- 27 Dec, 2022 25 commits
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David Woodhouse authored
Most notably, the KVM_XEN_EVTCHN_RESET feature had escaped documentation entirely. Along with how to turn most stuff off on SHUTDOWN_soft_reset. Signed-off-by:
David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20221226120320.1125390-6-dwmw2@infradead.org> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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David Woodhouse authored
These are (uint64_t)-1 magic values are a userspace ABI, allowing the shared info pages and other enlightenments to be disabled. This isn't a Xen ABI because Xen doesn't let the guest turn these off except with the full SHUTDOWN_soft_reset mechanism. Under KVM, the userspace VMM is expected to handle soft reset, and tear down the kernel parts of the enlightenments accordingly. Suggested-by:
Sean Christopherson <seanjc@google.com> Signed-off-by:
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Michal Luczaj authored
Port number is validated in kvm_xen_setattr_evtchn(). Remove superfluous checks in kvm_xen_eventfd_assign() and kvm_xen_eventfd_update(). Signed-off-by:
Michal Luczaj <mhal@rbox.co> Message-Id: <20221222203021.1944101-3-mhal@rbox.co> Signed-off-by:
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Paolo Bonzini authored
The evtchnfd structure itself must be protected by either kvm->lock or SRCU. Use the former in kvm_xen_eventfd_update(), since the lock is being taken anyway; kvm_xen_hcall_evtchn_send() instead is a reader and does not need kvm->lock, and is called in SRCU critical section from the kvm_x86_handle_exit function. It is also important to use rcu_read_{lock,unlock}() in kvm_xen_hcall_evtchn_send(), because idr_remove() will *not* use synchronize_srcu() to wait for readers to complete. Remove a superfluous if (kvm) check before calling synchronize_srcu() in kvm_xen_eventfd_deassign() where kvm has been dereferenced already. Co-developed-by: -
David Woodhouse authored
In particular, we shouldn't assume that being contiguous in guest virtual address space means being contiguous in guest *physical* address space. In dropping the manual calls to kvm_mmu_gva_to_gpa_system(), also drop the srcu_read_lock() that was around them. All call sites are reached from kvm_xen_hypercall() which is called from the handle_exit function with the read lock already held. 53639526 ("KVM: x86/xen: handle PV timers oneshot mode") 1a65105a ("KVM: x86/xen: handle PV spinlocks slowpath") Fixes: 2fd6df2f ("KVM: x86/xen: intercept EVTCHNOP_send from guests") Signed-off-by: -
Michal Luczaj authored
Release page irrespectively of kvm_vcpu_write_guest() return value. Suggested-by:
Paul Durrant <paul@xen.org> Fixes: 23200b7a ("KVM: x86/xen: intercept xen hypercalls if enabled") Signed-off-by:
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Sean Christopherson authored
Delete an extra block of code/documentation that snuck in when KVM's documentation was converted to ReST format. Fixes: 106ee47d ("docs: kvm: Convert api.txt to ReST format") Signed-off-by:
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Lai Jiangshan authored
"be split be split" -> "be split" Signed-off-by:
Lai Jiangshan <jiangshan.ljs@antgroup.com> Message-Id: <20221207120505.9175-1-jiangshanlai@gmail.com> Signed-off-by:
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Lai Jiangshan authored
No code is using KVM_MMU_READ_LOCK() or KVM_MMU_READ_UNLOCK(). They used to be in virt/kvm/pfncache.c: KVM_MMU_READ_LOCK(kvm); retry = mmu_notifier_retry_hva(kvm, mmu_seq, uhva); KVM_MMU_READ_UNLOCK(kvm); However, since 58cd407c ("KVM: Fix multiple races in gfn=>pfn cache refresh", 2022-05-25) the code is only relying on the MMU notifier's invalidation count and sequence number. Signed-off-by: -
Lukas Bulwahn authored
Commit a789aeba ("KVM: VMX: Rename "vmx/evmcs.{ch}" to "vmx/hyperv.{ch}"") renames the VMX specific Hyper-V files, but does not adjust the entry in MAINTAINERS. Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a broken reference. Repair this file reference in KVM X86 HYPER-V (KVM/hyper-v). Signed-off-by:
Lukas Bulwahn <lukas.bulwahn@gmail.com> Fixes: a789aeba ("KVM: VMX: Rename "vmx/evmcs.{ch}" to "vmx/hyperv.{ch}"") Reviewed-by:
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Oliver Upton authored
The loop marks vaddr as mapped after incrementing it by page size, thereby marking the *next* page as mapped. Set the bit in vpages_mapped first instead. Fixes: 56fc7732 ("KVM: selftests: Fill in vm->vpages_mapped bitmap in virt_map() too") Signed-off-by:
Oliver Upton <oliver.upton@linux.dev> Message-Id: <20221209015307.1781352-4-oliver.upton@linux.dev> Signed-off-by:
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Oliver Upton authored
Currently the ucall MMIO hole is placed immediately after slot0, which is a relatively safe address in the PA space. However, it is possible that the same address has already been used for something else (like the guest program image) in the VA space. At least in my own testing, building the vgic_irq test with clang leads to the MMIO hole appearing underneath gicv3_ops. Stop identity mapping the MMIO hole and instead find an unused VA to map to it. Yet another subtle detail of the KVM selftests library is that virt_pg_map() does not update vm->vpages_mapped. Switch over to virt_map() instead to guarantee that the chosen VA isn't to something else. Signed-off-by:
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Paolo Bonzini authored
Explain the meaning of the bit manipulations of vm_vaddr_populate_bitmap. These correspond to the "canonical addresses" of x86 and other architectures, but that is not obvious. Signed-off-by: -
Sean Christopherson authored
Use a magic value to signal a ucall_alloc() failure instead of simply doing GUEST_ASSERT(). GUEST_ASSERT() relies on ucall_alloc() and so a failure puts the guest into an infinite loop. Use -1 as the magic value, as a real ucall struct should never wrap. Reported-by:
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Sean Christopherson authored
Disable gnu-variable-sized-type-not-at-end so that tests and libraries can create overlays of variable sized arrays at the end of structs when using a fixed number of entries, e.g. to get/set a single MSR. It's possible to fudge around the warning, e.g. by defining a custom struct that hardcodes the number of entries, but that is a burden for both developers and readers of the code. lib/x86_64/processor.c:664:19: warning: field 'header' with variable sized type 'struct kvm_msrs' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] struct kvm_msrs header; ^ lib/x86_64/processor.c:772:19: warning: field 'header' with variable sized type 'struct kvm_msrs' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] struct kvm_msrs header; ^ lib/x86_64/processor.c:787:19: warning: field 'header' with variable sized type 'struct kvm_msrs' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] struct kvm_msrs header; ^ 3 warnings generated. x86_64/hyperv_tlb_flush.c:54:18: warning: field 'hv_vp_set' with variable sized type 'struct hv_vpset' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] struct hv_vpset hv_vp_set; ^ 1 warning generated. x86_64/xen_shinfo_test.c:137:25: warning: field 'info' with variable sized type 'struct kvm_irq_routing' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] struct kvm_irq_routing info; ^ 1 warning generated. Signed-off-by: -
Sean Christopherson authored
Include lib.mk before consuming $(CC) and document that lib.mk overwrites $(CC) unless make was invoked with -e or $(CC) was specified after make (which makes the environment override the Makefile). Including lib.mk after using it for probing, e.g. for -no-pie, can lead to weirdness. Signed-off-by:
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Sean Christopherson authored
Explicitly disable the compiler's builtin memcmp(), memcpy(), and memset(). Because only lib/string_override.c is built with -ffreestanding, the compiler reserves the right to do what it wants and can try to link the non-freestanding code to its own crud. /usr/bin/x86_64-linux-gnu-ld: /lib/x86_64-linux-gnu/libc.a(memcmp.o): in function `memcmp_ifunc': (.text+0x0): multiple definition of `memcmp'; tools/testing/selftests/kvm/lib/string_override.o: tools/testing/selftests/kvm/lib/string_override.c:15: first defined here clang: error: linker command failed with exit code 1 (use -v to see invocation) Fixes: 6b6f7148 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use") Reported-by:
Aaron Lewis <aaronlewis@google.com> Reported-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
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Sean Christopherson authored
Probe -no-pie with the actual set of CFLAGS used to compile the tests, clang whines about -no-pie being unused if the tests are compiled with -static. clang: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument] Signed-off-by:
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Sean Christopherson authored
Make the main() functions in the probing code proper prototypes so that compiling the probing code with more strict flags won't generate false negatives. <stdin>:1:5: error: function declaration isn’t a prototype [-Werror=strict-prototypes] Signed-off-by:
Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by:
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Sean Christopherson authored
Rename UNAME_M to ARCH_DIR and explicitly set it directly for x86. At this point, the name of the arch directory really doesn't have anything to do with `uname -m`, and UNAME_M is unnecessarily confusing given that its purpose is purely to identify the arch specific directory. Signed-off-by:
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Sean Christopherson authored
Fix a == vs. = typo in kvm_get_cpu_address_width() that results in @pa_bits being left unset if the CPU doesn't support enumerating its MAX_PHY_ADDR. Flagged by clang's unusued-value warning. lib/x86_64/processor.c:1034:51: warning: expression result unused [-Wunused-value] *pa_bits == kvm_cpu_has(X86_FEATURE_PAE) ? 36 : 32; Fixes: 3bd39635 ("KVM: selftests: Add X86_FEATURE_PAE and use it calc "fallback" MAXPHYADDR") Signed-off-by: -
Sean Christopherson authored
Use pattern matching to exclude everything except .c, .h, .S, and .sh files from Git. Manually adding every test target has an absurd maintenance cost, is comically error prone, and leads to bikeshedding over whether or not the targets should be listed in alphabetical order. Deliberately do not include the one-off assets, e.g. config, settings, .gitignore itself, etc as Git doesn't ignore files that are already in the repository. Adding the one-off assets won't prevent mistakes where developers forget to --force add files that don't match the "allowed". Signed-off-by:
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Sean Christopherson authored
Check that the number of pages per slot is non-zero in get_max_slots() prior to computing the remaining number of pages. clang generates code that uses an actual DIV for calculating the remaining, which causes a #DE if the total number of pages is less than the number of slots. traps: memslot_perf_te[97611] trap divide error ip:4030c4 sp:7ffd18ae58f0 error:0 in memslot_perf_test[401000+cb000] Fixes: a69170c6 ("KVM: selftests: memslot_perf_test: Report optimal memory slots") Signed-off-by: -
Sean Christopherson authored
Delete an unused struct definition in x86_64/vmx_tsc_adjust_test.c. Signed-off-by:
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Sean Christopherson authored
Define a literal '0' asm input constraint to aarch64/page_fault_test's guest_cas() as an unsigned long to make clang happy. tools/testing/selftests/kvm/aarch64/page_fault_test.c:120:16: error: value size does not match register size specified by the constraint and modifier [-Werror,-Wasm-operand-widths] :: "r" (0), "r" (TEST_DATA), "r" (guest_test_memory)); ^ tools/testing/selftests/kvm/aarch64/page_fault_test.c:119:15: note: use constraint modifier "w" "casal %0, %1, [%2]\n" ^~ %w0 Fixes: 35c58101 ("KVM: selftests: aarch64: Add aarch64/page_fault_test") Cc: Ricardo Koller <ricarkol@google.com> Signed-off-by:
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- 23 Dec, 2022 13 commits
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Sean Christopherson authored
Don't install a leaf TDP MMU SPTE if the parent page's level doesn't match the target level of the fault, and instead have the vCPU retry the faulting instruction after warning. Continuing on is completely unnecessary as the absolute worst case scenario of retrying is DoSing the vCPU, whereas continuing on all but guarantees bigger explosions, e.g. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/mmu/tdp_mmu.c:559! invalid opcode: 0000 [#1] SMP CPU: 1 PID: 1025 Comm: nx_huge_pages_t Tainted: G W 6.1.0-rc4+ #64 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:__handle_changed_spte.cold+0x95/0x9c RSP: 0018:ffffc9000072faf8 EFLAGS: 00010246 RAX: 00000000000000c1 RBX: ffffc90000731000 RCX: 0000000000000027 RDX: 0000000000000000 RSI: 00000000ffffdfff RDI: ffff888277c5b4c8 RBP: 0600000112400bf3 R08: ffff888277c5b4c0 R09: ffffc9000072f9a0 R10: 0000000000000001 R11: 0000000000000001 R12: 06000001126009f3 R13: 0000000000000002 R14: 0000000012600901 R15: 0000000012400b01 FS: 00007fba9f853740(0000) GS:ffff888277c40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010aa7a003 CR4: 0000000000172ea0 Call Trace: <TASK> kvm_tdp_mmu_map+0x3b0/0x510 kvm_tdp_page_fault+0x10c/0x130 kvm_mmu_page_fault+0x103/0x680 vmx_handle_exit+0x132/0x5a0 [kvm_intel] vcpu_enter_guest+0x60c/0x16f0 kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> Modules linked in: kvm_intel ---[ end trace 0000000000000000 ]--- Signed-off-by:
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Sean Christopherson authored
Re-check sp->nx_huge_page_disallowed under the tdp_mmu_pages_lock spinlock when adding a new shadow page in the TDP MMU. To ensure the NX reclaim kthread can't see a not-yet-linked shadow page, the page fault path links the new page table prior to adding the page to possible_nx_huge_pages. If the page is zapped by different task, e.g. because dirty logging is disabled, between linking the page and adding it to the list, KVM can end up triggering use-after-free by adding the zapped SP to the aforementioned list, as the zapped SP's memory is scheduled for removal via RCU callback. The bug is detected by the sanity checks guarded by CONFIG_DEBUG_LIST=y, i.e. the below splat is just one possible signature. ------------[ cut here ]------------ list_add corruption. prev->next should be next (ffffc9000071fa70), but was ffff88811125ee38. (prev=ffff88811125ee38). WARNING: CPU: 1 PID: 953 at lib/list_debug.c:30 __list_add_valid+0x79/0xa0 Modules linked in: kvm_intel CPU: 1 PID: 953 Comm: nx_huge_pages_t Tainted: G W 6.1.0-rc4+ #71 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:__list_add_valid+0x79/0xa0 RSP: 0018:ffffc900006efb68 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888116cae8a0 RCX: 0000000000000027 RDX: 0000000000000027 RSI: 0000000100001872 RDI: ffff888277c5b4c8 RBP: ffffc90000717000 R08: ffff888277c5b4c0 R09: ffffc900006efa08 R10: 0000000000199998 R11: 0000000000199a20 R12: ffff888116cae930 R13: ffff88811125ee38 R14: ffffc9000071fa70 R15: ffff88810b794f90 FS: 00007fc0415d2740(0000) GS:ffff888277c40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000115201006 CR4: 0000000000172ea0 Call Trace: <TASK> track_possible_nx_huge_page+0x53/0x80 kvm_tdp_mmu_map+0x242/0x2c0 kvm_tdp_page_fault+0x10c/0x130 kvm_mmu_page_fault+0x103/0x680 vmx_handle_exit+0x132/0x5a0 [kvm_intel] vcpu_enter_guest+0x60c/0x16f0 kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> ---[ end trace 0000000000000000 ]--- Fixes: 61f94478 ("KVM: x86/mmu: Set disallowed_nx_huge_page in TDP MMU before setting SPTE") Reported-by:
Greg Thelen <gthelen@google.com> Analyzed-by:
David Matlack <dmatlack@google.com> Cc: David Matlack <dmatlack@google.com> Cc: Ben Gardon <bgardon@google.com> Cc: Mingwei Zhang <mizhang@google.com> Signed-off-by:
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Sean Christopherson authored
Map the leaf SPTE when handling a TDP MMU page fault if and only if the target level is reached. A recent commit reworked the retry logic and incorrectly assumed that walking SPTEs would never "fail", as the loop either bails (retries) or installs parent SPs. However, the iterator itself will bail early if it detects a frozen (REMOVED) SPTE when stepping down. The TDP iterator also rereads the current SPTE before stepping down specifically to avoid walking into a part of the tree that is being removed, which means it's possible to terminate the loop without the guts of the loop observing the frozen SPTE, e.g. if a different task zaps a parent SPTE between the initial read and try_step_down()'s refresh. Mapping a leaf SPTE at the wrong level results in all kinds of badness as page table walkers interpret the SPTE as a page table, not a leaf, and walk into the weeds. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1025 at arch/x86/kvm/mmu/tdp_mmu.c:1070 kvm_tdp_mmu_map+0x481/0x510 Modules linked in: kvm_intel CPU: 1 PID: 1025 Comm: nx_huge_pages_t Tainted: G W 6.1.0-rc4+ #64 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_tdp_mmu_map+0x481/0x510 RSP: 0018:ffffc9000072fba8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffffc9000072fcc0 RCX: 0000000000000027 RDX: 0000000000000027 RSI: 00000000ffffdfff RDI: ffff888277c5b4c8 RBP: ffff888107d45a10 R08: ffff888277c5b4c0 R09: ffffc9000072fa48 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc9000073a0e0 R13: ffff88810fc54800 R14: ffff888107d1ae60 R15: ffff88810fc54f90 FS: 00007fba9f853740(0000) GS:ffff888277c40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010aa7a003 CR4: 0000000000172ea0 Call Trace: <TASK> kvm_tdp_page_fault+0x10c/0x130 kvm_mmu_page_fault+0x103/0x680 vmx_handle_exit+0x132/0x5a0 [kvm_intel] vcpu_enter_guest+0x60c/0x16f0 kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> ---[ end trace 0000000000000000 ]--- Invalid SPTE change: cannot replace a present leaf SPTE with another present leaf SPTE mapping a different PFN! as_id: 0 gfn: 100200 old_spte: 600000112400bf3 new_spte: 6000001126009f3 level: 2 ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/mmu/tdp_mmu.c:559! invalid opcode: 0000 [#1] SMP CPU: 1 PID: 1025 Comm: nx_huge_pages_t Tainted: G W 6.1.0-rc4+ #64 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:__handle_changed_spte.cold+0x95/0x9c RSP: 0018:ffffc9000072faf8 EFLAGS: 00010246 RAX: 00000000000000c1 RBX: ffffc90000731000 RCX: 0000000000000027 RDX: 0000000000000000 RSI: 00000000ffffdfff RDI: ffff888277c5b4c8 RBP: 0600000112400bf3 R08: ffff888277c5b4c0 R09: ffffc9000072f9a0 R10: 0000000000000001 R11: 0000000000000001 R12: 06000001126009f3 R13: 0000000000000002 R14: 0000000012600901 R15: 0000000012400b01 FS: 00007fba9f853740(0000) GS:ffff888277c40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010aa7a003 CR4: 0000000000172ea0 Call Trace: <TASK> kvm_tdp_mmu_map+0x3b0/0x510 kvm_tdp_page_fault+0x10c/0x130 kvm_mmu_page_fault+0x103/0x680 vmx_handle_exit+0x132/0x5a0 [kvm_intel] vcpu_enter_guest+0x60c/0x16f0 kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> Modules linked in: kvm_intel ---[ end trace 0000000000000000 ]--- Fixes: 63d28a25 ("KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry") Cc: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by:
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Sean Christopherson authored
Hoist the is_removed_spte() check above the "level == goal_level" check when walking SPTEs during a TDP MMU page fault to avoid attempting to map a leaf entry if said entry is frozen by a different task/vCPU. ------------[ cut here ]------------ WARNING: CPU: 3 PID: 939 at arch/x86/kvm/mmu/tdp_mmu.c:653 kvm_tdp_mmu_map+0x269/0x4b0 Modules linked in: kvm_intel CPU: 3 PID: 939 Comm: nx_huge_pages_t Not tainted 6.1.0-rc4+ #67 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_tdp_mmu_map+0x269/0x4b0 RSP: 0018:ffffc9000068fba8 EFLAGS: 00010246 RAX: 00000000000005a0 RBX: ffffc9000068fcc0 RCX: 0000000000000005 RDX: ffff88810741f000 RSI: ffff888107f04600 RDI: ffffc900006a3000 RBP: 060000010b000bf3 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 000ffffffffff000 R12: 0000000000000005 R13: ffff888113670000 R14: ffff888107464958 R15: 0000000000000000 FS: 00007f01c942c740(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000117013006 CR4: 0000000000172ea0 Call Trace: <TASK> kvm_tdp_page_fault+0x10c/0x130 kvm_mmu_page_fault+0x103/0x680 vmx_handle_exit+0x132/0x5a0 [kvm_intel] vcpu_enter_guest+0x60c/0x16f0 kvm_arch_vcpu_ioctl_run+0x1e2/0x9d0 kvm_vcpu_ioctl+0x271/0x660 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK> ---[ end trace 0000000000000000 ]--- Fixes: 63d28a25 ("KVM: x86/mmu: simplify kvm_tdp_mmu_map flow when guest has to retry") Cc: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by:
Robert Hoo <robert.hu@linux.intel.com> Message-Id: <20221213033030.83345-2-seanjc@google.com> Signed-off-by:
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Sean Christopherson authored
When stuffing the allowed secondary execution controls for nested VMX in response to CPUID updates, don't set the allowed-1 bit for a feature that isn't supported by KVM, i.e. isn't allowed by the canonical vmcs_config. WARN if KVM attempts to manipulate a feature that isn't supported. All features that are currently stuffed are always advertised to L1 for nested VMX if they are supported in KVM's base configuration, and no additional features should ever be added to the CPUID-induced stuffing (updating VMX MSRs in response to CPUID updates is a long-standing KVM flaw that is slowly being fixed). Signed-off-by:
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Sean Christopherson authored
Set ENABLE_USR_WAIT_PAUSE in KVM's supported VMX MSR configuration if the feature is supported in hardware and enabled in KVM's base, non-nested configuration, i.e. expose ENABLE_USR_WAIT_PAUSE to L1 if it's supported. This fixes a bug where saving/restoring, i.e. migrating, a vCPU will fail if WAITPKG (the associated CPUID feature) is enabled for the vCPU, and obviously allows L1 to enable the feature for L2. KVM already effectively exposes ENABLE_USR_WAIT_PAUSE to L1 by stuffing the allowed-1 control ina vCPU's virtual MSR_IA32_VMX_PROCBASED_CTLS2 when updating secondary controls in response to KVM_SET_CPUID(2), but (a) that depends on flawed code (KVM shouldn't touch VMX MSRs in response to CPUID updates) and (b) runs afoul of vmx_restore_control_msr()'s restriction that the guest value must be a strict subset of the supported host value. Although no past commit explicitly enabled nested support for WAITPKG, doing so is safe and functionally correct from an architectural perspective as no additional KVM support is needed to virtualize TPAUSE, UMONITOR, and UMWAIT for L2 relative to L1, and KVM already forwards VM-Exits to L1 as necessary (commit bf653b78, "KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit"). Note, KVM always keeps the hosts MSR_IA32_UMWAIT_CONTROL resident in hardware, i.e. always runs both L1 and L2 with the host's power management settings for TPAUSE and UMWAIT. See commit bf09fb6c ("KVM: VMX: Stop context switching MSR_IA32_UMWAIT_CONTROL") for more details. Fixes: e69e72fa ("KVM: x86: Add support for user wait instructions") Cc: stable@vger.kernel.org Reported-by:
Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by:
Jim Mattson <jmattson@google.com> Message-Id: <20221213062306.667649-2-seanjc@google.com> Signed-off-by:
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Sean Christopherson authored
Explicitly drop the result of kvm_vcpu_write_guest() when writing the "launch state" as part of VMCLEAR emulation, and add a comment to call out that KVM's behavior is architecturally valid. Intel's pseudocode effectively says that VMCLEAR is a nop if the target VMCS address isn't in memory, e.g. if the address points at MMIO. Add a FIXME to call out that suppressing failures on __copy_to_user() is wrong, as memory (a memslot) does exist in that case. Punt the issue to the future as open coding kvm_vcpu_write_guest() just to make sure the guest dies with -EFAULT isn't worth the extra complexity. The flaw will need to be addressed if KVM ever does something intelligent on uaccess failures, e.g. to support post-copy demand paging, but in that case KVM will need a more thorough overhaul, i.e. VMCLEAR shouldn't need to open code a core KVM helper. No functional change intended. Reported-by:
coverity-bot <keescook+coverity-bot@chromium.org> Addresses-Coverity-ID: 1527765 ("Error handling issues") Fixes: 587d7e72 ("kvm: nVMX: VMCLEAR should not cause the vCPU to shut down") Cc: Jim Mattson <jmattson@google.com> Signed-off-by:
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Sean Christopherson authored
Zero out the valid_bank_mask when using the fast variant of HVCALL_SEND_IPI_EX to send IPIs to all vCPUs. KVM requires the "var_cnt" and "valid_bank_mask" inputs to be consistent even when targeting all vCPUs. See commit bd1ba573 ("KVM: x86: Get the number of Hyper-V sparse banks from the VARHEAD field"). Fixes: 99848924 ("KVM: selftests: Hyper-V PV IPI selftest") Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
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Sean Christopherson authored
Add a sanity check in kvm_handle_memory_failure() to assert that a valid x86_exception structure is provided if the memory "failure" wants to propagate a fault into the guest. If a memory failure happens during a direct guest physical memory access, e.g. for nested VMX, KVM hardcodes the failure to X86EMUL_IO_NEEDED and doesn't provide an exception pointer (because the exception struct would just be filled with garbage). Signed-off-by:
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Peng Hao authored
kvm_apic_hw_enabled() only needs to return bool, there is no place to use the return value of MSR_IA32_APICBASE_ENABLE. Signed-off-by:
Peng Hao <flyingpeng@tencent.com> Message-Id: <CAPm50aJ=BLXNWT11+j36Dd6d7nz2JmOBk4u7o_NPQ0N61ODu1g@mail.gmail.com> Signed-off-by:
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Vitaly Kuznetsov authored
In kvm_hv_flush_tlb(), 'data_offset' and 'consumed_xmm_halves' variables are used in a mutually exclusive way: in 'hc->fast' we count in 'XMM halves' and increase 'data_offset' otherwise. Coverity discovered, that in one case both variables are incremented unconditionally. This doesn't seem to cause any issues as the only user of 'data_offset'/'consumed_xmm_halves' data is kvm_hv_get_tlb_flush_entries() -> kvm_hv_get_hc_data() which also takes into account 'hc->fast' but is still worth fixing. To make things explicit, put 'data_offset' and 'consumed_xmm_halves' to 'struct kvm_hv_hcall' as a union and use at call sites. This allows to remove explicit 'data_offset'/'consumed_xmm_halves' parameters from kvm_hv_get_hc_data()/kvm_get_sparse_vp_set()/kvm_hv_get_tlb_flush_entries() helpers. Note: 'struct kvm_hv_hcall' is allocated on stack in kvm_hv_hypercall() and is not zeroed, consumers are supposed to initialize the appropriate field if needed. Reported-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by:
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Adamos Ttofari authored
When scanning userspace I/OAPIC entries, intercept EOI for level-triggered IRQs if the current vCPU has a pending and/or in-service IRQ for the vector in its local API, even if the vCPU doesn't match the new entry's destination. This fixes a race between userspace I/OAPIC reconfiguration and IRQ delivery that results in the vector's bit being left set in the remote IRR due to the eventual EOI not being forwarded to the userspace I/OAPIC. Commit 0fc5a36d ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race") fixed the in-kernel IOAPIC, but not the userspace IOAPIC configuration, which has a similar race. Fixes: 0fc5a36d ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race") Signed-off-by:
Adamos Ttofari <attofari@amazon.de> Reviewed-by:
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Like Xu authored
The current vPMU can reuse the same pmc->perf_event for the same hardware event via pmc_pause/resume_counter(), but this optimization does not apply to a portion of the TSX events (e.g., "event=0x3c,in_tx=1, in_tx_cp=1"), where event->attr.sample_period is legally zero at creation, thus making the perf call to perf_event_period() meaningless (no need to adjust sample period in this case), and instead causing such reusable perf_events to be repeatedly released and created. Avoid releasing zero sample_period events by checking is_sampling_event() to follow the previously enable/disable optimization. Signed-off-by:
Like Xu <likexu@tencent.com> Message-Id: <20221207071506.15733-2-likexu@tencent.com> Signed-off-by:
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- 14 Dec, 2022 1 commit
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Sean Christopherson authored
Add ReST formatting to the set of userspace MSR exits/flags so that the resulting HTML docs generate a table instead of malformed gunk. This also fixes a warning that was introduced by a recent cleanup of the relevant documentation (yay copy+paste). >> Documentation/virt/kvm/api.rst:7287: WARNING: Block quote ends without a blank line; unexpected unindent. Fixes: 1ae09954 ("KVM: x86: Allow deflecting unknown MSR accesses to user space") Fixes: 1f158147 ("KVM: x86: Clean up KVM_CAP_X86_USER_SPACE_MSR documentation") Reported-by:kernel test robot <lkp@intel.com> Signed-off-by:
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- 12 Dec, 2022 1 commit
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Paolo Bonzini authored
x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes
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