summaryrefslogtreecommitdiff
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-07 23:40:51 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-07 23:40:51 +0300
commit192ad3c27a4895ee4b2fa31c5b54a932f5bb08c1 (patch)
tree5f818faaca9a304997d745aba9c19dbfedf5415a /Documentation
parenta2b28235335fee2586b4bd16448fb59ed6c80eef (diff)
parent109bbba5066b42431399b40e947243f049d8dc8d (diff)
downloadlinux-192ad3c27a4895ee4b2fa31c5b54a932f5bb08c1.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini: "ARM: - Page ownership tracking between host EL1 and EL2 - Rely on userspace page tables to create large stage-2 mappings - Fix incompatibility between pKVM and kmemleak - Fix the PMU reset state, and improve the performance of the virtual PMU - Move over to the generic KVM entry code - Address PSCI reset issues w.r.t. save/restore - Preliminary rework for the upcoming pKVM fixed feature - A bunch of MM cleanups - a vGIC fix for timer spurious interrupts - Various cleanups s390: - enable interpretation of specification exceptions - fix a vcpu_idx vs vcpu_id mixup x86: - fast (lockless) page fault support for the new MMU - new MMU now the default - increased maximum allowed VCPU count - allow inhibit IRQs on KVM_RUN while debugging guests - let Hyper-V-enabled guests run with virtualized LAPIC as long as they do not enable the Hyper-V "AutoEOI" feature - fixes and optimizations for the toggling of AMD AVIC (virtualized LAPIC) - tuning for the case when two-dimensional paging (EPT/NPT) is disabled - bugfixes and cleanups, especially with respect to vCPU reset and choosing a paging mode based on CR0/CR4/EFER - support for 5-level page table on AMD processors Generic: - MMU notifier invalidation callbacks do not take mmu_lock unless necessary - improved caching of LRU kvm_memory_slot - support for histogram statistics - add statistics for halt polling and remote TLB flush requests" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (210 commits) KVM: Drop unused kvm_dirty_gfn_invalid() KVM: x86: Update vCPU's hv_clock before back to guest when tsc_offset is adjusted KVM: MMU: mark role_regs and role accessors as maybe unused KVM: MIPS: Remove a "set but not used" variable x86/kvm: Don't enable IRQ when IRQ enabled in kvm_wait KVM: stats: Add VM stat for remote tlb flush requests KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count() KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page KVM: x86/mmu: Relocate kvm_mmu_page.tdp_mmu_page for better cache locality Revert "KVM: x86: mmu: Add guest physical address check in translate_gpa()" KVM: x86/mmu: Remove unused field mmio_cached in struct kvm_mmu_page kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710 kvm: x86: Increase MAX_VCPUS to 1024 kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation KVM: x86/mmu: Don't freak out if pml5_root is NULL on 4-level host KVM: s390: index kvm->arch.idle_mask by vcpu_idx KVM: s390: Enable specification exception interpretation KVM: arm64: Trim guest debug exception handling KVM: SVM: Add 5-level page table support for SVM ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virt/kvm/api.rst36
-rw-r--r--Documentation/virt/kvm/locking.rst6
2 files changed, 34 insertions, 8 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index c6212c2d5fe3..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
@@ -5208,6 +5209,9 @@ by a string of size ``name_size``.
#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)
@@ -5215,18 +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[];
};
@@ -5237,21 +5243,35 @@ 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:
@@ -5286,9 +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
diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
index 88fa495abbac..5d27da356836 100644
--- a/Documentation/virt/kvm/locking.rst
+++ b/Documentation/virt/kvm/locking.rst
@@ -21,6 +21,12 @@ 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