[PATCH v7 4/4] KVM: arm64/mmu: count KVM s2 mmu usage in secondary pagetable stats
From: Yosry Ahmed <hidden>
Date: 2022-08-23 00:47:12
Also in:
cgroups, kvm, kvmarm, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Count the pages used by KVM in arm64 for stage2 mmu in memory stats under secondary pagetable stats (e.g. "SecPageTables" in /proc/meminfo) to give better visibility into the memory consumption of KVM mmu in a similar way to how normal user page tables are accounted. Signed-off-by: Yosry Ahmed <redacted> Reviewed-by: Oliver Upton <redacted> Reviewed-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/mmu.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index c9a13e487187..34c5feed9dc1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c@@ -92,9 +92,13 @@ static bool kvm_is_device_pfn(unsigned long pfn) static void *stage2_memcache_zalloc_page(void *arg) { struct kvm_mmu_memory_cache *mc = arg; + void *virt; /* Allocated with __GFP_ZERO, so no need to zero */ - return kvm_mmu_memory_cache_alloc(mc); + virt = kvm_mmu_memory_cache_alloc(mc); + if (virt) + kvm_account_pgtable_pages(virt, 1); + return virt; } static void *kvm_host_zalloc_pages_exact(size_t size)
@@ -102,6 +106,21 @@ static void *kvm_host_zalloc_pages_exact(size_t size) return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); } +static void *kvm_s2_zalloc_pages_exact(size_t size) +{ + void *virt = kvm_host_zalloc_pages_exact(size); + + if (virt) + kvm_account_pgtable_pages(virt, (size >> PAGE_SHIFT)); + return virt; +} + +static void kvm_s2_free_pages_exact(void *virt, size_t size) +{ + kvm_account_pgtable_pages(virt, -(size >> PAGE_SHIFT)); + free_pages_exact(virt, size); +} + static void kvm_host_get_page(void *addr) { get_page(virt_to_page(addr));
@@ -112,6 +131,15 @@ static void kvm_host_put_page(void *addr) put_page(virt_to_page(addr)); } +static void kvm_s2_put_page(void *addr) +{ + struct page *p = virt_to_page(addr); + /* Dropping last refcount, the page will be freed */ + if (page_count(p) == 1) + kvm_account_pgtable_pages(addr, -1); + put_page(p); +} + static int kvm_host_page_count(void *addr) { return page_count(virt_to_page(addr));
@@ -625,10 +653,10 @@ static int get_user_mapping_size(struct kvm *kvm, u64 addr) static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = { .zalloc_page = stage2_memcache_zalloc_page, - .zalloc_pages_exact = kvm_host_zalloc_pages_exact, - .free_pages_exact = free_pages_exact, + .zalloc_pages_exact = kvm_s2_zalloc_pages_exact, + .free_pages_exact = kvm_s2_free_pages_exact, .get_page = kvm_host_get_page, - .put_page = kvm_host_put_page, + .put_page = kvm_s2_put_page, .page_count = kvm_host_page_count, .phys_to_virt = kvm_host_va, .virt_to_phys = kvm_host_pa,
--
2.37.1.595.g718a3a8f04-goog
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