Commit e9611bf9 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Documentation: kvm: fixes for locking.rst 



Separate the various locks clearly, and include the new names of blocked_vcpu_on_cpu_lock
and blocked_vcpu_on_cpu.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220322110720.222499-2-pbonzini@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 07ea4ab1

Documentation/virt/kvm/locking.rst

+19 −9
Original line number Diff line number Diff line
@@ -210,32 +210,41 @@ 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_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 +255,11 @@ 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

``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