Let's have the following variants for destroying pages: (1) uv_destroy(): Like uv_pin_shared() and uv_convert_from_secure(), "low level" helper that operates on paddr and doesn't mess with folios. (2) uv_destroy_folio(): Consumes a folio to which we hold a reference. (3) uv_destroy_pte(): Consumes a PTE that holds a reference through the mapping. Unfortunately we need uv_destroy_pte(), because pfn_folio() and friends are not available in pgtable.h. Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> --- arch/s390/include/asm/pgtable.h | 2 +- arch/s390/include/asm/uv.h | 10 ++++++++-- arch/s390/kernel/uv.c | 24 +++++++++++++++++------- arch/s390/mm/gmap.c | 6 ++++-- 4 files changed, 30 insertions(+), 12 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 60950e7a25f5..97e040617c29 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1199,7 +1199,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, * The notifier should have destroyed all protected vCPUs at this * point, so the destroy should be successful. */ - if (full && !uv_destroy_owned_page(pte_val(res) & PAGE_MASK)) + if (full && !uv_destroy_pte(res)) return res; /* * If something went wrong and the page could not be destroyed, or diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h index d2205ff97007..a1bef30066ef 100644 --- a/arch/s390/include/asm/uv.h +++ b/arch/s390/include/asm/uv.h @@ -483,7 +483,8 @@ static inline int is_prot_virt_host(void) int uv_pin_shared(unsigned long paddr); int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb); int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr); -int uv_destroy_owned_page(unsigned long paddr); +int uv_destroy_folio(struct folio *folio); +int uv_destroy_pte(pte_t pte); int uv_convert_owned_from_secure(unsigned long paddr); int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr); @@ -497,7 +498,12 @@ static inline int uv_pin_shared(unsigned long paddr) return 0; } -static inline int uv_destroy_owned_page(unsigned long paddr) +static inline int uv_destroy_folio(struct folio *folio) +{ + return 0; +} + +static inline int uv_destroy_pte(pte_t pte) { return 0; } diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 3d3250b406a6..61c1ce51c883 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(uv_pin_shared); * * @paddr: Absolute host address of page to be destroyed */ -static int uv_destroy_page(unsigned long paddr) +static int uv_destroy(unsigned long paddr) { struct uv_cb_cfs uvcb = { .header.cmd = UVC_CMD_DESTR_SEC_STOR, @@ -131,11 +131,10 @@ static int uv_destroy_page(unsigned long paddr) } /* - * The caller must already hold a reference to the page + * The caller must already hold a reference to the folio */ -int uv_destroy_owned_page(unsigned long paddr) +int uv_destroy_folio(struct folio *folio) { - struct folio *folio = phys_to_folio(paddr); int rc; /* See gmap_make_secure(): large folios cannot be secure */ @@ -143,13 +142,22 @@ int uv_destroy_owned_page(unsigned long paddr) return 0; folio_get(folio); - rc = uv_destroy_page(paddr); + rc = uv_destroy(folio_to_phys(folio)); if (!rc) clear_bit(PG_arch_1, &folio->flags); folio_put(folio); return rc; } +/* + * The present PTE still indirectly holds a folio reference through the mapping. + */ +int uv_destroy_pte(pte_t pte) +{ + VM_WARN_ON(!pte_present(pte)); + return uv_destroy_folio(pfn_folio(pte_pfn(pte))); +} + /* * Requests the Ultravisor to encrypt a guest page and make it * accessible to the host for paging (export). @@ -437,6 +445,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) { struct vm_area_struct *vma; unsigned long uaddr; + struct folio *folio; struct page *page; int rc; @@ -460,7 +469,8 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) page = follow_page(vma, uaddr, FOLL_WRITE | FOLL_GET); if (IS_ERR_OR_NULL(page)) goto out; - rc = uv_destroy_owned_page(page_to_phys(page)); + folio = page_folio(page); + rc = uv_destroy_folio(folio); /* * Fault handlers can race; it is possible that two CPUs will fault * on the same secure page. One CPU can destroy the page, reboot, @@ -472,7 +482,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr) */ if (rc) rc = uv_convert_owned_from_secure(page_to_phys(page)); - put_page(page); + folio_put(folio); out: mmap_read_unlock(gmap->mm); return rc; diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 094b43b121cd..0351cb139df4 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2756,13 +2756,15 @@ static const struct mm_walk_ops gather_pages_ops = { */ void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns) { + struct folio *folio; unsigned long i; for (i = 0; i < count; i++) { + folio = pfn_folio(pfns[i]); /* we always have an extra reference */ - uv_destroy_owned_page(pfn_to_phys(pfns[i])); + uv_destroy_folio(folio); /* get rid of the extra reference */ - put_page(pfn_to_page(pfns[i])); + folio_put(folio); cond_resched(); } } -- 2.44.0