[PATCH v3 kvm/queue 07/16] KVM: Refactor hva based memory invalidation code
From: Chao Peng
Date: Thu Dec 23 2021 - 07:32:13 EST
The purpose of this patch is for fd-based memslot to reuse the same
mmu_notifier based guest memory invalidation code for private pages.
No functional changes except renaming 'hva' to more neutral 'useraddr'
so that it can also cover 'offset' in a fd that private pages live in.
Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
---
include/linux/kvm_host.h | 8 ++++--
virt/kvm/kvm_main.c | 55 ++++++++++++++++++++++------------------
2 files changed, 36 insertions(+), 27 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 21f8b1880723..07863ff855cd 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1464,9 +1464,13 @@ static inline int memslot_id(struct kvm *kvm, gfn_t gfn)
}
static inline gfn_t
-hva_to_gfn_memslot(unsigned long hva, struct kvm_memory_slot *slot)
+useraddr_to_gfn_memslot(unsigned long useraddr, struct kvm_memory_slot *slot,
+ bool addr_is_hva)
{
- gfn_t gfn_offset = (hva - slot->userspace_addr) >> PAGE_SHIFT;
+ unsigned long useraddr_base = addr_is_hva ? slot->userspace_addr
+ : slot->ofs;
+
+ gfn_t gfn_offset = (useraddr - useraddr_base) >> PAGE_SHIFT;
return slot->base_gfn + gfn_offset;
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 47e96d1eb233..b7a1c4d7eaaa 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -486,16 +486,16 @@ static void kvm_mmu_notifier_invalidate_range(struct mmu_notifier *mn,
srcu_read_unlock(&kvm->srcu, idx);
}
-typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
+typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start,
unsigned long end);
-struct kvm_hva_range {
+struct kvm_useraddr_range {
unsigned long start;
unsigned long end;
pte_t pte;
- hva_handler_t handler;
+ gfn_handler_t handler;
on_lock_fn_t on_lock;
bool flush_on_ret;
bool may_block;
@@ -515,13 +515,13 @@ static void kvm_null_fn(void)
#define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
/* Iterate over each memslot intersecting [start, last] (inclusive) range */
-#define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \
- for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \
+#define kvm_for_each_memslot_in_useraddr_range(node, tree, start, last) \
+ for (node = interval_tree_iter_first(tree, start, last); \
node; \
node = interval_tree_iter_next(node, start, last)) \
-static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
- const struct kvm_hva_range *range)
+static __always_inline int __kvm_handle_useraddr_range(struct kvm *kvm,
+ const struct kvm_useraddr_range *range)
{
bool ret = false, locked = false;
struct kvm_gfn_range gfn_range;
@@ -540,17 +540,19 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
idx = srcu_read_lock(&kvm->srcu);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+ struct rb_root_cached *useraddr_tree;
struct interval_tree_node *node;
slots = __kvm_memslots(kvm, i);
- kvm_for_each_memslot_in_hva_range(node, slots,
+ useraddr_tree = &slots->hva_tree;
+ kvm_for_each_memslot_in_useraddr_range(node, useraddr_tree,
range->start, range->end - 1) {
- unsigned long hva_start, hva_end;
+ unsigned long useraddr_start, useraddr_end;
slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]);
- hva_start = max(range->start, slot->userspace_addr);
- hva_end = min(range->end, slot->userspace_addr +
- (slot->npages << PAGE_SHIFT));
+ useraddr_start = max(range->start, slot->userspace_addr);
+ useraddr_end = min(range->end, slot->userspace_addr +
+ (slot->npages << PAGE_SHIFT));
/*
* To optimize for the likely case where the address
@@ -562,11 +564,14 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
gfn_range.may_block = range->may_block;
/*
- * {gfn(page) | page intersects with [hva_start, hva_end)} =
+ * {gfn(page) | page intersects with [useraddr_start, useraddr_end)} =
* {gfn_start, gfn_start+1, ..., gfn_end-1}.
*/
- gfn_range.start = hva_to_gfn_memslot(hva_start, slot);
- gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot);
+ gfn_range.start = useraddr_to_gfn_memslot(useraddr_start,
+ slot, true);
+ gfn_range.end = useraddr_to_gfn_memslot(
+ useraddr_end + PAGE_SIZE - 1,
+ slot, true);
gfn_range.slot = slot;
if (!locked) {
@@ -597,10 +602,10 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
unsigned long start,
unsigned long end,
pte_t pte,
- hva_handler_t handler)
+ gfn_handler_t handler)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
- const struct kvm_hva_range range = {
+ const struct kvm_useraddr_range range = {
.start = start,
.end = end,
.pte = pte,
@@ -610,16 +615,16 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
.may_block = false,
};
- return __kvm_handle_hva_range(kvm, &range);
+ return __kvm_handle_useraddr_range(kvm, &range);
}
static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn,
unsigned long start,
unsigned long end,
- hva_handler_t handler)
+ gfn_handler_t handler)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
- const struct kvm_hva_range range = {
+ const struct kvm_useraddr_range range = {
.start = start,
.end = end,
.pte = __pte(0),
@@ -629,7 +634,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn
.may_block = false,
};
- return __kvm_handle_hva_range(kvm, &range);
+ return __kvm_handle_useraddr_range(kvm, &range);
}
static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
struct mm_struct *mm,
@@ -687,7 +692,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
- const struct kvm_hva_range hva_range = {
+ const struct kvm_useraddr_range useraddr_range = {
.start = range->start,
.end = range->end,
.pte = __pte(0),
@@ -711,7 +716,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
kvm->mn_active_invalidate_count++;
spin_unlock(&kvm->mn_invalidate_lock);
- __kvm_handle_hva_range(kvm, &hva_range);
+ __kvm_handle_useraddr_range(kvm, &useraddr_range);
return 0;
}
@@ -738,7 +743,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
- const struct kvm_hva_range hva_range = {
+ const struct kvm_useraddr_range useraddr_range = {
.start = range->start,
.end = range->end,
.pte = __pte(0),
@@ -749,7 +754,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
};
bool wake;
- __kvm_handle_hva_range(kvm, &hva_range);
+ __kvm_handle_useraddr_range(kvm, &useraddr_range);
/* Pairs with the increment in range_start(). */
spin_lock(&kvm->mn_invalidate_lock);
--
2.17.1