From dd422906799f240bfd400a5d376aa43f7b89c38a Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Thu, 18 Jul 2019 17:27:20 +0800 Subject: mm/balloon_compaction: avoid duplicate page removal A #GP is reported in the guest when requesting balloon inflation via virtio-balloon. The reason is that the virtio-balloon driver has removed the page from its internal page list (via balloon_page_pop), but balloon_page_enqueue_one also calls "list_del" to do the removal. This is necessary when it's used from balloon_page_enqueue_list, but not from balloon_page_enqueue. Move list_del to balloon_page_enqueue, and update comments accordingly. Fixes: 418a3ab1e778 (mm/balloon_compaction: List interfaces) Signed-off-by: Wei Wang Signed-off-by: Michael S. Tsirkin --- mm/balloon_compaction.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 83a7b614061f..d25664e1857b 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -21,7 +21,6 @@ static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info, * memory corruption is possible and we should stop execution. */ BUG_ON(!trylock_page(page)); - list_del(&page->lru); balloon_page_insert(b_dev_info, page); unlock_page(page); __count_vm_event(BALLOON_INFLATE); @@ -47,6 +46,7 @@ size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, spin_lock_irqsave(&b_dev_info->pages_lock, flags); list_for_each_entry_safe(page, tmp, pages, lru) { + list_del(&page->lru); balloon_page_enqueue_one(b_dev_info, page); n_pages++; } @@ -128,13 +128,19 @@ struct page *balloon_page_alloc(void) EXPORT_SYMBOL_GPL(balloon_page_alloc); /* - * balloon_page_enqueue - allocates a new page and inserts it into the balloon - * page list. + * balloon_page_enqueue - inserts a new page into the balloon page list. + * * @b_dev_info: balloon device descriptor where we will insert a new page to * @page: new page to enqueue - allocated using balloon_page_alloc. * * Driver must call it to properly enqueue a new allocated balloon page * before definitively removing it from the guest system. + * + * Drivers must not call balloon_page_enqueue on pages that have been + * pushed to a list with balloon_page_push before removing them with + * balloon_page_pop. To all pages on a list, use balloon_page_list_enqueue + * instead. + * * This function returns the page address for the recently enqueued page or * NULL in the case we fail to allocate a new page this turn. */ -- cgit v1.2.3-55-g7522 From cfe61801b0f11eb561f1adf452d995efaafbc68b Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Thu, 18 Jul 2019 08:19:24 -0400 Subject: balloon: fix up comments Lots of comments bitrotted. Fix them up. Fixes: 418a3ab1e778 (mm/balloon_compaction: List interfaces) Reviewed-by: Wei Wang Signed-off-by: Michael S. Tsirkin Reviewed-by: Ralph Campbell Acked-by: Nadav Amit --- mm/balloon_compaction.c | 67 +++++++++++++++++++++++++++---------------------- 1 file changed, 37 insertions(+), 30 deletions(-) diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index d25664e1857b..798275a51887 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -32,8 +32,8 @@ static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info, * @b_dev_info: balloon device descriptor where we will insert a new page to * @pages: pages to enqueue - allocated using balloon_page_alloc. * - * Driver must call it to properly enqueue a balloon pages before definitively - * removing it from the guest system. + * Driver must call this function to properly enqueue balloon pages before + * definitively removing them from the guest system. * * Return: number of pages that were enqueued. */ @@ -63,12 +63,13 @@ EXPORT_SYMBOL_GPL(balloon_page_list_enqueue); * @n_req_pages: number of requested pages. * * Driver must call this function to properly de-allocate a previous enlisted - * balloon pages before definetively releasing it back to the guest system. + * balloon pages before definitively releasing it back to the guest system. * This function tries to remove @n_req_pages from the ballooned pages and * return them to the caller in the @pages list. * - * Note that this function may fail to dequeue some pages temporarily empty due - * to compaction isolated pages. + * Note that this function may fail to dequeue some pages even if the balloon + * isn't empty - since the page list can be temporarily empty due to compaction + * of isolated pages. * * Return: number of pages that were added to the @pages list. */ @@ -112,12 +113,13 @@ EXPORT_SYMBOL_GPL(balloon_page_list_dequeue); /* * balloon_page_alloc - allocates a new page for insertion into the balloon - * page list. + * page list. * - * Driver must call it to properly allocate a new enlisted balloon page. - * Driver must call balloon_page_enqueue before definitively removing it from - * the guest system. This function returns the page address for the recently - * allocated page or NULL in the case we fail to allocate a new page this turn. + * Driver must call this function to properly allocate a new balloon page. + * Driver must call balloon_page_enqueue before definitively removing the page + * from the guest system. + * + * Return: struct page for the allocated page or NULL on allocation failure. */ struct page *balloon_page_alloc(void) { @@ -130,19 +132,15 @@ EXPORT_SYMBOL_GPL(balloon_page_alloc); /* * balloon_page_enqueue - inserts a new page into the balloon page list. * - * @b_dev_info: balloon device descriptor where we will insert a new page to + * @b_dev_info: balloon device descriptor where we will insert a new page * @page: new page to enqueue - allocated using balloon_page_alloc. * - * Driver must call it to properly enqueue a new allocated balloon page - * before definitively removing it from the guest system. + * Drivers must call this function to properly enqueue a new allocated balloon + * page before definitively removing the page from the guest system. * - * Drivers must not call balloon_page_enqueue on pages that have been - * pushed to a list with balloon_page_push before removing them with - * balloon_page_pop. To all pages on a list, use balloon_page_list_enqueue - * instead. - * - * This function returns the page address for the recently enqueued page or - * NULL in the case we fail to allocate a new page this turn. + * Drivers must not call balloon_page_enqueue on pages that have been pushed to + * a list with balloon_page_push before removing them with balloon_page_pop. To + * enqueue a list of pages, use balloon_page_list_enqueue instead. */ void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, struct page *page) @@ -157,14 +155,23 @@ EXPORT_SYMBOL_GPL(balloon_page_enqueue); /* * balloon_page_dequeue - removes a page from balloon's page list and returns - * the its address to allow the driver release the page. + * its address to allow the driver to release the page. * @b_dev_info: balloon device decriptor where we will grab a page from. * - * Driver must call it to properly de-allocate a previous enlisted balloon page - * before definetively releasing it back to the guest system. - * This function returns the page address for the recently dequeued page or - * NULL in the case we find balloon's page list temporarily empty due to - * compaction isolated pages. + * Driver must call this function to properly dequeue a previously enqueued page + * before definitively releasing it back to the guest system. + * + * Caller must perform its own accounting to ensure that this + * function is called only if some pages are actually enqueued. + * + * Note that this function may fail to dequeue some pages even if there are + * some enqueued pages - since the page list can be temporarily empty due to + * the compaction of isolated pages. + * + * TODO: remove the caller accounting requirements, and allow caller to wait + * until all pages can be dequeued. + * + * Return: struct page for the dequeued page, or NULL if no page was dequeued. */ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) { @@ -177,9 +184,9 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) if (n_pages != 1) { /* * If we are unable to dequeue a balloon page because the page - * list is empty and there is no isolated pages, then something + * list is empty and there are no isolated pages, then something * went out of track and some balloon pages are lost. - * BUG() here, otherwise the balloon driver may get stuck into + * BUG() here, otherwise the balloon driver may get stuck in * an infinite loop while attempting to release all its pages. */ spin_lock_irqsave(&b_dev_info->pages_lock, flags); @@ -230,8 +237,8 @@ int balloon_page_migrate(struct address_space *mapping, /* * We can not easily support the no copy case here so ignore it as it - * is unlikely to be use with ballon pages. See include/linux/hmm.h for - * user of the MIGRATE_SYNC_NO_COPY mode. + * is unlikely to be used with balloon pages. See include/linux/hmm.h + * for a user of the MIGRATE_SYNC_NO_COPY mode. */ if (mode == MIGRATE_SYNC_NO_COPY) return -EINVAL; -- cgit v1.2.3-55-g7522 From ae24fb49d01103c80d6ff3b78714259c1c62c958 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Mon, 22 Jul 2019 15:40:07 +0100 Subject: iommu/virtio: Update to most recent specification Following specification review a few things were changed in v8 of the virtio-iommu series [1], but have been omitted when merging the base driver. Add them now: * Remove the EXEC flag. * Add feature bit for the MMIO flag. * Change domain_bits to domain_range. * Add NOMEM status flag. [1] https://lore.kernel.org/linux-iommu/20190530170929.19366-1-jean-philippe.brucker@arm.com/ Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver") Reported-by: Eric Auger Signed-off-by: Jean-Philippe Brucker Signed-off-by: Michael S. Tsirkin Reviewed-by: Eric Auger Tested-by: Eric Auger Acked-by: Joerg Roedel --- drivers/iommu/virtio-iommu.c | 40 ++++++++++++++++++++++++++++----------- include/uapi/linux/virtio_iommu.h | 32 +++++++++++++++++-------------- 2 files changed, 47 insertions(+), 25 deletions(-) diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 433f4d2ee956..80a740df0737 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -2,7 +2,7 @@ /* * Virtio driver for the paravirtualized IOMMU * - * Copyright (C) 2018 Arm Limited + * Copyright (C) 2019 Arm Limited */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -47,7 +47,10 @@ struct viommu_dev { /* Device configuration */ struct iommu_domain_geometry geometry; u64 pgsize_bitmap; - u8 domain_bits; + u32 first_domain; + u32 last_domain; + /* Supported MAP flags */ + u32 map_flags; u32 probe_size; }; @@ -62,6 +65,7 @@ struct viommu_domain { struct viommu_dev *viommu; struct mutex mutex; /* protects viommu pointer */ unsigned int id; + u32 map_flags; spinlock_t mappings_lock; struct rb_root_cached mappings; @@ -113,6 +117,8 @@ static int viommu_get_req_errno(void *buf, size_t len) return -ENOENT; case VIRTIO_IOMMU_S_FAULT: return -EFAULT; + case VIRTIO_IOMMU_S_NOMEM: + return -ENOMEM; case VIRTIO_IOMMU_S_IOERR: case VIRTIO_IOMMU_S_DEVERR: default: @@ -607,15 +613,15 @@ static int viommu_domain_finalise(struct viommu_dev *viommu, { int ret; struct viommu_domain *vdomain = to_viommu_domain(domain); - unsigned int max_domain = viommu->domain_bits > 31 ? ~0 : - (1U << viommu->domain_bits) - 1; vdomain->viommu = viommu; + vdomain->map_flags = viommu->map_flags; domain->pgsize_bitmap = viommu->pgsize_bitmap; domain->geometry = viommu->geometry; - ret = ida_alloc_max(&viommu->domain_ids, max_domain, GFP_KERNEL); + ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, + viommu->last_domain, GFP_KERNEL); if (ret >= 0) vdomain->id = (unsigned int)ret; @@ -710,7 +716,7 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot) { int ret; - int flags; + u32 flags; struct virtio_iommu_req_map map; struct viommu_domain *vdomain = to_viommu_domain(domain); @@ -718,6 +724,9 @@ static int viommu_map(struct iommu_domain *domain, unsigned long iova, (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | (prot & IOMMU_MMIO ? VIRTIO_IOMMU_MAP_F_MMIO : 0); + if (flags & ~vdomain->map_flags) + return -EINVAL; + ret = viommu_add_mapping(vdomain, iova, paddr, size, flags); if (ret) return ret; @@ -1027,7 +1036,8 @@ static int viommu_probe(struct virtio_device *vdev) goto err_free_vqs; } - viommu->domain_bits = 32; + viommu->map_flags = VIRTIO_IOMMU_MAP_F_READ | VIRTIO_IOMMU_MAP_F_WRITE; + viommu->last_domain = ~0U; /* Optional features */ virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, @@ -1038,9 +1048,13 @@ static int viommu_probe(struct virtio_device *vdev) struct virtio_iommu_config, input_range.end, &input_end); - virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_BITS, - struct virtio_iommu_config, domain_bits, - &viommu->domain_bits); + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, + struct virtio_iommu_config, domain_range.start, + &viommu->first_domain); + + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_RANGE, + struct virtio_iommu_config, domain_range.end, + &viommu->last_domain); virtio_cread_feature(vdev, VIRTIO_IOMMU_F_PROBE, struct virtio_iommu_config, probe_size, @@ -1052,6 +1066,9 @@ static int viommu_probe(struct virtio_device *vdev) .force_aperture = true, }; + if (virtio_has_feature(vdev, VIRTIO_IOMMU_F_MMIO)) + viommu->map_flags |= VIRTIO_IOMMU_MAP_F_MMIO; + viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; virtio_device_ready(vdev); @@ -1130,9 +1147,10 @@ static void viommu_config_changed(struct virtio_device *vdev) static unsigned int features[] = { VIRTIO_IOMMU_F_MAP_UNMAP, - VIRTIO_IOMMU_F_DOMAIN_BITS, VIRTIO_IOMMU_F_INPUT_RANGE, + VIRTIO_IOMMU_F_DOMAIN_RANGE, VIRTIO_IOMMU_F_PROBE, + VIRTIO_IOMMU_F_MMIO, }; static struct virtio_device_id id_table[] = { diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h index ba1b460c9944..237e36a280cb 100644 --- a/include/uapi/linux/virtio_iommu.h +++ b/include/uapi/linux/virtio_iommu.h @@ -1,8 +1,8 @@ /* SPDX-License-Identifier: BSD-3-Clause */ /* - * Virtio-iommu definition v0.9 + * Virtio-iommu definition v0.12 * - * Copyright (C) 2018 Arm Ltd. + * Copyright (C) 2019 Arm Ltd. */ #ifndef _UAPI_LINUX_VIRTIO_IOMMU_H #define _UAPI_LINUX_VIRTIO_IOMMU_H @@ -11,26 +11,31 @@ /* Feature bits */ #define VIRTIO_IOMMU_F_INPUT_RANGE 0 -#define VIRTIO_IOMMU_F_DOMAIN_BITS 1 +#define VIRTIO_IOMMU_F_DOMAIN_RANGE 1 #define VIRTIO_IOMMU_F_MAP_UNMAP 2 #define VIRTIO_IOMMU_F_BYPASS 3 #define VIRTIO_IOMMU_F_PROBE 4 +#define VIRTIO_IOMMU_F_MMIO 5 -struct virtio_iommu_range { - __u64 start; - __u64 end; +struct virtio_iommu_range_64 { + __le64 start; + __le64 end; +}; + +struct virtio_iommu_range_32 { + __le32 start; + __le32 end; }; struct virtio_iommu_config { /* Supported page sizes */ - __u64 page_size_mask; + __le64 page_size_mask; /* Supported IOVA range */ - struct virtio_iommu_range input_range; + struct virtio_iommu_range_64 input_range; /* Max domain ID size */ - __u8 domain_bits; - __u8 padding[3]; + struct virtio_iommu_range_32 domain_range; /* Probe buffer size */ - __u32 probe_size; + __le32 probe_size; }; /* Request types */ @@ -49,6 +54,7 @@ struct virtio_iommu_config { #define VIRTIO_IOMMU_S_RANGE 0x05 #define VIRTIO_IOMMU_S_NOENT 0x06 #define VIRTIO_IOMMU_S_FAULT 0x07 +#define VIRTIO_IOMMU_S_NOMEM 0x08 struct virtio_iommu_req_head { __u8 type; @@ -78,12 +84,10 @@ struct virtio_iommu_req_detach { #define VIRTIO_IOMMU_MAP_F_READ (1 << 0) #define VIRTIO_IOMMU_MAP_F_WRITE (1 << 1) -#define VIRTIO_IOMMU_MAP_F_EXEC (1 << 2) -#define VIRTIO_IOMMU_MAP_F_MMIO (1 << 3) +#define VIRTIO_IOMMU_MAP_F_MMIO (1 << 2) #define VIRTIO_IOMMU_MAP_F_MASK (VIRTIO_IOMMU_MAP_F_READ | \ VIRTIO_IOMMU_MAP_F_WRITE | \ - VIRTIO_IOMMU_MAP_F_EXEC | \ VIRTIO_IOMMU_MAP_F_MMIO) struct virtio_iommu_req_map { -- cgit v1.2.3-55-g7522 From 73f628ec9e6bcc45b77c53fe6d0c0ec55eaf82af Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Fri, 26 Jul 2019 07:49:29 -0400 Subject: vhost: disable metadata prefetch optimization This seems to cause guest and host memory corruption. Disable for now until we get a better handle on that. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 819296332913..42a8c2a13ab1 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -96,7 +96,7 @@ struct vhost_uaddr { }; #if defined(CONFIG_MMU_NOTIFIER) && ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0 -#define VHOST_ARCH_CAN_ACCEL_UACCESS 1 +#define VHOST_ARCH_CAN_ACCEL_UACCESS 0 #else #define VHOST_ARCH_CAN_ACCEL_UACCESS 0 #endif -- cgit v1.2.3-55-g7522