diff options
Diffstat (limited to '0052-xen-arm-Construct-the-P2M-pages-pool-for-guests.patch')
| -rw-r--r-- | 0052-xen-arm-Construct-the-P2M-pages-pool-for-guests.patch | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/0052-xen-arm-Construct-the-P2M-pages-pool-for-guests.patch b/0052-xen-arm-Construct-the-P2M-pages-pool-for-guests.patch deleted file mode 100644 index a17ad53..0000000 --- a/0052-xen-arm-Construct-the-P2M-pages-pool-for-guests.patch +++ /dev/null @@ -1,189 +0,0 @@ -From 45336d8f88725aec65ee177b1b09abf6eef1dc8d Mon Sep 17 00:00:00 2001 -From: Henry Wang <Henry.Wang@arm.com> -Date: Tue, 11 Oct 2022 15:09:58 +0200 -Subject: [PATCH 052/126] xen/arm: Construct the P2M pages pool for guests - -This commit constructs the p2m pages pool for guests from the -data structure and helper perspective. - -This is implemented by: - -- Adding a `struct paging_domain` which contains a freelist, a -counter variable and a spinlock to `struct arch_domain` to -indicate the free p2m pages and the number of p2m total pages in -the p2m pages pool. - -- Adding a helper `p2m_get_allocation` to get the p2m pool size. - -- Adding a helper `p2m_set_allocation` to set the p2m pages pool -size. This helper should be called before allocating memory for -a guest. - -- Adding a helper `p2m_teardown_allocation` to free the p2m pages -pool. This helper should be called during the xl domain destory. - -This is part of CVE-2022-33747 / XSA-409. - -Signed-off-by: Henry Wang <Henry.Wang@arm.com> -Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> -master commit: 55914f7fc91a468649b8a3ec3f53ae1c4aca6670 -master date: 2022-10-11 14:28:39 +0200 ---- - xen/arch/arm/p2m.c | 88 ++++++++++++++++++++++++++++++++++++ - xen/include/asm-arm/domain.h | 10 ++++ - xen/include/asm-arm/p2m.h | 4 ++ - 3 files changed, 102 insertions(+) - -diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c -index 4ad3e0606e9c..6883d8627702 100644 ---- a/xen/arch/arm/p2m.c -+++ b/xen/arch/arm/p2m.c -@@ -50,6 +50,92 @@ static uint64_t generate_vttbr(uint16_t vmid, mfn_t root_mfn) - return (mfn_to_maddr(root_mfn) | ((uint64_t)vmid << 48)); - } - -+/* Return the size of the pool, rounded up to the nearest MB */ -+unsigned int p2m_get_allocation(struct domain *d) -+{ -+ unsigned long nr_pages = ACCESS_ONCE(d->arch.paging.p2m_total_pages); -+ -+ return ROUNDUP(nr_pages, 1 << (20 - PAGE_SHIFT)) >> (20 - PAGE_SHIFT); -+} -+ -+/* -+ * Set the pool of pages to the required number of pages. -+ * Returns 0 for success, non-zero for failure. -+ * Call with d->arch.paging.lock held. -+ */ -+int p2m_set_allocation(struct domain *d, unsigned long pages, bool *preempted) -+{ -+ struct page_info *pg; -+ -+ ASSERT(spin_is_locked(&d->arch.paging.lock)); -+ -+ for ( ; ; ) -+ { -+ if ( d->arch.paging.p2m_total_pages < pages ) -+ { -+ /* Need to allocate more memory from domheap */ -+ pg = alloc_domheap_page(NULL, 0); -+ if ( pg == NULL ) -+ { -+ printk(XENLOG_ERR "Failed to allocate P2M pages.\n"); -+ return -ENOMEM; -+ } -+ ACCESS_ONCE(d->arch.paging.p2m_total_pages) = -+ d->arch.paging.p2m_total_pages + 1; -+ page_list_add_tail(pg, &d->arch.paging.p2m_freelist); -+ } -+ else if ( d->arch.paging.p2m_total_pages > pages ) -+ { -+ /* Need to return memory to domheap */ -+ pg = page_list_remove_head(&d->arch.paging.p2m_freelist); -+ if( pg ) -+ { -+ ACCESS_ONCE(d->arch.paging.p2m_total_pages) = -+ d->arch.paging.p2m_total_pages - 1; -+ free_domheap_page(pg); -+ } -+ else -+ { -+ printk(XENLOG_ERR -+ "Failed to free P2M pages, P2M freelist is empty.\n"); -+ return -ENOMEM; -+ } -+ } -+ else -+ break; -+ -+ /* Check to see if we need to yield and try again */ -+ if ( preempted && general_preempt_check() ) -+ { -+ *preempted = true; -+ return -ERESTART; -+ } -+ } -+ -+ return 0; -+} -+ -+int p2m_teardown_allocation(struct domain *d) -+{ -+ int ret = 0; -+ bool preempted = false; -+ -+ spin_lock(&d->arch.paging.lock); -+ if ( d->arch.paging.p2m_total_pages != 0 ) -+ { -+ ret = p2m_set_allocation(d, 0, &preempted); -+ if ( preempted ) -+ { -+ spin_unlock(&d->arch.paging.lock); -+ return -ERESTART; -+ } -+ ASSERT(d->arch.paging.p2m_total_pages == 0); -+ } -+ spin_unlock(&d->arch.paging.lock); -+ -+ return ret; -+} -+ - /* Unlock the flush and do a P2M TLB flush if necessary */ - void p2m_write_unlock(struct p2m_domain *p2m) - { -@@ -1602,7 +1688,9 @@ int p2m_init(struct domain *d) - unsigned int cpu; - - rwlock_init(&p2m->lock); -+ spin_lock_init(&d->arch.paging.lock); - INIT_PAGE_LIST_HEAD(&p2m->pages); -+ INIT_PAGE_LIST_HEAD(&d->arch.paging.p2m_freelist); - - p2m->vmid = INVALID_VMID; - -diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h -index bb0a6adbe00b..1d8935778f3b 100644 ---- a/xen/include/asm-arm/domain.h -+++ b/xen/include/asm-arm/domain.h -@@ -40,6 +40,14 @@ struct vtimer { - uint64_t cval; - }; - -+struct paging_domain { -+ spinlock_t lock; -+ /* Free P2M pages from the pre-allocated P2M pool */ -+ struct page_list_head p2m_freelist; -+ /* Number of pages from the pre-allocated P2M pool */ -+ unsigned long p2m_total_pages; -+}; -+ - struct arch_domain - { - #ifdef CONFIG_ARM_64 -@@ -51,6 +59,8 @@ struct arch_domain - - struct hvm_domain hvm; - -+ struct paging_domain paging; -+ - struct vmmio vmmio; - - /* Continuable domain_relinquish_resources(). */ -diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h -index 3a2d51b35d71..18675b234570 100644 ---- a/xen/include/asm-arm/p2m.h -+++ b/xen/include/asm-arm/p2m.h -@@ -218,6 +218,10 @@ void p2m_restore_state(struct vcpu *n); - /* Print debugging/statistial info about a domain's p2m */ - void p2m_dump_info(struct domain *d); - -+unsigned int p2m_get_allocation(struct domain *d); -+int p2m_set_allocation(struct domain *d, unsigned long pages, bool *preempted); -+int p2m_teardown_allocation(struct domain *d); -+ - static inline void p2m_write_lock(struct p2m_domain *p2m) - { - write_lock(&p2m->lock); --- -2.37.4 - |