[PATCH 0/2] Documentation: kvm: improvements to locking.rst

[PATCH 0/2] Documentation: kvm: improvements to locking.rst

[Paolo Bonzini]

Improve the formatting and update the documentation.

Paolo Bonzini (2):
  Documentation: kvm: fixes for locking.rst
  Documentation: kvm: include new locks

 Documentation/virt/kvm/locking.rst | 43 +++++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 9 deletions(-)

-- 
2.35.1

[PATCH 1/2] Documentation: kvm: fixes for locking.rst

[Paolo Bonzini]

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

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Documentation/virt/kvm/locking.rst | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
index 5d27da356836..4f21063bfbd6 100644
--- a/Documentation/virt/kvm/locking.rst
+++ b/Documentation/virt/kvm/locking.rst
@@ -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
-- 
2.35.1

[PATCH 2/2] Documentation: kvm: include new locks

[Paolo Bonzini]

kvm->mn_invalidate_lock and kvm->slots_arch_lock were not included in the
documentation, add them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Documentation/virt/kvm/locking.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
index 4f21063bfbd6..486efcd36fd6 100644
--- a/Documentation/virt/kvm/locking.rst
+++ b/Documentation/virt/kvm/locking.rst
@@ -226,6 +226,12 @@ time it will be set using the Dirty tracking mechanism described above.
 :Comment:	'raw' because hardware enabling/disabling must be atomic /wrt
 		migration.
 
+``kvm->mn_invalidate_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:Type:          spinlock_t
+:Arch:          any
+:Protects:      mn_active_invalidate_count, mn_memslots_update_rcuwait
 
 ``kvm_arch::tsc_write_lock``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -255,6 +261,15 @@ 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.
 
+``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
-- 
2.35.1