>From d41751068ac80ca5a375909d6c01cb25716a4975 Mon Sep 17 00:00:00 2001 From: Oleksandr Andrushchenko Date: Wed, 23 May 2018 16:52:45 +0300 Subject: [PATCH] xen/balloon: Share common memory reservation routines Memory {increase|decrease}_reservation and VA mappings update/reset code used in balloon driver can be made common, so other drivers can also re-use the same functionality without open-coding. Create a dedicated file for the shared code and export corresponding symbols for other kernel modules. Signed-off-by: Oleksandr Andrushchenko --- drivers/xen/Makefile | 1 + drivers/xen/balloon.c | 71 ++------------------- drivers/xen/mem-reservation.c | 78 +++++++++++++++++++++++ include/xen/mem-reservation.h | 114 ++++++++++++++++++++++++++++++++++ 4 files changed, 199 insertions(+), 65 deletions(-) create mode 100644 drivers/xen/mem-reservation.c create mode 100644 include/xen/mem-reservation.h diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 451e833f5931..3c87b0c3aca6 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o obj-$(CONFIG_X86) += fallback.o obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o +obj-y += mem-reservation.o obj-y += events/ obj-y += xenbus/ diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 065f0b607373..1789be76e9c5 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -71,6 +71,7 @@ #include #include #include +#include static int xen_hotplug_unpopulated; @@ -157,13 +158,6 @@ static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); #define GFP_BALLOON \ (GFP_HIGHUSER | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC) -static void scrub_page(struct page *page) -{ -#ifdef CONFIG_XEN_SCRUB_PAGES - clear_highpage(page); -#endif -} - /* balloon_append: add the given page to the balloon. */ static void __balloon_append(struct page *page) { @@ -463,11 +457,6 @@ static enum bp_state increase_reservation(unsigned long nr_pages) int rc; unsigned long i; struct page *page; - struct xen_memory_reservation reservation = { - .address_bits = 0, - .extent_order = EXTENT_ORDER, - .domid = DOMID_SELF - }; if (nr_pages > ARRAY_SIZE(frame_list)) nr_pages = ARRAY_SIZE(frame_list); @@ -486,9 +475,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages) page = balloon_next_page(page); } - set_xen_guest_handle(reservation.extent_start, frame_list); - reservation.nr_extents = nr_pages; - rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); + rc = xenmem_reservation_increase(nr_pages, frame_list); if (rc <= 0) return BP_EAGAIN; @@ -496,29 +483,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages) page = balloon_retrieve(false); BUG_ON(page == NULL); -#ifdef CONFIG_XEN_HAVE_PVMMU - /* - * We don't support PV MMU when Linux and Xen is using - * different page granularity. - */ - BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); - - if (!xen_feature(XENFEAT_auto_translated_physmap)) { - unsigned long pfn = page_to_pfn(page); - - set_phys_to_machine(pfn, frame_list[i]); - - /* Link back into the page tables if not highmem. */ - if (!PageHighMem(page)) { - int ret; - ret = HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - mfn_pte(frame_list[i], PAGE_KERNEL), - 0); - BUG_ON(ret); - } - } -#endif + __xenmem_reservation_va_mapping_update(page, frame_list[i]); /* Relinquish the page back to the allocator. */ free_reserved_page(page); @@ -535,11 +500,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) unsigned long i; struct page *page, *tmp; int ret; - struct xen_memory_reservation reservation = { - .address_bits = 0, - .extent_order = EXTENT_ORDER, - .domid = DOMID_SELF - }; LIST_HEAD(pages); if (nr_pages > ARRAY_SIZE(frame_list)) @@ -553,7 +513,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) break; } adjust_managed_page_count(page, -1); - scrub_page(page); + xenmem_reservation_scrub_page(page); list_add(&page->lru, &pages); } @@ -575,25 +535,8 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) /* XENMEM_decrease_reservation requires a GFN */ frame_list[i++] = xen_page_to_gfn(page); -#ifdef CONFIG_XEN_HAVE_PVMMU - /* - * We don't support PV MMU when Linux and Xen is using - * different page granularity. - */ - BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); - - if (!xen_feature(XENFEAT_auto_translated_physmap)) { - unsigned long pfn = page_to_pfn(page); + __xenmem_reservation_va_mapping_reset(page); - if (!PageHighMem(page)) { - ret = HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - __pte_ma(0), 0); - BUG_ON(ret); - } - __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); - } -#endif list_del(&page->lru); balloon_append(page); @@ -601,9 +544,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) flush_tlb_all(); - set_xen_guest_handle(reservation.extent_start, frame_list); - reservation.nr_extents = nr_pages; - ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); + ret = xenmem_reservation_decrease(nr_pages, frame_list); BUG_ON(ret != nr_pages); balloon_stats.current_pages -= nr_pages; diff --git a/drivers/xen/mem-reservation.c b/drivers/xen/mem-reservation.c new file mode 100644 index 000000000000..5347c17a08c1 --- /dev/null +++ b/drivers/xen/mem-reservation.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 + +/****************************************************************************** + * Xen memory reservation utilities. + * + * Copyright (c) 2003, B Dragovic + * Copyright (c) 2003-2004, M Williamson, K Fraser + * Copyright (c) 2005 Dan M. Smith, IBM Corporation + * Copyright (c) 2010 Daniel Kiper + * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc. + */ + +#include + +/* + * Use one extent per PAGE_SIZE to avoid to break down the page into + * multiple frame. + */ +#define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1) + +#ifdef CONFIG_XEN_SCRUB_PAGES +void xenmem_reservation_scrub_page(struct page *page) +{ + clear_highpage(page); +} +EXPORT_SYMBOL_GPL(xenmem_reservation_scrub_page); +#endif + +#ifdef CONFIG_XEN_HAVE_PVMMU +void xenmem_reservation_va_mapping_update(unsigned long count, + struct page **pages, + xen_pfn_t *frames) +{ + int i; + + for (i = 0; i < count; i++) + __xenmem_reservation_va_mapping_update(pages[i], frames[i]); +} +EXPORT_SYMBOL_GPL(xenmem_reservation_va_mapping_update); + +void xenmem_reservation_va_mapping_reset(unsigned long count, + struct page **pages) +{ + int i; + + for (i = 0; i < count; i++) + __xenmem_reservation_va_mapping_reset(pages[i]); +} +EXPORT_SYMBOL_GPL(xenmem_reservation_va_mapping_reset); +#endif /* CONFIG_XEN_HAVE_PVMMU */ + +int xenmem_reservation_increase(int count, xen_pfn_t *frames) +{ + struct xen_memory_reservation reservation = { + .address_bits = 0, + .extent_order = EXTENT_ORDER, + .domid = DOMID_SELF + }; + + set_xen_guest_handle(reservation.extent_start, frames); + reservation.nr_extents = count; + return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); +} +EXPORT_SYMBOL_GPL(xenmem_reservation_increase); + +int xenmem_reservation_decrease(int count, xen_pfn_t *frames) +{ + struct xen_memory_reservation reservation = { + .address_bits = 0, + .extent_order = EXTENT_ORDER, + .domid = DOMID_SELF + }; + + set_xen_guest_handle(reservation.extent_start, frames); + reservation.nr_extents = count; + return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); +} +EXPORT_SYMBOL_GPL(xenmem_reservation_decrease); diff --git a/include/xen/mem-reservation.h b/include/xen/mem-reservation.h new file mode 100644 index 000000000000..d44443cdd60e --- /dev/null +++ b/include/xen/mem-reservation.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Xen memory reservation utilities. + * + * Copyright (c) 2003, B Dragovic + * Copyright (c) 2003-2004, M Williamson, K Fraser + * Copyright (c) 2005 Dan M. Smith, IBM Corporation + * Copyright (c) 2010 Daniel Kiper + * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc. + */ + +#ifndef _XENMEM_RESERVATION_H +#define _XENMEM_RESERVATION_H + +#include +#include + +#include +#include + +#include +#include + +#ifdef CONFIG_XEN_SCRUB_PAGES +void xenmem_reservation_scrub_page(struct page *page); +#else +static inline void xenmem_reservation_scrub_page(struct page *page) +{ +} +#endif + +static inline void +__xenmem_reservation_va_mapping_update(struct page *page, xen_pfn_t frame) +{ +#ifdef CONFIG_XEN_HAVE_PVMMU + BUG_ON(page == NULL); + + /* + * We don't support PV MMU when Linux and Xen is using + * different page granularity. + */ + BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); + + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + unsigned long pfn = page_to_pfn(page); + + set_phys_to_machine(pfn, frame); + + /* Link back into the page tables if not highmem. */ + if (!PageHighMem(page)) { + int ret; + + ret = HYPERVISOR_update_va_mapping( + (unsigned long)__va(pfn << PAGE_SHIFT), + mfn_pte(frame, PAGE_KERNEL), + 0); + BUG_ON(ret); + } + } +#endif +} + +static inline void +__xenmem_reservation_va_mapping_reset(struct page *page) +{ +#ifdef CONFIG_XEN_HAVE_PVMMU + /* + * We don't support PV MMU when Linux and Xen is using + * different page granularity. + */ + BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); + + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + unsigned long pfn = page_to_pfn(page); + + if (!PageHighMem(page)) { + int ret; + + ret = HYPERVISOR_update_va_mapping( + (unsigned long)__va(pfn << PAGE_SHIFT), + __pte_ma(0), 0); + BUG_ON(ret); + } + __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); + } +#endif +} + +#ifdef CONFIG_XEN_HAVE_PVMMU +void xenmem_reservation_va_mapping_update(unsigned long count, + struct page **pages, + xen_pfn_t *frames); + +void xenmem_reservation_va_mapping_reset(unsigned long count, + struct page **pages); +#else +static inline void xenmem_reservation_va_mapping_update(unsigned long count, + struct page **pages, + xen_pfn_t *frames) +{ +} + +static inline void xenmem_reservation_va_mapping_reset(unsigned long count, + struct page **pages) +{ +} +#endif + +int xenmem_reservation_increase(int count, xen_pfn_t *frames); + +int xenmem_reservation_decrease(int count, xen_pfn_t *frames); + +#endif -- 2.17.0