Small cleanup moving declarations of hyp-exported variables to
kvm_host.h and using macros to avoid having to refer to them with
kvm_nvhe_sym() in host.
No functional change intended.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-5-dbrazdil@google.com
PSCI driver exposes a struct containing the PSCI v0.1 function IDs
configured in the DT. However, the struct does not convey the
information whether these were set from DT or contain the default value
zero. This could be a problem for PSCI proxy in KVM protected mode.
Extend config passed to KVM with a bit mask with individual bits set
depending on whether the corresponding function pointer in psci_ops is
set, eg. set bit for PSCI_CPU_SUSPEND if psci_ops.cpu_suspend != NULL.
Previously config was split into multiple global variables. Put
everything into a single struct for convenience.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-2-dbrazdil@google.com
While protected KVM is installed, start trapping all host SMCs.
For now these are simply forwarded to EL3, except PSCI
CPU_ON/CPU_SUSPEND/SYSTEM_SUSPEND which are intercepted and the
hypervisor installed on newly booted cores.
Create new constant HCR_HOST_NVHE_PROTECTED_FLAGS with the new set of HCR
flags to use while the nVHE vector is installed when the kernel was
booted with the protected flag enabled. Switch back to the default HCR
flags when switching back to the stub vector.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-26-dbrazdil@google.com
Add a handler of SYSTEM_SUSPEND host PSCI SMCs. The semantics are
equivalent to CPU_SUSPEND, typically called on the last online CPU.
Reuse the same entry point and boot args struct as CPU_SUSPEND.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-24-dbrazdil@google.com
Add a handler of CPU_SUSPEND host PSCI SMCs. The SMC can either enter
a sleep state indistinguishable from a WFI or a deeper sleep state that
behaves like a CPU_OFF+CPU_ON except that the core is still considered
online while asleep.
The handler saves r0,pc of the host and makes the same call to EL3 with
the hyp CPU entry point. It either returns back to the handler and then
back to the host, or wakes up into the entry point and initializes EL2
state before dropping back to EL1. No EL2 state needs to be
saved/restored for this purpose.
CPU_ON and CPU_SUSPEND are both implemented using struct psci_boot_args
to store the state upon powerup, with each CPU having separate structs
for CPU_ON and CPU_SUSPEND so that CPU_SUSPEND can operate locklessly
and so that a CPU_ON call targeting a CPU cannot interfere with
a concurrent CPU_SUSPEND call on that CPU.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-23-dbrazdil@google.com
Add a handler of the CPU_ON PSCI call from host. When invoked, it looks
up the logical CPU ID corresponding to the provided MPIDR and populates
the state struct of the target CPU with the provided x0, pc. It then
calls CPU_ON itself, with an entry point in hyp that initializes EL2
state before returning ERET to the provided PC in EL1.
There is a simple atomic lock around the boot args struct. If it is
already locked, CPU_ON will return PENDING_ON error code.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-22-dbrazdil@google.com
All nVHE hyp code is currently executed as handlers of host's HVCs. This
will change as nVHE starts intercepting host's PSCI CPU_ON SMCs. The
newly booted CPU will need to initialize EL2 state and then enter the
host. Add __host_enter function that branches into the existing
host state-restoring code after the trap handler would have returned.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-21-dbrazdil@google.com
In preparation for adding a CPU entry point in nVHE hyp code, extract
most of __do_hyp_init hypervisor initialization code into a common
helper function. This will be invoked by the entry point to install KVM
on the newly booted CPU.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-20-dbrazdil@google.com
Forward the following PSCI SMCs issued by host to EL3 as they do not
require the hypervisor's intervention. This assumes that EL3 correctly
implements the PSCI specification.
Only function IDs implemented in Linux are included.
Where both 32-bit and 64-bit variants exist, it is assumed that the host
will always use the 64-bit variant.
* SMCs that only return information about the system
* PSCI_VERSION - PSCI version implemented by EL3
* PSCI_FEATURES - optional features supported by EL3
* AFFINITY_INFO - power state of core/cluster
* MIGRATE_INFO_TYPE - whether Trusted OS can be migrated
* MIGRATE_INFO_UP_CPU - resident core of Trusted OS
* operations which do not affect the hypervisor
* MIGRATE - migrate Trusted OS to a different core
* SET_SUSPEND_MODE - toggle OS-initiated mode
* system shutdown/reset
* SYSTEM_OFF
* SYSTEM_RESET
* SYSTEM_RESET2
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-19-dbrazdil@google.com
Add a host-initialized constant to KVM nVHE hyp code for converting
between EL2 linear map virtual addresses and physical addresses.
Also add `__hyp_pa` macro that performs the conversion.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-18-dbrazdil@google.com
Add a handler of PSCI SMCs in nVHE hyp code. The handler is initialized
with the version used by the host's PSCI driver and the function IDs it
was configured with. If the SMC function ID matches one of the
configured PSCI calls (for v0.1) or falls into the PSCI function ID
range (for v0.2+), the SMC is handled by the PSCI handler. For now, all
SMCs return PSCI_RET_NOT_SUPPORTED.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-17-dbrazdil@google.com
Add handler of host SMCs in KVM nVHE trap handler. Forward all SMCs to
EL3 and propagate the result back to EL1. This is done in preparation
for validating host SMCs in KVM protected mode.
The implementation assumes that firmware uses SMCCC v1.2 or older. That
means x0-x17 can be used both for arguments and results, other GPRs are
preserved.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-16-dbrazdil@google.com
When KVM starts validating host's PSCI requests, it will need to map
MPIDR back to the CPU ID. To this end, copy cpu_logical_map into nVHE
hyp memory when KVM is initialized.
Only copy the information for CPUs that are online at the point of KVM
initialization so that KVM rejects CPUs whose features were not checked
against the finalized capabilities.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-15-dbrazdil@google.com
When compiling with __KVM_NVHE_HYPERVISOR__, redefine per_cpu_offset()
to __hyp_per_cpu_offset() which looks up the base of the nVHE per-CPU
region of the given cpu and computes its offset from the
.hyp.data..percpu section.
This enables use of per_cpu_ptr() helpers in nVHE hyp code. Until now
only this_cpu_ptr() was supported by setting TPIDR_EL2.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-14-dbrazdil@google.com
Add rules for renaming the .data..ro_after_init ELF section in KVM nVHE
object files to .hyp.data..ro_after_init, linking it into the kernel
and mapping it in hyp at runtime.
The section is RW to the host, then mapped RO in hyp. The expectation is
that the host populates the variables in the section and they are never
changed by hyp afterwards.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-13-dbrazdil@google.com
MAIR_EL2 and TCR_EL2 are currently initialized from their _EL1 values.
This will not work once KVM starts intercepting PSCI ON/SUSPEND SMCs
and initializing EL2 state before EL1 state.
Obtain the EL1 values during KVM init and store them in the init params
struct. The struct will stay in memory and can be used when booting new
cores.
Take the opportunity to move copying the T0SZ value from idmap_t0sz in
KVM init rather than in .hyp.idmap.text. This avoids the need for the
idmap_t0sz symbol alias.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-12-dbrazdil@google.com
Once we start initializing KVM on newly booted cores before the rest of
the kernel, parameters to __do_hyp_init will need to be provided by EL2
rather than EL1. At that point it will not be possible to pass its three
arguments directly because PSCI_CPU_ON only supports one context
argument.
Refactor __do_hyp_init to accept its parameters in a struct. This
prepares the code for KVM booting cores as well as removes any limits on
the number of __do_hyp_init arguments.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com
KVM precomputes the hyp VA of __kvm_hyp_host_vector, essentially a
constant (minus ASLR), before passing it to __kvm_hyp_init.
Now that we have alternatives for converting kimg VA to hyp VA, replace
this with computing the constant inside __kvm_hyp_init, thus removing
the need for an argument.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-10-dbrazdil@google.com
- Fix alignment of the new HYP sections
- Fix GICR_TYPER access from userspace
-----BEGIN PGP SIGNATURE-----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=oova
-----END PGP SIGNATURE-----
Merge tag 'kvmarm-fixes-5.10-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master
KVM/arm64 fixes for v5.10, take #4
- Fix alignment of the new HYP sections
- Fix GICR_TYPER access from userspace
Registers x0/x1 get repeateadly pushed and poped during a host
HVC call. Instead, leave the registers on the stack, trading
a store instruction on the fast path for an add on the slow path.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Move the setting of SSBS directly into the HVC handler, using
the C helpers rather than the inline asssembly code.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Directly using the kimage_voffset variable is fine for now, but
will become more problematic as we start distrusting EL1.
Instead, patch the kimage_voffset into the HYP text, ensuring
we don't have to load an untrusted value later on.
Signed-off-by: Marc Zyngier <maz@kernel.org>
The nVHE percpu data is partially linked but the nVHE linker script did
not align the percpu section. The PERCPU_INPUT macro would then align
the data to a page boundary:
#define PERCPU_INPUT(cacheline) \
__per_cpu_start = .; \
*(.data..percpu..first) \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
. = ALIGN(cacheline); \
*(.data..percpu..read_mostly) \
. = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
PERCPU_DECRYPTED_SECTION \
__per_cpu_end = .;
but then when the final vmlinux linking happens the hypervisor percpu
data is included after page alignment and so the offsets potentially
don't match. On my build I saw that the .hyp.data..percpu section was
at address 0x20 and then the percpu data would begin at 0x1000 (because
of the page alignment in PERCPU_INPUT), but when linked into vmlinux,
everything would be shifted down by 0x20 bytes.
This manifests as one of the CPUs getting lost when running
kvm-unit-tests or starting any VM and subsequent soft lockup on a Cortex
A72 device.
Fixes: 30c953911c ("kvm: arm64: Set up hyp percpu data for nVHE")
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113150406.14314-1-jamie@nuviainc.com
Add the basic infrastructure to describe injection of exceptions
into a guest. So far, nothing uses this code path.
Signed-off-by: Marc Zyngier <maz@kernel.org>
In an effort to remove the vcpu PC manipulations from EL1 on nVHE
systems, move kvm_skip_instr() to be HYP-specific. EL1's intent
to increment PC post emulation is now signalled via a flag in the
vcpu structure.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Now that we can use function pointer, use a dispatch table to call
the individual HVC handlers, leading to more maintainable code.
Further improvements include helpers to declare the mapping of
local variables to values passed in the host context.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
* selftest fix
* Force PTE mapping on device pages provided via VFIO
* Fix detection of cacheable mapping at S2
* Fallback to PMD/PTE mappings for composite huge pages
* Fix accounting of Stage-2 PGD allocation
* Fix AArch32 handling of some of the debug registers
* Simplify host HYP entry
* Fix stray pointer conversion on nVHE TLB invalidation
* Fix initialization of the nVHE code
* Simplify handling of capabilities exposed to HYP
* Nuke VCPUs caught using a forbidden AArch32 EL0
x86:
* new nested virtualization selftest
* Miscellaneous fixes
* make W=1 fixes
* Reserve new CPUID bit in the KVM leaves
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAl+dhRAUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroPWCgf/U997UW/11IdNtkehQO/DFdx7lHev
+IahN1Pnbt92ZoR5nGhK9pgvDahIVhqTmUvgV+3fD24OnqXTpYTu1fliBvL6ynbN
J9Ycf0zFAgwfgTTD5UexTlEovnhX4xz7NDmd6rpxGDZdMaBHQFPkCXBFK45pf4nd
O349aHV0X1AA7Tt/sLhpXpi74Vake1xErLHKhIVLHKyo/zDm+Q0UZry068NNBzTr
St3+QSGlFXhuekVrZLh+DShh6rZGLyY9tcySt6o0Jk7fSs1lmEnPbBgeeqYmyHMd
Yn+ybhthmNkkpI8so70TA9roiVar4UmjnMBOiav62bo7ue26pKE5cWQyXw==
=mvBr
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"ARM:
- selftest fix
- force PTE mapping on device pages provided via VFIO
- fix detection of cacheable mapping at S2
- fallback to PMD/PTE mappings for composite huge pages
- fix accounting of Stage-2 PGD allocation
- fix AArch32 handling of some of the debug registers
- simplify host HYP entry
- fix stray pointer conversion on nVHE TLB invalidation
- fix initialization of the nVHE code
- simplify handling of capabilities exposed to HYP
- nuke VCPUs caught using a forbidden AArch32 EL0
x86:
- new nested virtualization selftest
- miscellaneous fixes
- make W=1 fixes
- reserve new CPUID bit in the KVM leaves"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: vmx: remove unused variable
KVM: selftests: Don't require THP to run tests
KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again
KVM: selftests: test behavior of unmapped L2 APIC-access address
KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()
KVM: x86: replace static const variables with macros
KVM: arm64: Handle Asymmetric AArch32 systems
arm64: cpufeature: upgrade hyp caps to final
arm64: cpufeature: reorder cpus_have_{const, final}_cap()
KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code()
KVM: arm64: Force PTE mapping on fault resulting in a device mapping
KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes
KVM: arm64: Fix masks in stage2_pte_cacheable()
KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR
KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT
KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition
KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation
KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call
x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
- Force PTE mapping on device pages provided via VFIO
- Fix detection of cacheable mapping at S2
- Fallback to PMD/PTE mappings for composite huge pages
- Fix accounting of Stage-2 PGD allocation
- Fix AArch32 handling of some of the debug registers
- Simplify host HYP entry
- Fix stray pointer conversion on nVHE TLB invalidation
- Fix initialization of the nVHE code
- Simplify handling of capabilities exposed to HYP
- Nuke VCPUs caught using a forbidden AArch32 EL0
-----BEGIN PGP SIGNATURE-----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=gVaX
-----END PGP SIGNATURE-----
Merge tag 'kvmarm-fixes-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 5.10, take #1
- Force PTE mapping on device pages provided via VFIO
- Fix detection of cacheable mapping at S2
- Fallback to PMD/PTE mappings for composite huge pages
- Fix accounting of Stage-2 PGD allocation
- Fix AArch32 handling of some of the debug registers
- Simplify host HYP entry
- Fix stray pointer conversion on nVHE TLB invalidation
- Fix initialization of the nVHE code
- Simplify handling of capabilities exposed to HYP
- Nuke VCPUs caught using a forbidden AArch32 EL0
Setting PSTATE.PAN when entering EL2 on nVHE doesn't make much
sense as this bit only means something for translation regimes
that include EL0. This obviously isn't the case in the nVHE case,
so let's drop this setting.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Link: https://lore.kernel.org/r/20201026095116.72051-4-maz@kernel.org
The new calling convention says that pointers coming from the SMCCC
interface are turned into their HYP version in the host HVC handler.
However, there is still a stray kern_hyp_va() in the TLB invalidation
code, which could result in a corrupted pointer.
Drop the spurious conversion.
Fixes: a071261d93 ("KVM: arm64: nVHE: Fix pointers during SMCCC convertion")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201026095116.72051-3-maz@kernel.org
The hyp-init code starts by stashing a register in TPIDR_EL2
in in order to free a register. This happens no matter if the
HVC call is legal or not.
Although nothing wrong seems to come out of it, it feels odd
to alter the EL2 state for something that eventually returns
an error.
Instead, use the fact that we know exactly which bits of the
__kvm_hyp_init call are non-zero to perform the check with
a series of EOR/ROR instructions, combined with a build-time
check that the value is the one we expect.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201026095116.72051-2-maz@kernel.org
On Cortex-A77 r0p0 and r1p0, a sequence of a non-cacheable or device load
and a store exclusive or PAR_EL1 read can cause a deadlock.
The workaround requires a DMB SY before and after a PAR_EL1 register
read. In addition, it's possible an interrupt (doing a device read) or
KVM guest exit could be taken between the DMB and PAR read, so we
also need a DMB before returning from interrupt and before returning to
a guest.
A deadlock is still possible with the workaround as KVM guests must also
have the workaround. IOW, a malicious guest can deadlock an affected
systems.
This workaround also depends on a firmware counterpart to enable the h/w
to insert DMB SY after load and store exclusive instructions. See the
errata document SDEN-1152370 v10 [1] for more information.
[1] https://static.docs.arm.com/101992/0010/Arm_Cortex_A77_MP074_Software_Developer_Errata_Notice_v10.pdf
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: kvmarm@lists.cs.columbia.edu
Link: https://lore.kernel.org/r/20201028182839.166037-2-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Commit a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table
data from struct kvm") dropped the ISB after __load_guest_stage2(),
only leaving the one that is required when the speculative AT
workaround is in effect.
As Andrew points it: "This alternative is 'backwards' to avoid a
double ISB as there is one in __load_guest_stage2 when the workaround
is active."
Restore the missing ISB, conditionned on the AT workaround not being
active.
Fixes: a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table data from struct kvm")
Reported-by: Andrew Scull <ascull@google.com>
Reported-by: Thomas Tai <thomas.tai@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Add hyp percpu section to linker script and rename the corresponding ELF
sections of hyp/nvhe object files. This moves all nVHE-specific percpu
variables to the new hyp percpu section.
Allocate sufficient amount of memory for all percpu hyp regions at global KVM
init time and create corresponding hyp mappings.
The base addresses of hyp percpu regions are kept in a dynamically allocated
array in the kernel.
Add NULL checks in PMU event-reset code as it may run before KVM memory is
initialized.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-10-dbrazdil@google.com
Host CPU context is stored in a global per-cpu variable `kvm_host_data`.
In preparation for introducing independent per-CPU region for nVHE hyp,
create two separate instances of `kvm_host_data`, one for VHE and one
for nVHE.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-9-dbrazdil@google.com
Hyp keeps track of which cores require SSBD callback by accessing a
kernel-proper global variable. Create an nVHE symbol of the same name
and copy the value from kernel proper to nVHE as KVM is being enabled
on a core.
Done in preparation for separating percpu memory owned by kernel
proper and nVHE.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-8-dbrazdil@google.com
this_cpu_ptr is meant for use in kernel proper because it selects between
TPIDR_EL1/2 based on nVHE/VHE. __hyp_this_cpu_ptr was used in hyp to always
select TPIDR_EL2. Unify all users behind this_cpu_ptr and friends by
selecting _EL2 register under __KVM_NVHE_HYPERVISOR__. VHE continues
selecting the register using alternatives.
Under CONFIG_DEBUG_PREEMPT, the kernel helpers perform a preemption check
which is omitted by the hyp helpers. Preserve the behavior for nVHE by
overriding the corresponding macros under __KVM_NVHE_HYPERVISOR__. Extend
the checks into VHE hyp code.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-5-dbrazdil@google.com
Relying on objcopy to prefix the ELF section names of the nVHE hyp code
is brittle and prevents us from using wildcards to match specific
section names.
Improve the build rules by partially linking all '.nvhe.o' files and
prefixing their ELF section names using a linker script. Continue using
objcopy for prefixing ELF symbol names.
One immediate advantage of this approach is that all subsections
matching a pattern can be merged into a single prefixed section, eg.
.text and .text.* can be linked into a single '.hyp.text'. This removes
the need for -fno-reorder-functions on GCC and will be useful in the
future too: LTO builds use .text subsections, compilers routinely
generate .rodata subsections, etc.
Partially linking all hyp code into a single object file also makes it
easier to analyze.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-2-dbrazdil@google.com
Owing to the fact that the host kernel is always mitigated, we can
drastically simplify the WA2 handling by keeping the mitigation
state ON when entering the guest. This means the guest is either
unaffected or not mitigated.
This results in a nice simplification of the mitigation space,
and the removal of a lot of code that was never really used anyway.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
The host need not concern itself with the pointer differences for the
hyp interfaces that are shared between VHE and nVHE so leave it to the
hyp to handle.
As the SMCCC function IDs are converted into function calls, it is a
suitable place to also convert any pointer arguments into hyp pointers.
This, additionally, eases the reuse of the handlers in different
contexts.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-20-ascull@google.com
To complete the transition to SMCCC, the hyp initialization is given a
function ID. This looks neater than comparing the hyp stub function IDs
to the page table physical address.
Some care is taken to only clobber x0-3 before the host context is saved
as only those registers can be clobbered accoring to SMCCC. Fortunately,
only a few acrobatics are needed. The possible new tpidr_el2 is moved to
the argument in x2 so that it can be stashed in tpidr_el2 early to free
up a scratch register. The page table configuration then makes use of
x0-2.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-19-ascull@google.com
Rather than passing arbitrary function pointers to run at hyp, define
and equivalent set of SMCCC functions.
Since the SMCCC functions are strongly tied to the original function
prototypes, it is not expected for the host to ever call an invalid ID
but a warning is raised if this does ever occur.
As __kvm_vcpu_run is used for every switch between the host and a guest,
it is explicitly singled out to be identified before the other function
IDs to improve the performance of the hot path.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-18-ascull@google.com
Rather than some being kernel pointer and others being hyp pointers,
standardize on all pointers being hyp pointers.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-15-ascull@google.com
Restore the host context when panicking from hyp to give the best chance
of the panic being clean.
The host requires that registers be preserved such as x18 for the shadow
callstack. If the panic is caused by an exception from EL1, the host
context is still valid so the panic can return straight back to the
host. If the panic comes from EL2 then it's most likely that the hyp
context is active and the host context needs to be restored.
There are windows before and after the host context is saved and
restored that restoration is attempted incorrectly and the panic won't
be clean.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-14-ascull@google.com
Save and restore the host context when switching to and from hyp. This
gives hyp its own context that the host will not see as a step towards a
full trust boundary between the two.
SP_EL0 and pointer authentication keys are currently shared between the
host and hyp so don't need to be switched yet.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-13-ascull@google.com
If the guest context is loaded when a panic is triggered, restore the
hyp context so e.g. the shadow call stack works when hyp_panic() is
called and SP_EL0 is valid when the host's panic() is called.
Use the hyp context's __hyp_running_vcpu field to track when hyp
transitions to and from the guest vcpu so the exception handlers know
whether the context needs to be restored.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-11-ascull@google.com
During __guest_enter, save and restore from a new hyp context rather
than the host context. This is preparation for separation of the hyp and
host context in nVHE.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-9-ascull@google.com
The ESB at the start of the host vector may cause SErrors to be consumed
to DISR_EL1. However, this is not checked for the host so the SError
could go unhandled.
Remove the ESB so that SErrors are not consumed but are instead left
pending for the host to consume. __guest_enter already defers entry into
a guest if there are any SErrors pending.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200915104643.2543892-8-ascull@google.com
The host is treated differently from the guests when an exception is
taken so introduce a separate vector that is specialized for the host.
This also allows the nVHE specific code to move out of hyp-entry.S and
into nvhe/host.S.
The host is only expected to make HVC calls and anything else is
considered invalid and results in a panic.
Hyp initialization is now passed the vector that is used for the host
and it is swapped for the guest vector during the context switch.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-7-ascull@google.com
hyp_panic is able to find all the context it needs from within itself so
remove the argument. The __hyp_panic wrapper becomes redundant so is
also removed.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-3-ascull@google.com
The __activate_vm wrapper serves no useful function and has a misleading
name as it simply calls __load_guest_stage2 and does not touch
HCR_EL2.VM so remove it.
Also rename __deactivate_vm to __load_host_stage2 to match naming
pattern.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-2-ascull@google.com
KVM has a one instruction window where it will allow an SError exception
to be consumed by the hypervisor without treating it as a hypervisor bug.
This is used to consume asynchronous external abort that were caused by
the guest.
As we are about to add another location that survives unexpected exceptions,
generalise this code to make it behave like the host's extable.
KVM's version has to be mapped to EL2 to be accessible on nVHE systems.
The SError vaxorcism code is a one instruction window, so has two entries
in the extable. Because the KVM code is copied for VHE and nVHE, we end up
with four entries, half of which correspond with code that isn't mapped.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
- Split the VHE and nVHE hypervisor code bases, build the EL2 code
separately, allowing for the VHE code to now be built with instrumentation
- Level-based TLB invalidation support
- Restructure of the vcpu register storage to accomodate the NV code
- Pointer Authentication available for guests on nVHE hosts
- Simplification of the system register table parsing
- MMU cleanups and fixes
- A number of post-32bit cleanups and other fixes
-----BEGIN PGP SIGNATURE-----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=Ukr4
-----END PGP SIGNATURE-----
Merge tag 'kvmarm-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next-5.6
KVM/arm64 updates for Linux 5.9:
- Split the VHE and nVHE hypervisor code bases, build the EL2 code
separately, allowing for the VHE code to now be built with instrumentation
- Level-based TLB invalidation support
- Restructure of the vcpu register storage to accomodate the NV code
- Pointer Authentication available for guests on nVHE hosts
- Simplification of the system register table parsing
- MMU cleanups and fixes
- A number of post-32bit cleanups and other fixes
Some compilers may put a subset of generated functions into '.text.*'
ELF sections and the linker may leverage this division to optimize ELF
layout. Unfortunately, the recently introduced HYPCOPY command assumes
that all executable code (with the exception of specialized sections
such as '.hyp.idmap.text') is in the '.text' section. If this
assumption is broken, code in '.text.*' will be merged into kernel
proper '.text' instead of the '.hyp.text' that is mapped in EL2.
To ensure that this cannot happen, insert an OBJDUMP assertion into
HYPCOPY. The command dumps a list of ELF sections in the input object
file and greps for '.text.'. If found, compilation fails. Tested with
both binutils' and LLVM's objdump (the output format is different).
GCC offers '-fno-reorder-functions' to disable this behaviour. Select
the flag if it is available. From inspection of GCC source (latest
Git in July 2020), this flag does force all code into '.text'.
By default, GCC uses profile data, heuristics and attributes to select
a subsection.
LLVM/Clang currently does not have a similar optimization pass. It can
place static constructors into '.text.startup' and it's optimizer can
be provided with profile data to reorder hot/cold functions. Neither
of these is applicable to nVHE hyp code. If this changes in the future,
the OBJDUMP assertion should alert users to the problem.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200730132519.48787-1-dbrazdil@google.com
Switch the hypervisor code to using ctxt_sys_reg/__vcpu_sys_reg instead
of raw sys_regs accesses. No intended functionnal change.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Since we often have a precise idea of the level we're dealing with
when invalidating TLBs, we can provide it to as a hint to our
invalidation helper.
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.
This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.
The new structure is called struct kvm_s2_mmu.
There is no intended functional change by this patch alone.
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: Marc Zyngier <maz@kernel.org>
With nVHE code now fully separated from the rest of the kernel, the effects of
the __hyp_text macro (which had to be applied on all nVHE code) can be
achieved with build rules instead. The macro used to:
(a) move code to .hyp.text ELF section, now done by renaming .text using
`objcopy`, and
(b) `notrace` and `__noscs` would negate effects of CC_FLAGS_FTRACE and
CC_FLAGS_SCS, respectivelly, now those flags are erased from
KBUILD_CFLAGS (same way as in EFI stub).
Note that by removing __hyp_text from code shared with VHE, all VHE code is now
compiled into .text and without `notrace` and `__noscs`.
Use of '.pushsection .hyp.text' removed from assembly files as this is now also
covered by the build rules.
For MAINTAINERS: if needed to re-run, uses of macro were removed with the
following command. Formatting was fixed up manually.
find arch/arm64/kvm/hyp -type f -name '*.c' -o -name '*.h' \
-exec sed -i 's/ __hyp_text//g' {} +
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-15-dbrazdil@google.com
The following files in hyp/ contain only code shared by VHE/nVHE:
vgic-v3-sr.c, aarch32.c, vgic-v2-cpuif-proxy.c, entry.S, fpsimd.S
Compile them under both configurations. Deletions in image-vars.h reflect
eliminated dependencies of nVHE code on the rest of the kernel.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-14-dbrazdil@google.com
timer-sr.c contains a HVC handler for setting CNTVOFF_EL2 and two helper
functions for controlling access to physical counter. The former is used by
both VHE/nVHE and is duplicated, the latter are used only by nVHE and moved
to nvhe/timer-sr.c.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-13-dbrazdil@google.com
sysreg-sr.c contains KVM's code for saving/restoring system registers, with
some code shared between VHE/nVHE. These common routines are moved to
a header file, VHE-specific code is moved to vhe/sysreg-sr.c and nVHE-specific
code to nvhe/sysreg-sr.c.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-12-dbrazdil@google.com
debug-sr.c contains KVM's code for context-switching debug registers, with some
code shared between VHE/nVHE. These common routines are moved to a header file,
VHE-specific code is moved to vhe/debug-sr.c and nVHE-specific code to
nvhe/debug-sr.c.
Functions are slightly refactored to move code hidden behind `has_vhe()` checks
to the corresponding .c files.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-11-dbrazdil@google.com
switch.c implements context-switching for KVM, with large parts shared between
VHE/nVHE. These common routines are moved to a header file, VHE-specific code
is moved to vhe/switch.c and nVHE-specific code is moved to nvhe/switch.c.
Previously __kvm_vcpu_run needed a different symbol name for VHE/nVHE. This
is cleaned up and the caller in arm.c simplified.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-10-dbrazdil@google.com
tlb.c contains code for flushing the TLB, with code shared between VHE/nVHE.
Because common code is small, duplicate tlb.c and specialize each copy for
VHE/nVHE.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-9-dbrazdil@google.com
hyp-init.S contains the identity mapped initialisation code for the
non-VHE code that runs at EL2. It is only used for non-VHE.
Adjust code that calls into this to use the prefixed symbol name.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com
hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly
shared between VHE/nVHE, therefore compile it under both VHE and nVHE build
rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__.
Adjust code which selects which KVM hyp vecs to install to choose the correct
VHE/nVHE symbol.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
Add new folders arch/arm64/kvm/hyp/{vhe,nvhe} and Makefiles for building code
that runs in EL2 under VHE/nVHE KVM, repsectivelly. Add an include folder for
hyp-specific header files which will include code common to VHE/nVHE.
Build nVHE code with -D__KVM_NVHE_HYPERVISOR__, VHE code with
-D__KVM_VHE_HYPERVISOR__.
Under nVHE compile each source file into a `.hyp.tmp.o` object first, then
prefix all its symbols with "__kvm_nvhe_" using `objcopy` and produce
a `.hyp.o`. Suffixes were chosen so that it would be possible for VHE and nVHE
to share some source files, but compiled with different CFLAGS.
The nVHE ELF symbol prefix is added to kallsyms.c as ignored. EL2-only symbols
will never appear in EL1 stack traces.
Due to symbol prefixing, add a section in image-vars.h for aliases of symbols
that are defined in nVHE EL2 and accessed by kernel in EL1 or vice versa.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-4-dbrazdil@google.com
