diff options
Diffstat (limited to 'Documentation/virt/kvm')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 68 | ||||
| -rw-r--r-- | Documentation/virt/kvm/locking.rst | 14 |
2 files changed, 56 insertions, 26 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index dae68e68ca23..a6729c8cf063 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -3357,6 +3357,7 @@ flags which can include the following: - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] + - KVM_GUESTDBG_BLOCKIRQ: avoid injecting interrupts/NMI/SMI [x86] For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints are enabled in memory so we need to ensure breakpoint exceptions are @@ -5077,7 +5078,7 @@ of bytes successfully copied is returned. If the call completes successfully then ``length`` is returned. 4.131 KVM_GET_SREGS2 ------------------- +-------------------- :Capability: KVM_CAP_SREGS2 :Architectures: x86 @@ -5090,17 +5091,17 @@ This ioctl (when supported) replaces the KVM_GET_SREGS. :: -struct kvm_sregs2 { - /* out (KVM_GET_SREGS2) / in (KVM_SET_SREGS2) */ - struct kvm_segment cs, ds, es, fs, gs, ss; - struct kvm_segment tr, ldt; - struct kvm_dtable gdt, idt; - __u64 cr0, cr2, cr3, cr4, cr8; - __u64 efer; - __u64 apic_base; - __u64 flags; - __u64 pdptrs[4]; -}; + struct kvm_sregs2 { + /* out (KVM_GET_SREGS2) / in (KVM_SET_SREGS2) */ + struct kvm_segment cs, ds, es, fs, gs, ss; + struct kvm_segment tr, ldt; + struct kvm_dtable gdt, idt; + __u64 cr0, cr2, cr3, cr4, cr8; + __u64 efer; + __u64 apic_base; + __u64 flags; + __u64 pdptrs[4]; + }; flags values for ``kvm_sregs2``: @@ -5110,7 +5111,7 @@ flags values for ``kvm_sregs2``: 4.132 KVM_SET_SREGS2 ------------------- +-------------------- :Capability: KVM_CAP_SREGS2 :Architectures: x86 @@ -5201,12 +5202,16 @@ trailing ``'\0'``, is indicated by the ``name_size`` field in the header. The descriptors block is only needed to be read once for the lifetime of the file descriptor contains a sequence of ``struct kvm_stats_desc``, each followed by a string of size ``name_size``. +:: #define KVM_STATS_TYPE_SHIFT 0 #define KVM_STATS_TYPE_MASK (0xF << KVM_STATS_TYPE_SHIFT) #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT) #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT) #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT) + #define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST #define KVM_STATS_UNIT_SHIFT 4 #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT) @@ -5214,18 +5219,20 @@ by a string of size ``name_size``. #define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT) #define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT) #define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT) + #define KVM_STATS_UNIT_MAX KVM_STATS_UNIT_CYCLES #define KVM_STATS_BASE_SHIFT 8 #define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT) #define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT) #define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT) + #define KVM_STATS_BASE_MAX KVM_STATS_BASE_POW2 struct kvm_stats_desc { __u32 flags; __s16 exponent; __u16 size; __u32 offset; - __u32 unused; + __u32 bucket_size; char name[]; }; @@ -5234,24 +5241,40 @@ by this descriptor. Its endianness is CPU native. The following flags are supported: Bits 0-3 of ``flags`` encode the type: + * ``KVM_STATS_TYPE_CUMULATIVE`` - The statistics data is cumulative. The value of data can only be increased. + The statistics reports a cumulative count. The value of data can only be increased. Most of the counters used in KVM are of this type. The corresponding ``size`` field for this type is always 1. All cumulative statistics data are read/write. * ``KVM_STATS_TYPE_INSTANT`` - The statistics data is instantaneous. Its value can be increased or + The statistics reports an instantaneous value. Its value can be increased or decreased. This type is usually used as a measurement of some resources, like the number of dirty pages, the number of large pages, etc. All instant statistics are read only. The corresponding ``size`` field for this type is always 1. * ``KVM_STATS_TYPE_PEAK`` - The statistics data is peak. The value of data can only be increased, and - represents a peak value for a measurement, for example the maximum number + The statistics data reports a peak value, for example the maximum number of items in a hash table bucket, the longest time waited and so on. + The value of data can only be increased. The corresponding ``size`` field for this type is always 1. + * ``KVM_STATS_TYPE_LINEAR_HIST`` + The statistic is reported as a linear histogram. The number of + buckets is specified by the ``size`` field. The size of buckets is specified + by the ``hist_param`` field. The range of the Nth bucket (1 <= N < ``size``) + is [``hist_param``*(N-1), ``hist_param``*N), while the range of the last + bucket is [``hist_param``*(``size``-1), +INF). (+INF means positive infinity + value.) The bucket value indicates how many samples fell in the bucket's range. + * ``KVM_STATS_TYPE_LOG_HIST`` + The statistic is reported as a logarithmic histogram. The number of + buckets is specified by the ``size`` field. The range of the first bucket is + [0, 1), while the range of the last bucket is [pow(2, ``size``-2), +INF). + Otherwise, The Nth bucket (1 < N < ``size``) covers + [pow(2, N-2), pow(2, N-1)). The bucket value indicates how many samples fell + in the bucket's range. Bits 4-7 of ``flags`` encode the unit: + * ``KVM_STATS_UNIT_NONE`` There is no unit for the value of statistics data. This usually means that the value is a simple counter of an event. @@ -5266,6 +5289,7 @@ Bits 4-7 of ``flags`` encode the unit: Bits 8-11 of ``flags``, together with ``exponent``, encode the scale of the unit: + * ``KVM_STATS_BASE_POW10`` The scale is based on power of 10. It is used for measurement of time and CPU clock cycles. For example, an exponent of -9 can be used with @@ -5282,9 +5306,9 @@ unsigned 64bit data. The ``offset`` field is the offset from the start of Data Block to the start of the corresponding statistics data. -The ``unused`` field is reserved for future support for other types of -statistics data, like log/linear histogram. Its value is always 0 for the types -defined above. +The ``bucket_size`` field is used as a parameter for histogram statistics data. +It is only used by linear histogram statistics data, specifying the size of a +bucket. The ``name`` field is the name string of the statistics data. The name string starts at the end of ``struct kvm_stats_desc``. The maximum length including @@ -7213,7 +7237,7 @@ supported in the host. A VMM can check whether the service is available to the guest on migration. 8.33 KVM_CAP_HYPERV_ENFORCE_CPUID ------------------------------ +--------------------------------- Architectures: x86 diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst index 35eca377543d..5d27da356836 100644 --- a/Documentation/virt/kvm/locking.rst +++ b/Documentation/virt/kvm/locking.rst @@ -21,14 +21,20 @@ The acquisition orders for mutexes are as follows: can be taken inside a kvm->srcu read-side critical section, while kvm->slots_lock cannot. +- kvm->mn_active_invalidate_count ensures that pairs of + invalidate_range_start() and invalidate_range_end() callbacks + use the same memslots array. kvm->slots_lock and kvm->slots_arch_lock + are taken on the waiting side in install_new_memslots, so MMU notifiers + must not take either kvm->slots_lock or kvm->slots_arch_lock. + On x86: - vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock -- kvm->arch.mmu_lock is an rwlock. kvm->arch.tdp_mmu_pages_lock is - taken inside kvm->arch.mmu_lock, and cannot be taken without already - holding kvm->arch.mmu_lock (typically with ``read_lock``, otherwise - there's no need to take kvm->arch.tdp_mmu_pages_lock at all). +- kvm->arch.mmu_lock is an rwlock. kvm->arch.tdp_mmu_pages_lock and + kvm->arch.mmu_unsync_pages_lock are taken inside kvm->arch.mmu_lock, and + cannot be taken without already holding kvm->arch.mmu_lock (typically with + ``read_lock`` for the TDP MMU, thus the need for additional spinlocks). Everything else is a leaf: no other lock is taken inside the critical sections. |