Signed-off-by: NMarc Zyngier <maz@kernel.org>

# Conflicts:
#	arch/arm64/kvm/mmu.c

Fix following warnings caused by mismatch bewteen function parameters
and comments.
arch/arm64/kvm/mmu.c:128: warning: Function parameter or member 'mmu' not described in '__unmap_stage2_range'
arch/arm64/kvm/mmu.c:128: warning: Function parameter or member 'may_block' not described in '__unmap_stage2_range'
arch/arm64/kvm/mmu.c:128: warning: Excess function parameter 'kvm' description in '__unmap_stage2_range'
arch/arm64/kvm/mmu.c:499: warning: Function parameter or member 'writable' not described in 'kvm_phys_addr_ioremap'
arch/arm64/kvm/mmu.c:538: warning: Function parameter or member 'mmu' not described in 'stage2_wp_range'
arch/arm64/kvm/mmu.c:538: warning: Excess function parameter 'kvm' description in 'stage2_wp_range'
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/1600307269-50957-1-git-send-email-tanxiaofei@huawei.com

As a result of a KVM_SET_USER_MEMORY_REGION ioctl, KVM flushes the
dcache for the memslot being changed to ensure a consistent view of memory
between the host and the guest: the host runs with caches enabled, and
it is possible for the data written by the hypervisor to still be in the
caches, but the guest is running with stage 1 disabled, meaning data
accesses are to Device-nGnRnE memory, bypassing the caches entirely.

Flushing the dcache is not necessary when KVM enables FWB, because it
forces the guest to uses cacheable memory accesses.

The current behaviour does not change, as the dcache flush helpers execute
the cache operation only if FWB is not enabled, but walking the stage 2
table is avoided.
Signed-off-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915170442.131635-1-alexandru.elisei@arm.com

When userspace uses hugetlbfs for the VM memory, user_mem_abort() tries to
use the same block size to map the faulting IPA in stage 2. If stage 2
cannot the same block mapping because the block size doesn't fit in the
memslot or the memslot is not properly aligned, user_mem_abort() will fall
back to a page mapping, regardless of the block size. We can do better for
PUD backed hugetlbfs by checking if a PMD block mapping is supported before
deciding to use a page.

vma_pagesize is an unsigned long, use 1UL instead of 1ULL when assigning
its value.
Signed-off-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200910133351.118191-1-alexandru.elisei@arm.com

Signed-off-by: NMarc Zyngier <maz@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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-18-ascull@google.com

Using the same register-bound variable for both arguments and results
means these values share a type. That type must allow the arguments to
be assigned to it and must also be assignable to the unsigned long
fields of struct arm_smccc_res.

This restriction on types causes compiler warnings when the argument
cannot be implicitly assigned to an unsigned long, for example the
pointers that are used in the KVM hyp interface.

By separating the arguments and results into their own variables, the
type constraint is lifted allowing the arguments to avoid the need for
any type conversion.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200915104643.2543892-17-ascull@google.com

Vendor specific hypervisor services have their own region of function
identifiers reserved by SMCCC. Extend the list of owners to include this
case.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200915104643.2543892-16-ascull@google.com

Rather than some being kernel pointer and others being hyp pointers,
standardize on all pointers being hyp pointers.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-13-ascull@google.com

To avoid duplicating the context save and restore macros, move them into
a shareable header.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-12-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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-11-ascull@google.com

Hyp now has its own nominal context for saving and restoring its state
when switching to and from a guest. Update the related comments and
utilities to match the new name.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-10-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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-7-ascull@google.com

Introduce a percpu variable to hold the address of the selected hyp
vector that will be used with guests. This avoids the selection process
each time a guest is being entered and can be used by nVHE when a
separate vector is introduced for the host.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-6-ascull@google.com

Make CHOOSE_HYP_SYM select the symbol of the active hypervisor for the
host, the nVHE symbol for nVHE and the VHE symbol for VHE. The nVHE and
VHE hypervisors see their own symbols without prefixes and trigger a
link error when trying to use a symbol of the other hypervisor.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20200915104643.2543892-5-ascull@google.com

The kvm_host_data_t typedef is used inconsistently and goes against the
kernel's coding style. Remove it in favour of the full struct specifier.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-4-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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc 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: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-2-ascull@google.com

Signed-off-by: NMarc Zyngier <maz@kernel.org>

Now that the guest stage-2 page-tables are managed independently from
the host stage-1 page-tables, we can avoid constraining the IPA size
based on the host and instead limit it only based on the PARange field
of the ID_AA64MMFR0 register.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-22-will@kernel.org

The stage-2 page-tables are entirely encapsulated by the 'pgt' field of
'struct kvm_s2_mmu', so remove the unused 'pgd' field.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-21-will@kernel.org

Now that KVM is using the generic page-table code to manage the guest
stage-2 page-tables, we can remove a bunch of unused macros, #defines
and static inline functions from the old implementation.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-20-will@kernel.org

In preparation for removing the 'pgd' field of 'struct kvm_s2_mmu',
update the few remaining users to check the 'pgt' field instead.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-19-will@kernel.org

Convert user_mem_abort() to call kvm_pgtable_stage2_relax_perms() when
handling a stage-2 permission fault and kvm_pgtable_stage2_map() when
handling a stage-2 translation fault, rather than walking the page-table
manually.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Reviewed-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-18-will@kernel.org

Add support for relaxing the permissions of a stage-2 mapping (i.e.
adding additional permissions) to the generic page-table code.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-17-will@kernel.org

Convert stage2_flush_memslot() to call the kvm_pgtable_stage2_flush()
function of the generic page-table code instead of walking the page-table
directly.
Signed-off-by: NQuentin Perret <qperret@google.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200911132529.19844-16-will@kernel.org

Add support for cache flushing a range of the stage-2 address space to
the generic page-table code.
Signed-off-by: NQuentin Perret <qperret@google.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200911132529.19844-15-will@kernel.org

Convert stage2_wp_range() to call the kvm_pgtable_stage2_wrprotect()
function of the generic page-table code instead of walking the page-table
directly.
Signed-off-by: NQuentin Perret <qperret@google.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200911132529.19844-14-will@kernel.org

Add a stage-2 wrprotect() operation to the generic page-table code.
Signed-off-by: NQuentin Perret <qperret@google.com>
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200911132529.19844-13-will@kernel.org

Convert the page-aging functions and access fault handler to use the
generic page-table code instead of walking the page-table directly.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Reviewed-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-12-will@kernel.org

Add stage-2 mkyoung(), mkold() and is_young() operations to the generic
page-table code.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-11-will@kernel.org

Convert unmap_stage2_range() to use kvm_pgtable_stage2_unmap() instead
of walking the page-table directly.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-10-will@kernel.org

Convert kvm_set_spte_hva() to use kvm_pgtable_stage2_map() instead
of stage2_set_pte().
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-9-will@kernel.org

Convert kvm_phys_addr_ioremap() to use kvm_pgtable_stage2_map() instead
of stage2_set_pte().
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-8-will@kernel.org