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-rw-r--r--arch/x86/include/asm/xen/page.h18
-rw-r--r--arch/x86/xen/p2m.c254
-rw-r--r--drivers/xen/balloon.c86
3 files changed, 14 insertions, 344 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index e9f52fe2d56a..358dcd338915 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -57,7 +57,6 @@ extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count);
-extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
/*
* Helper functions to write or read unsigned long values to/from
@@ -154,21 +153,12 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
return mfn;
pfn = mfn_to_pfn_no_overrides(mfn);
- if (__pfn_to_mfn(pfn) != mfn) {
- /*
- * If this appears to be a foreign mfn (because the pfn
- * doesn't map back to the mfn), then check the local override
- * table to see if there's a better pfn to use.
- *
- * m2p_find_override_pfn returns ~0 if it doesn't find anything.
- */
- pfn = m2p_find_override_pfn(mfn, ~0);
- }
+ if (__pfn_to_mfn(pfn) != mfn)
+ pfn = ~0;
/*
- * pfn is ~0 if there are no entries in the m2p for mfn or if the
- * entry doesn't map back to the mfn and m2p_override doesn't have a
- * valid entry for it.
+ * pfn is ~0 if there are no entries in the m2p for mfn or the
+ * entry doesn't map back to the mfn.
*/
if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
pfn = mfn;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index df40b2888eae..c9bc53f64359 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -84,8 +84,6 @@
#define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE)
-static void __init m2p_override_init(void);
-
unsigned long *xen_p2m_addr __read_mostly;
EXPORT_SYMBOL_GPL(xen_p2m_addr);
unsigned long xen_p2m_size __read_mostly;
@@ -402,8 +400,6 @@ void __init xen_vmalloc_p2m_tree(void)
xen_p2m_size = xen_max_p2m_pfn;
xen_inv_extra_mem();
-
- m2p_override_init();
}
unsigned long get_phys_to_machine(unsigned long pfn)
@@ -652,100 +648,21 @@ bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
return true;
}
-#define M2P_OVERRIDE_HASH_SHIFT 10
-#define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT)
-
-static struct list_head *m2p_overrides;
-static DEFINE_SPINLOCK(m2p_override_lock);
-
-static void __init m2p_override_init(void)
-{
- unsigned i;
-
- m2p_overrides = alloc_bootmem_align(
- sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH,
- sizeof(unsigned long));
-
- for (i = 0; i < M2P_OVERRIDE_HASH; i++)
- INIT_LIST_HEAD(&m2p_overrides[i]);
-}
-
-static unsigned long mfn_hash(unsigned long mfn)
-{
- return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT);
-}
-
-/* Add an MFN override for a particular page */
-static int m2p_add_override(unsigned long mfn, struct page *page,
- struct gnttab_map_grant_ref *kmap_op)
-{
- unsigned long flags;
- unsigned long pfn;
- unsigned long uninitialized_var(address);
- unsigned level;
- pte_t *ptep = NULL;
-
- pfn = page_to_pfn(page);
- if (!PageHighMem(page)) {
- address = (unsigned long)__va(pfn << PAGE_SHIFT);
- ptep = lookup_address(address, &level);
- if (WARN(ptep == NULL || level != PG_LEVEL_4K,
- "m2p_add_override: pfn %lx not mapped", pfn))
- return -EINVAL;
- }
-
- 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);
- }
- }
- spin_lock_irqsave(&m2p_override_lock, flags);
- list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
- spin_unlock_irqrestore(&m2p_override_lock, flags);
-
- /* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in
- * this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other
- * pfn so that the following mfn_to_pfn(mfn) calls will return the
- * pfn from the m2p_override (the backend pfn) instead.
- * We need to do this because the pages shared by the frontend
- * (xen-blkfront) can be already locked (lock_page, called by
- * do_read_cache_page); when the userspace backend tries to use them
- * with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
- * do_blockdev_direct_IO is going to try to lock the same pages
- * again resulting in a deadlock.
- * As a side effect get_user_pages_fast might not be safe on the
- * frontend pages while they are being shared with the backend,
- * because mfn_to_pfn (that ends up being called by GUPF) will
- * return the backend pfn rather than the frontend pfn. */
- pfn = mfn_to_pfn_no_overrides(mfn);
- if (__pfn_to_mfn(pfn) == mfn)
- set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
-
- return 0;
-}
-
int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
- bool lazy = false;
pte_t *pte;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
- if (kmap_ops &&
- !in_interrupt() &&
- paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
- arch_enter_lazy_mmu_mode();
- lazy = true;
+ if (kmap_ops) {
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
+ kmap_ops, count);
+ if (ret)
+ goto out;
}
for (i = 0; i < count; i++) {
@@ -773,160 +690,22 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
ret = -ENOMEM;
goto out;
}
-
- if (kmap_ops) {
- ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]);
- if (ret)
- goto out;
- }
}
out:
- if (lazy)
- arch_leave_lazy_mmu_mode();
-
return ret;
}
EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
-static struct page *m2p_find_override(unsigned long mfn)
-{
- unsigned long flags;
- struct list_head *bucket;
- struct page *p, *ret;
-
- if (unlikely(!m2p_overrides))
- return NULL;
-
- ret = NULL;
- bucket = &m2p_overrides[mfn_hash(mfn)];
-
- spin_lock_irqsave(&m2p_override_lock, flags);
-
- list_for_each_entry(p, bucket, lru) {
- if (page_private(p) == mfn) {
- ret = p;
- break;
- }
- }
-
- spin_unlock_irqrestore(&m2p_override_lock, flags);
-
- return ret;
-}
-
-static int m2p_remove_override(struct page *page,
- struct gnttab_unmap_grant_ref *kunmap_op,
- unsigned long mfn)
-{
- unsigned long flags;
- unsigned long pfn;
- unsigned long uninitialized_var(address);
- unsigned level;
- pte_t *ptep = NULL;
-
- pfn = page_to_pfn(page);
-
- if (!PageHighMem(page)) {
- address = (unsigned long)__va(pfn << PAGE_SHIFT);
- ptep = lookup_address(address, &level);
-
- if (WARN(ptep == NULL || level != PG_LEVEL_4K,
- "m2p_remove_override: pfn %lx not mapped", pfn))
- return -EINVAL;
- }
-
- spin_lock_irqsave(&m2p_override_lock, flags);
- list_del(&page->lru);
- spin_unlock_irqrestore(&m2p_override_lock, flags);
-
- if (kunmap_op != NULL) {
- if (!PageHighMem(page)) {
- struct multicall_space mcs;
- struct gnttab_unmap_and_replace *unmap_op;
- struct page *scratch_page = get_balloon_scratch_page();
- unsigned long scratch_page_address = (unsigned long)
- __va(page_to_pfn(scratch_page) << PAGE_SHIFT);
-
- /*
- * 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 (kunmap_op->handle == -1)
- xen_mc_flush();
- /*
- * Now if kmap_op->handle is negative it means that the
- * hypercall actually returned an error.
- */
- if (kunmap_op->handle == GNTST_general_error) {
- pr_warn("m2p_remove_override: pfn %lx mfn %lx, failed to modify kernel mappings",
- pfn, mfn);
- put_balloon_scratch_page();
- return -1;
- }
-
- xen_mc_batch();
-
- mcs = __xen_mc_entry(
- sizeof(struct gnttab_unmap_and_replace));
- unmap_op = mcs.args;
- unmap_op->host_addr = kunmap_op->host_addr;
- unmap_op->new_addr = scratch_page_address;
- unmap_op->handle = kunmap_op->handle;
-
- MULTI_grant_table_op(mcs.mc,
- GNTTABOP_unmap_and_replace, unmap_op, 1);
-
- mcs = __xen_mc_entry(0);
- MULTI_update_va_mapping(mcs.mc, scratch_page_address,
- pfn_pte(page_to_pfn(scratch_page),
- PAGE_KERNEL_RO), 0);
-
- xen_mc_issue(PARAVIRT_LAZY_MMU);
-
- put_balloon_scratch_page();
- }
- }
-
- /* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present
- * somewhere in this domain, even before being added to the
- * m2p_override (see comment above in m2p_add_override).
- * If there are no other entries in the m2p_override corresponding
- * to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for
- * the original pfn (the one shared by the frontend): the backend
- * cannot do any IO on this page anymore because it has been
- * unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of
- * the original pfn causes mfn_to_pfn(mfn) to return the frontend
- * pfn again. */
- mfn &= ~FOREIGN_FRAME_BIT;
- pfn = mfn_to_pfn_no_overrides(mfn);
- if (__pfn_to_mfn(pfn) == FOREIGN_FRAME(mfn) &&
- m2p_find_override(mfn) == NULL)
- set_phys_to_machine(pfn, mfn);
-
- return 0;
-}
-
int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
int i, ret = 0;
- bool lazy = false;
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
- if (kunmap_ops &&
- !in_interrupt() &&
- paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
- arch_enter_lazy_mmu_mode();
- lazy = true;
- }
-
for (i = 0; i < count; i++) {
unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
unsigned long pfn = page_to_pfn(pages[i]);
@@ -940,32 +719,15 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
WARN_ON(!PagePrivate(pages[i]));
ClearPagePrivate(pages[i]);
set_phys_to_machine(pfn, pages[i]->index);
-
- if (kunmap_ops)
- ret = m2p_remove_override(pages[i], &kunmap_ops[i], mfn);
- if (ret)
- goto out;
}
-
+ if (kunmap_ops)
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ kunmap_ops, count);
out:
- if (lazy)
- arch_leave_lazy_mmu_mode();
return ret;
}
EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
-unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
-{
- struct page *p = m2p_find_override(mfn);
- unsigned long ret = pfn;
-
- if (p)
- ret = page_to_pfn(p);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
-
#ifdef CONFIG_XEN_DEBUG_FS
#include <linux/debugfs.h>
#include "debugfs.h"
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 3860d02729dc..0b52d92cb2e5 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -92,7 +92,6 @@ EXPORT_SYMBOL_GPL(balloon_stats);
/* We increase/decrease in batches which fit in a page */
static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)];
-static DEFINE_PER_CPU(struct page *, balloon_scratch_page);
/* List of ballooned pages, threaded through the mem_map array. */
@@ -423,22 +422,12 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
page = pfn_to_page(pfn);
#ifdef CONFIG_XEN_HAVE_PVMMU
- /*
- * Ballooned out frames are effectively replaced with
- * a scratch frame. Ensure direct mappings and the
- * p2m are consistent.
- */
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
if (!PageHighMem(page)) {
- struct page *scratch_page = get_balloon_scratch_page();
-
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
- pfn_pte(page_to_pfn(scratch_page),
- PAGE_KERNEL_RO), 0);
+ __pte_ma(0), 0);
BUG_ON(ret);
-
- put_balloon_scratch_page();
}
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
@@ -500,18 +489,6 @@ static void balloon_process(struct work_struct *work)
mutex_unlock(&balloon_mutex);
}
-struct page *get_balloon_scratch_page(void)
-{
- struct page *ret = get_cpu_var(balloon_scratch_page);
- BUG_ON(ret == NULL);
- return ret;
-}
-
-void put_balloon_scratch_page(void)
-{
- put_cpu_var(balloon_scratch_page);
-}
-
/* Resets the Xen limit, sets new target, and kicks off processing. */
void balloon_set_new_target(unsigned long target)
{
@@ -605,61 +582,13 @@ static void __init balloon_add_region(unsigned long start_pfn,
}
}
-static int alloc_balloon_scratch_page(int cpu)
-{
- if (per_cpu(balloon_scratch_page, cpu) != NULL)
- return 0;
-
- per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL);
- if (per_cpu(balloon_scratch_page, cpu) == NULL) {
- pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu);
- return -ENOMEM;
- }
-
- return 0;
-}
-
-
-static int balloon_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
- switch (action) {
- case CPU_UP_PREPARE:
- if (alloc_balloon_scratch_page(cpu))
- return NOTIFY_BAD;
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block balloon_cpu_notifier = {
- .notifier_call = balloon_cpu_notify,
-};
-
static int __init balloon_init(void)
{
- int i, cpu;
+ int i;
if (!xen_domain())
return -ENODEV;
- if (!xen_feature(XENFEAT_auto_translated_physmap)) {
- register_cpu_notifier(&balloon_cpu_notifier);
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- if (alloc_balloon_scratch_page(cpu)) {
- put_online_cpus();
- unregister_cpu_notifier(&balloon_cpu_notifier);
- return -ENOMEM;
- }
- }
- put_online_cpus();
- }
-
pr_info("Initialising balloon driver\n");
balloon_stats.current_pages = xen_pv_domain()
@@ -696,15 +625,4 @@ static int __init balloon_init(void)
subsys_initcall(balloon_init);
-static int __init balloon_clear(void)
-{
- int cpu;
-
- for_each_possible_cpu(cpu)
- per_cpu(balloon_scratch_page, cpu) = NULL;
-
- return 0;
-}
-early_initcall(balloon_clear);
-
MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-10 02:23:12 +0300