diff options
Diffstat (limited to '0069-xen-arm-p2m-Populate-pages-for-GICv2-mapping-in-p2m_.patch')
| -rw-r--r-- | 0069-xen-arm-p2m-Populate-pages-for-GICv2-mapping-in-p2m_.patch | 169 |
1 files changed, 0 insertions, 169 deletions
diff --git a/0069-xen-arm-p2m-Populate-pages-for-GICv2-mapping-in-p2m_.patch b/0069-xen-arm-p2m-Populate-pages-for-GICv2-mapping-in-p2m_.patch deleted file mode 100644 index 67cdb7a..0000000 --- a/0069-xen-arm-p2m-Populate-pages-for-GICv2-mapping-in-p2m_.patch +++ /dev/null @@ -1,169 +0,0 @@ -From f8915cd5dbe0f51e9bb31a54fe40600b839dd707 Mon Sep 17 00:00:00 2001 -From: Henry Wang <Henry.Wang@arm.com> -Date: Tue, 25 Oct 2022 09:21:12 +0000 -Subject: [PATCH 069/126] xen/arm: p2m: Populate pages for GICv2 mapping in - p2m_init() - -Hardware using GICv2 needs to create a P2M mapping of 8KB GICv2 area -when the domain is created. Considering the worst case of page tables -which requires 6 P2M pages as the two pages will be consecutive but not -necessarily in the same L3 page table and keep a buffer, populate 16 -pages as the default value to the P2M pages pool in p2m_init() at the -domain creation stage to satisfy the GICv2 requirement. For GICv3, the -above-mentioned P2M mapping is not necessary, but since the allocated -16 pages here would not be lost, hence populate these pages -unconditionally. - -With the default 16 P2M pages populated, there would be a case that -failures would happen in the domain creation with P2M pages already in -use. To properly free the P2M for this case, firstly support the -optionally preemption of p2m_teardown(), then call p2m_teardown() and -p2m_set_allocation(d, 0, NULL) non-preemptively in p2m_final_teardown(). -As non-preemptive p2m_teardown() should only return 0, use a -BUG_ON to confirm that. - -Since p2m_final_teardown() is called either after -domain_relinquish_resources() where relinquish_p2m_mapping() has been -called, or from failure path of domain_create()/arch_domain_create() -where mappings that require p2m_put_l3_page() should never be created, -relinquish_p2m_mapping() is not added in p2m_final_teardown(), add -in-code comments to refer this. - -Fixes: cbea5a1149ca ("xen/arm: Allocate and free P2M pages from the P2M pool") -Suggested-by: Julien Grall <jgrall@amazon.com> -Signed-off-by: Henry Wang <Henry.Wang@arm.com> -Reviewed-by: Julien Grall <jgrall@amazon.com> -Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com> -(cherry picked from commit: c7cff1188802646eaa38e918e5738da0e84949be) ---- - xen/arch/arm/domain.c | 2 +- - xen/arch/arm/p2m.c | 34 ++++++++++++++++++++++++++++++++-- - xen/include/asm-arm/p2m.h | 14 ++++++++++---- - 3 files changed, 43 insertions(+), 7 deletions(-) - -diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c -index a5ffd952ecd0..b11359b8cca3 100644 ---- a/xen/arch/arm/domain.c -+++ b/xen/arch/arm/domain.c -@@ -1041,7 +1041,7 @@ int domain_relinquish_resources(struct domain *d) - return ret; - - PROGRESS(p2m): -- ret = p2m_teardown(d); -+ ret = p2m_teardown(d, true); - if ( ret ) - return ret; - -diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c -index 25eb1d84cbc1..f6012f2a538f 100644 ---- a/xen/arch/arm/p2m.c -+++ b/xen/arch/arm/p2m.c -@@ -1664,7 +1664,7 @@ static void p2m_free_vmid(struct domain *d) - spin_unlock(&vmid_alloc_lock); - } - --int p2m_teardown(struct domain *d) -+int p2m_teardown(struct domain *d, bool allow_preemption) - { - struct p2m_domain *p2m = p2m_get_hostp2m(d); - unsigned long count = 0; -@@ -1672,6 +1672,9 @@ int p2m_teardown(struct domain *d) - unsigned int i; - int rc = 0; - -+ if ( page_list_empty(&p2m->pages) ) -+ return 0; -+ - p2m_write_lock(p2m); - - /* -@@ -1695,7 +1698,7 @@ int p2m_teardown(struct domain *d) - p2m_free_page(p2m->domain, pg); - count++; - /* Arbitrarily preempt every 512 iterations */ -- if ( !(count % 512) && hypercall_preempt_check() ) -+ if ( allow_preemption && !(count % 512) && hypercall_preempt_check() ) - { - rc = -ERESTART; - break; -@@ -1715,7 +1718,20 @@ void p2m_final_teardown(struct domain *d) - if ( !p2m->domain ) - return; - -+ /* -+ * No need to call relinquish_p2m_mapping() here because -+ * p2m_final_teardown() is called either after domain_relinquish_resources() -+ * where relinquish_p2m_mapping() has been called, or from failure path of -+ * domain_create()/arch_domain_create() where mappings that require -+ * p2m_put_l3_page() should never be created. For the latter case, also see -+ * comment on top of the p2m_set_entry() for more info. -+ */ -+ -+ BUG_ON(p2m_teardown(d, false)); - ASSERT(page_list_empty(&p2m->pages)); -+ -+ while ( p2m_teardown_allocation(d) == -ERESTART ) -+ continue; /* No preemption support here */ - ASSERT(page_list_empty(&d->arch.paging.p2m_freelist)); - - if ( p2m->root ) -@@ -1782,6 +1798,20 @@ int p2m_init(struct domain *d) - if ( rc ) - return rc; - -+ /* -+ * Hardware using GICv2 needs to create a P2M mapping of 8KB GICv2 area -+ * when the domain is created. Considering the worst case for page -+ * tables and keep a buffer, populate 16 pages to the P2M pages pool here. -+ * For GICv3, the above-mentioned P2M mapping is not necessary, but since -+ * the allocated 16 pages here would not be lost, hence populate these -+ * pages unconditionally. -+ */ -+ spin_lock(&d->arch.paging.lock); -+ rc = p2m_set_allocation(d, 16, NULL); -+ spin_unlock(&d->arch.paging.lock); -+ if ( rc ) -+ return rc; -+ - return 0; - } - -diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h -index 18675b234570..ea7ca41d82b2 100644 ---- a/xen/include/asm-arm/p2m.h -+++ b/xen/include/asm-arm/p2m.h -@@ -194,14 +194,18 @@ int p2m_init(struct domain *d); - - /* - * The P2M resources are freed in two parts: -- * - p2m_teardown() will be called when relinquish the resources. It -- * will free large resources (e.g. intermediate page-tables) that -- * requires preemption. -+ * - p2m_teardown() will be called preemptively when relinquish the -+ * resources, in which case it will free large resources (e.g. intermediate -+ * page-tables) that requires preemption. - * - p2m_final_teardown() will be called when domain struct is been - * freed. This *cannot* be preempted and therefore one small - * resources should be freed here. -+ * Note that p2m_final_teardown() will also call p2m_teardown(), to properly -+ * free the P2M when failures happen in the domain creation with P2M pages -+ * already in use. In this case p2m_teardown() is called non-preemptively and -+ * p2m_teardown() will always return 0. - */ --int p2m_teardown(struct domain *d); -+int p2m_teardown(struct domain *d, bool allow_preemption); - void p2m_final_teardown(struct domain *d); - - /* -@@ -266,6 +270,8 @@ mfn_t p2m_get_entry(struct p2m_domain *p2m, gfn_t gfn, - /* - * Direct set a p2m entry: only for use by the P2M code. - * The P2M write lock should be taken. -+ * TODO: Add a check in __p2m_set_entry() to avoid creating a mapping in -+ * arch_domain_create() that requires p2m_put_l3_page() to be called. - */ - int p2m_set_entry(struct p2m_domain *p2m, - gfn_t sgfn, --- -2.37.4 - |