MDSCR_EL1 were propagated to the host when VHE was
enabled, leading to unexpected exception being delivered.
Moving this register to the list of registers that are always
context-switched fixes the issue.
Fixes: 9c6c356832 ("arm64: KVM: VHE: Split save/restore of registers shared between guest and host")
Cc: stable@vger.kernel.org #4.6
Reported-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
Tested-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Now that we only have the "merged page tables" case to deal with,
there is a bunch of things we can simplify in the HYP code (both
at init and teardown time).
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
__hyp_panic_string is passed via the HYP panic code to the panic
function, and is being "upgraded" to a kernel address, as it is
referenced by the HYP code (in a PC-relative way).
This is a bit silly, and we'd be better off obtaining the kernel
address and not mess with it at all. This patch implements this
with a tiny bit of asm glue, by forcing the string pointer to be
read from the literal pool.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Now that we have a helper to extract the EC from an ESR_ELx value, make
use of this in the arm64 KVM code for simplicity and consistency. There
should be no functional changes as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Dave P Martin <dave.martin@arm.com>
Cc: Huang Shijie <shijie.huang@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add ARCH_HAS_KCOV to ARM64 config. To avoid potential crashes, disable
instrumentation of the files in arch/arm64/kvm/hyp/*.
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The GICv3 backend of the vgic is quite barrier heavy, in order
to ensure synchronization of the system registers and the
memory mapped view for a potential GICv2 guest.
But when the guest is using a GICv3 model, there is absolutely
no need to execute all these heavy barriers, and it is actually
beneficial to avoid them altogether.
This patch makes the synchonization conditional, and ensures
that we do not change the EL1 SRE settings if we do not need to.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Both our GIC emulations are "strict", in the sense that we either
emulate a GICv2 or a GICv3, and not a GICv3 with GICv2 legacy
support.
But when running on a GICv3 host, we still allow the guest to
tinker with the ICC_SRE_EL1 register during its time slice:
it can switch SRE off, observe that it is off, and yet on the
next world switch, find the SRE bit to be set again. Not very
nice.
An obvious solution is to always trap accesses to ICC_SRE_EL1
(by clearing ICC_SRE_EL2.Enable), and to let the handler return
the programmed value on a read, or ignore the write.
That way, the guest can always observe that our GICv3 is SRE==1
only.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When saving the state of the list registers, it is critical to
reset them zero, as we could otherwise leave unexpected EOI
interrupts pending for virtual level interrupts.
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
- x86: miscellaneous fixes, AVIC support (local APIC virtualization,
AMD version)
- s390: polling for interrupts after a VCPU goes to halted state is
now enabled for s390; use hardware provided information about facility
bits that do not need any hypervisor activity, and other fixes for
cpu models and facilities; improve perf output; floating interrupt
controller improvements.
- MIPS: miscellaneous fixes
- PPC: bugfixes only
- ARM: 16K page size support, generic firmware probing layer for
timer and GIC
Christoffer Dall (KVM-ARM maintainer) says:
"There are a few changes in this pull request touching things outside
KVM, but they should all carry the necessary acks and it made the
merge process much easier to do it this way."
though actually the irqchip maintainers' acks didn't make it into the
patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
later acked at http://mid.gmane.org/573351D1.4060303@arm.com
"more formally and for documentation purposes".
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small release overall.
x86:
- miscellaneous fixes
- AVIC support (local APIC virtualization, AMD version)
s390:
- polling for interrupts after a VCPU goes to halted state is now
enabled for s390
- use hardware provided information about facility bits that do not
need any hypervisor activity, and other fixes for cpu models and
facilities
- improve perf output
- floating interrupt controller improvements.
MIPS:
- miscellaneous fixes
PPC:
- bugfixes only
ARM:
- 16K page size support
- generic firmware probing layer for timer and GIC
Christoffer Dall (KVM-ARM maintainer) says:
"There are a few changes in this pull request touching things
outside KVM, but they should all carry the necessary acks and it
made the merge process much easier to do it this way."
though actually the irqchip maintainers' acks didn't make it into the
patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
later acked at http://mid.gmane.org/573351D1.4060303@arm.com ('more
formally and for documentation purposes')"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (82 commits)
KVM: MTRR: remove MSR 0x2f8
KVM: x86: make hwapic_isr_update and hwapic_irr_update look the same
svm: Manage vcpu load/unload when enable AVIC
svm: Do not intercept CR8 when enable AVIC
svm: Do not expose x2APIC when enable AVIC
KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore
svm: Add VMEXIT handlers for AVIC
svm: Add interrupt injection via AVIC
KVM: x86: Detect and Initialize AVIC support
svm: Introduce new AVIC VMCB registers
KVM: split kvm_vcpu_wake_up from kvm_vcpu_kick
KVM: x86: Introducing kvm_x86_ops VCPU blocking/unblocking hooks
KVM: x86: Introducing kvm_x86_ops VM init/destroy hooks
KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg
KVM: x86: Misc LAPIC changes to expose helper functions
KVM: shrink halt polling even more for invalid wakeups
KVM: s390: set halt polling to 80 microseconds
KVM: halt_polling: provide a way to qualify wakeups during poll
KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts
kvm: Conditionally register IRQ bypass consumer
...
- virt_to_page/page_address optimisations
- Support for NUMA systems described using device-tree
- Support for hibernate/suspend-to-disk
- Proper support for maxcpus= command line parameter
- Detection and graceful handling of AArch64-only CPUs
- Miscellaneous cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
- virt_to_page/page_address optimisations
- support for NUMA systems described using device-tree
- support for hibernate/suspend-to-disk
- proper support for maxcpus= command line parameter
- detection and graceful handling of AArch64-only CPUs
- miscellaneous cleanups and non-critical fixes
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
arm64: do not enforce strict 16 byte alignment to stack pointer
arm64: kernel: Fix incorrect brk randomization
arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
arm64: secondary_start_kernel: Remove unnecessary barrier
arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
arm64: Replace hard-coded values in the pmd/pud_bad() macros
arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
arm64: Fix typo in the pmdp_huge_get_and_clear() definition
arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
arm64: always use STRICT_MM_TYPECHECKS
arm64: kvm: Fix kvm teardown for systems using the extended idmap
arm64: kaslr: increase randomization granularity
arm64: kconfig: drop CONFIG_RTC_LIB dependency
arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
arm64: hibernate: Refuse to hibernate if the boot cpu is offline
arm64: kernel: Add support for hibernate/suspend-to-disk
PM / Hibernate: Call flush_icache_range() on pages restored in-place
arm64: Add new asm macro copy_page
arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
arm64: kernel: Include _AC definition in page.h
...
The ARMv8.1 architecture extensions introduce support for hardware
updates of the access and dirty information in page table entries. With
VTCR_EL2.HA enabled (bit 21), when the CPU accesses an IPA with the
PTE_AF bit cleared in the stage 2 page table, instead of raising an
Access Flag fault to EL2 the CPU sets the actual page table entry bit
(10). To ensure that kernel modifications to the page table do not
inadvertently revert a bit set by hardware updates, certain Stage 2
software pte/pmd operations must be performed atomically.
The main user of the AF bit is the kvm_age_hva() mechanism. The
kvm_age_hva_handler() function performs a "test and clear young" action
on the pte/pmd. This needs to be atomic in respect of automatic hardware
updates of the AF bit. Since the AF bit is in the same position for both
Stage 1 and Stage 2, the patch reuses the existing
ptep_test_and_clear_young() functionality if
__HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG is defined. Otherwise, the
existing pte_young/pte_mkold mechanism is preserved.
The kvm_set_s2pte_readonly() (and the corresponding pmd equivalent) have
to perform atomic modifications in order to avoid a race with updates of
the AF bit. The arm64 implementation has been re-written using
exclusives.
Currently, kvm_set_s2pte_writable() (and pmd equivalent) take a pointer
argument and modify the pte/pmd in place. However, these functions are
only used on local variables rather than actual page table entries, so
it makes more sense to follow the pte_mkwrite() approach for stage 1
attributes. The change to kvm_s2pte_mkwrite() makes it clear that these
functions do not modify the actual page table entries.
The (pte|pmd)_mkyoung() uses on Stage 2 entries (setting the AF bit
explicitly) do not need to be modified since hardware updates of the
dirty status are not supported by KVM, so there is no possibility of
losing such information.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
If memory is located above 1<<VA_BITS, kvm adds an extra level to its page
tables, merging the runtime tables and boot tables that contain the idmap.
This lets us avoid the trampoline dance during initialisation.
This also means there is no trampoline page mapped, so
__cpu_reset_hyp_mode() can't call __kvm_hyp_reset() in this page. The good
news is the idmap is still mapped, so we don't need the trampoline page.
The bad news is we can't call it directly as the idmap is above
HYP_PAGE_OFFSET, so its address is masked by kvm_call_hyp.
Add a function __extended_idmap_trampoline which will branch into
__kvm_hyp_reset in the idmap, change kvm_hyp_reset_entry() to return
this address if __kvm_cpu_uses_extended_idmap(). In this case
__kvm_hyp_reset() will still switch to the boot tables (which are the
merged tables that were already in use), and branch into the idmap (where
it already was).
This fixes boot failures on these systems, where we fail to execute the
missing trampoline page when tearing down kvm in init_subsystems():
[ 2.508922] kvm [1]: 8-bit VMID
[ 2.512057] kvm [1]: Hyp mode initialized successfully
[ 2.517242] kvm [1]: interrupt-controller@e1140000 IRQ13
[ 2.522622] kvm [1]: timer IRQ3
[ 2.525783] Kernel panic - not syncing: HYP panic:
[ 2.525783] PS:200003c9 PC:0000007ffffff820 ESR:86000005
[ 2.525783] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000
[ 2.525783] VCPU: (null)
[ 2.525783]
[ 2.547667] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.6.0-rc5+ #1
[ 2.555137] Hardware name: Default string Default string/Default string, BIOS ROD0084E 09/03/2015
[ 2.563994] Call trace:
[ 2.566432] [<ffffff80080888d0>] dump_backtrace+0x0/0x240
[ 2.571818] [<ffffff8008088b24>] show_stack+0x14/0x20
[ 2.576858] [<ffffff80083423ac>] dump_stack+0x94/0xb8
[ 2.581899] [<ffffff8008152130>] panic+0x10c/0x250
[ 2.586677] [<ffffff8008152024>] panic+0x0/0x250
[ 2.591281] SMP: stopping secondary CPUs
[ 3.649692] SMP: failed to stop secondary CPUs 0-2,4-7
[ 3.654818] Kernel Offset: disabled
[ 3.658293] Memory Limit: none
[ 3.661337] ---[ end Kernel panic - not syncing: HYP panic:
[ 3.661337] PS:200003c9 PC:0000007ffffff820 ESR:86000005
[ 3.661337] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000
[ 3.661337] VCPU: (null)
[ 3.661337]
Reported-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The existing arm64 hcall implementations are limited in that they only
allow for two distinct hcalls; with the x0 register either zero or not
zero. Also, the API of the hyp-stub exception vector routines and the
KVM exception vector routines differ; hyp-stub uses a non-zero value in
x0 to implement __hyp_set_vectors, whereas KVM uses it to implement
kvm_call_hyp.
To allow for additional hcalls to be defined and to make the arm64 hcall
API more consistent across exception vector routines, change the hcall
implementations to reserve all x0 values below 0xfff for hcalls such
as {s,g}et_vectors().
Define two new preprocessor macros HVC_GET_VECTORS, and HVC_SET_VECTORS
to be used as hcall type specifiers and convert the existing
__hyp_get_vectors() and __hyp_set_vectors() routines to use these new
macros when executing an HVC call. Also, change the corresponding
hyp-stub and KVM el1_sync exception vector routines to use these new
macros.
Signed-off-by: Geoff Levand <geoff@infradead.org>
[Merged two hcall patches, moved immediate value from esr to x0, use lr
as a scratch register, changed limit to 0xfff]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Today the 'hvc' calling KVM or the hyp-stub is expected to preserve all
registers. KVM saves/restores the registers it needs on the EL2 stack using
do_el2_call(). The hyp-stub has no stack, later patches need to be able to
be able to clobber the link register.
Move the link register save/restore to the the call sites.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
We always thought that 40bits of PA range would be the minimum people
would actually build. Anything less is terrifyingly small.
Turns out that we were both right and wrong. Nobody has ever built
such a system, but the ARM Foundation Model has a PARange set to 36bits.
Just because we can. Oh well. Now, the KVM API explicitely says that
we offer a 40bit PA space to the VM, so we shouldn't run KVM on
the Foundation Model at all.
That being said, this patch offers a less agressive alternative, and
loudly warns about the configuration being unsupported. You'll still
be able to run VMs (at your own risks, though).
This is just a workaround until we have a proper userspace API where
we report the PARange to userspace.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When we detect support for 16bit VMID in ID_AA64MMFR1, we set the
VTCR_EL2_VS field to 1 to make use of 16bit vmids. But, with
commit 3a3604bc5e ("arm64: KVM: Switch to C-based stage2 init")
this is broken and we corrupt VTCR_EL2:T0SZ instead of updating the VS
field. VTCR_EL2_VS was actually defined to the field shift (19) and
not the real value for VS. This patch fixes the issue.
Fixes: commit 3a3604bc5e ("arm64: KVM: Switch to C-based stage2 init")
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
