diff --git a/arch/arm64/kvm/hyp/include/nvhe/gfp.h b/arch/arm64/kvm/hyp/include/nvhe/gfp.h index 55b3f0ce5bc8..a915bf2d8344 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/gfp.h +++ b/arch/arm64/kvm/hyp/include/nvhe/gfp.h @@ -59,6 +59,7 @@ static inline void hyp_set_page_refcounted(struct hyp_page *p) /* Allocation */ void *hyp_alloc_pages(struct hyp_pool *pool, unsigned int order); +void hyp_split_page(struct hyp_page *page); void hyp_get_page(void *addr); void hyp_put_page(void *addr); diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 695026ffc6b7..fc54fda72313 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -36,7 +36,18 @@ static const u8 pkvm_hyp_id = 1; static void *host_s2_zalloc_pages_exact(size_t size) { - return hyp_alloc_pages(&host_s2_mem, get_order(size)); + void *addr = hyp_alloc_pages(&host_s2_mem, get_order(size)); + + hyp_split_page(hyp_virt_to_page(addr)); + + /* + * The size of concatenated PGDs is always a power of two of PAGE_SIZE, + * so there should be no need to free any of the tail pages to make the + * allocation exact. + */ + WARN_ON(size != (PAGE_SIZE << get_order(size))); + + return addr; } static void *host_s2_zalloc_page(void *pool) diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index 237e03bf0cb1..ed92d659a156 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -140,6 +140,20 @@ void hyp_get_page(void *addr) hyp_page_ref_inc(p); } +void hyp_split_page(struct hyp_page *p) +{ + unsigned short order = p->order; + unsigned int i; + + p->order = 0; + for (i = 1; i < (1 << order); i++) { + struct hyp_page *tail = p + i; + + tail->order = 0; + hyp_set_page_refcounted(tail); + } +} + void *hyp_alloc_pages(struct hyp_pool *pool, unsigned int order) { unsigned int i = order;