| Message ID | 20210726175357.1572951-4-mizhang@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add detailed page size stats in KVM stats | expand |
On Mon, Jul 26, 2021 at 10:54 AM Mingwei Zhang <mizhang@google.com> wrote: > > Existing KVM code tracks the number of large pages regardless of their > sizes. Therefore, when large page of 1GB (or larger) is adopted, the > information becomes less useful because lpages counts a mix of 1G and 2M > pages. > > So remove the lpages since it is easy for user space to aggregate the info. > Instead, provide a comprehensive page stats of all sizes from 4K to 512G. > > Suggested-by: Ben Gardon <bgardon@google.com> > Suggested-by: Jing Zhang <jingzhangos@google.com> > Signed-off-by: Mingwei Zhang <mizhang@google.com> > --- > arch/x86/include/asm/kvm_host.h | 10 +++++++++- > arch/x86/kvm/mmu.h | 2 ++ > arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- > arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- > arch/x86/kvm/x86.c | 7 +++++-- > 5 files changed, 37 insertions(+), 29 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 974cbfb1eefe..2e4b6fd36e62 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { > u64 mmu_recycled; > u64 mmu_cache_miss; > u64 mmu_unsync; > - u64 lpages; > u64 nx_lpage_splits; > u64 max_mmu_page_hash_collisions; > + union { > + struct { > + atomic64_t pages_4k; > + atomic64_t pages_2m; > + atomic64_t pages_1g; > + atomic64_t pages_512g; > + }; > + atomic64_t pages[4]; > + } page_stats; > }; > > struct kvm_vcpu_stat { > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > index 83e6c6965f1e..ad5638815311 100644 > --- a/arch/x86/kvm/mmu.h > +++ b/arch/x86/kvm/mmu.h > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > } > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > + > #endif > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 442cc554ebd6..7e0fc760739b 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > return flush; > } > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > +{ > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > +} > + > /* > * Rules for using mmu_spte_clear_track_bits: > * It sets the sptep from present to nonpresent, and track the > * state bits, it is used to clear the last level sptep. > * Returns non-zero if the PTE was previously valid. > */ > -static int mmu_spte_clear_track_bits(u64 *sptep) > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > { > kvm_pfn_t pfn; > u64 old_spte = *sptep; > + int level = sptep_to_sp(sptep)->role.level; > > if (!spte_has_volatile_bits(old_spte)) > __update_clear_spte_fast(sptep, 0ull); > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > if (!is_shadow_present_pte(old_spte)) > return 0; > > + if (is_last_spte(old_spte, level)) You can drop this check since it's part of the contract for calling this function. > + kvm_update_page_stats(kvm, level, -1); > + > pfn = spte_to_pfn(old_spte); > > /* > @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) > } > } > > -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) > +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > + u64 *sptep) > { > - mmu_spte_clear_track_bits(sptep); > + mmu_spte_clear_track_bits(kvm, sptep); > __pte_list_remove(sptep, rmap_head); > } > > @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > static void drop_spte(struct kvm *kvm, u64 *sptep) > { > - if (mmu_spte_clear_track_bits(sptep)) > + if (mmu_spte_clear_track_bits(kvm, sptep)) > rmap_remove(kvm, sptep); > } > > @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > if (is_large_pte(*sptep)) { > WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > drop_spte(kvm, sptep); > - --kvm->stat.lpages; > return true; > } > > @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > while ((sptep = rmap_get_first(rmap_head, &iter))) { > rmap_printk("spte %p %llx.\n", sptep, *sptep); > > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > flush = true; > } > > @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > need_flush = 1; > > if (pte_write(pte)) { > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > goto restart; > } else { > new_spte = kvm_mmu_changed_pte_notifier_make_spte( > *sptep, new_pfn); > > - mmu_spte_clear_track_bits(sptep); > + mmu_spte_clear_track_bits(kvm, sptep); > mmu_spte_set(sptep, new_spte); > } > } > @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, > if (is_shadow_present_pte(pte)) { > if (is_last_spte(pte, sp->role.level)) { > drop_spte(kvm, spte); > - if (is_large_pte(pte)) > - --kvm->stat.lpages; > } else { > child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); > drop_parent_pte(child, spte); > @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > trace_kvm_mmu_set_spte(level, gfn, sptep); > > if (!was_rmapped) { > - if (is_large_pte(*sptep)) > - ++vcpu->kvm->stat.lpages; > + kvm_update_page_stats(vcpu->kvm, level, 1); > rmap_count = rmap_add(vcpu, sptep, gfn); > if (rmap_count > RMAP_RECYCLE_THRESHOLD) > rmap_recycle(vcpu, sptep, gfn); > @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > pfn, PG_LEVEL_NUM)) { > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > > if (kvm_available_flush_tlb_with_range()) > kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index cba2ab5db2a0..eae404c15364 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > bool was_leaf = was_present && is_last_spte(old_spte, level); > bool is_leaf = is_present && is_last_spte(new_spte, level); > bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); > - bool was_large, is_large; > > WARN_ON(level > PT64_ROOT_MAX_LEVEL); > WARN_ON(level < PG_LEVEL_4K); > @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > return; > } > > - /* > - * Update large page stats if a large page is being zapped, created, or > - * is replacing an existing shadow page. > - */ > - was_large = was_leaf && is_large_pte(old_spte); > - is_large = is_leaf && is_large_pte(new_spte); > - if (was_large != is_large) { > - if (was_large) > - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); > - else > - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); > - } > + if (is_leaf != was_leaf) > + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); > > if (was_leaf && is_dirty_spte(old_spte) && > (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8166ad113fb2..3858d36d3c49 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { > STATS_DESC_COUNTER(VM, mmu_recycled), > STATS_DESC_COUNTER(VM, mmu_cache_miss), > STATS_DESC_ICOUNTER(VM, mmu_unsync), > - STATS_DESC_ICOUNTER(VM, lpages), > STATS_DESC_ICOUNTER(VM, nx_lpage_splits), > - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) > + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) > }; > static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == > sizeof(struct kvm_vm_stat) / sizeof(u64)); > -- > 2.32.0.432.gabb21c7263-goog >
On Mon, Jul 26, 2021 at 1:41 PM Ben Gardon <bgardon@google.com> wrote: > > On Mon, Jul 26, 2021 at 10:54 AM Mingwei Zhang <mizhang@google.com> wrote: > > > > Existing KVM code tracks the number of large pages regardless of their > > sizes. Therefore, when large page of 1GB (or larger) is adopted, the > > information becomes less useful because lpages counts a mix of 1G and 2M > > pages. > > > > So remove the lpages since it is easy for user space to aggregate the info. > > Instead, provide a comprehensive page stats of all sizes from 4K to 512G. > > > > Suggested-by: Ben Gardon <bgardon@google.com> > > Suggested-by: Jing Zhang <jingzhangos@google.com> > > Signed-off-by: Mingwei Zhang <mizhang@google.com> Besides the check which can be dropped in mmu_spte_clear_track_bits, this looks good to me. Reviewed-by: Ben Gardon <bgardon@google.com> > > --- > > arch/x86/include/asm/kvm_host.h | 10 +++++++++- > > arch/x86/kvm/mmu.h | 2 ++ > > arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- > > arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- > > arch/x86/kvm/x86.c | 7 +++++-- > > 5 files changed, 37 insertions(+), 29 deletions(-) > > > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > > index 974cbfb1eefe..2e4b6fd36e62 100644 > > --- a/arch/x86/include/asm/kvm_host.h > > +++ b/arch/x86/include/asm/kvm_host.h > > @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { > > u64 mmu_recycled; > > u64 mmu_cache_miss; > > u64 mmu_unsync; > > - u64 lpages; > > u64 nx_lpage_splits; > > u64 max_mmu_page_hash_collisions; > > + union { > > + struct { > > + atomic64_t pages_4k; > > + atomic64_t pages_2m; > > + atomic64_t pages_1g; > > + atomic64_t pages_512g; > > + }; > > + atomic64_t pages[4]; > > + } page_stats; > > }; > > > > struct kvm_vcpu_stat { > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > > index 83e6c6965f1e..ad5638815311 100644 > > --- a/arch/x86/kvm/mmu.h > > +++ b/arch/x86/kvm/mmu.h > > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > > + > > #endif > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index 442cc554ebd6..7e0fc760739b 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > > return flush; > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > > +{ > > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > > +} > > + > > /* > > * Rules for using mmu_spte_clear_track_bits: > > * It sets the sptep from present to nonpresent, and track the > > * state bits, it is used to clear the last level sptep. > > * Returns non-zero if the PTE was previously valid. > > */ > > -static int mmu_spte_clear_track_bits(u64 *sptep) > > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > > { > > kvm_pfn_t pfn; > > u64 old_spte = *sptep; > > + int level = sptep_to_sp(sptep)->role.level; > > > > if (!spte_has_volatile_bits(old_spte)) > > __update_clear_spte_fast(sptep, 0ull); > > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > > if (!is_shadow_present_pte(old_spte)) > > return 0; > > > > + if (is_last_spte(old_spte, level)) > > You can drop this check since it's part of the contract for calling > this function. > > > + kvm_update_page_stats(kvm, level, -1); > > + > > pfn = spte_to_pfn(old_spte); > > > > /* > > @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) > > } > > } > > > > -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) > > +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > + u64 *sptep) > > { > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > __pte_list_remove(sptep, rmap_head); > > } > > > > @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > > > static void drop_spte(struct kvm *kvm, u64 *sptep) > > { > > - if (mmu_spte_clear_track_bits(sptep)) > > + if (mmu_spte_clear_track_bits(kvm, sptep)) > > rmap_remove(kvm, sptep); > > } > > > > @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > > if (is_large_pte(*sptep)) { > > WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > > drop_spte(kvm, sptep); > > - --kvm->stat.lpages; > > return true; > > } > > > > @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > while ((sptep = rmap_get_first(rmap_head, &iter))) { > > rmap_printk("spte %p %llx.\n", sptep, *sptep); > > > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > flush = true; > > } > > > > @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > need_flush = 1; > > > > if (pte_write(pte)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > goto restart; > > } else { > > new_spte = kvm_mmu_changed_pte_notifier_make_spte( > > *sptep, new_pfn); > > > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > mmu_spte_set(sptep, new_spte); > > } > > } > > @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, > > if (is_shadow_present_pte(pte)) { > > if (is_last_spte(pte, sp->role.level)) { > > drop_spte(kvm, spte); > > - if (is_large_pte(pte)) > > - --kvm->stat.lpages; > > } else { > > child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); > > drop_parent_pte(child, spte); > > @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > > trace_kvm_mmu_set_spte(level, gfn, sptep); > > > > if (!was_rmapped) { > > - if (is_large_pte(*sptep)) > > - ++vcpu->kvm->stat.lpages; > > + kvm_update_page_stats(vcpu->kvm, level, 1); > > rmap_count = rmap_add(vcpu, sptep, gfn); > > if (rmap_count > RMAP_RECYCLE_THRESHOLD) > > rmap_recycle(vcpu, sptep, gfn); > > @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > > if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && > > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > > pfn, PG_LEVEL_NUM)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > > > if (kvm_available_flush_tlb_with_range()) > > kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > > index cba2ab5db2a0..eae404c15364 100644 > > --- a/arch/x86/kvm/mmu/tdp_mmu.c > > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > > @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > bool was_leaf = was_present && is_last_spte(old_spte, level); > > bool is_leaf = is_present && is_last_spte(new_spte, level); > > bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); > > - bool was_large, is_large; > > > > WARN_ON(level > PT64_ROOT_MAX_LEVEL); > > WARN_ON(level < PG_LEVEL_4K); > > @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > return; > > } > > > > - /* > > - * Update large page stats if a large page is being zapped, created, or > > - * is replacing an existing shadow page. > > - */ > > - was_large = was_leaf && is_large_pte(old_spte); > > - is_large = is_leaf && is_large_pte(new_spte); > > - if (was_large != is_large) { > > - if (was_large) > > - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); > > - else > > - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); > > - } > > + if (is_leaf != was_leaf) > > + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); > > > > if (was_leaf && is_dirty_spte(old_spte) && > > (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 8166ad113fb2..3858d36d3c49 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { > > STATS_DESC_COUNTER(VM, mmu_recycled), > > STATS_DESC_COUNTER(VM, mmu_cache_miss), > > STATS_DESC_ICOUNTER(VM, mmu_unsync), > > - STATS_DESC_ICOUNTER(VM, lpages), > > STATS_DESC_ICOUNTER(VM, nx_lpage_splits), > > - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) > > + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) > > }; > > static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == > > sizeof(struct kvm_vm_stat) / sizeof(u64)); > > -- > > 2.32.0.432.gabb21c7263-goog > >
On Mon, Jul 26, 2021 at 10:53:57AM -0700, Mingwei Zhang wrote: > Existing KVM code tracks the number of large pages regardless of their > sizes. Therefore, when large page of 1GB (or larger) is adopted, the > information becomes less useful because lpages counts a mix of 1G and 2M > pages. > > So remove the lpages since it is easy for user space to aggregate the info. > Instead, provide a comprehensive page stats of all sizes from 4K to 512G. > > Suggested-by: Ben Gardon <bgardon@google.com> > Suggested-by: Jing Zhang <jingzhangos@google.com> > Signed-off-by: Mingwei Zhang <mizhang@google.com> > --- > arch/x86/include/asm/kvm_host.h | 10 +++++++++- > arch/x86/kvm/mmu.h | 2 ++ > arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- > arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- > arch/x86/kvm/x86.c | 7 +++++-- > 5 files changed, 37 insertions(+), 29 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 974cbfb1eefe..2e4b6fd36e62 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { > u64 mmu_recycled; > u64 mmu_cache_miss; > u64 mmu_unsync; > - u64 lpages; > u64 nx_lpage_splits; > u64 max_mmu_page_hash_collisions; > + union { > + struct { > + atomic64_t pages_4k; > + atomic64_t pages_2m; > + atomic64_t pages_1g; > + atomic64_t pages_512g; > + }; > + atomic64_t pages[4]; > + } page_stats; > }; > > struct kvm_vcpu_stat { > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > index 83e6c6965f1e..ad5638815311 100644 > --- a/arch/x86/kvm/mmu.h > +++ b/arch/x86/kvm/mmu.h > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > } > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > + > #endif > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 442cc554ebd6..7e0fc760739b 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > return flush; > } > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > +{ > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > +} > + > /* > * Rules for using mmu_spte_clear_track_bits: > * It sets the sptep from present to nonpresent, and track the > * state bits, it is used to clear the last level sptep. > * Returns non-zero if the PTE was previously valid. > */ > -static int mmu_spte_clear_track_bits(u64 *sptep) > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > { > kvm_pfn_t pfn; > u64 old_spte = *sptep; > + int level = sptep_to_sp(sptep)->role.level; > > if (!spte_has_volatile_bits(old_spte)) > __update_clear_spte_fast(sptep, 0ull); > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > if (!is_shadow_present_pte(old_spte)) > return 0; > > + if (is_last_spte(old_spte, level)) > + kvm_update_page_stats(kvm, level, -1); > + > pfn = spte_to_pfn(old_spte); > > /* > @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) > } > } > > -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) > +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > + u64 *sptep) > { > - mmu_spte_clear_track_bits(sptep); > + mmu_spte_clear_track_bits(kvm, sptep); > __pte_list_remove(sptep, rmap_head); > } > > @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > static void drop_spte(struct kvm *kvm, u64 *sptep) > { > - if (mmu_spte_clear_track_bits(sptep)) > + if (mmu_spte_clear_track_bits(kvm, sptep)) > rmap_remove(kvm, sptep); > } > > @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > if (is_large_pte(*sptep)) { > WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > drop_spte(kvm, sptep); > - --kvm->stat.lpages; > return true; > } > > @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > while ((sptep = rmap_get_first(rmap_head, &iter))) { > rmap_printk("spte %p %llx.\n", sptep, *sptep); > > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > flush = true; > } > > @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > need_flush = 1; > > if (pte_write(pte)) { > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > goto restart; > } else { > new_spte = kvm_mmu_changed_pte_notifier_make_spte( > *sptep, new_pfn); > > - mmu_spte_clear_track_bits(sptep); > + mmu_spte_clear_track_bits(kvm, sptep); > mmu_spte_set(sptep, new_spte); > } > } > @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, > if (is_shadow_present_pte(pte)) { > if (is_last_spte(pte, sp->role.level)) { > drop_spte(kvm, spte); > - if (is_large_pte(pte)) > - --kvm->stat.lpages; > } else { > child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); > drop_parent_pte(child, spte); > @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > trace_kvm_mmu_set_spte(level, gfn, sptep); > > if (!was_rmapped) { > - if (is_large_pte(*sptep)) > - ++vcpu->kvm->stat.lpages; > + kvm_update_page_stats(vcpu->kvm, level, 1); > rmap_count = rmap_add(vcpu, sptep, gfn); > if (rmap_count > RMAP_RECYCLE_THRESHOLD) > rmap_recycle(vcpu, sptep, gfn); > @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > pfn, PG_LEVEL_NUM)) { > - pte_list_remove(rmap_head, sptep); > + pte_list_remove(kvm, rmap_head, sptep); > > if (kvm_available_flush_tlb_with_range()) > kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index cba2ab5db2a0..eae404c15364 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > bool was_leaf = was_present && is_last_spte(old_spte, level); > bool is_leaf = is_present && is_last_spte(new_spte, level); > bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); > - bool was_large, is_large; > > WARN_ON(level > PT64_ROOT_MAX_LEVEL); > WARN_ON(level < PG_LEVEL_4K); > @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > return; > } > > - /* > - * Update large page stats if a large page is being zapped, created, or > - * is replacing an existing shadow page. > - */ > - was_large = was_leaf && is_large_pte(old_spte); > - is_large = is_leaf && is_large_pte(new_spte); > - if (was_large != is_large) { > - if (was_large) > - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); > - else > - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); > - } > + if (is_leaf != was_leaf) > + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); > > if (was_leaf && is_dirty_spte(old_spte) && > (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8166ad113fb2..3858d36d3c49 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { > STATS_DESC_COUNTER(VM, mmu_recycled), > STATS_DESC_COUNTER(VM, mmu_cache_miss), > STATS_DESC_ICOUNTER(VM, mmu_unsync), > - STATS_DESC_ICOUNTER(VM, lpages), > STATS_DESC_ICOUNTER(VM, nx_lpage_splits), > - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) > + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), > + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) FYI this will make the stat names "page_stats.pages_4k", "page_stats.pages_2m", etc. Is that ok? If you want the stat names to be just "pages_4k", "pages_2m", etc. you can make the page_stats union anonymous. > }; > static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == > sizeof(struct kvm_vm_stat) / sizeof(u64)); > -- > 2.32.0.432.gabb21c7263-goog >
Hi David and Ben, Thank you both for the suggestions. It Makes sense to me and I will update the patch set with the change added in the next version. Regards. -Mingwei On Tue, Jul 27, 2021 at 8:36 AM David Matlack <dmatlack@google.com> wrote: > > On Mon, Jul 26, 2021 at 10:53:57AM -0700, Mingwei Zhang wrote: > > Existing KVM code tracks the number of large pages regardless of their > > sizes. Therefore, when large page of 1GB (or larger) is adopted, the > > information becomes less useful because lpages counts a mix of 1G and 2M > > pages. > > > > So remove the lpages since it is easy for user space to aggregate the info. > > Instead, provide a comprehensive page stats of all sizes from 4K to 512G. > > > > Suggested-by: Ben Gardon <bgardon@google.com> > > Suggested-by: Jing Zhang <jingzhangos@google.com> > > Signed-off-by: Mingwei Zhang <mizhang@google.com> > > --- > > arch/x86/include/asm/kvm_host.h | 10 +++++++++- > > arch/x86/kvm/mmu.h | 2 ++ > > arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- > > arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- > > arch/x86/kvm/x86.c | 7 +++++-- > > 5 files changed, 37 insertions(+), 29 deletions(-) > > > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > > index 974cbfb1eefe..2e4b6fd36e62 100644 > > --- a/arch/x86/include/asm/kvm_host.h > > +++ b/arch/x86/include/asm/kvm_host.h > > @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { > > u64 mmu_recycled; > > u64 mmu_cache_miss; > > u64 mmu_unsync; > > - u64 lpages; > > u64 nx_lpage_splits; > > u64 max_mmu_page_hash_collisions; > > + union { > > + struct { > > + atomic64_t pages_4k; > > + atomic64_t pages_2m; > > + atomic64_t pages_1g; > > + atomic64_t pages_512g; > > + }; > > + atomic64_t pages[4]; > > + } page_stats; > > }; > > > > struct kvm_vcpu_stat { > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > > index 83e6c6965f1e..ad5638815311 100644 > > --- a/arch/x86/kvm/mmu.h > > +++ b/arch/x86/kvm/mmu.h > > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > > + > > #endif > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index 442cc554ebd6..7e0fc760739b 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > > return flush; > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > > +{ > > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > > +} > > + > > /* > > * Rules for using mmu_spte_clear_track_bits: > > * It sets the sptep from present to nonpresent, and track the > > * state bits, it is used to clear the last level sptep. > > * Returns non-zero if the PTE was previously valid. > > */ > > -static int mmu_spte_clear_track_bits(u64 *sptep) > > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > > { > > kvm_pfn_t pfn; > > u64 old_spte = *sptep; > > + int level = sptep_to_sp(sptep)->role.level; > > > > if (!spte_has_volatile_bits(old_spte)) > > __update_clear_spte_fast(sptep, 0ull); > > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > > if (!is_shadow_present_pte(old_spte)) > > return 0; > > > > + if (is_last_spte(old_spte, level)) > > + kvm_update_page_stats(kvm, level, -1); > > + > > pfn = spte_to_pfn(old_spte); > > > > /* > > @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) > > } > > } > > > > -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) > > +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > + u64 *sptep) > > { > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > __pte_list_remove(sptep, rmap_head); > > } > > > > @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > > > static void drop_spte(struct kvm *kvm, u64 *sptep) > > { > > - if (mmu_spte_clear_track_bits(sptep)) > > + if (mmu_spte_clear_track_bits(kvm, sptep)) > > rmap_remove(kvm, sptep); > > } > > > > @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > > if (is_large_pte(*sptep)) { > > WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > > drop_spte(kvm, sptep); > > - --kvm->stat.lpages; > > return true; > > } > > > > @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > while ((sptep = rmap_get_first(rmap_head, &iter))) { > > rmap_printk("spte %p %llx.\n", sptep, *sptep); > > > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > flush = true; > > } > > > > @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > need_flush = 1; > > > > if (pte_write(pte)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > goto restart; > > } else { > > new_spte = kvm_mmu_changed_pte_notifier_make_spte( > > *sptep, new_pfn); > > > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > mmu_spte_set(sptep, new_spte); > > } > > } > > @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, > > if (is_shadow_present_pte(pte)) { > > if (is_last_spte(pte, sp->role.level)) { > > drop_spte(kvm, spte); > > - if (is_large_pte(pte)) > > - --kvm->stat.lpages; > > } else { > > child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); > > drop_parent_pte(child, spte); > > @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > > trace_kvm_mmu_set_spte(level, gfn, sptep); > > > > if (!was_rmapped) { > > - if (is_large_pte(*sptep)) > > - ++vcpu->kvm->stat.lpages; > > + kvm_update_page_stats(vcpu->kvm, level, 1); > > rmap_count = rmap_add(vcpu, sptep, gfn); > > if (rmap_count > RMAP_RECYCLE_THRESHOLD) > > rmap_recycle(vcpu, sptep, gfn); > > @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > > if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && > > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > > pfn, PG_LEVEL_NUM)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > > > if (kvm_available_flush_tlb_with_range()) > > kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > > index cba2ab5db2a0..eae404c15364 100644 > > --- a/arch/x86/kvm/mmu/tdp_mmu.c > > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > > @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > bool was_leaf = was_present && is_last_spte(old_spte, level); > > bool is_leaf = is_present && is_last_spte(new_spte, level); > > bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); > > - bool was_large, is_large; > > > > WARN_ON(level > PT64_ROOT_MAX_LEVEL); > > WARN_ON(level < PG_LEVEL_4K); > > @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > return; > > } > > > > - /* > > - * Update large page stats if a large page is being zapped, created, or > > - * is replacing an existing shadow page. > > - */ > > - was_large = was_leaf && is_large_pte(old_spte); > > - is_large = is_leaf && is_large_pte(new_spte); > > - if (was_large != is_large) { > > - if (was_large) > > - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); > > - else > > - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); > > - } > > + if (is_leaf != was_leaf) > > + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); > > > > if (was_leaf && is_dirty_spte(old_spte) && > > (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 8166ad113fb2..3858d36d3c49 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { > > STATS_DESC_COUNTER(VM, mmu_recycled), > > STATS_DESC_COUNTER(VM, mmu_cache_miss), > > STATS_DESC_ICOUNTER(VM, mmu_unsync), > > - STATS_DESC_ICOUNTER(VM, lpages), > > STATS_DESC_ICOUNTER(VM, nx_lpage_splits), > > - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) > > + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) > > FYI this will make the stat names "page_stats.pages_4k", > "page_stats.pages_2m", etc. Is that ok? > > If you want the stat names to be just "pages_4k", "pages_2m", etc. you > can make the page_stats union anonymous. > > > }; > > static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == > > sizeof(struct kvm_vm_stat) / sizeof(u64)); > > -- > > 2.32.0.432.gabb21c7263-goog > >
On Mon, Jul 26, 2021, Ben Gardon wrote: > On Mon, Jul 26, 2021 at 10:54 AM Mingwei Zhang <mizhang@google.com> wrote: > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > > index 83e6c6965f1e..ad5638815311 100644 > > --- a/arch/x86/kvm/mmu.h > > +++ b/arch/x86/kvm/mmu.h > > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > > + > > #endif > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index 442cc554ebd6..7e0fc760739b 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > > return flush; > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > > +{ > > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > > +} This can be static inline in the header. Ignoring prolog+RET, it's four instructions, and two of those are sign extending input params. > > + > > /* > > * Rules for using mmu_spte_clear_track_bits: > > * It sets the sptep from present to nonpresent, and track the > > * state bits, it is used to clear the last level sptep. > > * Returns non-zero if the PTE was previously valid. > > */ > > -static int mmu_spte_clear_track_bits(u64 *sptep) > > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > > { > > kvm_pfn_t pfn; > > u64 old_spte = *sptep; > > + int level = sptep_to_sp(sptep)->role.level; > > > > if (!spte_has_volatile_bits(old_spte)) > > __update_clear_spte_fast(sptep, 0ull); > > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > > if (!is_shadow_present_pte(old_spte)) > > return 0; > > > > + if (is_last_spte(old_spte, level)) > > You can drop this check since it's part of the contract for calling > this function. Ah, nice! I overlooked that.
On Thu, Jul 29, 2021 at 11:45 AM Sean Christopherson <seanjc@google.com> wrote: > > On Mon, Jul 26, 2021, Ben Gardon wrote: > > On Mon, Jul 26, 2021 at 10:54 AM Mingwei Zhang <mizhang@google.com> wrote: > > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > > > index 83e6c6965f1e..ad5638815311 100644 > > > --- a/arch/x86/kvm/mmu.h > > > +++ b/arch/x86/kvm/mmu.h > > > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > > > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > > > } > > > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > > > + > > > #endif > > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > > index 442cc554ebd6..7e0fc760739b 100644 > > > --- a/arch/x86/kvm/mmu/mmu.c > > > +++ b/arch/x86/kvm/mmu/mmu.c > > > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > > > return flush; > > > } > > > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > > > +{ > > > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > > > +} > > This can be static inline in the header. Ignoring prolog+RET, it's four instructions, > and two of those are sign extending input params. will do.It is really nice to see that this big function has been finally shrinked to a single-line routine.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 974cbfb1eefe..2e4b6fd36e62 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { u64 mmu_recycled; u64 mmu_cache_miss; u64 mmu_unsync; - u64 lpages; u64 nx_lpage_splits; u64 max_mmu_page_hash_collisions; + union { + struct { + atomic64_t pages_4k; + atomic64_t pages_2m; + atomic64_t pages_1g; + atomic64_t pages_512g; + }; + atomic64_t pages[4]; + } page_stats; }; struct kvm_vcpu_stat { diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 83e6c6965f1e..ad5638815311 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) return smp_load_acquire(&kvm->arch.memslots_have_rmaps); } +void kvm_update_page_stats(struct kvm *kvm, int level, int count); + #endif diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 442cc554ebd6..7e0fc760739b 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) return flush; } +void kvm_update_page_stats(struct kvm *kvm, int level, int count) +{ + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); +} + /* * Rules for using mmu_spte_clear_track_bits: * It sets the sptep from present to nonpresent, and track the * state bits, it is used to clear the last level sptep. * Returns non-zero if the PTE was previously valid. */ -static int mmu_spte_clear_track_bits(u64 *sptep) +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) { kvm_pfn_t pfn; u64 old_spte = *sptep; + int level = sptep_to_sp(sptep)->role.level; if (!spte_has_volatile_bits(old_spte)) __update_clear_spte_fast(sptep, 0ull); @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) if (!is_shadow_present_pte(old_spte)) return 0; + if (is_last_spte(old_spte, level)) + kvm_update_page_stats(kvm, level, -1); + pfn = spte_to_pfn(old_spte); /* @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) } } -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, + u64 *sptep) { - mmu_spte_clear_track_bits(sptep); + mmu_spte_clear_track_bits(kvm, sptep); __pte_list_remove(sptep, rmap_head); } @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) static void drop_spte(struct kvm *kvm, u64 *sptep) { - if (mmu_spte_clear_track_bits(sptep)) + if (mmu_spte_clear_track_bits(kvm, sptep)) rmap_remove(kvm, sptep); } @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) if (is_large_pte(*sptep)) { WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); drop_spte(kvm, sptep); - --kvm->stat.lpages; return true; } @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, while ((sptep = rmap_get_first(rmap_head, &iter))) { rmap_printk("spte %p %llx.\n", sptep, *sptep); - pte_list_remove(rmap_head, sptep); + pte_list_remove(kvm, rmap_head, sptep); flush = true; } @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, need_flush = 1; if (pte_write(pte)) { - pte_list_remove(rmap_head, sptep); + pte_list_remove(kvm, rmap_head, sptep); goto restart; } else { new_spte = kvm_mmu_changed_pte_notifier_make_spte( *sptep, new_pfn); - mmu_spte_clear_track_bits(sptep); + mmu_spte_clear_track_bits(kvm, sptep); mmu_spte_set(sptep, new_spte); } } @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, if (is_shadow_present_pte(pte)) { if (is_last_spte(pte, sp->role.level)) { drop_spte(kvm, spte); - if (is_large_pte(pte)) - --kvm->stat.lpages; } else { child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); drop_parent_pte(child, spte); @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, trace_kvm_mmu_set_spte(level, gfn, sptep); if (!was_rmapped) { - if (is_large_pte(*sptep)) - ++vcpu->kvm->stat.lpages; + kvm_update_page_stats(vcpu->kvm, level, 1); rmap_count = rmap_add(vcpu, sptep, gfn); if (rmap_count > RMAP_RECYCLE_THRESHOLD) rmap_recycle(vcpu, sptep, gfn); @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, pfn, PG_LEVEL_NUM)) { - pte_list_remove(rmap_head, sptep); + pte_list_remove(kvm, rmap_head, sptep); if (kvm_available_flush_tlb_with_range()) kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index cba2ab5db2a0..eae404c15364 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, bool was_leaf = was_present && is_last_spte(old_spte, level); bool is_leaf = is_present && is_last_spte(new_spte, level); bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); - bool was_large, is_large; WARN_ON(level > PT64_ROOT_MAX_LEVEL); WARN_ON(level < PG_LEVEL_4K); @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, return; } - /* - * Update large page stats if a large page is being zapped, created, or - * is replacing an existing shadow page. - */ - was_large = was_leaf && is_large_pte(old_spte); - is_large = is_leaf && is_large_pte(new_spte); - if (was_large != is_large) { - if (was_large) - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); - else - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); - } + if (is_leaf != was_leaf) + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); if (was_leaf && is_dirty_spte(old_spte) && (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8166ad113fb2..3858d36d3c49 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { STATS_DESC_COUNTER(VM, mmu_recycled), STATS_DESC_COUNTER(VM, mmu_cache_miss), STATS_DESC_ICOUNTER(VM, mmu_unsync), - STATS_DESC_ICOUNTER(VM, lpages), STATS_DESC_ICOUNTER(VM, nx_lpage_splits), - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) }; static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == sizeof(struct kvm_vm_stat) / sizeof(u64));
Existing KVM code tracks the number of large pages regardless of their sizes. Therefore, when large page of 1GB (or larger) is adopted, the information becomes less useful because lpages counts a mix of 1G and 2M pages. So remove the lpages since it is easy for user space to aggregate the info. Instead, provide a comprehensive page stats of all sizes from 4K to 512G. Suggested-by: Ben Gardon <bgardon@google.com> Suggested-by: Jing Zhang <jingzhangos@google.com> Signed-off-by: Mingwei Zhang <mizhang@google.com> --- arch/x86/include/asm/kvm_host.h | 10 +++++++++- arch/x86/kvm/mmu.h | 2 ++ arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- arch/x86/kvm/x86.c | 7 +++++-- 5 files changed, 37 insertions(+), 29 deletions(-)