- 24 Jun, 2021 29 commits
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Jing Zhang authored
This new API provides a file descriptor for every VM and VCPU to read KVM statistics data in binary format. It is meant to provide a lightweight, flexible, scalable and efficient lock-free solution for user space telemetry applications to pull the statistics data periodically for large scale systems. The pulling frequency could be as high as a few times per second. The statistics descriptors are defined by KVM in kernel and can be by userspace to discover VM/VCPU statistics during the one-time setup stage. The statistics data itself could be read out by userspace telemetry periodically without any extra parsing or setup effort. There are a few existed interface protocols and definitions, but no one can fulfil all the requirements this interface implemented as below: 1. During high frequency periodic stats reading, there should be no extra efforts except the stats data read itself. 2. Support stats annotation, like type (cumulative, instantaneous, peak, histogram, etc) and unit (counter, time, size, cycles, etc). 3. The stats data reading should be free of lock/synchronization. We don't care about the consistency between all the stats data. All stats data can not be read out at exactly the same time. We really care about the change or trend of the stats data. The lock-free solution is not just for efficiency and scalability, also for the stats data accuracy and usability. For example, in the situation that all the stats data readings are protected by a global lock, if one VCPU died somehow with that lock held, then all stats data reading would be blocked, then we have no way from stats data that which VCPU has died. 4. The stats data reading workload can be handed over to other unprivileged process. Reviewed-by:
David Matlack <dmatlack@google.com> Reviewed-by:
Ricardo Koller <ricarkol@google.com> Reviewed-by:
Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by:
Fuad Tabba <tabba@google.com> Signed-off-by:
Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-6-jingzhangos@google.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Jing Zhang authored
Add a VCPU ioctl to get a statistics file descriptor by which a read functionality is provided for userspace to read out VCPU stats header, descriptors and data. Define VCPU statistics descriptors and header for all architectures. Reviewed-by:
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Jing Zhang authored
Add a VM ioctl to get a statistics file descriptor by which a read functionality is provided for userspace to read out VM stats header, descriptors and data. Define VM statistics descriptors and header for all architectures. Reviewed-by:
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Jing Zhang authored
This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by:
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Jing Zhang authored
Generic KVM stats are those collected in architecture independent code or those supported by all architectures; put all generic statistics in a separate structure. This ensures that they are defined the same way in the statistics API which is being added, removing duplication among different architectures in the declaration of the descriptors. No functional change intended. Reviewed-by:
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Sean Christopherson authored
Treat a NULL shadow page in the "is a TDP MMU" check as valid, non-TDP root. KVM uses a "direct" PAE paging MMU when TDP is disabled and the guest is running with paging disabled. In that case, root_hpa points at the pae_root page (of which only 32 bytes are used), not a standard shadow page, and the WARN fires (a lot). Fixes: 0b873fd7 ("KVM: x86/mmu: Remove redundant is_tdp_mmu_enabled check") Cc: David Matlack <dmatlack@google.com> Signed-off-by:
Sean Christopherson <seanjc@google.com> Message-Id: <20210622072454.3449146-1-seanjc@google.com> Signed-off-by:
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Sean Christopherson authored
Add an x86-only test to verify that x86's MMU reacts to CPUID updates that impact the MMU. KVM has had multiple bugs where it fails to reconfigure the MMU after the guest's vCPU model changes. Sadly, this test is effectively limited to shadow paging because the hardware page walk handler doesn't support software disabling of GBPAGES support, and KVM doesn't manually walk the GVA->GPA on faults for performance reasons (doing so would large defeat the benefits of TDP). Don't require !TDP for the tests as there is still value in running the tests with TDP, even though the tests will fail (barring KVM hacks). E.g. KVM should not completely explode if MAXPHYADDR results in KVM using 4-level vs. 5-level paging for the guest. Signed-off-by:
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Sean Christopherson authored
Add x86-64 hugepage support in the form of a x86-only variant of virt_pg_map() that takes an explicit page size. To keep things simple, follow the existing logic for 4k pages and disallow creating a hugepage if the upper-level entry is present, even if the desired pfn matches. Opportunistically fix a double "beyond beyond" reported by checkpatch. Signed-off-by:
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Sean Christopherson authored
In preparation for adding hugepage support, replace "pageMapL4Entry", "pageDirectoryPointerEntry", and "pageDirectoryEntry" with a common "pageUpperEntry", and add a helper to create an upper level entry. All upper level entries have the same layout, using unique structs provides minimal value and requires a non-trivial amount of code duplication. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Add a helper to retrieve a PTE pointer given a PFN, address, and level in preparation for adding hugepage support. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Rename the "address" field to "pfn" in x86's page table structs to match reality. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Add a helper to allocate a page for use in constructing the guest's page tables. All architectures have identical address and memslot requirements (which appear to be arbitrary anyways). No functional change intended. Signed-off-by:
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Sean Christopherson authored
Drop the EPTP memslot param from all EPT helpers and shove the hardcoded '0' down to the vm_phy_page_alloc() calls. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Drop the memslot param from virt_pg_map() and virt_map() and shove the hardcoded '0' down to the vm_phy_page_alloc() calls. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Drop the memslot param(s) from vm_vaddr_alloc() now that all callers directly specific '0' as the memslot. Drop the memslot param from virt_pgd_alloc() as well since vm_vaddr_alloc() is its only user. I.e. shove the hardcoded '0' down to the vm_phy_pages_alloc() calls. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Use KVM_UTIL_MIN_ADDR as the minimum for x86-64's CPUID array. The system page size was likely used as the minimum because _something_ had to be provided. Increasing the min from 0x1000 to 0x2000 should have no meaningful impact on the test, and will allow changing vm_vaddr_alloc() to use KVM_UTIL_MIN_VADDR as the default. Signed-off-by:
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Sean Christopherson authored
Use the common page allocation helper for the xAPIC IPI test, effectively raising the minimum virtual address from 0x1000 to 0x2000. Presumably the test won't explode if it can't get a page at address 0x1000... Cc: Peter Shier <pshier@google.com> Signed-off-by:
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Sean Christopherson authored
Switch to the vm_vaddr_alloc_page() helper for x86-64's "kernel" allocations now that the helper uses the same min virtual address as the open coded versions. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Reduce the minimum virtual address of page allocations from 0x10000 to KVM_UTIL_MIN_VADDR (0x2000). Both values appear to be completely arbitrary, and reducing the min to KVM_UTIL_MIN_VADDR will allow for additional consolidation of code. Signed-off-by:
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Sean Christopherson authored
Add wrappers to allocate 1 and N pages of memory using de facto standard values as the defaults for minimum virtual address, data memslot, and page table memslot. Convert all compatible users. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Use the de facto standard minimum virtual address for Hyper-V's hcall params page. It's the allocator's job to not double-allocate memory, i.e. there's no reason to force different regions for the params vs. hcall page. This will allow adding a page allocation helper with a "standard" minimum address. Signed-off-by:
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Sean Christopherson authored
Refactor x86's GDT/TSS allocations to for memslot '0' at its vm_addr_alloc() call sites instead of passing in '0' from on high. This is a step toward using a common helper for allocating pages. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Use memslot '0' for all vm_vaddr_alloc() calls when loading the test binary. This is the first step toward adding a helper to handle page allocations with a default value for the target memslot. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Fix an apparent copy-paste goof in hyperv_features where hcall_page (which is two pages, so technically just the first page) gets zeroed twice, and hcall_params gets zeroed none times. Signed-off-by:
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Sean Christopherson authored
Drop an unnecessary include of asm/barrier.h from dirty_log_test.c to allow the test to build on arm64. arm64, s390, and x86 all build cleanly without the include (PPC and MIPS aren't supported in KVM's selftests). arm64's barrier.h includes linux/kasan-checks.h, which is not copied into tools/. In file included from ../../../../tools/include/asm/barrier.h:8, from dirty_log_test.c:19: .../arm64/include/asm/barrier.h:12:10: fatal error: linux/kasan-checks.h: No such file or directory 12 | #include <linux/kasan-checks.h> | ^~~~~~~~~~~~~~~~~~~~~~ compilation terminated. Fixes: 84292e56 ("KVM: selftests: Add dirty ring buffer test") Cc: Peter Xu <peterx@redhat.com> Signed-off-by: -
Sean Christopherson authored
Mark #ACs that won't be reinjected to the guest as wanted by L0 so that KVM handles split-lock #AC from L2 instead of forwarding the exception to L1. Split-lock #AC isn't yet virtualized, i.e. L1 will treat it like a regular #AC and do the wrong thing, e.g. reinject it into L2. Fixes: e6f8b6c1 ("KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest") Cc: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by:
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Colin Ian King authored
In the case where kvm_memslots_have_rmaps(kvm) is false the boolean variable flush is not set and is uninitialized. If is_tdp_mmu_enabled(kvm) is true then the call to kvm_tdp_mmu_zap_collapsible_sptes passes the uninitialized value of flush into the call. Fix this by initializing flush to false. Addresses-Coverity: ("Uninitialized scalar variable") Fixes: e2209710 ("KVM: x86/mmu: Skip rmap operations if rmaps not allocated") Signed-off-by:Colin Ian King <colin.king@canonical.com> Reviewed-by:
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Hou Wenlong authored
Commit 22f232d1 ("KVM: selftests: x86: Set supported CPUIDs on default VM") moved vcpu_set_cpuid into vm_create_with_vcpus, but dirty_log_test doesn't use it to create vm. So vcpu's CPUIDs is not set, the guest's pa_bits in kvm would be smaller than the value queried by userspace. However, the dirty track memory slot is in the highest GPA, the reserved bits in gpte would be set with wrong pa_bits. For shadow paging, page fault would fail in permission_fault and be injected into guest. Since guest doesn't have idt, it finally leads to vm_exit for triple fault. Move vcpu_set_cpuid into vm_vcpu_add_default to set supported CPUIDs on default vcpu, since almost all tests need it. Fixes: 22f232d1 ("KVM: selftests: x86: Set supported CPUIDs on default VM") Signed-off-by:
Hou Wenlong <houwenlong93@linux.alibaba.com> Message-Id: <411ea2173f89abce56fc1fca5af913ed9c5a89c9.1624351343.git.houwenlong93@linux.alibaba.com> Signed-off-by:
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Jim Mattson authored
Failed VM-entry is often due to a faulty core. To help identify bad cores, print the id of the last logical processor that attempted VM-entry whenever dumping a VMCS or VMCB. Signed-off-by:
Jim Mattson <jmattson@google.com> Message-Id: <20210621221648.1833148-1-jmattson@google.com> Signed-off-by:
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- 23 Jun, 2021 1 commit
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Paolo Bonzini authored
Merge branch 'topic/ppc-kvm' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into HEAD - Support for the H_RPT_INVALIDATE hypercall - Conversion of Book3S entry/exit to C - Bug fixes
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- 22 Jun, 2021 4 commits
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Nathan Chancellor authored
LLVM does not emit optimal byteswap assembly, which results in high stack usage in kvmhv_enter_nested_guest() due to the inlining of byteswap_pt_regs(). With LLVM 12.0.0: arch/powerpc/kvm/book3s_hv_nested.c:289:6: error: stack frame size of 2512 bytes in function 'kvmhv_enter_nested_guest' [-Werror,-Wframe-larger-than=] long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) ^ 1 error generated. While this gets fixed in LLVM, mark byteswap_pt_regs() as noinline_for_stack so that it does not get inlined and break the build due to -Werror by default in arch/powerpc/. Not inlining saves approximately 800 bytes with LLVM 12.0.0: arch/powerpc/kvm/book3s_hv_nested.c:290:6: warning: stack frame size of 1728 bytes in function 'kvmhv_enter_nested_guest' [-Wframe-larger-than=] long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) ^ 1 warning generated. Cc: stable@vger.kernel.org # v4.20+ Reported-by:kernel test robot <lkp@intel.com> Signed-off-by:
Nathan Chancellor <nathan@kernel.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1292 Link: https://bugs.llvm.org/show_bug.cgi?id=49610 Link: https://lore.kernel.org/r/202104031853.vDT0Qjqj-lkp@intel.com/ Link: https://gist.github.com/ba710e3703bf45043a31e2806c843ffd Link: https://lore.kernel.org/r/20210621182440.990242-1-nathan@kernel.org
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Bharata B Rao authored
In the nested KVM case, replace H_TLB_INVALIDATE by the new hcall H_RPT_INVALIDATE if available. The availability of this hcall is determined from "hcall-rpt-invalidate" string in ibm,hypertas-functions DT property. Signed-off-by:
Bharata B Rao <bharata@linux.ibm.com> Reviewed-by:
Fabiano Rosas <farosas@linux.ibm.com> Reviewed-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
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Bharata B Rao authored
Now that we have H_RPT_INVALIDATE fully implemented, enable support for the same via KVM_CAP_PPC_RPT_INVALIDATE KVM capability Signed-off-by:
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Bharata B Rao authored
Enable support for process-scoped invalidations from nested guests and partition-scoped invalidations for nested guests. Process-scoped invalidations for any level of nested guests are handled by implementing H_RPT_INVALIDATE handler in the nested guest exit path in L0. Partition-scoped invalidation requests are forwarded to the right nested guest, handled there and passed down to L0 for eventual handling. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Squash in fixup patch] Signed-off-by:
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- 21 Jun, 2021 5 commits
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Sean Christopherson authored
Calculate the max VMCS index for vmcs12 by walking the array to find the actual max index. Hardcoding the index is prone to bitrot, and the calculation is only done on KVM bringup (albeit on every CPU, but there aren't _that_ many null entries in the array). Fixes: 3c0f9936 ("KVM: nVMX: Add a TSC multiplier field in VMCS12") Signed-off-by:
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Jim Mattson authored
As part of smaller maxphyaddr emulation, kvm needs to intercept present page faults to see if it needs to add the RSVD flag (bit 3) to the error code. However, there is no need to intercept page faults that already have the RSVD flag set. When setting up the page fault intercept, add the RSVD flag into the #PF error code mask field (but not the #PF error code match field) to skip the intercept when the RSVD flag is already set. Signed-off-by:
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Bharata B Rao authored
H_RPT_INVALIDATE does two types of TLB invalidations: 1. Process-scoped invalidations for guests when LPCR[GTSE]=0. This is currently not used in KVM as GTSE is not usually disabled in KVM. 2. Partition-scoped invalidations that an L1 hypervisor does on behalf of an L2 guest. This is currently handled by H_TLB_INVALIDATE hcall and this new replaces the old that. This commit enables process-scoped invalidations for L1 guests. Support for process-scoped and partition-scoped invalidations from/for nested guests will be added separately. Process scoped tlbie invalidations from L1 and nested guests need RS register for TLBIE instruction to contain both PID and LPID. This patch introduces primitives that execute tlbie instruction with both PID and LPID set in prepartion for H_RPT_INVALIDATE hcall. A description of H_RPT_INVALIDATE follows: int64 /* H_Success: Return code on successful completion */ /* H_Busy - repeat the call with the same */ /* H_Parameter, H_P2, H_P3, H_P4, H_P5 : Invalid parameters */ hcall(const uint64 H_RPT_INVALIDATE, /* Invalidate RPT translation lookaside information */ uint64 id, /* PID/LPID to invalidate */ uint64 target, /* Invalidation target */ uint64 type, /* Type of lookaside information */ uint64 pg_sizes, /* Page sizes */ uint64 start, /* Start of Effective Address (EA) range (inclusive) */ uint64 end) /* End of EA range (exclusive) */ Invalidation targets (target) ----------------------------- Core MMU 0x01 /* All virtual processors in the partition */ Core local MMU 0x02 /* Current virtual processor */ Nest MMU 0x04 /* All nest/accelerator agents in use by the partition */ A combination of the above can be specified, except core and core local. Type of translation to invalidate (type) --------------------------------------- NESTED 0x0001 /* invalidate nested guest partition-scope */ TLB 0x0002 /* Invalidate TLB */ PWC 0x0004 /* Invalidate Page Walk Cache */ PRT 0x0008 /* Invalidate caching of Process Table Entries if NESTED is clear */ PAT 0x0008 /* Invalidate caching of Partition Table Entries if NESTED is set */ A combination of the above can be specified. Page size mask (pages) ---------------------- 4K 0x01 64K 0x02 2M 0x04 1G 0x08 All sizes (-1UL) A combination of the above can be specified. All page sizes can be selected with -1. Semantics: Invalidate radix tree lookaside information matching the parameters given. * Return H_P2, H_P3 or H_P4 if target, type, or pageSizes parameters are different from the defined values. * Return H_PARAMETER if NESTED is set and pid is not a valid nested LPID allocated to this partition * Return H_P5 if (start, end) doesn't form a valid range. Start and end should be a valid Quadrant address and end > start. * Return H_NotSupported if the partition is not in running in radix translation mode. * May invalidate more translation information than requested. * If start = 0 and end = -1, set the range to cover all valid addresses. Else start and end should be aligned to 4kB (lower 11 bits clear). * If NESTED is clear, then invalidate process scoped lookaside information. Else pid specifies a nested LPID, and the invalidation is performed on nested guest partition table and nested guest partition scope real addresses. * If pid = 0 and NESTED is clear, then valid addresses are quadrant 3 and quadrant 0 spaces, Else valid addresses are quadrant 0. * Pages which are fully covered by the range are to be invalidated. Those which are partially covered are considered outside invalidation range, which allows a caller to optimally invalidate ranges that may contain mixed page sizes. * Return H_SUCCESS on success. Signed-off-by:
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Bharata B Rao authored
Add a field to mmu_psize_def to store the page size encodings of H_RPT_INVALIDATE hcall. Initialize this while scanning the radix AP encodings. This will be used when invalidating with required page size encoding in the hcall. Signed-off-by:
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Aneesh Kumar K.V authored
The type values H_RPTI_TYPE_PRT and H_RPTI_TYPE_PAT indicate invalidating the caching of process and partition scoped entries respectively. Signed-off-by:
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- 20 Jun, 2021 1 commit
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Suraj Jitindar Singh authored
The POWER9 vCPU TLB management code assumes all threads in a core share a TLB, and that TLBIEL execued by one thread will invalidate TLBs for all threads. This is not the case for SMT8 capable POWER9 and POWER10 (big core) processors, where the TLB is split between groups of threads. This results in TLB multi-hits, random data corruption, etc. Fix this by introducing cpu_first_tlb_thread_sibling etc., to determine which siblings share TLBs, and use that in the guest TLB flushing code. [npiggin@gmail.com: add changelog and comment] Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Reviewed-by:
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