kernel/arch/mips/kvm, branch linux-5.1.y

KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID

2019-06-09T07:16:12Z

commit a86cb413f4bf273a9d341a3ab2c2ca44e12eb317 upstream. KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all architectures. However, on s390x, the amount of usable CPUs is determined during runtime - it is depending on the features of the machine the code is running on. Since we are using the vcpu_id as an index into the SCA structures that are defined by the hardware (see e.g. the sca_add_vcpu() function), it is not only the amount of CPUs that is limited by the hard- ware, but also the range of IDs that we can use. Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too. So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common code into the architecture specific code, and on s390x we have to return the same value here as for KVM_CAP_MAX_VCPUS. This problem has been discovered with the kvm_create_max_vcpus selftest. With this change applied, the selftest now passes on s390x, too. Reviewed-by: Andrew Jones Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand Signed-off-by: Thomas Huth Message-Id: <20190523164309.13345-9-thuth@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

MIPS: MemoryMapID (MMID) Support

2019-02-04T18:56:41Z

Introduce support for using MemoryMapIDs (MMIDs) as an alternative to Address Space IDs (ASIDs). The major difference between the two is that MMIDs are global - ie. an MMID uniquely identifies an address space across all coherent CPUs. In contrast ASIDs are non-global per-CPU IDs, wherein each address space is allocated a separate ASID for each CPU upon which it is used. This global namespace allows a new GINVT instruction be used to globally invalidate TLB entries associated with a particular MMID across all coherent CPUs in the system, removing the need for IPIs to invalidate entries with separate ASIDs on each CPU. The allocation scheme used here is largely borrowed from arm64 (see arch/arm64/mm/context.c). In essence we maintain a bitmap to track available MMIDs, and MMIDs in active use at the time of a rollover to a new MMID version are preserved in the new version. The allocation scheme requires efficient 64 bit atomics in order to perform reasonably, so this support depends upon CONFIG_GENERIC_ATOMIC64=n (ie. currently it will only be included in MIPS64 kernels). The first, and currently only, available CPU with support for MMIDs is the MIPS I6500. This CPU supports 16 bit MMIDs, and so for now we cap our MMIDs to 16 bits wide in order to prevent the bitmap growing to absurd sizes if any future CPU does implement 32 bit MMIDs as the architecture manuals suggest is recommended. When MMIDs are in use we also make use of GINVT instruction which is available due to the global nature of MMIDs. By executing a sequence of GINVT & SYNC 0x14 instructions we can avoid the overhead of an IPI to each remote CPU in many cases. One complication is that GINVT will invalidate wired entries (in all cases apart from type 0, which targets the entire TLB). In order to avoid GINVT invalidating any wired TLB entries we set up, we make sure to create those entries using a reserved MMID (0) that we never associate with any address space. Also of note is that KVM will require further work in order to support MMIDs & GINVT, since KVM is involved in allocating IDs for guests & in configuring the MMU. That work is not part of this patch, so for now when MMIDs are in use KVM is disabled. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org

MIPS: mm: Add set_cpu_context() for ASID assignments

2019-02-04T18:56:33Z

When we gain MMID support we'll be storing MMIDs as atomic64_t values and accessing them via atomic64_* functions. This necessitates that we don't use cpu_context() as the left hand side of an assignment, ie. as a modifiable lvalue. In preparation for this introduce a new set_cpu_context() function & replace all assignments with cpu_context() on their left hand side with an equivalent call to set_cpu_context(). To enforce that cpu_context() should not be used for assignments, we rewrite it as a static inline function. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org

MIPS: mm: Unify ASID version checks

2019-02-04T18:56:30Z

Introduce a new check_mmu_context() function to check an mm's ASID version & get a new one if it's outdated, and a check_switch_mmu_context() function which additionally sets up the new ASID & page directory. Simplify switch_mm() & various get_new_mmu_context() callsites in MIPS KVM by making use of the new functions, which will help reduce the amount of code that requires modification to gain MMID support. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org

MIPS: mm: Remove redundant get_new_mmu_context() cpu argument

2019-02-04T18:56:14Z

get_new_mmu_context() accepts a cpu argument, but implicitly assumes that this is always equal to smp_processor_id() by operating on the local CPU's TLB & icache. Remove the cpu argument and have get_new_mmu_context() call smp_processor_id() instead. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org

Merge tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-12-29T21:03:29Z

Pull Kconfig updates from Masahiro Yamada: - support -y option for merge_config.sh to avoid downgrading =y to =m - remove S_OTHER symbol type, and touch include/config/*.h files correctly - fix file name and line number in lexer warnings - fix memory leak when EOF is encountered in quotation - resolve all shift/reduce conflicts of the parser - warn no new line at end of file - make 'source' statement more strict to take only string literal - rewrite the lexer and remove the keyword lookup table - convert to SPDX License Identifier - compile C files independently instead of including them from zconf.y - fix various warnings of gconfig - misc cleanups * tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits) kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings kconfig: add static qualifiers to fix gconf warnings kconfig: split the lexer out of zconf.y kconfig: split some C files out of zconf.y kconfig: convert to SPDX License Identifier kconfig: remove keyword lookup table entirely kconfig: update current_pos in the second lexer kconfig: switch to ASSIGN_VAL state in the second lexer kconfig: stop associating kconf_id with yylval kconfig: refactor end token rules kconfig: stop supporting '.' and '/' in unquoted words treewide: surround Kconfig file paths with double quotes microblaze: surround string default in Kconfig with double quotes kconfig: use T_WORD instead of T_VARIABLE for variables kconfig: use specific tokens instead of T_ASSIGN for assignments kconfig: refactor scanning and parsing "option" properties kconfig: use distinct tokens for type and default properties kconfig: remove redundant token defines kconfig: rename depends_list to comment_option_list ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2018-12-26T19:46:28Z

Pull KVM updates from Paolo Bonzini: "ARM: - selftests improvements - large PUD support for HugeTLB - single-stepping fixes - improved tracing - various timer and vGIC fixes x86: - Processor Tracing virtualization - STIBP support - some correctness fixes - refactorings and splitting of vmx.c - use the Hyper-V range TLB flush hypercall - reduce order of vcpu struct - WBNOINVD support - do not use -ftrace for __noclone functions - nested guest support for PAUSE filtering on AMD - more Hyper-V enlightenments (direct mode for synthetic timers) PPC: - nested VFIO s390: - bugfixes only this time" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits) KVM: x86: Add CPUID support for new instruction WBNOINVD kvm: selftests: ucall: fix exit mmio address guessing Revert "compiler-gcc: disable -ftracer for __noclone functions" KVM: VMX: Move VM-Enter + VM-Exit handling to non-inline sub-routines KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm blobs KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixup MAINTAINERS: Add arch/x86/kvm sub-directories to existing KVM/x86 entry KVM/x86: Use SVM assembly instruction mnemonics instead of .byte streams KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range() KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp() KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() KVM: Make kvm_set_spte_hva() return int KVM: Replace old tlb flush function with new one to flush a specified range. KVM/MMU: Add tlb flush with range helper function KVM/VMX: Add hv tlb range flush support x86/hyper-v: Add HvFlushGuestAddressList hypercall support KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops KVM: x86: Disable Intel PT when VMXON in L1 guest KVM: x86: Set intercept for Intel PT MSRs read/write KVM: x86: Implement Intel PT MSRs read/write emulation ...

treewide: surround Kconfig file paths with double quotes

2018-12-21T15:25:54Z

The Kconfig lexer supports special characters such as '.' and '/' in the parameter context. In my understanding, the reason is just to support bare file paths in the source statement. I do not see a good reason to complicate Kconfig for the room of ambiguity. The majority of code already surrounds file paths with double quotes, and it makes sense since file paths are constant string literals. Make it treewide consistent now. Signed-off-by: Masahiro Yamada Acked-by: Wolfram Sang Acked-by: Geert Uytterhoeven Acked-by: Ingo Molnar

KVM: Make kvm_set_spte_hva() return int

2018-12-21T10:28:41Z

The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by: Lan Tianyu Acked-by: Paul Mackerras Signed-off-by: Paolo Bonzini

kvm: introduce manual dirty log reprotect

2018-12-14T11:34:19Z

There are two problems with KVM_GET_DIRTY_LOG. First, and less important, it can take kvm->mmu_lock for an extended period of time. Second, its user can actually see many false positives in some cases. The latter is due to a benign race like this: 1. KVM_GET_DIRTY_LOG returns a set of dirty pages and write protects them. 2. The guest modifies the pages, causing them to be marked ditry. 3. Userspace actually copies the pages. 4. KVM_GET_DIRTY_LOG returns those pages as dirty again, even though they were not written to since (3). This is especially a problem for large guests, where the time between (1) and (3) can be substantial. This patch introduces a new capability which, when enabled, makes KVM_GET_DIRTY_LOG not write-protect the pages it returns. Instead, userspace has to explicitly clear the dirty log bits just before using the content of the page. The new KVM_CLEAR_DIRTY_LOG ioctl can also operate on a 64-page granularity rather than requiring to sync a full memslot; this way, the mmu_lock is taken for small amounts of time, and only a small amount of time will pass between write protection of pages and the sending of their content. Signed-off-by: Paolo Bonzini