[PATCH v5.5 06/30] KVM: Use "new" memslot's address space ID instead of dedicated param

From: Sean Christopherson
Date: Wed Nov 03 2021 - 20:27:49 EST


Now that the address space ID is stored in every slot, including fake
slots used for deletion, use the slot's as_id instead of passing in the
redundant information as a param to kvm_set_memslot(). This will greatly
simplify future memslot work by avoiding passing a large number of
variables around purely to honor @as_id.

Drop a comment in the DELETE path about new->as_id being provided purely
for debug, as that's now a lie.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
virt/kvm/kvm_main.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e5c2d10f6111..39a64e02a43a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1536,7 +1536,7 @@ static void kvm_copy_memslots_arch(struct kvm_memslots *to,

static int kvm_set_memslot(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
- struct kvm_memory_slot *new, int as_id,
+ struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
struct kvm_memory_slot *slot, old;
@@ -1559,7 +1559,7 @@ static int kvm_set_memslot(struct kvm *kvm,
*/
mutex_lock(&kvm->slots_arch_lock);

- slots = kvm_dup_memslots(__kvm_memslots(kvm, as_id), change);
+ slots = kvm_dup_memslots(__kvm_memslots(kvm, new->as_id), change);
if (!slots) {
mutex_unlock(&kvm->slots_arch_lock);
return -ENOMEM;
@@ -1579,7 +1579,7 @@ static int kvm_set_memslot(struct kvm *kvm,
* dropped by update_memslots anyway. We'll also revert to the
* old memslots if preparing the new memory region fails.
*/
- slots = install_new_memslots(kvm, as_id, slots);
+ slots = install_new_memslots(kvm, new->as_id, slots);

/* From this point no new shadow pages pointing to a deleted,
* or moved, memslot will be created.
@@ -1601,7 +1601,7 @@ static int kvm_set_memslot(struct kvm *kvm,
* to retrieve memslots *after* acquiring slots_arch_lock, thus
* the active memslots are guaranteed to be fresh.
*/
- kvm_copy_memslots_arch(slots, __kvm_memslots(kvm, as_id));
+ kvm_copy_memslots_arch(slots, __kvm_memslots(kvm, new->as_id));
}

/*
@@ -1618,7 +1618,7 @@ static int kvm_set_memslot(struct kvm *kvm,
WARN_ON_ONCE(change != KVM_MR_CREATE);
memset(&old, 0, sizeof(old));
old.id = new->id;
- old.as_id = as_id;
+ old.as_id = new->as_id;
}

/* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */
@@ -1629,7 +1629,7 @@ static int kvm_set_memslot(struct kvm *kvm,
goto out_slots;

update_memslots(slots, new, change);
- slots = install_new_memslots(kvm, as_id, slots);
+ slots = install_new_memslots(kvm, new->as_id, slots);

/*
* Update the total number of memslot pages before calling the arch
@@ -1651,7 +1651,7 @@ static int kvm_set_memslot(struct kvm *kvm,

out_slots:
if (change == KVM_MR_DELETE || change == KVM_MR_MOVE)
- slots = install_new_memslots(kvm, as_id, slots);
+ slots = install_new_memslots(kvm, new->as_id, slots);
else
mutex_unlock(&kvm->slots_arch_lock);
kvfree(slots);
@@ -1723,13 +1723,9 @@ int __kvm_set_memory_region(struct kvm *kvm,

memset(&new, 0, sizeof(new));
new.id = id;
- /*
- * This is only for debugging purpose; it should never be
- * referenced for a removed memslot.
- */
new.as_id = as_id;

- return kvm_set_memslot(kvm, mem, &new, as_id, KVM_MR_DELETE);
+ return kvm_set_memslot(kvm, mem, &new, KVM_MR_DELETE);
}

new.as_id = as_id;
@@ -1792,7 +1788,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
bitmap_set(new.dirty_bitmap, 0, new.npages);
}

- r = kvm_set_memslot(kvm, mem, &new, as_id, change);
+ r = kvm_set_memslot(kvm, mem, &new, change);
if (r)
goto out_bitmap;

--
2.33.1.1089.g2158813163f-goog