[Patch v4 08/18] KVM: x86/mmu: Track unused mmu_shadowed_info_cache pages count via global counter

From: Vipin Sharma
Date: Mon Mar 06 2023 - 17:42:17 EST


Add unused pages in mmu_shadowed_info_cache to global MMU unused page
cache counter i.e. kvm_total_unused_cached_pages. These pages will be
freed by MMU shrinker in future commit.

Signed-off-by: Vipin Sharma <vipinsh@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/mmu/mmu.c | 8 ++++----
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4322c7020d5d..185719dbeb81 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -792,7 +792,8 @@ struct kvm_vcpu_arch {
struct kvm_mmu_memory_cache mmu_page_header_cache;

/*
- * Protect allocation and release of pages from mmu_shadow_page_cache.
+ * Protect allocation and release of pages from mmu_shadow_page_cache
+ * and mmu_shadowed_info_cache.
*/
struct mutex mmu_shadow_page_cache_lock;

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0a0962d8108b..b7ca31b5699c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -715,8 +715,8 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect)
return r;

if (maybe_indirect) {
- r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_shadowed_info_cache,
- PT64_ROOT_MAX_LEVEL);
+ r = mmu_topup_sp_memory_cache(&vcpu->arch.mmu_shadowed_info_cache,
+ PT64_ROOT_MAX_LEVEL);
if (r)
return r;
}
@@ -729,8 +729,8 @@ static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
kvm_mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache);
mutex_lock(&vcpu->arch.mmu_shadow_page_cache_lock);
mmu_free_sp_memory_cache(&vcpu->arch.mmu_shadow_page_cache);
+ mmu_free_sp_memory_cache(&vcpu->arch.mmu_shadowed_info_cache);
mutex_unlock(&vcpu->arch.mmu_shadow_page_cache_lock);
- kvm_mmu_free_memory_cache(&vcpu->arch.mmu_shadowed_info_cache);
kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
}

@@ -2197,7 +2197,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm,
sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache);
sp->spt = mmu_sp_memory_cache_alloc(caches->shadow_page_cache);
if (!role.direct)
- sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache);
+ sp->shadowed_translation = mmu_sp_memory_cache_alloc(caches->shadowed_info_cache);

set_page_private(virt_to_page(sp->spt), (unsigned long)sp);

--
2.40.0.rc0.216.gc4246ad0f0-goog