On Fri, Nov 19, 2021 at 3:58 PM David Matlack <dmatlack@xxxxxxxxxx> wrote:
>
> Instead of passing a pointer to the root page table and the root level
> seperately, pass in a pointer to the kvm_mmu_page that backs the root.
> This reduces the number of arguments by 1, cutting down on line lengths.
>
> No functional change intended.
>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
Reviewed-by: Ben Gardon <bgardon@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu/tdp_iter.c | 5 ++++-
> arch/x86/kvm/mmu/tdp_iter.h | 10 +++++-----
> arch/x86/kvm/mmu/tdp_mmu.c | 14 +++++---------
> 3 files changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/tdp_iter.c b/arch/x86/kvm/mmu/tdp_iter.c
> index b3ed302c1a35..92b3a075525a 100644
> --- a/arch/x86/kvm/mmu/tdp_iter.c
> +++ b/arch/x86/kvm/mmu/tdp_iter.c
> @@ -39,9 +39,12 @@ void tdp_iter_restart(struct tdp_iter *iter)
> * Sets a TDP iterator to walk a pre-order traversal of the paging structure
> * rooted at root_pt, starting with the walk to translate next_last_level_gfn.
> */
> -void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
> +void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
I think this is an artifact of the days when I thought we could avoid
allocating struct kvm_mmu_pages for the TDP MMU.
Trying to do that turned out to be a huge pain though and the memory
savings weren't great.
Happy to see this cleaned up.
> int min_level, gfn_t next_last_level_gfn)
> {
> + u64 *root_pt = root->spt;
> + int root_level = root->role.level;
> +
> WARN_ON(root_level < 1);
> WARN_ON(root_level > PT64_ROOT_MAX_LEVEL);
>
> diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h
> index b1748b988d3a..ec1f58013428 100644
> --- a/arch/x86/kvm/mmu/tdp_iter.h
> +++ b/arch/x86/kvm/mmu/tdp_iter.h
> @@ -51,17 +51,17 @@ struct tdp_iter {
> * Iterates over every SPTE mapping the GFN range [start, end) in a
> * preorder traversal.
> */
> -#define for_each_tdp_pte_min_level(iter, root, root_level, min_level, start, end) \
> - for (tdp_iter_start(&iter, root, root_level, min_level, start); \
> +#define for_each_tdp_pte_min_level(iter, root, min_level, start, end) \
> + for (tdp_iter_start(&iter, root, min_level, start); \
> iter.valid && iter.gfn < end; \
> tdp_iter_next(&iter))
>
> -#define for_each_tdp_pte(iter, root, root_level, start, end) \
> - for_each_tdp_pte_min_level(iter, root, root_level, PG_LEVEL_4K, start, end)
> +#define for_each_tdp_pte(iter, root, start, end) \
> + for_each_tdp_pte_min_level(iter, root, PG_LEVEL_4K, start, end)
>
> tdp_ptep_t spte_to_child_pt(u64 pte, int level);
>
> -void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
> +void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
> int min_level, gfn_t next_last_level_gfn);
> void tdp_iter_next(struct tdp_iter *iter);
> void tdp_iter_restart(struct tdp_iter *iter);
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 2221e074d8ea..5ca0fa659245 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -632,7 +632,7 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
> }
>
> #define tdp_root_for_each_pte(_iter, _root, _start, _end) \
> - for_each_tdp_pte(_iter, _root->spt, _root->role.level, _start, _end)
> + for_each_tdp_pte(_iter, _root, _start, _end)
>
> #define tdp_root_for_each_leaf_pte(_iter, _root, _start, _end) \
> tdp_root_for_each_pte(_iter, _root, _start, _end) \
> @@ -642,8 +642,7 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
> else
>
> #define tdp_mmu_for_each_pte(_iter, _mmu, _start, _end) \
> - for_each_tdp_pte(_iter, __va(_mmu->root_hpa), \
> - _mmu->shadow_root_level, _start, _end)
> + for_each_tdp_pte(_iter, to_shadow_page(_mmu->root_hpa), _start, _end)
>
> static inline bool tdp_mmu_iter_need_resched(struct kvm *kvm, struct tdp_iter *iter)
> {
> @@ -738,8 +737,7 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
>
> rcu_read_lock();
>
> - for_each_tdp_pte_min_level(iter, root->spt, root->role.level,
> - min_level, start, end) {
> + for_each_tdp_pte_min_level(iter, root, min_level, start, end) {
> retry:
> if (can_yield &&
> tdp_mmu_iter_cond_resched(kvm, &iter, flush, shared)) {
> @@ -1201,8 +1199,7 @@ static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
>
> BUG_ON(min_level > KVM_MAX_HUGEPAGE_LEVEL);
>
> - for_each_tdp_pte_min_level(iter, root->spt, root->role.level,
> - min_level, start, end) {
> + for_each_tdp_pte_min_level(iter, root, min_level, start, end) {
> retry:
> if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true))
> continue;
> @@ -1450,8 +1447,7 @@ static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
>
> rcu_read_lock();
>
> - for_each_tdp_pte_min_level(iter, root->spt, root->role.level,
> - min_level, gfn, gfn + 1) {
> + for_each_tdp_pte_min_level(iter, root, min_level, gfn, gfn + 1) {
> if (!is_shadow_present_pte(iter.old_spte) ||
> !is_last_spte(iter.old_spte, iter.level))
> continue;
> --
> 2.34.0.rc2.393.gf8c9666880-goog
>
