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KVM: Fix comments that refer to the non-existent install_new_memslots()

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Fix stale comments that were left behind when install_new_memslots() was
replaced by kvm_swap_active_memslots() as part of the scalable memslots
rework.

Fixes: a54d806688 ("KVM: Keep memslots in tree-based structures instead of array-based ones")
Signed-off-by: Jun Miao <jun.miao@intel.com>
Link: https://lore.kernel.org/r/20230223052851.1054799-1-jun.miao@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Jun Miao
2023-02-23 13:28:51 +08:00
committed by Sean Christopherson
parent 7ffc2e8951
commit b0d237087c
3 changed files with 10 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/virt/kvm/locking.rst
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@@ -21,7 +21,7 @@ The acquisition orders for mutexes are as follows:
- kvm->mn_active_invalidate_count ensures that pairs of - kvm->mn_active_invalidate_count ensures that pairs of
invalidate_range_start() and invalidate_range_end() callbacks invalidate_range_start() and invalidate_range_end() callbacks
use the same memslots array. kvm->slots_lock and kvm->slots_arch_lock 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 are taken on the waiting side when modifying memslots, so MMU notifiers
must not take either kvm->slots_lock or kvm->slots_arch_lock. must not take either kvm->slots_lock or kvm->slots_arch_lock.
For SRCU: For SRCU:

4
include/linux/kvm_host.h
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@@ -58,7 +58,7 @@
/* /*
* Bit 63 of the memslot generation number is an "update in-progress flag", * Bit 63 of the memslot generation number is an "update in-progress flag",
* e.g. is temporarily set for the duration of install_new_memslots(). * e.g. is temporarily set for the duration of kvm_swap_active_memslots().
* This flag effectively creates a unique generation number that is used to * This flag effectively creates a unique generation number that is used to
* mark cached memslot data, e.g. MMIO accesses, as potentially being stale, * mark cached memslot data, e.g. MMIO accesses, as potentially being stale,
* i.e. may (or may not) have come from the previous memslots generation. * i.e. may (or may not) have come from the previous memslots generation.
@@ -713,7 +713,7 @@ struct kvm {
* use by the VM. To be used under the slots_lock (above) or in a * use by the VM. To be used under the slots_lock (above) or in a
* kvm->srcu critical section where acquiring the slots_lock would * kvm->srcu critical section where acquiring the slots_lock would
* lead to deadlock with the synchronize_srcu in * lead to deadlock with the synchronize_srcu in
* install_new_memslots. * kvm_swap_active_memslots().
*/ */
struct mutex slots_arch_lock; struct mutex slots_arch_lock;
struct mm_struct *mm; /* userspace tied to this vm */ struct mm_struct *mm; /* userspace tied to this vm */

14
virt/kvm/kvm_main.c
View File

@@ -1298,7 +1298,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
* At this point, pending calls to invalidate_range_start() * At this point, pending calls to invalidate_range_start()
* have completed but no more MMU notifiers will run, so * have completed but no more MMU notifiers will run, so
* mn_active_invalidate_count may remain unbalanced. * mn_active_invalidate_count may remain unbalanced.
* No threads can be waiting in install_new_memslots as the * No threads can be waiting in kvm_swap_active_memslots() as the
* last reference on KVM has been dropped, but freeing * last reference on KVM has been dropped, but freeing
* memslots would deadlock without this manual intervention. * memslots would deadlock without this manual intervention.
*/ */
@@ -1742,13 +1742,13 @@ static void kvm_invalidate_memslot(struct kvm *kvm,
kvm_arch_flush_shadow_memslot(kvm, old); kvm_arch_flush_shadow_memslot(kvm, old);
kvm_arch_guest_memory_reclaimed(kvm); kvm_arch_guest_memory_reclaimed(kvm);
/* Was released by kvm_swap_active_memslots, reacquire. */ /* Was released by kvm_swap_active_memslots(), reacquire. */
mutex_lock(&kvm->slots_arch_lock); mutex_lock(&kvm->slots_arch_lock);
/* /*
* Copy the arch-specific field of the newly-installed slot back to the * Copy the arch-specific field of the newly-installed slot back to the
* old slot as the arch data could have changed between releasing * old slot as the arch data could have changed between releasing
* slots_arch_lock in install_new_memslots() and re-acquiring the lock * slots_arch_lock in kvm_swap_active_memslots() and re-acquiring the lock
* above. Writers are required to retrieve memslots *after* acquiring * above. Writers are required to retrieve memslots *after* acquiring
* slots_arch_lock, thus the active slot's data is guaranteed to be fresh. * slots_arch_lock, thus the active slot's data is guaranteed to be fresh.
*/ */
@@ -1810,11 +1810,11 @@ static int kvm_set_memslot(struct kvm *kvm,
int r; int r;
/* /*
* Released in kvm_swap_active_memslots. * Released in kvm_swap_active_memslots().
* *
* Must be held from before the current memslots are copied until * Must be held from before the current memslots are copied until after
* after the new memslots are installed with rcu_assign_pointer, * the new memslots are installed with rcu_assign_pointer, then
* then released before the synchronize srcu in kvm_swap_active_memslots. * released before the synchronize srcu in kvm_swap_active_memslots().
* *
* When modifying memslots outside of the slots_lock, must be held * When modifying memslots outside of the slots_lock, must be held
* before reading the pointer to the current memslots until after all * before reading the pointer to the current memslots until after all