| Message ID | 20220606222058.86688-5-yosryahmed@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: mm: count KVM mmu usage in memory stats | expand |
Hi Yosry, On Mon, Jun 06, 2022 at 10:20:58PM +0000, Yosry Ahmed wrote: > Count the pages used by KVM in arm64 for stage2 mmu in secondary pagetable > stats. You could probably benefit from being a bit more verbose in the commit message here as well, per Sean's feedback. > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > --- > 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 f5651a05b6a85..80bc92601fd96 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); Probably more of a note to myself with the parallel fault series, but this is a race waiting to happen. This only works because stage 2 pages are dropped behind the write lock. Besides the commit message nit: Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index f5651a05b6a85..80bc92601fd96 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,
Count the pages used by KVM in arm64 for stage2 mmu in secondary pagetable stats. Signed-off-by: Yosry Ahmed <yosryahmed@google.com> --- arch/arm64/kvm/mmu.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-)