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-rw-r--r--arch/x86/include/asm/xen/page.h3
-rw-r--r--arch/x86/xen/p2m.c76
-rw-r--r--drivers/block/xen-blkback/blkback.c2
-rw-r--r--drivers/xen/gntdev.c32
-rw-r--r--drivers/xen/grant-table.c6
-rw-r--r--include/xen/grant_table.h1
6 files changed, 104 insertions, 16 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index bc12c12299c3..3138d33b8949 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -12,6 +12,7 @@
#include <asm/pgtable.h>
#include <xen/interface/xen.h>
+#include <xen/grant_table.h>
#include <xen/features.h>
/* Xen machine address */
@@ -48,7 +49,7 @@ extern unsigned long set_phys_range_identity(unsigned long pfn_s,
unsigned long pfn_e);
extern int m2p_add_override(unsigned long mfn, struct page *page,
- bool clear_pte);
+ struct gnttab_map_grant_ref *kmap_op);
extern int m2p_remove_override(struct page *page, bool clear_pte);
extern struct page *m2p_find_override(unsigned long mfn);
extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 6e56b65edafb..a8ee9a45c359 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -161,7 +161,9 @@
#include <asm/xen/page.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
+#include <xen/grant_table.h>
+#include "multicalls.h"
#include "xen-ops.h"
static void __init m2p_override_init(void);
@@ -676,7 +678,8 @@ static unsigned long mfn_hash(unsigned long mfn)
}
/* Add an MFN override for a particular page */
-int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
+int m2p_add_override(unsigned long mfn, struct page *page,
+ struct gnttab_map_grant_ref *kmap_op)
{
unsigned long flags;
unsigned long pfn;
@@ -700,9 +703,20 @@ int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
return -ENOMEM;
- if (clear_pte && !PageHighMem(page))
- /* Just zap old mapping for now */
- pte_clear(&init_mm, address, ptep);
+ if (kmap_op != NULL) {
+ if (!PageHighMem(page)) {
+ struct multicall_space mcs =
+ xen_mc_entry(sizeof(*kmap_op));
+
+ MULTI_grant_table_op(mcs.mc,
+ GNTTABOP_map_grant_ref, kmap_op, 1);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+ }
+ /* let's use dev_bus_addr to record the old mfn instead */
+ kmap_op->dev_bus_addr = page->index;
+ page->index = (unsigned long) kmap_op;
+ }
spin_lock_irqsave(&m2p_override_lock, flags);
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
spin_unlock_irqrestore(&m2p_override_lock, flags);
@@ -736,14 +750,56 @@ int m2p_remove_override(struct page *page, bool clear_pte)
spin_lock_irqsave(&m2p_override_lock, flags);
list_del(&page->lru);
spin_unlock_irqrestore(&m2p_override_lock, flags);
- set_phys_to_machine(pfn, page->index);
WARN_ON(!PagePrivate(page));
ClearPagePrivate(page);
- if (clear_pte && !PageHighMem(page))
- set_pte_at(&init_mm, address, ptep,
- pfn_pte(pfn, PAGE_KERNEL));
- /* No tlb flush necessary because the caller already
- * left the pte unmapped. */
+
+ if (clear_pte) {
+ struct gnttab_map_grant_ref *map_op =
+ (struct gnttab_map_grant_ref *) page->index;
+ set_phys_to_machine(pfn, map_op->dev_bus_addr);
+ if (!PageHighMem(page)) {
+ struct multicall_space mcs;
+ struct gnttab_unmap_grant_ref *unmap_op;
+
+ /*
+ * It might be that we queued all the m2p grant table
+ * hypercalls in a multicall, then m2p_remove_override
+ * get called before the multicall has actually been
+ * issued. In this case handle is going to -1 because
+ * it hasn't been modified yet.
+ */
+ if (map_op->handle == -1)
+ xen_mc_flush();
+ /*
+ * Now if map_op->handle is negative it means that the
+ * hypercall actually returned an error.
+ */
+ if (map_op->handle == GNTST_general_error) {
+ printk(KERN_WARNING "m2p_remove_override: "
+ "pfn %lx mfn %lx, failed to modify kernel mappings",
+ pfn, mfn);
+ return -1;
+ }
+
+ mcs = xen_mc_entry(
+ sizeof(struct gnttab_unmap_grant_ref));
+ unmap_op = mcs.args;
+ unmap_op->host_addr = map_op->host_addr;
+ unmap_op->handle = map_op->handle;
+ unmap_op->dev_bus_addr = 0;
+
+ MULTI_grant_table_op(mcs.mc,
+ GNTTABOP_unmap_grant_ref, unmap_op, 1);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ set_pte_at(&init_mm, address, ptep,
+ pfn_pte(pfn, PAGE_KERNEL));
+ __flush_tlb_single(address);
+ map_op->host_addr = 0;
+ }
+ } else
+ set_phys_to_machine(pfn, page->index);
return 0;
}
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 2330a9ad5e95..1540792b1e54 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -396,7 +396,7 @@ static int xen_blkbk_map(struct blkif_request *req,
continue;
ret = m2p_add_override(PFN_DOWN(map[i].dev_bus_addr),
- blkbk->pending_page(pending_req, i), false);
+ blkbk->pending_page(pending_req, i), NULL);
if (ret) {
pr_alert(DRV_PFX "Failed to install M2P override for %lx (ret: %d)\n",
(unsigned long)map[i].dev_bus_addr, ret);
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 7b9b1d1b75a5..3e3603f35242 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -83,6 +83,7 @@ struct grant_map {
struct ioctl_gntdev_grant_ref *grants;
struct gnttab_map_grant_ref *map_ops;
struct gnttab_unmap_grant_ref *unmap_ops;
+ struct gnttab_map_grant_ref *kmap_ops;
struct page **pages;
};
@@ -116,10 +117,12 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL);
add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL);
add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL);
+ add->kmap_ops = kzalloc(sizeof(add->kmap_ops[0]) * count, GFP_KERNEL);
add->pages = kzalloc(sizeof(add->pages[0]) * count, GFP_KERNEL);
if (NULL == add->grants ||
NULL == add->map_ops ||
NULL == add->unmap_ops ||
+ NULL == add->kmap_ops ||
NULL == add->pages)
goto err;
@@ -129,6 +132,7 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
for (i = 0; i < count; i++) {
add->map_ops[i].handle = -1;
add->unmap_ops[i].handle = -1;
+ add->kmap_ops[i].handle = -1;
}
add->index = 0;
@@ -142,6 +146,7 @@ err:
kfree(add->grants);
kfree(add->map_ops);
kfree(add->unmap_ops);
+ kfree(add->kmap_ops);
kfree(add);
return NULL;
}
@@ -243,10 +248,35 @@ static int map_grant_pages(struct grant_map *map)
gnttab_set_unmap_op(&map->unmap_ops[i], addr,
map->flags, -1 /* handle */);
}
+ } else {
+ /*
+ * Setup the map_ops corresponding to the pte entries pointing
+ * to the kernel linear addresses of the struct pages.
+ * These ptes are completely different from the user ptes dealt
+ * with find_grant_ptes.
+ */
+ for (i = 0; i < map->count; i++) {
+ unsigned level;
+ unsigned long address = (unsigned long)
+ pfn_to_kaddr(page_to_pfn(map->pages[i]));
+ pte_t *ptep;
+ u64 pte_maddr = 0;
+ BUG_ON(PageHighMem(map->pages[i]));
+
+ ptep = lookup_address(address, &level);
+ pte_maddr = arbitrary_virt_to_machine(ptep).maddr;
+ gnttab_set_map_op(&map->kmap_ops[i], pte_maddr,
+ map->flags |
+ GNTMAP_host_map |
+ GNTMAP_contains_pte,
+ map->grants[i].ref,
+ map->grants[i].domid);
+ }
}
pr_debug("map %d+%d\n", map->index, map->count);
- err = gnttab_map_refs(map->map_ops, map->pages, map->count);
+ err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
+ map->pages, map->count);
if (err)
return err;
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 4f44b347b24a..8c71ab801756 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -448,7 +448,8 @@ unsigned int gnttab_max_grant_frames(void)
EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
- struct page **pages, unsigned int count)
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
{
int i, ret;
pte_t *pte;
@@ -488,8 +489,7 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
*/
return -EOPNOTSUPP;
}
- ret = m2p_add_override(mfn, pages[i],
- map_ops[i].flags & GNTMAP_contains_pte);
+ ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
if (ret)
return ret;
}
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index b1fab6b5b3ef..6b99bfbd785d 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -156,6 +156,7 @@ unsigned int gnttab_max_grant_frames(void);
#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
+ struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count);
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct page **pages, unsigned int count);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.