As alluded to in commit f36f3f2846b5 ("KVM: add "new" argument to
kvm_arch_commit_memory_region"), a bunch of other places where struct
kvm_memory_slot is used, needs to be refactored to preserve the
"const"ness of struct kvm_memory_slot across-the-board.
Signed-off-by: Hamza Mahfooz <[email protected]>
---
arch/x86/include/asm/kvm_host.h | 4 +--
arch/x86/kvm/mmu/mmu.c | 58 ++++++++++++++++++---------------
arch/x86/kvm/mmu/mmu_internal.h | 4 +--
arch/x86/kvm/mmu/tdp_mmu.c | 7 ++--
arch/x86/kvm/mmu/tdp_mmu.h | 6 ++--
arch/x86/kvm/x86.c | 7 ++--
6 files changed, 44 insertions(+), 42 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 974cbfb1eefe..a195e1c32018 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1536,12 +1536,12 @@ void kvm_mmu_uninit_vm(struct kvm *kvm);
void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu);
void kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
- struct kvm_memory_slot *memslot,
+ const struct kvm_memory_slot *memslot,
int start_level);
void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
const struct kvm_memory_slot *memslot);
void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
- struct kvm_memory_slot *memslot);
+ const struct kvm_memory_slot *memslot);
void kvm_mmu_zap_all(struct kvm *kvm);
void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen);
unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 845d114ae075..39ee8df5cc1f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -784,7 +784,7 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
return &slot->arch.lpage_info[level - 2][idx];
}
-static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
+static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot,
gfn_t gfn, int count)
{
struct kvm_lpage_info *linfo;
@@ -797,12 +797,12 @@ static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
}
}
-void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn)
{
update_gfn_disallow_lpage_count(slot, gfn, 1);
}
-void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn)
{
update_gfn_disallow_lpage_count(slot, gfn, -1);
}
@@ -989,7 +989,7 @@ static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep)
}
static struct kvm_rmap_head *__gfn_to_rmap(gfn_t gfn, int level,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
unsigned long idx;
@@ -1216,7 +1216,7 @@ static bool spte_wrprot_for_clear_dirty(u64 *sptep)
* Returns true iff any D or W bits were cleared.
*/
static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
u64 *sptep;
struct rmap_iterator iter;
@@ -1375,7 +1375,7 @@ static bool rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
}
static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
u64 *sptep;
struct rmap_iterator iter;
@@ -1440,7 +1440,7 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct slot_rmap_walk_iterator {
/* input fields. */
- struct kvm_memory_slot *slot;
+ const struct kvm_memory_slot *slot;
gfn_t start_gfn;
gfn_t end_gfn;
int start_level;
@@ -1467,16 +1467,20 @@ rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level)
static void
slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator,
- struct kvm_memory_slot *slot, int start_level,
+ const struct kvm_memory_slot *slot, int start_level,
int end_level, gfn_t start_gfn, gfn_t end_gfn)
{
- iterator->slot = slot;
- iterator->start_level = start_level;
- iterator->end_level = end_level;
- iterator->start_gfn = start_gfn;
- iterator->end_gfn = end_gfn;
+ struct slot_rmap_walk_iterator iter = {
+ .slot = slot,
+ .start_gfn = start_gfn,
+ .end_gfn = end_gfn,
+ .start_level = start_level,
+ .end_level = end_level,
+ };
+
+ rmap_walk_init_level(&iter, iterator->start_level);
- rmap_walk_init_level(iterator, iterator->start_level);
+ memcpy(iterator, &iter, sizeof(struct slot_rmap_walk_iterator));
}
static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator)
@@ -5274,12 +5278,13 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_max_root_level,
EXPORT_SYMBOL_GPL(kvm_configure_mmu);
/* The return value indicates if tlb flush on all vcpus is needed. */
-typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot);
+typedef bool (*slot_level_handler) (struct kvm *kvm,
+ struct kvm_rmap_head *rmap_head,
+ const struct kvm_memory_slot *slot);
/* The caller should hold mmu-lock before calling this function. */
static __always_inline bool
-slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot,
slot_level_handler fn, int start_level, int end_level,
gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield,
bool flush)
@@ -5306,7 +5311,7 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
}
static __always_inline bool
-slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot,
slot_level_handler fn, int start_level, int end_level,
bool flush_on_yield)
{
@@ -5317,7 +5322,7 @@ slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
}
static __always_inline bool
-slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
+slot_handle_leaf(struct kvm *kvm, const struct kvm_memory_slot *memslot,
slot_level_handler fn, bool flush_on_yield)
{
return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K,
@@ -5576,7 +5581,8 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
if (start >= end)
continue;
- flush = slot_handle_level_range(kvm, memslot,
+ flush = slot_handle_level_range(kvm,
+ (const struct kvm_memory_slot *) memslot,
kvm_zap_rmapp, PG_LEVEL_4K,
KVM_MAX_HUGEPAGE_LEVEL, start,
end - 1, true, flush);
@@ -5604,13 +5610,13 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
static bool slot_rmap_write_protect(struct kvm *kvm,
struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
return __rmap_write_protect(kvm, rmap_head, false);
}
void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
- struct kvm_memory_slot *memslot,
+ const struct kvm_memory_slot *memslot,
int start_level)
{
bool flush = false;
@@ -5646,7 +5652,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
struct kvm_rmap_head *rmap_head,
- struct kvm_memory_slot *slot)
+ const struct kvm_memory_slot *slot)
{
u64 *sptep;
struct rmap_iterator iter;
@@ -5685,10 +5691,8 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
}
void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
- const struct kvm_memory_slot *memslot)
+ const struct kvm_memory_slot *slot)
{
- /* FIXME: const-ify all uses of struct kvm_memory_slot. */
- struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
bool flush = false;
if (kvm_memslots_have_rmaps(kvm)) {
@@ -5724,7 +5728,7 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
}
void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
- struct kvm_memory_slot *memslot)
+ const struct kvm_memory_slot *memslot)
{
bool flush = false;
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 35567293c1fd..ee4ad9c99219 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -124,8 +124,8 @@ static inline bool is_nx_huge_page_enabled(void)
int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync);
-void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
-void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
+void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
+void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
struct kvm_memory_slot *slot, u64 gfn,
int min_level);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 0853370bd811..5d8d69d56a81 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1242,8 +1242,8 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
* only affect leaf SPTEs down to min_level.
* Returns true if an SPTE has been changed and the TLBs need to be flushed.
*/
-bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
- int min_level)
+bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *slot, int min_level)
{
struct kvm_mmu_page *root;
bool spte_set = false;
@@ -1313,7 +1313,8 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
* each SPTE. Returns true if an SPTE has been changed and the TLBs need to
* be flushed.
*/
-bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
+bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *slot)
{
struct kvm_mmu_page *root;
bool spte_set = false;
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 1cae4485b3bc..49437dbb4804 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -61,10 +61,10 @@ bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
-bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
- int min_level);
+bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
+ const struct kvm_memory_slot *slot, int min_level);
bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
- struct kvm_memory_slot *slot);
+ const struct kvm_memory_slot *slot);
void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
struct kvm_memory_slot *slot,
gfn_t gfn, unsigned long mask,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c6dc1b445231..970e95110175 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11473,7 +11473,7 @@ static void kvm_mmu_update_cpu_dirty_logging(struct kvm *kvm, bool enable)
static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
struct kvm_memory_slot *old,
- struct kvm_memory_slot *new,
+ const struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
bool log_dirty_pages = new->flags & KVM_MEM_LOG_DIRTY_PAGES;
@@ -11553,10 +11553,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
kvm_mmu_change_mmu_pages(kvm,
kvm_mmu_calculate_default_mmu_pages(kvm));
- /*
- * FIXME: const-ify all uses of struct kvm_memory_slot.
- */
- kvm_mmu_slot_apply_flags(kvm, old, (struct kvm_memory_slot *) new, change);
+ kvm_mmu_slot_apply_flags(kvm, old, new, change);
/* Free the arrays associated with the old memslot. */
if (change == KVM_MR_MOVE)
--
2.32.0
On 13/07/21 04:33, Hamza Mahfooz wrote:
> As alluded to in commit f36f3f2846b5 ("KVM: add "new" argument to
> kvm_arch_commit_memory_region"), a bunch of other places where struct
> kvm_memory_slot is used, needs to be refactored to preserve the
> "const"ness of struct kvm_memory_slot across-the-board.
>
> Signed-off-by: Hamza Mahfooz <[email protected]>
Queued, thanks.
Paolo
> ---
> arch/x86/include/asm/kvm_host.h | 4 +--
> arch/x86/kvm/mmu/mmu.c | 58 ++++++++++++++++++---------------
> arch/x86/kvm/mmu/mmu_internal.h | 4 +--
> arch/x86/kvm/mmu/tdp_mmu.c | 7 ++--
> arch/x86/kvm/mmu/tdp_mmu.h | 6 ++--
> arch/x86/kvm/x86.c | 7 ++--
> 6 files changed, 44 insertions(+), 42 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 974cbfb1eefe..a195e1c32018 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1536,12 +1536,12 @@ void kvm_mmu_uninit_vm(struct kvm *kvm);
> void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu);
> void kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
> void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
> - struct kvm_memory_slot *memslot,
> + const struct kvm_memory_slot *memslot,
> int start_level);
> void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
> const struct kvm_memory_slot *memslot);
> void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
> - struct kvm_memory_slot *memslot);
> + const struct kvm_memory_slot *memslot);
> void kvm_mmu_zap_all(struct kvm *kvm);
> void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen);
> unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm);
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 845d114ae075..39ee8df5cc1f 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -784,7 +784,7 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
> return &slot->arch.lpage_info[level - 2][idx];
> }
>
> -static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
> +static void update_gfn_disallow_lpage_count(const struct kvm_memory_slot *slot,
> gfn_t gfn, int count)
> {
> struct kvm_lpage_info *linfo;
> @@ -797,12 +797,12 @@ static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
> }
> }
>
> -void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
> +void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn)
> {
> update_gfn_disallow_lpage_count(slot, gfn, 1);
> }
>
> -void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
> +void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn)
> {
> update_gfn_disallow_lpage_count(slot, gfn, -1);
> }
> @@ -989,7 +989,7 @@ static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep)
> }
>
> static struct kvm_rmap_head *__gfn_to_rmap(gfn_t gfn, int level,
> - struct kvm_memory_slot *slot)
> + const struct kvm_memory_slot *slot)
> {
> unsigned long idx;
>
> @@ -1216,7 +1216,7 @@ static bool spte_wrprot_for_clear_dirty(u64 *sptep)
> * Returns true iff any D or W bits were cleared.
> */
> static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
> - struct kvm_memory_slot *slot)
> + const struct kvm_memory_slot *slot)
> {
> u64 *sptep;
> struct rmap_iterator iter;
> @@ -1375,7 +1375,7 @@ static bool rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
> }
>
> static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
> - struct kvm_memory_slot *slot)
> + const struct kvm_memory_slot *slot)
> {
> u64 *sptep;
> struct rmap_iterator iter;
> @@ -1440,7 +1440,7 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
>
> struct slot_rmap_walk_iterator {
> /* input fields. */
> - struct kvm_memory_slot *slot;
> + const struct kvm_memory_slot *slot;
> gfn_t start_gfn;
> gfn_t end_gfn;
> int start_level;
> @@ -1467,16 +1467,20 @@ rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level)
>
> static void
> slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator,
> - struct kvm_memory_slot *slot, int start_level,
> + const struct kvm_memory_slot *slot, int start_level,
> int end_level, gfn_t start_gfn, gfn_t end_gfn)
> {
> - iterator->slot = slot;
> - iterator->start_level = start_level;
> - iterator->end_level = end_level;
> - iterator->start_gfn = start_gfn;
> - iterator->end_gfn = end_gfn;
> + struct slot_rmap_walk_iterator iter = {
> + .slot = slot,
> + .start_gfn = start_gfn,
> + .end_gfn = end_gfn,
> + .start_level = start_level,
> + .end_level = end_level,
> + };
> +
> + rmap_walk_init_level(&iter, iterator->start_level);
>
> - rmap_walk_init_level(iterator, iterator->start_level);
> + memcpy(iterator, &iter, sizeof(struct slot_rmap_walk_iterator));
> }
>
> static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator)
> @@ -5274,12 +5278,13 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_max_root_level,
> EXPORT_SYMBOL_GPL(kvm_configure_mmu);
>
> /* The return value indicates if tlb flush on all vcpus is needed. */
> -typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_head,
> - struct kvm_memory_slot *slot);
> +typedef bool (*slot_level_handler) (struct kvm *kvm,
> + struct kvm_rmap_head *rmap_head,
> + const struct kvm_memory_slot *slot);
>
> /* The caller should hold mmu-lock before calling this function. */
> static __always_inline bool
> -slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
> +slot_handle_level_range(struct kvm *kvm, const struct kvm_memory_slot *memslot,
> slot_level_handler fn, int start_level, int end_level,
> gfn_t start_gfn, gfn_t end_gfn, bool flush_on_yield,
> bool flush)
> @@ -5306,7 +5311,7 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
> }
>
> static __always_inline bool
> -slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
> +slot_handle_level(struct kvm *kvm, const struct kvm_memory_slot *memslot,
> slot_level_handler fn, int start_level, int end_level,
> bool flush_on_yield)
> {
> @@ -5317,7 +5322,7 @@ slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
> }
>
> static __always_inline bool
> -slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
> +slot_handle_leaf(struct kvm *kvm, const struct kvm_memory_slot *memslot,
> slot_level_handler fn, bool flush_on_yield)
> {
> return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K,
> @@ -5576,7 +5581,8 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
> if (start >= end)
> continue;
>
> - flush = slot_handle_level_range(kvm, memslot,
> + flush = slot_handle_level_range(kvm,
> + (const struct kvm_memory_slot *) memslot,
> kvm_zap_rmapp, PG_LEVEL_4K,
> KVM_MAX_HUGEPAGE_LEVEL, start,
> end - 1, true, flush);
> @@ -5604,13 +5610,13 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
>
> static bool slot_rmap_write_protect(struct kvm *kvm,
> struct kvm_rmap_head *rmap_head,
> - struct kvm_memory_slot *slot)
> + const struct kvm_memory_slot *slot)
> {
> return __rmap_write_protect(kvm, rmap_head, false);
> }
>
> void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
> - struct kvm_memory_slot *memslot,
> + const struct kvm_memory_slot *memslot,
> int start_level)
> {
> bool flush = false;
> @@ -5646,7 +5652,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
>
> static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
> struct kvm_rmap_head *rmap_head,
> - struct kvm_memory_slot *slot)
> + const struct kvm_memory_slot *slot)
> {
> u64 *sptep;
> struct rmap_iterator iter;
> @@ -5685,10 +5691,8 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
> }
>
> void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
> - const struct kvm_memory_slot *memslot)
> + const struct kvm_memory_slot *slot)
> {
> - /* FIXME: const-ify all uses of struct kvm_memory_slot. */
> - struct kvm_memory_slot *slot = (struct kvm_memory_slot *)memslot;
> bool flush = false;
>
> if (kvm_memslots_have_rmaps(kvm)) {
> @@ -5724,7 +5728,7 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
> }
>
> void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
> - struct kvm_memory_slot *memslot)
> + const struct kvm_memory_slot *memslot)
> {
> bool flush = false;
>
> diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
> index 35567293c1fd..ee4ad9c99219 100644
> --- a/arch/x86/kvm/mmu/mmu_internal.h
> +++ b/arch/x86/kvm/mmu/mmu_internal.h
> @@ -124,8 +124,8 @@ static inline bool is_nx_huge_page_enabled(void)
>
> int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, bool can_unsync);
>
> -void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
> -void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
> +void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
> +void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
> bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
> struct kvm_memory_slot *slot, u64 gfn,
> int min_level);
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 0853370bd811..5d8d69d56a81 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -1242,8 +1242,8 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
> * only affect leaf SPTEs down to min_level.
> * Returns true if an SPTE has been changed and the TLBs need to be flushed.
> */
> -bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
> - int min_level)
> +bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
> + const struct kvm_memory_slot *slot, int min_level)
> {
> struct kvm_mmu_page *root;
> bool spte_set = false;
> @@ -1313,7 +1313,8 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
> * each SPTE. Returns true if an SPTE has been changed and the TLBs need to
> * be flushed.
> */
> -bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
> +bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
> + const struct kvm_memory_slot *slot)
> {
> struct kvm_mmu_page *root;
> bool spte_set = false;
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
> index 1cae4485b3bc..49437dbb4804 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.h
> +++ b/arch/x86/kvm/mmu/tdp_mmu.h
> @@ -61,10 +61,10 @@ bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
> bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
> bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
>
> -bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
> - int min_level);
> +bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
> + const struct kvm_memory_slot *slot, int min_level);
> bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
> - struct kvm_memory_slot *slot);
> + const struct kvm_memory_slot *slot);
> void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
> struct kvm_memory_slot *slot,
> gfn_t gfn, unsigned long mask,
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index c6dc1b445231..970e95110175 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -11473,7 +11473,7 @@ static void kvm_mmu_update_cpu_dirty_logging(struct kvm *kvm, bool enable)
>
> static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
> struct kvm_memory_slot *old,
> - struct kvm_memory_slot *new,
> + const struct kvm_memory_slot *new,
> enum kvm_mr_change change)
> {
> bool log_dirty_pages = new->flags & KVM_MEM_LOG_DIRTY_PAGES;
> @@ -11553,10 +11553,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
> kvm_mmu_change_mmu_pages(kvm,
> kvm_mmu_calculate_default_mmu_pages(kvm));
>
> - /*
> - * FIXME: const-ify all uses of struct kvm_memory_slot.
> - */
> - kvm_mmu_slot_apply_flags(kvm, old, (struct kvm_memory_slot *) new, change);
> + kvm_mmu_slot_apply_flags(kvm, old, new, change);
>
> /* Free the arrays associated with the old memslot. */
> if (change == KVM_MR_MOVE)
>
Hi, Hamza,
On Mon, Jul 12, 2021 at 10:33:38PM -0400, Hamza Mahfooz wrote:
> @@ -1467,16 +1467,20 @@ rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level)
>
> static void
> slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator,
> - struct kvm_memory_slot *slot, int start_level,
> + const struct kvm_memory_slot *slot, int start_level,
> int end_level, gfn_t start_gfn, gfn_t end_gfn)
> {
> - iterator->slot = slot;
> - iterator->start_level = start_level;
> - iterator->end_level = end_level;
> - iterator->start_gfn = start_gfn;
> - iterator->end_gfn = end_gfn;
> + struct slot_rmap_walk_iterator iter = {
> + .slot = slot,
> + .start_gfn = start_gfn,
> + .end_gfn = end_gfn,
> + .start_level = start_level,
> + .end_level = end_level,
> + };
> +
> + rmap_walk_init_level(&iter, iterator->start_level);
Here it should be s/iterator->//.
>
> - rmap_walk_init_level(iterator, iterator->start_level);
> + memcpy(iterator, &iter, sizeof(struct slot_rmap_walk_iterator));
> }
This patch breaks kvm/queue with above issue. Constify of kvm_memory_slot
pointer should have nothing to do with this so at least it should need a
separate patch. At the meantime I also don't understand why memcpy() here,
which seems to be even slower..
--
Peter Xu
Hey Peter,
On Fri, Jul 30 2021 at 04:19:21 PM -0400, Peter Xu <[email protected]>
wrote:
> This patch breaks kvm/queue with above issue. Constify of
> kvm_memory_slot
> pointer should have nothing to do with this so at least it should
> need a
> separate patch. At the meantime I also don't understand why memcpy()
> here,
> which seems to be even slower..
To const-ify the slot member of struct slot_rmap_walk_iterator, we need
to
initialize a new struct and then copy it over (otherwise we would need
to relay
on casting again or the compiler will complain about it).
On Fri, Jul 30 2021 at 04:19:21 PM -0400, Peter Xu <[email protected]>
wrote:
> separate patch. At the meantime I also don't understand why memcpy()
> here,
> which seems to be even slower..
Alright, I've now had a chance to compare the object code generated
before
my patch is applied, with what is generated after it is applied and the
same object code is generated for arch/x86/kvm/mmu/mmu.c in both cases
(at
least when compiling with clang, however I suspect other optimizing
compilers would behave similarly).