diff --git a/xen/arch/riscv/include/asm/paging.h b/xen/arch/riscv/include/asm/paging.h index fe462be223..c1d225d02b 100644 --- a/xen/arch/riscv/include/asm/paging.h +++ b/xen/arch/riscv/include/asm/paging.h @@ -15,4 +15,6 @@ int paging_refill_from_domheap(struct domain *d, unsigned int nr_pages); void paging_free_page(struct domain *d, struct page_info *pg); +struct page_info *paging_alloc_page(struct domain *d); + #endif /* ASM_RISCV_PAGING_H */ diff --git a/xen/arch/riscv/p2m.c b/xen/arch/riscv/p2m.c index 48e75b1867..9e1a660316 100644 --- a/xen/arch/riscv/p2m.c +++ b/xen/arch/riscv/p2m.c @@ -357,6 +357,19 @@ int p2m_set_allocation(struct domain *d, unsigned long pages, bool *preempted) return rc; } +static struct page_info *p2m_alloc_page(struct p2m_domain *p2m) +{ + struct page_info *pg = paging_alloc_page(p2m->domain); + + if ( pg ) + { + page_list_add(pg, &p2m->pages); + clear_and_clean_page(pg, p2m->clean_dcache); + } + + return pg; +} + static int p2m_set_type(pte_t *pte, p2m_type_t t) { int rc = 0; @@ -497,6 +510,33 @@ static pte_t p2m_pte_from_mfn(mfn_t mfn, p2m_type_t t, bool is_table) return e; } +/* Generate table entry with correct attributes. */ +static pte_t page_to_p2m_table(const struct page_info *page) +{ + /* + * p2m_invalid will be ignored inside p2m_pte_from_mfn() as is_table is + * set to true and p2m_type_t shouldn't be applied for PTEs which + * describe an intermediate table. + */ + return p2m_pte_from_mfn(page_to_mfn(page), p2m_invalid, true); +} + +/* Allocate a new page table page and hook it in via the given entry. */ +static int p2m_create_table(struct p2m_domain *p2m, pte_t *entry) +{ + struct page_info *page; + + ASSERT(!pte_is_valid(*entry)); + + page = p2m_alloc_page(p2m); + if ( page == NULL ) + return -ENOMEM; + + p2m_write_pte(entry, page_to_p2m_table(page), p2m->clean_dcache); + + return 0; +} + #define P2M_TABLE_MAP_NONE 0 #define P2M_TABLE_MAP_NOMEM 1 #define P2M_TABLE_SUPER_PAGE 2 @@ -521,9 +561,42 @@ static int p2m_next_level(struct p2m_domain *p2m, bool alloc_tbl, unsigned int level, pte_t **table, unsigned int offset) { - panic("%s: hasn't been implemented yet\n", __func__); + pte_t *entry; + mfn_t mfn; - return P2M_TABLE_MAP_NONE; + /* The function p2m_next_level() is never called at the last level */ + ASSERT(level != 0); + + entry = *table + offset; + + if ( !pte_is_valid(*entry) ) + { + int ret; + + if ( !alloc_tbl ) + return P2M_TABLE_MAP_NONE; + + ret = p2m_create_table(p2m, entry); + if ( ret ) + return P2M_TABLE_MAP_NOMEM; + } + + if ( pte_is_mapping(*entry) ) + return P2M_TABLE_SUPER_PAGE; + + mfn = mfn_from_pte(*entry); + + unmap_domain_page(*table); + + /* + * TODO: There's an inefficiency here: + * In p2m_create_table(), the page is mapped to clear it. + * Then that mapping is torn down in p2m_create_table(), + * only to be re-established here. + */ + *table = map_domain_page(mfn); + + return P2M_TABLE_NORMAL; } static void p2m_put_foreign_page(struct page_info *pg) diff --git a/xen/arch/riscv/paging.c b/xen/arch/riscv/paging.c index 09631c9894..76a203edbb 100644 --- a/xen/arch/riscv/paging.c +++ b/xen/arch/riscv/paging.c @@ -117,6 +117,18 @@ void paging_free_page(struct domain *d, struct page_info *pg) spin_unlock(&d->arch.paging.lock); } +struct page_info *paging_alloc_page(struct domain *d) +{ + struct page_info *pg; + + spin_lock(&d->arch.paging.lock); + pg = page_list_remove_head(&d->arch.paging.freelist); + d->arch.paging.total_pages--; + spin_unlock(&d->arch.paging.lock); + + return pg; +} + /* Domain paging struct initialization. */ int paging_domain_init(struct domain *d) {