switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page().
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather
than exclusive, and has fixed a bunch of errors which were caused by its
unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
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Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page()
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
rather than exclusive, and has fixed a bunch of errors which were
caused by its unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics
flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim
accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
shmem: restrict noswap option to initial user namespace
mm/khugepaged: fix conflicting mods to collapse_file()
sparse: remove unnecessary 0 values from rc
mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
maple_tree: fix allocation in mas_sparse_area()
mm: do not increment pgfault stats when page fault handler retries
zsmalloc: allow only one active pool compaction context
selftests/mm: add new selftests for KSM
mm: add new KSM process and sysfs knobs
mm: add new api to enable ksm per process
mm: shrinkers: fix debugfs file permissions
mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
migrate_pages_batch: fix statistics for longterm pin retry
userfaultfd: use helper function range_in_vma()
lib/show_mem.c: use for_each_populated_zone() simplify code
mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
fs/buffer: convert create_page_buffers to folio_create_buffers
fs/buffer: add folio_create_empty_buffers helper
...
The existing pKVM code attempts to advertise CSV2/3 using values
initialized to 0, but never set. To advertise CSV2/3 to protected
guests, pass the CSV2/3 values to hyp when initializing hyp's
view of guests' ID_AA64PFR0_EL1.
Similar to non-protected KVM, these are system-wide, rather than
per cpu, for simplicity.
Fixes: 6c30bfb18d ("KVM: arm64: Add handlers for protected VM System Registers")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20230404152321.413064-1-tabba@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
As a stepping stone towards deprivileging the host's access to the
guest's vCPU structures, introduce some naive flush/sync routines to
copy most of the host vCPU into the hyp vCPU on vCPU run and back
again on return to EL1.
This allows us to run using the pKVM hyp structures when KVM is
initialised in protected mode.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-27-will@kernel.org
Rather than relying on the host to free the previously-donated pKVM
hypervisor VM pages explicitly on teardown, introduce a dedicated
teardown memcache which allows the host to reclaim guest memory
resources without having to keep track of all of the allocations made by
the pKVM hypervisor at EL2.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
[maz: dropped __maybe_unused from unmap_donated_memory_noclear()]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-21-will@kernel.org
Extend the initialisation of guest data structures within the pKVM
hypervisor at EL2 so that we instantiate a memory pool and a full
'struct kvm_s2_mmu' structure for each VM, with a stage-2 page-table
entirely independent from the one managed by the host at EL1.
The 'struct kvm_pgtable_mm_ops' used by the page-table code is populated
with a set of callbacks that can manage guest pages in the hypervisor
without any direct intervention from the host, allocating page-table
pages from the provided pool and returning these to the host on VM
teardown. To keep things simple, the stage-2 MMU for the guest is
configured identically to the host stage-2 in the VTCR register and so
the IPA size of the guest must match the PA size of the host.
For now, the new page-table is unused as there is no way for the host
to map anything into it. Yet.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-20-will@kernel.org
The host at EL1 and the pKVM hypervisor at EL2 will soon need to
exchange memory pages dynamically for creating and destroying VM state.
Indeed, the hypervisor will rely on the host to donate memory pages it
can use to create guest stage-2 page-tables and to store VM and vCPU
metadata. In order to ease this process, introduce a
'struct hyp_memcache' which is essentially a linked list of available
pages, indexed by physical addresses so that it can be passed
meaningfully between the different virtual address spaces configured at
EL1 and EL2.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-18-will@kernel.org
Mapping pages in a guest page-table from within the pKVM hypervisor at
EL2 may require cache maintenance to ensure that the initialised page
contents is visible even to non-cacheable (e.g. MMU-off) accesses from
the guest.
In preparation for performing this maintenance at EL2, introduce a
per-vCPU fixmap which allows the pKVM hypervisor to map guest pages
temporarily into its stage-1 page-table for the purposes of cache
maintenance and, in future, poisoning on the reclaim path. The use of a
fixmap avoids the need for memory allocation or locking on the map()
path.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-15-will@kernel.org
Introduce a global table (and lock) to track pKVM instances at EL2, and
provide hypercalls that can be used by the untrusted host to create and
destroy pKVM VMs and their vCPUs. pKVM VM/vCPU state is directly
accessible only by the trusted hypervisor (EL2).
Each pKVM VM is directly associated with an untrusted host KVM instance,
and is referenced by the host using an opaque handle. Future patches
will provide hypercalls to allow the host to initialize/set/get pKVM
VM/vCPU state using the opaque handle.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
[maz: silence warning on unmap_donated_memory_noclear()]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-13-will@kernel.org
In preparation for introducing VM and vCPU state at EL2, rename the
existing 'struct host_kvm' and its singleton 'host_kvm' instance to
'host_mmu' so as to avoid confusion between the structure tracking the
host stage-2 MMU state and the host instance of a 'struct kvm' for a
protected guest.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-12-will@kernel.org
Introduce a static initializer macro for 'hyp_spinlock_t' so that it is
straightforward to instantiate global locks at EL2. This will be later
utilised for locking the VM table in the hypervisor.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-11-will@kernel.org
nvhe/mem_protect.h refers to __load_stage2() in the definition of
__load_host_stage2() but doesn't include the relevant header.
Include asm/kvm_mmu.h in nvhe/mem_protect.h so that users of the latter
don't have to do this themselves.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-10-will@kernel.org
Add helpers allowing the hypervisor to check whether a range of pages
are currently shared by the host, and 'pin' them if so by blocking host
unshare operations until the memory has been unpinned.
This will allow the hypervisor to take references on host-provided
data-structures (e.g. 'struct kvm') with the guarantee that these pages
will remain in a stable state until the hypervisor decides to release
them, for example during guest teardown.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-9-will@kernel.org
Transferring ownership information of a memory region from one component
to another can be achieved using a "donate" operation, which results
in the previous owner losing access to the underlying pages entirely
and the new owner having exclusive access to the page.
Implement a do_donate() helper, along the same lines as do_{un,}share,
and provide this functionality for the host-{to,from}-hyp cases as this
will later be used to donate/reclaim memory pages to store VM metadata
at EL2.
In a similar manner to the sharing transitions, permission checks are
performed by the hypervisor to ensure that the component initiating the
transition really is the owner of the page and also that the completer
does not currently have a page mapped at the target address.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-7-will@kernel.org
The 'pkvm_component_id' enum type provides constants to refer to the
host and the hypervisor, yet this information is duplicated by the
'pkvm_hyp_id' constant.
Remove the definition of 'pkvm_hyp_id' and move the 'pkvm_component_id'
type definition to 'mem_protect.h' so that it can be used outside of
the memory protection code, for example when initialising the owner for
hypervisor-owned pages.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-6-will@kernel.org
The EL2 'vmemmap' array in nVHE Protected mode is currently very sparse:
only memory pages owned by the hypervisor itself have a matching 'struct
hyp_page'. However, as the size of this struct has been reduced
significantly since its introduction, it appears that we can now afford
to back the vmemmap for all of memory.
Having an easily accessible 'struct hyp_page' for every physical page in
memory provides the hypervisor with a simple mechanism to store metadata
(e.g. a refcount) that wouldn't otherwise fit in the very limited number
of software bits available in the host stage-2 page-table entries. This
will be used in subsequent patches when pinning host memory pages for
use by the hypervisor at EL2.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-4-will@kernel.org
We will soon need to manipulate 'struct hyp_page' refcounts from outside
page_alloc.c, so move the helpers to a common header file to allow them
to be reused easily.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-2-will@kernel.org
The architecture refers to the register field identifying advanced SIMD as
AdvSIMD but the kernel refers to it as ASIMD. Use the architecture's
naming. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-15-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We generally refer to the baseline feature implemented as _IMP so in
preparation for automatic generation of register defines update those for
ID_AA64PFR0_EL1 to reflect this.
In the case of ASIMD we don't actually use the define so just remove it.
No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-14-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The kernel refers to ID_AA64MMFR2_EL1.CnP as CNP. In preparation for
automatic generation of defines for the system registers bring the naming
used by the kernel in sync with that of DDI0487H.a. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-13-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In preparation for converting the ID_AA64MMFR1_EL1 system register
defines to automatic generation, rename them to follow the conventions
used by other automatically generated registers:
* Add _EL1 in the register name.
* Rename fields to match the names in the ARM ARM:
* LOR -> LO
* HPD -> HPDS
* VHE -> VH
* HADBS -> HAFDBS
* SPECSEI -> SpecSEI
* VMIDBITS -> VMIDBits
There should be no functional change as a result of this patch.
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-11-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
For some reason we refer to ID_AA64MMFR0_EL1.ASIDBits as ASID. Add BITS
into the name, bringing the naming into sync with DDI0487H.a. Due to the
large amount of MixedCase in this register which isn't really consistent
with either the kernel style or the majority of the architecture the use of
upper case is preserved. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-10-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
For some reason we refer to ID_AA64MMFR0_EL1.BigEnd as BIGENDEL. Remove the
EL from the name, bringing the naming into sync with DDI0487H.a. Due to the
large amount of MixedCase in this register which isn't really consistent
with either the kernel style or the majority of the architecture the use of
upper case is preserved. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-9-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Our standard is to include the _EL1 in the constant names for registers but
we did not do that for ID_AA64PFR1_EL1, update to do so in preparation for
conversion to automatic generation. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-8-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64PFR0_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-7-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64MMFR2_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64MMFR0_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220905225425.1871461-5-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64ISAR2_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220704170302.2609529-17-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64ISAR1_EL1 to follow the convention. No functional changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220704170302.2609529-16-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
* ultravisor communication device driver
* fix TEID on terminating storage key ops
RISC-V:
* Added Sv57x4 support for G-stage page table
* Added range based local HFENCE functions
* Added remote HFENCE functions based on VCPU requests
* Added ISA extension registers in ONE_REG interface
* Updated KVM RISC-V maintainers entry to cover selftests support
ARM:
* Add support for the ARMv8.6 WFxT extension
* Guard pages for the EL2 stacks
* Trap and emulate AArch32 ID registers to hide unsupported features
* Ability to select and save/restore the set of hypercalls exposed
to the guest
* Support for PSCI-initiated suspend in collaboration with userspace
* GICv3 register-based LPI invalidation support
* Move host PMU event merging into the vcpu data structure
* GICv3 ITS save/restore fixes
* The usual set of small-scale cleanups and fixes
x86:
* New ioctls to get/set TSC frequency for a whole VM
* Allow userspace to opt out of hypercall patching
* Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
AMD SEV improvements:
* Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
* V_TSC_AUX support
Nested virtualization improvements for AMD:
* Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
nested vGIF)
* Allow AVIC to co-exist with a nested guest running
* Fixes for LBR virtualizations when a nested guest is running,
and nested LBR virtualization support
* PAUSE filtering for nested hypervisors
Guest support:
* Decoupling of vcpu_is_preempted from PV spinlocks
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"S390:
- ultravisor communication device driver
- fix TEID on terminating storage key ops
RISC-V:
- Added Sv57x4 support for G-stage page table
- Added range based local HFENCE functions
- Added remote HFENCE functions based on VCPU requests
- Added ISA extension registers in ONE_REG interface
- Updated KVM RISC-V maintainers entry to cover selftests support
ARM:
- Add support for the ARMv8.6 WFxT extension
- Guard pages for the EL2 stacks
- Trap and emulate AArch32 ID registers to hide unsupported features
- Ability to select and save/restore the set of hypercalls exposed to
the guest
- Support for PSCI-initiated suspend in collaboration with userspace
- GICv3 register-based LPI invalidation support
- Move host PMU event merging into the vcpu data structure
- GICv3 ITS save/restore fixes
- The usual set of small-scale cleanups and fixes
x86:
- New ioctls to get/set TSC frequency for a whole VM
- Allow userspace to opt out of hypercall patching
- Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
AMD SEV improvements:
- Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
- V_TSC_AUX support
Nested virtualization improvements for AMD:
- Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
nested vGIF)
- Allow AVIC to co-exist with a nested guest running
- Fixes for LBR virtualizations when a nested guest is running, and
nested LBR virtualization support
- PAUSE filtering for nested hypervisors
Guest support:
- Decoupling of vcpu_is_preempted from PV spinlocks"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (199 commits)
KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
KVM: selftests: x86: Sync the new name of the test case to .gitignore
Documentation: kvm: reorder ARM-specific section about KVM_SYSTEM_EVENT_SUSPEND
x86, kvm: use correct GFP flags for preemption disabled
KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer
x86/kvm: Alloc dummy async #PF token outside of raw spinlock
KVM: x86: avoid calling x86 emulator without a decoded instruction
KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)
s390/uv_uapi: depend on CONFIG_S390
KVM: selftests: x86: Fix test failure on arch lbr capable platforms
KVM: LAPIC: Trace LAPIC timer expiration on every vmentry
KVM: s390: selftest: Test suppression indication on key prot exception
KVM: s390: Don't indicate suppression on dirtying, failing memop
selftests: drivers/s390x: Add uvdevice tests
drivers/s390/char: Add Ultravisor io device
MAINTAINERS: Update KVM RISC-V entry to cover selftests support
RISC-V: KVM: Introduce ISA extension register
RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
...
The macros for accessing fields in ID_AA64ISAR0_EL1 omit the _EL1 from the
name of the register. In preparation for converting this register to be
automatically generated update the names to include an _EL1, there should
be no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220503170233.507788-8-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The architecture reference manual refers to the field in bits 23:20 of
ID_AA64ISAR0_EL1 with the name "atomic" but the kernel defines for this
bitfield use the name "atomics". Bring the two into sync to make it easier
to cross reference with the specification.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220503170233.507788-7-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.
This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).
Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-3-kaleshsingh@google.com
QARMA3 is relaxed version of the QARMA5 algorithm which expected to
reduce the latency of calculation while still delivering a suitable
level of security.
Support for QARMA3 can be discovered via ID_AA64ISAR2_EL1
APA3, bits [15:12] Indicates whether the QARMA3 algorithm is
implemented in the PE for address
authentication in AArch64 state.
GPA3, bits [11:8] Indicates whether the QARMA3 algorithm is
implemented in the PE for generic code
authentication in AArch64 state.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220224124952.119612-4-vladimir.murzin@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
* kvm-arm64/pkvm-hyp-sharing:
: .
: Series from Quentin Perret, implementing HYP page share/unshare:
:
: This series implements an unshare hypercall at EL2 in nVHE
: protected mode, and makes use of it to unmmap guest-specific
: data-structures from EL2 stage-1 during guest tear-down.
: Crucially, the implementation of the share and unshare
: routines use page refcounts in the host kernel to avoid
: accidentally unmapping data-structures that overlap a common
: page.
: [...]
: .
KVM: arm64: pkvm: Unshare guest structs during teardown
KVM: arm64: Expose unshare hypercall to the host
KVM: arm64: Implement do_unshare() helper for unsharing memory
KVM: arm64: Implement __pkvm_host_share_hyp() using do_share()
KVM: arm64: Implement do_share() helper for sharing memory
KVM: arm64: Introduce wrappers for host and hyp spin lock accessors
KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages
KVM: arm64: pkvm: Refcount the pages shared with EL2
KVM: arm64: Introduce kvm_share_hyp()
KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2
KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table
KVM: arm64: Fixup hyp stage-1 refcount
KVM: arm64: Refcount hyp stage-1 pgtable pages
KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator
Signed-off-by: Marc Zyngier <maz@kernel.org>
Introduce an unshare hypercall which can be used to unmap memory from
the hypervisor stage-1 in nVHE protected mode. This will be useful to
update the EL2 ownership state of pages during guest teardown, and
avoids keeping dangling mappings to unreferenced portions of memory.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-14-qperret@google.com
Explicitly name the combination of SW0 | SW1 as reserved in the pte and
introduce a new PKVM_NOPAGE meta-state which, although not directly
stored in the software bits of the pte, can be used to represent an
entry for which there is no underlying page. This is distinct from an
invalid pte, as stage-2 identity mappings for the host are created
lazily and so an invalid pte there is the same as a valid mapping for
the purposes of ownership information.
This state will be used for permission checking during page transitions
in later patches.
Reviewed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-9-qperret@google.com
* kvm-arm64/pkvm-cleanups-5.17:
: .
: pKVM cleanups from Quentin Perret:
:
: This series is a collection of various fixes and cleanups for KVM/arm64
: when running in nVHE protected mode. The first two patches are real
: fixes/improvements, the following two are minor cleanups, and the last
: two help satisfy my paranoia so they're certainly optional.
: .
KVM: arm64: pkvm: Make kvm_host_owns_hyp_mappings() robust to VHE
KVM: arm64: pkvm: Stub io map functions
KVM: arm64: Make __io_map_base static
KVM: arm64: Make the hyp memory pool static
KVM: arm64: pkvm: Disable GICv2 support
KVM: arm64: pkvm: Fix hyp_pool max order
Signed-off-by: Marc Zyngier <maz@kernel.org>
The __io_map_base variable is used at EL2 to track the end of the
hypervisor's "private" VA range in nVHE protected mode. However it
doesn't need to be used outside of mm.c, so let's make it static to keep
all the hyp VA allocation logic in one place.
Signed-off-by: Quentin Perret <qperret@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211208152300.2478542-5-qperret@google.com
The hyp memory pool struct is sized to fit exactly the needs of the
hypervisor stage-1 page-table allocator, so it is important it is not
used for anything else. As it is currently used only from setup.c,
reduce its visibility by marking it static.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211208152300.2478542-4-qperret@google.com
kvm/hyp/reserved_mem.c contains host code executing at EL1 and is not
linked into the hypervisor object. Move the file into kvm/pkvm.c and
rework the headers so that the definitions shared between the host and
the hypervisor live in asm/kvm_pkvm.h.
Signed-off-by: Will Deacon <will@kernel.org>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211202171048.26924-4-will@kernel.org
- More progress on the protected VM front, now with the full
fixed feature set as well as the limitation of some hypercalls
after initialisation.
- Cleanup of the RAZ/WI sysreg handling, which was pointlessly
complicated
- Fixes for the vgic placement in the IPA space, together with a
bunch of selftests
- More memcg accounting of the memory allocated on behalf of a guest
- Timer and vgic selftests
- Workarounds for the Apple M1 broken vgic implementation
- KConfig cleanups
- New kvmarm.mode=none option, for those who really dislike us
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Merge tag 'kvmarm-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for Linux 5.16
- More progress on the protected VM front, now with the full
fixed feature set as well as the limitation of some hypercalls
after initialisation.
- Cleanup of the RAZ/WI sysreg handling, which was pointlessly
complicated
- Fixes for the vgic placement in the IPA space, together with a
bunch of selftests
- More memcg accounting of the memory allocated on behalf of a guest
- Timer and vgic selftests
- Workarounds for the Apple M1 broken vgic implementation
- KConfig cleanups
- New kvmarm.mode=none option, for those who really dislike us
Place kvm_handle_pvm_restricted() next to its little friends such
as kvm_handle_pvm_sysreg().
This allows to make inject_undef64() static.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20211013120346.2926621-10-maz@kernel.org
kvm_fixed_config.h is pkvm specific, and would be better placed
near its users. At the same time, include/nvhe/sys_regs.h is now
almost empty.
Merge the two into arch/arm64/kvm/hyp/include/nvhe/fixed_config.h.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20211013120346.2926621-9-maz@kernel.org
Rather than exposing a whole set of helper functions to retrieve
individual ID registers, use the existing decoding tree and expose
a single helper instead.
This allow a number of functions to be made static, and we now
have a single entry point to maintain.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20211013120346.2926621-3-maz@kernel.org
Protected VMs have more restricted features that need to be
trapped. Moreover, the host should not be trusted to set the
appropriate trapping registers and their values.
Initialize the trapping registers, i.e., hcr_el2, mdcr_el2, and
cptr_el2 at EL2 for protected guests, based on the values of the
guest's feature id registers.
No functional change intended as trap handlers introduced in the
previous patch are still not hooked in to the guest exit
handlers.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010145636.1950948-9-tabba@google.com
Add system register handlers for protected VMs. These cover Sys64
registers (including feature id registers), and debug.
No functional change intended as these are not hooked in yet to
the guest exit handlers introduced earlier. So when trapping is
triggered, the exit handlers let the host handle it, as before.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010145636.1950948-8-tabba@google.com
The KVM page-table library refcounts the pages of concatenated stage-2
PGDs individually. However, when running KVM in protected mode, the
host's stage-2 PGD is currently managed by EL2 as a single high-order
compound page, which can cause the refcount of the tail pages to reach 0
when they shouldn't, hence corrupting the page-table.
Fix this by introducing a new hyp_split_page() helper in the EL2 page
allocator (matching the kernel's split_page() function), and make use of
it from host_s2_zalloc_pages_exact().
Fixes: 1025c8c0c6 ("KVM: arm64: Wrap the host with a stage 2")
Acked-by: Will Deacon <will@kernel.org>
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211005090155.734578-5-qperret@google.com
* kvm-arm64/mmu/vmid-cleanups:
: Cleanup the stage-2 configuration by providing a single helper,
: and tidy up some of the ordering requirements for the VMID
: allocator.
KVM: arm64: Upgrade VMID accesses to {READ,WRITE}_ONCE
KVM: arm64: Unify stage-2 programming behind __load_stage2()
KVM: arm64: Move kern_hyp_va() usage in __load_guest_stage2() into the callers
Signed-off-by: Marc Zyngier <maz@kernel.org>
The protected mode relies on a separate helper to load the
S2 context. Move over to the __load_guest_stage2() helper
instead, and rename it to __load_stage2() to present a unified
interface.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210806113109.2475-5-will@kernel.org
The __pkvm_create_mappings() function is no longer used outside of
nvhe/mm.c, make it static.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-22-qperret@google.com
The host kernel is currently able to change EL2 stage-1 mappings without
restrictions thanks to the __pkvm_create_mappings() hypercall. But in a
world where the host is no longer part of the TCB, this clearly poses a
problem.
To fix this, introduce a new hypercall to allow the host to share a
physical memory page with the hypervisor, and remove the
__pkvm_create_mappings() variant. The new hypercall implements
ownership and permission checks before allowing the sharing operation,
and it annotates the shared page in the hypervisor stage-1 and host
stage-2 page-tables.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-21-qperret@google.com
Refactor the hypervisor stage-1 locking in nVHE protected mode to expose
a new pkvm_create_mappings_locked() function. This will be used in later
patches to allow walking and changing the hypervisor stage-1 without
releasing the lock.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-20-qperret@google.com
Now that we mark memory owned by the hypervisor in the host stage-2
during __pkvm_init(), we no longer need to rely on the host to
explicitly mark the hyp sections later on.
Remove the __pkvm_mark_hyp() hypercall altogether.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-19-qperret@google.com
Introduce a helper usable in nVHE protected mode to check whether a
physical address is in a RAM region or not.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-16-qperret@google.com
Allow references to the hypervisor's owner id from outside
mem_protect.c.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-15-qperret@google.com
We will need to manipulate the host stage-2 page-table from outside
mem_protect.c soon. Introduce two functions allowing this, and make
them usable to users of mem_protect.h.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-14-qperret@google.com
We will soon start annotating shared pages in page-tables in nVHE
protected mode. Define all the states in which a page can be (owned,
shared and owned, shared and borrowed), and provide helpers allowing to
convert this into SW bits annotations using the matching prot
attributes.
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-13-qperret@google.com
Introduce a poor man's lockdep implementation at EL2 which allows to
BUG() whenever a hyp spinlock is not held when it should. Hide this
feature behind a new Kconfig option that targets the EL2 object
specifically, instead of piggy backing on the existing CONFIG_LOCKDEP.
EL2 cannot WARN() cleanly to report locking issues, hence BUG() is the
only option and it is not clear whether we want this widely enabled.
This is most likely going to be useful for local testing until the EL2
WARN() situation has improved.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-3-qperret@google.com
Introduce hyp_spin_is_locked() so that functions can easily assert that
a given lock is held (albeit possibly by another CPU!) without having to
drag full lockdep support up to EL2.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-2-qperret@google.com
The hyp_page refcount is currently encoded on 4 bytes even though we
never need to count that many objects in a page. Make it 2 bytes to save
some space in the vmemmap.
As overflows are more likely to happen as well, make sure to catch those
with a BUG in the increment function.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-8-qperret@google.com
The hyp_page order is currently encoded on 4 bytes even though it is
guaranteed to be smaller than this. Make it 2 bytes to reduce the hyp
vmemmap overhead.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-7-qperret@google.com
Each struct hyp_page currently contains a pointer to a hyp_pool struct
where the page should be freed if its refcount reaches 0. However, this
information can always be inferred from the context in the EL2 code, so
drop the pointer to save a few bytes in the vmemmap.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-6-qperret@google.com
We currently maintain two separate memory pools for the host stage-2,
one for pages used in the page-table when mapping memory regions, and
the other to map MMIO regions. The former is large enough to map all of
memory with page granularity and the latter can cover an arbitrary
portion of IPA space, but allows to 'recycle' pages.
However, this split makes accounting difficult to manage as pages at
intermediate levels of the page-table may be used to map both memory and
MMIO regions. Simplify the scheme by merging both pools into one. This
means we can now hit the -ENOMEM case in the memory abort path, but
we're still guaranteed forward-progress in the worst case by unmapping
MMIO regions. On the plus side this also means we can usually map a lot
more MMIO space at once if memory ranges happen to be mapped with block
mappings.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-5-qperret@google.com
The list_head member of struct hyp_page is only needed when the page is
attached to a free-list, which by definition implies the page is free.
As such, nothing prevents us from using the page itself to store the
list_head, hence reducing the size of the vmemmap.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-4-qperret@google.com
The hyp_page refcount helpers currently rely on the hyp_pool lock for
serialization. However, this means the refcounts can't be changed from
the buddy allocator core as it already holds the lock, which means pages
have to go through odd transient states.
For example, when a page is freed, its refcount is set to 0, and the
lock is transiently released before the page can be attached to a free
list in the buddy tree. This is currently harmless as the allocator
checks the list node of each page to see if it is available for
allocation or not, but it means the page refcount can't be trusted to
represent the state of the page even if the pool lock is held.
In order to fix this, remove the pool locking from the refcount helpers,
and move all the logic to the buddy allocator. This will simplify the
removal of the list node from struct hyp_page in a later patch.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-2-qperret@google.com
When KVM runs in nVHE protected mode, use the host stage 2 to unmap the
hypervisor sections by marking them as owned by the hypervisor itself.
The long-term goal is to ensure the EL2 code can remain robust
regardless of the host's state, so this starts by making sure the host
cannot e.g. write to the .hyp sections directly.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-39-qperret@google.com
When KVM runs in protected nVHE mode, make use of a stage 2 page-table
to give the hypervisor some control over the host memory accesses. The
host stage 2 is created lazily using large block mappings if possible,
and will default to page mappings in absence of a better solution.
>From this point on, memory accesses from the host to protected memory
regions (e.g. not 'owned' by the host) are fatal and lead to hyp_panic().
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-36-qperret@google.com
Extend the memory pool allocated for the hypervisor to include enough
pages to map all of memory at page granularity for the host stage 2.
While at it, also reserve some memory for device mappings.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-27-qperret@google.com
When memory protection is enabled, the EL2 code needs the ability to
create and manage its own page-table. To do so, introduce a new set of
hypercalls to bootstrap a memory management system at EL2.
This leads to the following boot flow in nVHE Protected mode:
1. the host allocates memory for the hypervisor very early on, using
the memblock API;
2. the host creates a set of stage 1 page-table for EL2, installs the
EL2 vectors, and issues the __pkvm_init hypercall;
3. during __pkvm_init, the hypervisor re-creates its stage 1 page-table
and stores it in the memory pool provided by the host;
4. the hypervisor then extends its stage 1 mappings to include a
vmemmap in the EL2 VA space, hence allowing to use the buddy
allocator introduced in a previous patch;
5. the hypervisor jumps back in the idmap page, switches from the
host-provided page-table to the new one, and wraps up its
initialization by enabling the new allocator, before returning to
the host.
6. the host can free the now unused page-table created for EL2, and
will now need to issue hypercalls to make changes to the EL2 stage 1
mappings instead of modifying them directly.
Note that for the sake of simplifying the review, this patch focuses on
the hypervisor side of things. In other words, this only implements the
new hypercalls, but does not make use of them from the host yet. The
host-side changes will follow in a subsequent patch.
Credits to Will for __pkvm_init_switch_pgd.
Acked-by: Will Deacon <will@kernel.org>
Co-authored-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-18-qperret@google.com
When memory protection is enabled, the hyp code will require a basic
form of memory management in order to allocate and free memory pages at
EL2. This is needed for various use-cases, including the creation of hyp
mappings or the allocation of stage 2 page tables.
To address these use-case, introduce a simple memory allocator in the
hyp code. The allocator is designed as a conventional 'buddy allocator',
working with a page granularity. It allows to allocate and free
physically contiguous pages from memory 'pools', with a guaranteed order
alignment in the PA space. Each page in a memory pool is associated
with a struct hyp_page which holds the page's metadata, including its
refcount, as well as its current order, hence mimicking the kernel's
buddy system in the GFP infrastructure. The hyp_page metadata are made
accessible through a hyp_vmemmap, following the concept of
SPARSE_VMEMMAP in the kernel.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-13-qperret@google.com
With nVHE, the host currently creates all stage 1 hypervisor mappings at
EL1 during boot, installs them at EL2, and extends them as required
(e.g. when creating a new VM). But in a world where the host is no
longer trusted, it cannot have full control over the code mapped in the
hypervisor.
In preparation for enabling the hypervisor to create its own stage 1
mappings during boot, introduce an early page allocator, with minimal
functionality. This allocator is designed to be used only during early
bootstrap of the hyp code when memory protection is enabled, which will
then switch to using a full-fledged page allocator after init.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-11-qperret@google.com
We will soon need to synchronise multiple CPUs in the hyp text at EL2.
The qspinlock-based locking used by the host is overkill for this purpose
and relies on the kernel's "percpu" implementation for the MCS nodes.
Implement a simple ticket locking scheme based heavily on the code removed
by commit c11090474d ("arm64: locking: Replace ticket lock implementation
with qspinlock").
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-4-qperret@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
