From: Alexandre Chartre <alexandre.chartre@oracle.com>
To: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
peterz@infradead.org, kvm@vger.kernel.org, x86@kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: konrad.wilk@oracle.com, jan.setjeeilers@oracle.com,
liran.alon@oracle.com, jwadams@google.com, graf@amazon.de,
rppt@linux.vnet.ibm.com, alexandre.chartre@oracle.com
Subject: [RFC v2 10/26] mm/asi: Keep track of VA ranges mapped in ASI page-table
Date: Thu, 11 Jul 2019 16:25:22 +0200 [thread overview]
Message-ID: <1562855138-19507-11-git-send-email-alexandre.chartre@oracle.com> (raw)
In-Reply-To: <1562855138-19507-1-git-send-email-alexandre.chartre@oracle.com>
Add functions to keep track of VA ranges mapped in an ASI page-table.
This will be used when unmapping to ensure the same range is unmapped,
at the same page-table level. This is also be used to handle mapping
and unmapping of overlapping VA ranges.
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
---
arch/x86/include/asm/asi.h | 3 ++
arch/x86/mm/asi.c | 3 ++
arch/x86/mm/asi_pagetable.c | 71 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 77 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/asi.h b/arch/x86/include/asm/asi.h
index b5dbc49..be1c190 100644
--- a/arch/x86/include/asm/asi.h
+++ b/arch/x86/include/asm/asi.h
@@ -24,6 +24,7 @@ enum page_table_level {
struct asi {
spinlock_t lock; /* protect all attributes */
pgd_t *pgd; /* ASI page-table */
+ struct list_head mapping_list; /* list of VA range mapping */
/*
* An ASI page-table can have direct references to the full kernel
@@ -69,6 +70,8 @@ struct asi_session {
void asi_init_backend(struct asi *asi);
void asi_fini_backend(struct asi *asi);
+void asi_init_range_mapping(struct asi *asi);
+void asi_fini_range_mapping(struct asi *asi);
extern struct asi *asi_create(void);
extern void asi_destroy(struct asi *asi);
diff --git a/arch/x86/mm/asi.c b/arch/x86/mm/asi.c
index dfde245..25633a6 100644
--- a/arch/x86/mm/asi.c
+++ b/arch/x86/mm/asi.c
@@ -104,6 +104,8 @@ struct asi *asi_create(void)
if (!asi)
return NULL;
+ asi_init_range_mapping(asi);
+
page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
if (!page)
goto error;
@@ -133,6 +135,7 @@ void asi_destroy(struct asi *asi)
if (asi->pgd)
free_page((unsigned long)asi->pgd);
+ asi_fini_range_mapping(asi);
asi_fini_backend(asi);
kfree(asi);
diff --git a/arch/x86/mm/asi_pagetable.c b/arch/x86/mm/asi_pagetable.c
index 0169395..a09a22d 100644
--- a/arch/x86/mm/asi_pagetable.c
+++ b/arch/x86/mm/asi_pagetable.c
@@ -5,10 +5,21 @@
*/
#include <linux/mm.h>
+#include <linux/slab.h>
#include <asm/asi.h>
/*
+ * Structure to keep track of address ranges mapped into an ASI.
+ */
+struct asi_range_mapping {
+ struct list_head list;
+ void *ptr; /* range start address */
+ size_t size; /* range size */
+ enum page_table_level level; /* mapping level */
+};
+
+/*
* Get the pointer to the beginning of a page table directory from a page
* table directory entry.
*/
@@ -75,6 +86,39 @@ void asi_fini_backend(struct asi *asi)
}
}
+void asi_init_range_mapping(struct asi *asi)
+{
+ INIT_LIST_HEAD(&asi->mapping_list);
+}
+
+void asi_fini_range_mapping(struct asi *asi)
+{
+ struct asi_range_mapping *range, *range_next;
+
+ list_for_each_entry_safe(range, range_next, &asi->mapping_list, list) {
+ list_del(&range->list);
+ kfree(range);
+ }
+}
+
+/*
+ * Return the range mapping starting at the specified address, or NULL if
+ * no such range is found.
+ */
+static struct asi_range_mapping *asi_get_range_mapping(struct asi *asi,
+ void *ptr)
+{
+ struct asi_range_mapping *range;
+
+ lockdep_assert_held(&asi->lock);
+ list_for_each_entry(range, &asi->mapping_list, list) {
+ if (range->ptr == ptr)
+ return range;
+ }
+
+ return NULL;
+}
+
/*
* Check if an offset in the address space isolation page-table is valid,
* i.e. check that the offset is on a page effectively belonging to the
@@ -574,6 +618,7 @@ static int asi_copy_pgd_range(struct asi *asi,
int asi_map_range(struct asi *asi, void *ptr, size_t size,
enum page_table_level level)
{
+ struct asi_range_mapping *range_mapping;
unsigned long addr = (unsigned long)ptr;
unsigned long end = addr + ((unsigned long)size);
unsigned long flags;
@@ -582,8 +627,34 @@ int asi_map_range(struct asi *asi, void *ptr, size_t size,
pr_debug("ASI %p: MAP %px/%lx/%d\n", asi, ptr, size, level);
spin_lock_irqsave(&asi->lock, flags);
+
+ /* check if the range is already mapped */
+ range_mapping = asi_get_range_mapping(asi, ptr);
+ if (range_mapping) {
+ pr_debug("ASI %p: MAP %px/%lx/%d already mapped\n",
+ asi, ptr, size, level);
+ err = -EBUSY;
+ goto done;
+ }
+
+ /* map new range */
+ range_mapping = kmalloc(sizeof(*range_mapping), GFP_KERNEL);
+ if (!range_mapping) {
+ err = -ENOMEM;
+ goto done;
+ }
+
err = asi_copy_pgd_range(asi, asi->pgd, current->mm->pgd,
addr, end, level);
+ if (err)
+ goto done;
+
+ INIT_LIST_HEAD(&range_mapping->list);
+ range_mapping->ptr = ptr;
+ range_mapping->size = size;
+ range_mapping->level = level;
+ list_add(&range_mapping->list, &asi->mapping_list);
+done:
spin_unlock_irqrestore(&asi->lock, flags);
return err;
--
1.7.1
next prev parent reply other threads:[~2019-07-11 14:28 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 14:25 [RFC v2 00/27] Kernel Address Space Isolation Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 01/26] mm/x86: Introduce kernel address space isolation Alexandre Chartre
2019-07-11 21:33 ` Thomas Gleixner
2019-07-12 7:43 ` Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 02/26] mm/asi: Abort isolation on interrupt, exception and context switch Alexandre Chartre
2019-07-11 20:11 ` Andi Kleen
2019-07-11 20:17 ` Mike Rapoport
2019-07-11 20:41 ` Alexandre Chartre
2019-07-12 0:05 ` Andy Lutomirski
2019-07-12 7:50 ` Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 03/26] mm/asi: Handle page fault due to address space isolation Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 04/26] mm/asi: Functions to track buffers allocated for an ASI page-table Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 05/26] mm/asi: Add ASI page-table entry offset functions Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 06/26] mm/asi: Add ASI page-table entry allocation functions Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 07/26] mm/asi: Add ASI page-table entry set functions Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 08/26] mm/asi: Functions to populate an ASI page-table from a VA range Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 09/26] mm/asi: Helper functions to map module into ASI Alexandre Chartre
2019-07-11 14:25 ` Alexandre Chartre [this message]
2019-07-11 14:25 ` [RFC v2 11/26] mm/asi: Functions to clear ASI page-table entries for a VA range Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 12/26] mm/asi: Function to copy page-table entries for percpu buffer Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 13/26] mm/asi: Add asi_remap() function Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 14/26] mm/asi: Handle ASI mapped range leaks and overlaps Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 15/26] mm/asi: Initialize the ASI page-table with core mappings Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 16/26] mm/asi: Option to map current task into ASI Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 17/26] rcu: Move tree.h static forward declarations to tree.c Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 18/26] rcu: Make percpu rcu_data non-static Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 19/26] mm/asi: Add option to map RCU data Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 20/26] mm/asi: Add option to map cpu_hw_events Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 21/26] mm/asi: Make functions to read cr3/cr4 ASI aware Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 22/26] KVM: x86/asi: Introduce address_space_isolation module parameter Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 23/26] KVM: x86/asi: Introduce KVM address space isolation Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 24/26] KVM: x86/asi: Populate the KVM ASI page-table Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 25/26] KVM: x86/asi: Switch to KVM address space on entry to guest Alexandre Chartre
2019-07-11 14:25 ` [RFC v2 26/26] KVM: x86/asi: Map KVM memslots and IO buses into KVM ASI Alexandre Chartre
2019-07-11 14:40 ` [RFC v2 00/27] Kernel Address Space Isolation Alexandre Chartre
2019-07-11 22:38 ` Dave Hansen
2019-07-12 8:09 ` Alexandre Chartre
2019-07-12 13:51 ` Dave Hansen
2019-07-12 14:06 ` Alexandre Chartre
2019-07-12 15:23 ` Thomas Gleixner
2019-07-12 10:44 ` Thomas Gleixner
2019-07-12 11:56 ` Alexandre Chartre
2019-07-12 12:50 ` Peter Zijlstra
2019-07-12 13:43 ` Alexandre Chartre
2019-07-12 13:58 ` Dave Hansen
2019-07-12 14:36 ` Andy Lutomirski
2019-07-14 18:17 ` Alexander Graf
2019-07-12 13:54 ` Dave Hansen
2019-07-12 15:20 ` Peter Zijlstra
2019-07-12 15:16 ` Thomas Gleixner
2019-07-12 16:37 ` Alexandre Chartre
2019-07-12 16:45 ` Andy Lutomirski
2019-07-14 17:11 ` Mike Rapoport
2019-07-12 19:06 ` Peter Zijlstra
2019-07-14 15:06 ` Andy Lutomirski
2019-07-15 10:33 ` Peter Zijlstra
2019-07-12 19:48 ` Thomas Gleixner
2019-07-15 8:23 ` Alexandre Chartre
2019-07-15 8:28 ` Thomas Gleixner
2019-07-12 16:00 ` Thomas Gleixner
2019-07-12 11:44 ` Peter Zijlstra
2019-07-12 12:17 ` Alexandre Chartre
2019-07-12 12:36 ` Peter Zijlstra
2019-07-12 12:47 ` Alexandre Chartre
2019-07-12 13:07 ` Peter Zijlstra
2019-07-12 13:46 ` Alexandre Chartre
2019-07-31 16:31 ` Dario Faggioli
2019-08-22 12:31 ` Alexandre Chartre
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