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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-02 12:09:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-02 12:09:02 -0700
commit38904911e86495d4690f8d805720b90e65426c71 (patch)
tree6a162530ad117c636fc1e144ee223099b85eefd4 /Documentation/virt/kvm/locking.rst
parent6f34f8c3d6178527d4c02aa3a53c370cc70cb91e (diff)
parentc15e0ae42c8e5a61e9aca8aac920517cf7b3e94e (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr - Documentation improvements - Prevent module exit until all VMs are freed - PMU Virtualization fixes - Fix for kvm_irq_delivery_to_apic_fast() NULL-pointer dereferences - Other miscellaneous bugfixes * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits) KVM: x86: fix sending PV IPI KVM: x86/mmu: do compare-and-exchange of gPTE via the user address KVM: x86: Remove redundant vm_entry_controls_clearbit() call KVM: x86: cleanup enter_rmode() KVM: x86: SVM: fix tsc scaling when the host doesn't support it kvm: x86: SVM: remove unused defines KVM: x86: SVM: move tsc ratio definitions to svm.h KVM: x86: SVM: fix avic spec based definitions again KVM: MIPS: remove reference to trap&emulate virtualization KVM: x86: document limitations of MSR filtering KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr KVM: x86/emulator: Emulate RDPID only if it is enabled in guest KVM: x86/pmu: Fix and isolate TSX-specific performance event logic KVM: x86: mmu: trace kvm_mmu_set_spte after the new SPTE was set KVM: x86/svm: Clear reserved bits written to PerfEvtSeln MSRs KVM: x86: Trace all APICv inhibit changes and capture overall status KVM: x86: Add wrappers for setting/clearing APICv inhibits KVM: x86: Make APICv inhibit reasons an enum and cleanup naming KVM: X86: Handle implicit supervisor access with SMAP KVM: X86: Rename variable smap to not_smap in permission_fault() ...
Diffstat (limited to 'Documentation/virt/kvm/locking.rst')
-rw-r--r--Documentation/virt/kvm/locking.rst43
1 files changed, 34 insertions, 9 deletions
diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
index 5d27da356836..845a561629f1 100644
--- a/Documentation/virt/kvm/locking.rst
+++ b/Documentation/virt/kvm/locking.rst
@@ -210,32 +210,47 @@ time it will be set using the Dirty tracking mechanism described above.
3. Reference
------------
-:Name: kvm_lock
+``kvm_lock``
+^^^^^^^^^^^^
+
:Type: mutex
:Arch: any
:Protects: - vm_list
-:Name: kvm_count_lock
+``kvm_count_lock``
+^^^^^^^^^^^^^^^^^^
+
:Type: raw_spinlock_t
:Arch: any
:Protects: - hardware virtualization enable/disable
:Comment: 'raw' because hardware enabling/disabling must be atomic /wrt
migration.
-:Name: kvm_arch::tsc_write_lock
-:Type: raw_spinlock
+``kvm->mn_invalidate_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:Type: spinlock_t
+:Arch: any
+:Protects: mn_active_invalidate_count, mn_memslots_update_rcuwait
+
+``kvm_arch::tsc_write_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:Type: raw_spinlock_t
:Arch: x86
:Protects: - kvm_arch::{last_tsc_write,last_tsc_nsec,last_tsc_offset}
- tsc offset in vmcb
:Comment: 'raw' because updating the tsc offsets must not be preempted.
-:Name: kvm->mmu_lock
-:Type: spinlock_t
+``kvm->mmu_lock``
+^^^^^^^^^^^^^^^^^
+:Type: spinlock_t or rwlock_t
:Arch: any
:Protects: -shadow page/shadow tlb entry
:Comment: it is a spinlock since it is used in mmu notifier.
-:Name: kvm->srcu
+``kvm->srcu``
+^^^^^^^^^^^^^
:Type: srcu lock
:Arch: any
:Protects: - kvm->memslots
@@ -246,10 +261,20 @@ time it will be set using the Dirty tracking mechanism described above.
The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu
if it is needed by multiple functions.
-:Name: blocked_vcpu_on_cpu_lock
+``kvm->slots_arch_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^
+:Type: mutex
+:Arch: any (only needed on x86 though)
+:Protects: any arch-specific fields of memslots that have to be modified
+ in a ``kvm->srcu`` read-side critical section.
+:Comment: must be held before reading the pointer to the current memslots,
+ until after all changes to the memslots are complete
+
+``wakeup_vcpus_on_cpu_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:Type: spinlock_t
:Arch: x86
-:Protects: blocked_vcpu_on_cpu
+:Protects: wakeup_vcpus_on_cpu
:Comment: This is a per-CPU lock and it is used for VT-d posted-interrupts.
When VT-d posted-interrupts is supported and the VM has assigned
devices, we put the blocked vCPU on the list blocked_vcpu_on_cpu