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2022-11-11KVM: arm64: Rename 'host_kvm' to 'host_mmu'Will Deacon
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
2022-11-11KVM: arm64: Add hyp_spinlock_t static initializerFuad Tabba
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
2022-11-11KVM: arm64: Include asm/kvm_mmu.h in nvhe/mem_protect.hWill Deacon
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
2022-11-11KVM: arm64: Add helpers to pin memory shared with the hypervisor at EL2Quentin Perret
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
2022-11-11KVM: arm64: Prevent the donation of no-map pagesQuentin Perret
Memory regions marked as "no-map" in the host device-tree routinely include TrustZone carev-outs and DMA pools. Although donating such pages to the hypervisor may not breach confidentiality, it could be used to corrupt its state in uncontrollable ways. To prevent this, let's block host-initiated memory transitions targeting "no-map" pages altogether in nVHE protected mode as there should be no valid reason to do this in current operation. Thankfully, the pKVM EL2 hypervisor has a full copy of the host's list of memblock regions, so we can easily check for the presence of the MEMBLOCK_NOMAP flag on a region containing pages being donated from the host. Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> 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/20221110190259.26861-8-will@kernel.org
2022-11-11KVM: arm64: Implement do_donate() helper for donating memoryWill Deacon
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
2022-11-11KVM: arm64: Unify identifiers used to distinguish host and hypervisorWill Deacon
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
2022-11-11KVM: arm64: Fix-up hyp stage-1 refcounts for all pages mapped at EL2Quentin Perret
In order to allow unmapping arbitrary memory pages from the hypervisor stage-1 page-table, fix-up the initial refcount for pages that have been mapped before the 'vmemmap' array was up and running so that it accurately accounts for all existing hypervisor mappings. This is achieved by traversing the entire hypervisor stage-1 page-table during initialisation of EL2 and updating the corresponding 'struct hyp_page' for each valid mapping. 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/20221110190259.26861-5-will@kernel.org
2022-11-11KVM: arm64: Back the hypervisor 'struct hyp_page' array for all memoryQuentin Perret
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
2022-11-11KVM: arm64: Allow attaching of non-coalescable pages to a hyp poolQuentin Perret
All the contiguous pages used to initialize a 'struct hyp_pool' are considered coalescable, which means that the hyp page allocator will actively try to merge them with their buddies on the hyp_put_page() path. However, using hyp_put_page() on a page that is not part of the inital memory range given to a hyp_pool() is currently unsupported. In order to allow dynamically extending hyp pools at run-time, add a check to __hyp_attach_page() to allow inserting 'external' pages into the free-list of order 0. This will be necessary to allow lazy donation of pages from the host to the hypervisor when allocating guest stage-2 page-table pages 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/20221110190259.26861-3-will@kernel.org
2022-11-11KVM: arm64: Move hyp refcount manipulation helpers to common header fileQuentin Perret
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
2022-11-11KVM: arm64: Fix typo in commentZhiyuan Dai
Fix typo in comment (nVHE/VHE). Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1667737840-702-1-git-send-email-daizhiyuan@phytium.com.cn
2022-11-11KVM: arm64: Fix pvtime documentationUsama Arif
This includes table format and using reST labels for cross-referencing to vcpu.rst. Suggested-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Usama Arif <usama.arif@bytedance.com> Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221103131210.3603385-1-usama.arif@bytedance.com
2022-11-10KVM: arm64: Fix PAR_TO_HPFAR() to work independently of PA_BITS.Ryan Roberts
Kernel configs with PAGE_SIZE=64KB and PA_BITS=48 still advertise 52 bit IPA space on HW that implements LPA. This is by design (admitedly this is a very unlikely configuration in the real world). However on such a config, attempting to create a vm with the guest kernel placed above 48 bits in IPA space results in misbehaviour due to the hypervisor incorrectly interpretting a faulting IPA. Fix up PAR_TO_HPFAR() to always take 52 bits out of the PAR rather than masking to CONFIG_ARM64_PA_BITS. If the system has a smaller implemented PARange this should be safe because the bits are res0. A more robust approach would be to discover the IPA size in use by the page-table and mask based on that, to avoid relying on res0 reading back as zero. But this information is difficult to access safely from the code's location, so take the easy way out. Fixes: bc1d7de8c550 ("kvm: arm64: Add 52bit support for PAR to HPFAR conversoin") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> [maz: commit message fixes] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221103150507.32948-3-ryan.roberts@arm.com
2022-11-10KVM: arm64: Fix kvm init failure when mode!=vhe and VA_BITS=52.Ryan Roberts
For nvhe and protected modes, the hyp stage 1 page-tables were previously configured to have the same number of VA bits as the kernel's idmap. However, for kernel configs with VA_BITS=52 and where the kernel is loaded in physical memory below 48 bits, the idmap VA bits is actually smaller than the kernel's normal stage 1 VA bits. This can lead to kernel addresses that can't be mapped into the hypervisor, leading to kvm initialization failure during boot: kvm [1]: IPA Size Limit: 48 bits kvm [1]: Cannot map world-switch code kvm [1]: error initializing Hyp mode: -34 Fix this by ensuring that the hyp stage 1 VA size is the maximum of what's used for the idmap and the regular kernel stage 1. At the same time, refactor the code so that the hyp VA bits is only calculated in one place. Prior to 7ba8f2b2d652, the idmap was always 52 bits for a 52 VA bits kernel and therefore the hyp stage1 was also always 52 bits. Fixes: 7ba8f2b2d652 ("arm64: mm: use a 48-bit ID map when possible on 52-bit VA builds") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> [maz: commit message fixes] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221103150507.32948-2-ryan.roberts@arm.com
2022-11-10KVM: selftests: aarch64: Add mix of tests into page_fault_testRicardo Koller
Add some mix of tests into page_fault_test: memory regions with all the pairwise combinations of read-only, userfaultfd, and dirty-logging. For example, writing into a read-only region which has a hole handled with userfaultfd. Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-15-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Add readonly memslot tests into page_fault_testRicardo Koller
Add some readonly memslot tests into page_fault_test. Mark the data and/or page-table memory regions as readonly, perform some accesses, and check that the right fault is triggered when expected (e.g., a store with no write-back should lead to an mmio exit). Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-14-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Add dirty logging tests into page_fault_testRicardo Koller
Add some dirty logging tests into page_fault_test. Mark the data and/or page-table memory regions for dirty logging, perform some accesses, and check that the dirty log bits are set or clean when expected. Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-13-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Add userfaultfd tests into page_fault_testRicardo Koller
Add some userfaultfd tests into page_fault_test. Punch holes into the data and/or page-table memslots, perform some accesses, and check that the faults are taken (or not taken) when expected. Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-12-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Add aarch64/page_fault_testRicardo Koller
Add a new test for stage 2 faults when using different combinations of guest accesses (e.g., write, S1PTW), backing source type (e.g., anon) and types of faults (e.g., read on hugetlbfs with a hole). The next commits will add different handling methods and more faults (e.g., uffd and dirty logging). This first commit starts by adding two sanity checks for all types of accesses: AF setting by the hw, and accessing memslots with holes. Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-11-ricarkol@google.com
2022-11-10KVM: selftests: Use the right memslot for code, page-tables, and data ↵Ricardo Koller
allocations Now that kvm_vm allows specifying different memslots for code, page tables, and data, use the appropriate memslot when making allocations in common/libraty code. Change them accordingly: - code (allocated by lib/elf) use the CODE memslot - stacks, exception tables, and other core data pages (like the TSS in x86) use the DATA memslot - page tables and the PGD use the PT memslot - test data (anything allocated with vm_vaddr_alloc()) uses the TEST_DATA memslot No functional change intended. All allocators keep using memslot #0. Cc: Sean Christopherson <seanjc@google.com> Cc: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-10-ricarkol@google.com
2022-11-10KVM: selftests: Fix alignment in virt_arch_pgd_alloc() and vm_vaddr_alloc()Ricardo Koller
Refactor virt_arch_pgd_alloc() and vm_vaddr_alloc() in both RISC-V and aarch64 to fix the alignment of parameters in a couple of calls. This will make it easier to fix the alignment in a future commit that adds an extra parameter (that happens to be very long). No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-9-ricarkol@google.com
2022-11-10KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_typeRicardo Koller
The vm_create() helpers are hardcoded to place most page types (code, page-tables, stacks, etc) in the same memslot #0, and always backed with anonymous 4K. There are a couple of issues with that. First, tests willing to differ a bit, like placing page-tables in a different backing source type must replicate much of what's already done by the vm_create() functions. Second, the hardcoded assumption of memslot #0 holding most things is spread everywhere; this makes it very hard to change. Fix the above issues by having selftests specify how they want memory to be laid out. Start by changing ____vm_create() to not create memslot #0; a test (to come) will specify all memslots used by the VM. Then, add the vm->memslots[] array to specify the right memslot for different memory allocators, e.g.,: lib/elf should use the vm->[MEM_REGION_CODE] memslot. This will be used as a way to specify the page-tables memslots (to be backed by huge pages for example). There is no functional change intended. The current commit lays out memory exactly as before. A future commit will change the allocators to get the region they should be using, e.g.,: like the page table allocators using the pt memslot. Cc: Sean Christopherson <seanjc@google.com> Cc: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-8-ricarkol@google.com
2022-11-10KVM: selftests: Stash backing_src_type in struct userspace_mem_regionRicardo Koller
Add the backing_src_type into struct userspace_mem_region. This struct already stores a lot of info about memory regions, except the backing source type. This info will be used by a future commit in order to determine the method for punching a hole. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-7-ricarkol@google.com
2022-11-10tools: Copy bitfield.h from the kernel sourcesRicardo Koller
Copy bitfield.h from include/linux/bitfield.h. A subsequent change will make use of some FIELD_{GET,PREP} macros defined in this header. The header was copied as-is, no changes needed. Cc: Jakub Kicinski <kuba@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-6-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macrosRicardo Koller
Define macros for memory type indexes and construct DEFAULT_MAIR_EL1 with macros from asm/sysreg.h. The index macros can then be used when constructing PTEs (instead of using raw numbers). Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-5-ricarkol@google.com
2022-11-10KVM: selftests: Add missing close and munmap in __vm_mem_region_delete()Ricardo Koller
Deleting a memslot (when freeing a VM) is not closing the backing fd, nor it's unmapping the alias mapping. Fix by adding the missing close and munmap. Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-4-ricarkol@google.com
2022-11-10KVM: selftests: aarch64: Add virt_get_pte_hva() library functionRicardo Koller
Add a library function to get the PTE (a host virtual address) of a given GVA. This will be used in a future commit by a test to clear and check the access flag of a particular page. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-3-ricarkol@google.com
2022-11-10KVM: selftests: Add a userfaultfd libraryRicardo Koller
Move the generic userfaultfd code out of demand_paging_test.c into a common library, userfaultfd_util. This library consists of a setup and a stop function. The setup function starts a thread for handling page faults using the handler callback function. This setup returns a uffd_desc object which is then used in the stop function (to wait and destroy the threads). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221017195834.2295901-2-ricarkol@google.com
2022-11-10KVM: arm64: selftests: Test with every breakpoint/watchpointReiji Watanabe
Currently, the debug-exceptions test always uses only {break,watch}point#0 and the highest numbered context-aware breakpoint. Modify the test to use all {break,watch}points and context-aware breakpoints supported on the system. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-10-reijiw@google.com
2022-11-10KVM: arm64: selftests: Add a test case for a linked watchpointReiji Watanabe
Currently, the debug-exceptions test doesn't have a test case for a linked watchpoint. Add a test case for the linked watchpoint to the test. The new test case uses the highest numbered context-aware breakpoint (for Context ID match), and the watchpoint#0, which is linked to the context-aware breakpoint. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-9-reijiw@google.com
2022-11-10KVM: arm64: selftests: Add a test case for a linked breakpointReiji Watanabe
Currently, the debug-exceptions test doesn't have a test case for a linked breakpoint. Add a test case for the linked breakpoint to the test. The new test case uses a pair of breakpoints. One is the higiest numbered context-aware breakpoint (for Context ID match), and the other one is the breakpoint#0 (for Address Match), which is linked to the context-aware breakpoint. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-8-reijiw@google.com
2022-11-10KVM: arm64: selftests: Change debug_version() to take ID_AA64DFR0_EL1Reiji Watanabe
Change debug_version() to take the ID_AA64DFR0_EL1 value instead of vcpu as an argument, and change its callsite to read ID_AA64DFR0_EL1 (and pass it to debug_version()). Subsequent patches will reuse the register value in the callsite. No functional change intended. Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-7-reijiw@google.com
2022-11-10KVM: arm64: selftests: Stop unnecessary test stage tracking of debug-exceptionsReiji Watanabe
Currently, debug-exceptions test unnecessarily tracks some test stages using GUEST_SYNC(). The code for it needs to be updated as test cases are added or removed. Stop doing the unnecessary stage tracking, as they are not so useful and are a bit pain to maintain. Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-6-reijiw@google.com
2022-11-10KVM: arm64: selftests: Add helpers to enable debug exceptionsReiji Watanabe
Add helpers to enable breakpoint and watchpoint exceptions. No functional change intended. Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-5-reijiw@google.com
2022-11-10KVM: arm64: selftests: Remove the hard-coded {b,w}pn#0 from debug-exceptionsReiji Watanabe
Remove the hard-coded {break,watch}point #0 from the guest_code() in debug-exceptions to allow {break,watch}point number to be specified. Change reset_debug_state() to zeroing all dbg{b,w}{c,v}r_el0 registers so that guest_code() can use the function to reset those registers even when non-zero {break,watch}points are specified for guest_code(). Subsequent patches will add test cases for non-zero {break,watch}points. Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-4-reijiw@google.com
2022-11-10KVM: arm64: selftests: Add write_dbg{b,w}{c,v}r helpers in debug-exceptionsReiji Watanabe
Introduce helpers in the debug-exceptions test to write to dbg{b,w}{c,v}r registers. Those helpers will be useful for test cases that will be added to the test in subsequent patches. No functional change intended. Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-3-reijiw@google.com
2022-11-10KVM: arm64: selftests: Use FIELD_GET() to extract ID register fieldsReiji Watanabe
Use FIELD_GET() macro to extract ID register fields for existing aarch64 selftests code. No functional change intended. Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020054202.2119018-2-reijiw@google.com
2022-11-10KVM: selftests: memslot_perf_test: Report optimal memory slotsGavin Shan
The memory area in each slot should be aligned to host page size. Otherwise, the test will fail. For example, the following command fails with the following messages with 64KB-page-size-host and 4KB-pae-size-guest. It's not user friendly to abort the test. Lets do something to report the optimal memory slots, instead of failing the test. # ./memslot_perf_test -v -s 1000 Number of memory slots: 999 Testing map performance with 1 runs, 5 seconds each Adding slots 1..999, each slot with 8 pages + 216 extra pages last ==== Test Assertion Failure ==== lib/kvm_util.c:824: vm_adjust_num_guest_pages(vm->mode, npages) == npages pid=19872 tid=19872 errno=0 - Success 1 0x00000000004065b3: vm_userspace_mem_region_add at kvm_util.c:822 2 0x0000000000401d6b: prepare_vm at memslot_perf_test.c:273 3 (inlined by) test_execute at memslot_perf_test.c:756 4 (inlined by) test_loop at memslot_perf_test.c:994 5 (inlined by) main at memslot_perf_test.c:1073 6 0x0000ffff7ebb4383: ?? ??:0 7 0x00000000004021ff: _start at :? Number of guest pages is not compatible with the host. Try npages=16 Report the optimal memory slots instead of failing the test when the memory area in each slot isn't aligned to host page size. With this applied, the optimal memory slots is reported. # ./memslot_perf_test -v -s 1000 Number of memory slots: 999 Testing map performance with 1 runs, 5 seconds each Memslot count too high for this test, decrease the cap (max is 514) Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-7-gshan@redhat.com
2022-11-10KVM: selftests: memslot_perf_test: Consolidate memoryGavin Shan
The addresses and sizes passed to vm_userspace_mem_region_add() and madvise() should be aligned to host page size, which can be 64KB on aarch64. So it's wrong by passing additional fixed 4KB memory area to various tests. Fix it by passing additional fixed 64KB memory area to various tests. We also add checks to ensure that none of host/guest page size exceeds 64KB. MEM_TEST_MOVE_SIZE is fixed up to 192KB either. With this, the following command works fine on 64KB-page-size-host and 4KB-page-size-guest. # ./memslot_perf_test -v -s 512 Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-6-gshan@redhat.com
2022-11-10KVM: selftests: memslot_perf_test: Support variable guest page sizeGavin Shan
The test case is obviously broken on aarch64 because non-4KB guest page size is supported. The guest page size on aarch64 could be 4KB, 16KB or 64KB. This supports variable guest page size, mostly for aarch64. - The host determines the guest page size when virtual machine is created. The value is also passed to guest through the synchronization area. - The number of guest pages are unknown until the virtual machine is to be created. So all the related macros are dropped. Instead, their values are dynamically calculated based on the guest page size. - The static checks on memory sizes and pages becomes dependent on guest page size, which is unknown until the virtual machine is about to be created. So all the static checks are converted to dynamic checks, done in check_memory_sizes(). - As the address passed to madvise() should be aligned to host page, the size of page chunk is automatically selected, other than one page. - MEM_TEST_MOVE_SIZE has fixed and non-working 64KB. It will be consolidated in next patch. However, the comments about how it's calculated has been correct. - All other changes included in this patch are almost mechanical replacing '4096' with 'guest_page_size'. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-5-gshan@redhat.com
2022-11-10KVM: selftests: memslot_perf_test: Probe memory slots for onceGavin Shan
prepare_vm() is called in every iteration and run. The allowed memory slots (KVM_CAP_NR_MEMSLOTS) are probed for multiple times. It's not free and unnecessary. Move the probing logic for the allowed memory slots to parse_args() for once, which is upper layer of prepare_vm(). No functional change intended. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-4-gshan@redhat.com
2022-11-10KVM: selftests: memslot_perf_test: Consolidate loop conditions in prepare_vm()Gavin Shan
There are two loops in prepare_vm(), which have different conditions. 'slot' is treated as meory slot index in the first loop, but index of the host virtual address array in the second loop. It makes it a bit hard to understand the code. Change the usage of 'slot' in the second loop, to treat it as the memory slot index either. No functional change intended. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-3-gshan@redhat.com
2022-11-10KVM: selftests: memslot_perf_test: Use data->nslots in prepare_vm()Gavin Shan
In prepare_vm(), 'data->nslots' is assigned with 'max_mem_slots - 1' at the beginning, meaning they are interchangeable. Use 'data->nslots' isntead of 'max_mem_slots - 1'. With this, it becomes easier to move the logic of probing number of slots into upper layer in subsequent patches. No functional change intended. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221020071209.559062-2-gshan@redhat.com
2022-11-10KVM: arm64: Handle stage-2 faults in parallelOliver Upton
The stage-2 map walker has been made parallel-aware, and as such can be called while only holding the read side of the MMU lock. Rip out the conditional locking in user_mem_abort() and instead grab the read lock. Continue to take the write lock from other callsites to kvm_pgtable_stage2_map(). Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107220033.1895655-1-oliver.upton@linux.dev
2022-11-10KVM: arm64: Make table->block changes parallel-awareOliver Upton
stage2_map_walker_try_leaf() and friends now handle stage-2 PTEs generically, and perform the correct flush when a table PTE is removed. Additionally, they've been made parallel-aware, using an atomic break to take ownership of the PTE. Stop clearing the PTE in the pre-order callback and instead let stage2_map_walker_try_leaf() deal with it. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107220006.1895572-1-oliver.upton@linux.dev
2022-11-10KVM: arm64: Make leaf->leaf PTE changes parallel-awareOliver Upton
Convert stage2_map_walker_try_leaf() to use the new break-before-make helpers, thereby making the handler parallel-aware. As before, avoid the break-before-make if recreating the existing mapping. Additionally, retry execution if another vCPU thread is modifying the same PTE. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Ben Gardon <bgardon@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107215934.1895478-1-oliver.upton@linux.dev
2022-11-10KVM: arm64: Make block->table PTE changes parallel-awareOliver Upton
In order to service stage-2 faults in parallel, stage-2 table walkers must take exclusive ownership of the PTE being worked on. An additional requirement of the architecture is that software must perform a 'break-before-make' operation when changing the block size used for mapping memory. Roll these two concepts together into helpers for performing a 'break-before-make' sequence. Use a special PTE value to indicate a PTE has been locked by a software walker. Additionally, use an atomic compare-exchange to 'break' the PTE when the stage-2 page tables are possibly shared with another software walker. Elide the DSB + TLBI if the evicted PTE was invalid (and thus not subject to break-before-make). All of the atomics do nothing for now, as the stage-2 walker isn't fully ready to perform parallel walks. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107215855.1895367-1-oliver.upton@linux.dev
2022-11-10KVM: arm64: Split init and set for table PTEOliver Upton
Create a helper to initialize a table and directly call smp_store_release() to install it (for now). Prepare for a subsequent change that generalizes PTE writes with a helper. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107215644.1895162-11-oliver.upton@linux.dev
2022-11-10KVM: arm64: Atomically update stage 2 leaf attributes in parallel walksOliver Upton
The stage2 attr walker is already used for parallel walks. Since commit f783ef1c0e82 ("KVM: arm64: Add fast path to handle permission relaxation during dirty logging"), KVM acquires the read lock when write-unprotecting a PTE. However, the walker only uses a simple store to update the PTE. This is safe as the only possible race is with hardware updates to the access flag, which is benign. However, a subsequent change to KVM will allow more changes to the stage 2 page tables to be done in parallel. Prepare the stage 2 attribute walker by performing atomic updates to the PTE when walking in parallel. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221107215644.1895162-10-oliver.upton@linux.dev