- 05 Dec, 2022 8 commits
-
-
Marc Zyngier authored
* kvm-arm64/parallel-faults: : . : Parallel stage-2 fault handling, courtesy of Oliver Upton. : From the cover letter: : : "Presently KVM only takes a read lock for stage 2 faults if it believes : the fault can be fixed by relaxing permissions on a PTE (write unprotect : for dirty logging). Otherwise, stage 2 faults grab the write lock, which : predictably can pile up all the vCPUs in a sufficiently large VM. : : Like the TDP MMU for x86, this series loosens the locking around : manipulations of the stage 2 page tables to allow parallel faults. RCU : and atomics are exploited to safely build/destroy the stage 2 page : tables in light of multiple software observers." : . KVM: arm64: Reject shared table walks in the hyp code KVM: arm64: Don't acquire RCU read lock for exclusive table walks KVM: arm64: Take a pointer to walker data in kvm_dereference_pteref() KVM: arm64: Handle stage-2 faults in parallel KVM: arm64: Make table->block changes parallel-aware KVM: arm64: Make leaf->leaf PTE changes parallel-aware KVM: arm64: Make block->table PTE changes parallel-aware KVM: arm64: Split init and set for table PTE KVM: arm64: Atomically update stage 2 leaf attributes in parallel walks KVM: arm64: Protect stage-2 traversal with RCU KVM: arm64: Tear down unlinked stage-2 subtree after break-before-make KVM: arm64: Use an opaque type for pteps KVM: arm64: Add a helper to tear down unlinked stage-2 subtrees KVM: arm64: Don't pass kvm_pgtable through kvm_pgtable_walk_data KVM: arm64: Pass mm_ops through the visitor context KVM: arm64: Stash observed pte value in visitor context KVM: arm64: Combine visitor arguments into a context structure Signed-off-by:Marc Zyngier <maz@kernel.org>
-
Marc Zyngier authored
* kvm-arm64/dirty-ring: : . : Add support for the "per-vcpu dirty-ring tracking with a bitmap : and sprinkles on top", courtesy of Gavin Shan. : : This branch drags the kvmarm-fixes-6.1-3 tag which was already : merged in 6.1-rc4 so that the branch is in a working state. : . KVM: Push dirty information unconditionally to backup bitmap KVM: selftests: Automate choosing dirty ring size in dirty_log_test KVM: selftests: Clear dirty ring states between two modes in dirty_log_test KVM: selftests: Use host page size to map ring buffer in dirty_log_test KVM: arm64: Enable ring-based dirty memory tracking KVM: Support dirty ring in conjunction with bitmap KVM: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/52bit-fixes: : . : 52bit PA fixes, courtesy of Ryan Roberts. From the cover letter: : : "I've been adding support for FEAT_LPA2 to KVM and as part of that work have been : testing various (84) configurations of HW, host and guest kernels on FVP. This : has thrown up a couple of pre-existing bugs, for which the fixes are provided." : . KVM: arm64: Fix benign bug with incorrect use of VA_BITS KVM: arm64: Fix PAR_TO_HPFAR() to work independently of PA_BITS. KVM: arm64: Fix kvm init failure when mode!=vhe and VA_BITS=52. Signed-off-by: -
Ryan Roberts authored
get_user_mapping_size() uses kvm's pgtable library to walk a user space page table created by the kernel, and in doing so, passes metadata that the library needs, including ia_bits, which defines the size of the input address. For the case where the kernel is compiled for 52 VA bits but runs on HW that does not support LVA, it will fall back to 48 VA bits at runtime. Therefore we must use vabits_actual rather than VA_BITS to get the true address size. This is benign in the current code base because the pgtable library only uses it for error checking. Fixes: 6011cf68 ("KVM: arm64: Walk userspace page tables to compute the THP mapping size") Signed-off-by:
Ryan Roberts <ryan.roberts@arm.com> Signed-off-by:
-
Marc Zyngier authored
* kvm-arm64/selftest/access-tracking: : . : Small series to add support for arm64 to access_tracking_perf_test and : correct a couple bugs along the way. : : Patches courtesy of Oliver Upton. : . KVM: selftests: Build access_tracking_perf_test for arm64 KVM: selftests: Have perf_test_util signal when to stop vCPUs Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/selftest/s2-faults: : . : New KVM/arm64 selftests exercising various sorts of S2 faults, courtesy : of Ricardo Koller. From the cover letter: : : "This series adds a new aarch64 selftest for testing stage 2 fault handling : for various combinations of guest accesses (e.g., write, S1PTW), backing : sources (e.g., anon), and types of faults (e.g., read on hugetlbfs with a : hole, write on a readonly memslot). Each test tries a different combination : and then checks that the access results in the right behavior (e.g., uffd : faults with the right address and write/read flag). [...]" : . KVM: selftests: aarch64: Add mix of tests into page_fault_test KVM: selftests: aarch64: Add readonly memslot tests into page_fault_test KVM: selftests: aarch64: Add dirty logging tests into page_fault_test KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test KVM: selftests: aarch64: Add aarch64/page_fault_test KVM: selftests: Use the right memslot for code, page-tables, and data allocations KVM: selftests: Fix alignment in virt_arch_pgd_alloc() and vm_vaddr_alloc() KVM: selftests: Add vm->memslots[] and enum kvm_mem_region_type KVM: selftests: Stash backing_src_type in struct userspace_mem_region tools: Copy bitfield.h from the kernel sources KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros KVM: selftests: Add missing close and munmap in __vm_mem_region_delete() KVM: selftests: aarch64: Add virt_get_pte_hva() library function KVM: selftests: Add a userfaultfd library Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/selftest/linked-bps: : . : Additional selftests for the arm64 breakpoints/watchpoints, : courtesy of Reiji Watanabe. From the cover letter: : : "This series adds test cases for linked {break,watch}points to the : debug-exceptions test, and expands {break,watch}point tests to : use non-zero {break,watch}points (the current test always uses : {break,watch}point#0)." : . KVM: arm64: selftests: Test with every breakpoint/watchpoint KVM: arm64: selftests: Add a test case for a linked watchpoint KVM: arm64: selftests: Add a test case for a linked breakpoint KVM: arm64: selftests: Change debug_version() to take ID_AA64DFR0_EL1 KVM: arm64: selftests: Stop unnecessary test stage tracking of debug-exceptions KVM: arm64: selftests: Add helpers to enable debug exceptions KVM: arm64: selftests: Remove the hard-coded {b,w}pn#0 from debug-exceptions KVM: arm64: selftests: Add write_dbg{b,w}{c,v}r helpers in debug-exceptions KVM: arm64: selftests: Use FIELD_GET() to extract ID register fields Signed-off-by: -
Marc Zyngier authored
* kvm-arm64/selftest/memslot-fixes: : . : KVM memslot selftest fixes for non-4kB page sizes, courtesy : of Gavin Shan. From the cover letter: : : "kvm/selftests/memslots_perf_test doesn't work with 64KB-page-size-host : and 4KB-page-size-guest on aarch64. In the implementation, the host and : guest page size have been hardcoded to 4KB. It's ovbiously not working : on aarch64 which supports 4KB, 16KB, 64KB individually on host and guest. : : This series tries to fix it. After the series is applied, the test runs : successfully with 64KB-page-size-host and 4KB-page-size-guest." : . KVM: selftests: memslot_perf_test: Report optimal memory slots KVM: selftests: memslot_perf_test: Consolidate memory KVM: selftests: memslot_perf_test: Support variable guest page size KVM: selftests: memslot_perf_test: Probe memory slots for once KVM: selftests: memslot_perf_test: Consolidate loop conditions in prepare_vm() KVM: selftests: memslot_perf_test: Use data->nslots in prepare_vm() Signed-off-by:
-
- 29 Nov, 2022 2 commits
-
-
Oliver Upton authored
Does exactly what it says on the tin. Reviewed-by:
Gavin Shan <gshan@redhat.com> Signed-off-by:
Oliver Upton <oliver.upton@linux.dev> Signed-off-by:
-
Oliver Upton authored
Signal that a test run is complete through perf_test_args instead of having tests open code a similar solution. Ensure that the field resets to false at the beginning of a test run as the structure is reused between test runs, eliminating a couple of bugs: access_tracking_perf_test hangs indefinitely on a subsequent test run, as 'done' remains true. The bug doesn't amount to much right now, as x86 supports a single guest mode. However, this is a precondition of enabling the test for other architectures with >1 guest mode, like arm64. memslot_modification_stress_test has the exact opposite problem, where subsequent test runs complete immediately as 'run_vcpus' remains false. Co-developed-by:
Sean Christopherson <seanjc@google.com> Signed-off-by:
-
- 22 Nov, 2022 3 commits
-
-
Oliver Upton authored
Exclusive table walks are the only supported table walk in the hyp, as there is no construct like RCU available in the hypervisor code. Reject any attempt to do a shared table walk by returning an error and allowing the caller to clean up the mess. Suggested-by:
Will Deacon <will@kernel.org> Signed-off-by:
-
Oliver Upton authored
Marek reported a BUG resulting from the recent parallel faults changes, as the hyp stage-1 map walker attempted to allocate table memory while holding the RCU read lock: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 2 locks held by swapper/0/1: #0: ffff80000a8a44d0 (kvm_hyp_pgd_mutex){+.+.}-{3:3}, at: __create_hyp_mappings+0x80/0xc4 #1: ffff80000a927720 (rcu_read_lock){....}-{1:2}, at: kvm_pgtable_walk+0x0/0x1f4 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc3+ #5918 Hardware name: Raspberry Pi 3 Model B (DT) Call trace: dump_backtrace.part.0+0xe4/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x8c/0xb8 dump_stack+0x18/0x34 __might_resched+0x178/0x220 __might_sleep+0x48/0xa0 prepare_alloc_pages+0x178/0x1a0 __alloc_pages+0x9c/0x109c alloc_page_interleave+0x1c/0xc4 alloc_pages+0xec/0x160 get_zeroed_page+0x1c/0x44 kvm_hyp_zalloc_page+0x14/0x20 hyp_map_walker+0xd4/0x134 kvm_pgtable_visitor_cb.isra.0+0x38/0x5c __kvm_pgtable_walk+0x1a4/0x220 kvm_pgtable_walk+0x104/0x1f4 kvm_pgtable_hyp_map+0x80/0xc4 __create_hyp_mappings+0x9c/0xc4 kvm_mmu_init+0x144/0x1cc kvm_arch_init+0xe4/0xef4 kvm_init+0x3c/0x3d0 arm_init+0x20/0x30 do_one_initcall+0x74/0x400 kernel_init_freeable+0x2e0/0x350 kernel_init+0x24/0x130 ret_from_fork+0x10/0x20 Since the hyp stage-1 table walkers are serialized by kvm_hyp_pgd_mutex, RCU protection really doesn't add anything. Don't acquire the RCU read lock for an exclusive walk. Reported-by:Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
-
Oliver Upton authored
Rather than passing through the state of the KVM_PGTABLE_WALK_SHARED flag, just take a pointer to the whole walker structure instead. Move around struct kvm_pgtable and the RCU indirection such that the associated ifdeffery remains in one place while ensuring the walker + flags definitions precede their use. No functional change intended. Signed-off-by:
-
- 12 Nov, 2022 1 commit
-
-
Gavin Shan authored
In mark_page_dirty_in_slot(), we bail out when no running vcpu exists and a running vcpu context is strictly required by architecture. It may cause backwards compatible issue. Currently, saving vgic/its tables is the only known case where no running vcpu context is expected. We may have other unknown cases where no running vcpu context exists and it's reported by the warning message and we bail out without pushing the dirty information to the backup bitmap. For this, the application is going to enable the backup bitmap for the unknown cases. However, the dirty information can't be pushed to the backup bitmap even though the backup bitmap is enabled for those unknown cases in the application, until the unknown cases are added to the allowed list of non-running vcpu context with extra code changes to the host kernel. In order to make the new application, where the backup bitmap has been enabled, to work with the unchanged host, we continue to push the dirty information to the backup bitmap instead of bailing out early. With the added check on 'memslot->dirty_bitmap' to mark_page_dirty_in_slot(), the kernel crash is avoided silently by the combined conditions: no running vcpu context, kvm_arch_allow_write_without_running_vcpu() returns 'true', and the backup bitmap (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) isn't enabled yet. Suggested-by:
-
- 10 Nov, 2022 26 commits
-
-
Ryan Roberts authored
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: bc1d7de8 ("kvm: arm64: Add 52bit support for PAR to HPFAR conversoin") Signed-off-by:
-
Ryan Roberts authored
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 7ba8f2b2, the idmap was always 52 bits for a 52 VA bits kernel and therefore the hyp stage1 was also always 52 bits. Fixes: 7ba8f2b2 ("arm64: mm: use a 48-bit ID map when possible on 52-bit VA builds") Signed-off-by:
-
Ricardo Koller authored
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:
-
Ricardo Koller authored
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 authored
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 authored
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 authored
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 authored
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:
Andrew Jones <andrew.jones@linux.dev> Signed-off-by:
-
Ricardo Koller authored
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:
-
Ricardo Koller authored
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 authored
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:
-
Ricardo Koller authored
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 authored
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:
-
Ricardo Koller authored
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:
Ben Gardon <bgardon@google.com> Signed-off-by:
-
Ricardo Koller authored
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:
-
Ricardo Koller authored
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:
-
Reiji Watanabe authored
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:
-
Reiji Watanabe authored
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 authored
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 authored
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 authored
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 authored
Add helpers to enable breakpoint and watchpoint exceptions. No functional change intended. Signed-off-by:
-
Reiji Watanabe authored
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 authored
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 authored
Use FIELD_GET() macro to extract ID register fields for existing aarch64 selftests code. No functional change intended. Signed-off-by:
-
Gavin Shan authored
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:Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by:
-
