*/
#include <linux/sched.h>
#include <linux/highmem.h>
+#include <linux/debugfs.h>
#include <linux/bug.h>
+#include <linux/module.h>
+#include <linux/gfp.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+#include <asm/fixmap.h>
#include <asm/mmu_context.h>
+#include <asm/setup.h>
#include <asm/paravirt.h>
#include <asm/linkage.h>
#include <xen/page.h>
#include <xen/interface/xen.h>
+#include <xen/interface/version.h>
+#include <xen/hvc-console.h>
#include "multicalls.h"
#include "mmu.h"
+#include "debugfs.h"
+
+#define MMU_UPDATE_HISTO 30
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct {
+ u32 pgd_update;
+ u32 pgd_update_pinned;
+ u32 pgd_update_batched;
+
+ u32 pud_update;
+ u32 pud_update_pinned;
+ u32 pud_update_batched;
+
+ u32 pmd_update;
+ u32 pmd_update_pinned;
+ u32 pmd_update_batched;
+
+ u32 pte_update;
+ u32 pte_update_pinned;
+ u32 pte_update_batched;
+
+ u32 mmu_update;
+ u32 mmu_update_extended;
+ u32 mmu_update_histo[MMU_UPDATE_HISTO];
+
+ u32 prot_commit;
+ u32 prot_commit_batched;
+
+ u32 set_pte_at;
+ u32 set_pte_at_batched;
+ u32 set_pte_at_pinned;
+ u32 set_pte_at_current;
+ u32 set_pte_at_kernel;
+} mmu_stats;
+
+static u8 zero_stats;
+
+static inline void check_zero(void)
+{
+ if (unlikely(zero_stats)) {
+ memset(&mmu_stats, 0, sizeof(mmu_stats));
+ zero_stats = 0;
+ }
+}
+
+#define ADD_STATS(elem, val) \
+ do { check_zero(); mmu_stats.elem += (val); } while(0)
+
+#else /* !CONFIG_XEN_DEBUG_FS */
+
+#define ADD_STATS(elem, val) do { (void)(val); } while(0)
+
+#endif /* CONFIG_XEN_DEBUG_FS */
+
+
+/*
+ * Identity map, in addition to plain kernel map. This needs to be
+ * large enough to allocate page table pages to allocate the rest.
+ * Each page can map 2MB.
+ */
+static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
+
+#ifdef CONFIG_X86_64
+/* l3 pud for userspace vsyscall mapping */
+static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
+#endif /* CONFIG_X86_64 */
+
+/*
+ * Note about cr3 (pagetable base) values:
+ *
+ * xen_cr3 contains the current logical cr3 value; it contains the
+ * last set cr3. This may not be the current effective cr3, because
+ * its update may be being lazily deferred. However, a vcpu looking
+ * at its own cr3 can use this value knowing that it everything will
+ * be self-consistent.
+ *
+ * xen_current_cr3 contains the actual vcpu cr3; it is set once the
+ * hypercall to set the vcpu cr3 is complete (so it may be a little
+ * out of date, but it will never be set early). If one vcpu is
+ * looking at another vcpu's cr3 value, it should use this variable.
+ */
+DEFINE_PER_CPU(unsigned long, xen_cr3); /* cr3 stored as physaddr */
+DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */
+
+
+/*
+ * Just beyond the highest usermode address. STACK_TOP_MAX has a
+ * redzone above it, so round it up to a PGD boundary.
+ */
+#define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
+
#define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
#define TOP_ENTRIES (MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE)
}
/* Build the parallel p2m_top_mfn structures */
-void xen_setup_mfn_list_list(void)
+void xen_build_mfn_list_list(void)
{
unsigned pfn, idx;
- for(pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) {
+ for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top_mfn[topidx] = virt_to_mfn(p2m_top[topidx]);
}
- for(idx = 0; idx < ARRAY_SIZE(p2m_top_mfn_list); idx++) {
+ for (idx = 0; idx < ARRAY_SIZE(p2m_top_mfn_list); idx++) {
unsigned topidx = idx * P2M_ENTRIES_PER_PAGE;
p2m_top_mfn_list[idx] = virt_to_mfn(&p2m_top_mfn[topidx]);
}
+}
+void xen_setup_mfn_list_list(void)
+{
BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
unsigned pfn;
- for(pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
+ for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) {
unsigned topidx = p2m_top_index(pfn);
p2m_top[topidx] = &mfn_list[pfn];
}
+
+ xen_build_mfn_list_list();
}
unsigned long get_phys_to_machine(unsigned long pfn)
}
EXPORT_SYMBOL_GPL(get_phys_to_machine);
-static void alloc_p2m(unsigned long **pp, unsigned long *mfnp)
+/* install a new p2m_top page */
+bool install_p2mtop_page(unsigned long pfn, unsigned long *p)
{
- unsigned long *p;
+ unsigned topidx = p2m_top_index(pfn);
+ unsigned long **pfnp, *mfnp;
unsigned i;
- p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL);
- BUG_ON(p == NULL);
+ pfnp = &p2m_top[topidx];
+ mfnp = &p2m_top_mfn[topidx];
- for(i = 0; i < P2M_ENTRIES_PER_PAGE; i++)
+ for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++)
p[i] = INVALID_P2M_ENTRY;
- if (cmpxchg(pp, p2m_missing, p) != p2m_missing)
- free_page((unsigned long)p);
- else
+ if (cmpxchg(pfnp, p2m_missing, p) == p2m_missing) {
*mfnp = virt_to_mfn(p);
+ return true;
+ }
+
+ return false;
}
-void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+static void alloc_p2m(unsigned long pfn)
{
- unsigned topidx, idx;
+ unsigned long *p;
- if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
- BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
- return;
- }
+ p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL);
+ BUG_ON(p == NULL);
+
+ if (!install_p2mtop_page(pfn, p))
+ free_page((unsigned long)p);
+}
+
+/* Try to install p2m mapping; fail if intermediate bits missing */
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+ unsigned topidx, idx;
if (unlikely(pfn >= MAX_DOMAIN_PAGES)) {
BUG_ON(mfn != INVALID_P2M_ENTRY);
- return;
+ return true;
}
topidx = p2m_top_index(pfn);
if (p2m_top[topidx] == p2m_missing) {
- /* no need to allocate a page to store an invalid entry */
if (mfn == INVALID_P2M_ENTRY)
- return;
- alloc_p2m(&p2m_top[topidx], &p2m_top_mfn[topidx]);
+ return true;
+ return false;
}
idx = p2m_index(pfn);
p2m_top[topidx][idx] = mfn;
+
+ return true;
+}
+
+void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+ if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
+ BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
+ return;
+ }
+
+ if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
+ alloc_p2m(pfn);
+
+ if (!__set_phys_to_machine(pfn, mfn))
+ BUG();
+ }
+}
+
+unsigned long arbitrary_virt_to_mfn(void *vaddr)
+{
+ xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
+
+ return PFN_DOWN(maddr.maddr);
}
-xmaddr_t arbitrary_virt_to_machine(unsigned long address)
+xmaddr_t arbitrary_virt_to_machine(void *vaddr)
{
+ unsigned long address = (unsigned long)vaddr;
unsigned int level;
- pte_t *pte = lookup_address(address, &level);
- unsigned offset = address & ~PAGE_MASK;
+ pte_t *pte;
+ unsigned offset;
- BUG_ON(pte == NULL);
+ /*
+ * if the PFN is in the linear mapped vaddr range, we can just use
+ * the (quick) virt_to_machine() p2m lookup
+ */
+ if (virt_addr_valid(vaddr))
+ return virt_to_machine(vaddr);
- return XMADDR((pte_mfn(*pte) << PAGE_SHIFT) + offset);
+ /* otherwise we have to do a (slower) full page-table walk */
+
+ pte = lookup_address(address, &level);
+ BUG_ON(pte == NULL);
+ offset = address & ~PAGE_MASK;
+ return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
}
void make_lowmem_page_readonly(void *vaddr)
}
-static bool page_pinned(void *ptr)
+static bool xen_page_pinned(void *ptr)
{
struct page *page = virt_to_page(ptr);
return PagePinned(page);
}
-static void extend_mmu_update(const struct mmu_update *update)
+static void xen_extend_mmu_update(const struct mmu_update *update)
{
struct multicall_space mcs;
struct mmu_update *u;
mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));
- if (mcs.mc != NULL)
+ if (mcs.mc != NULL) {
+ ADD_STATS(mmu_update_extended, 1);
+ ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);
+
mcs.mc->args[1]++;
- else {
+
+ if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
+ ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
+ else
+ ADD_STATS(mmu_update_histo[0], 1);
+ } else {
+ ADD_STATS(mmu_update, 1);
mcs = __xen_mc_entry(sizeof(*u));
MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
+ ADD_STATS(mmu_update_histo[1], 1);
}
u = mcs.args;
xen_mc_batch();
- u.ptr = virt_to_machine(ptr).maddr;
+ /* ptr may be ioremapped for 64-bit pagetable setup */
+ u.ptr = arbitrary_virt_to_machine(ptr).maddr;
u.val = pmd_val_ma(val);
- extend_mmu_update(&u);
+ xen_extend_mmu_update(&u);
+
+ ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
xen_mc_issue(PARAVIRT_LAZY_MMU);
void xen_set_pmd(pmd_t *ptr, pmd_t val)
{
+ ADD_STATS(pmd_update, 1);
+
/* If page is not pinned, we can just update the entry
directly */
- if (!page_pinned(ptr)) {
+ if (!xen_page_pinned(ptr)) {
*ptr = val;
return;
}
+ ADD_STATS(pmd_update_pinned, 1);
+
xen_set_pmd_hyper(ptr, val);
}
*/
void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
-
- pgd = swapper_pg_dir + pgd_index(vaddr);
- if (pgd_none(*pgd)) {
- BUG();
- return;
- }
- pud = pud_offset(pgd, vaddr);
- if (pud_none(*pud)) {
- BUG();
- return;
- }
- pmd = pmd_offset(pud, vaddr);
- if (pmd_none(*pmd)) {
- BUG();
- return;
- }
- pte = pte_offset_kernel(pmd, vaddr);
- /* <mfn,flags> stored as-is, to permit clearing entries */
- xen_set_pte(pte, mfn_pte(mfn, flags));
-
- /*
- * It's enough to flush this one mapping.
- * (PGE mappings get flushed as well)
- */
- __flush_tlb_one(vaddr);
+ set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
}
void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pteval)
{
- /* updates to init_mm may be done without lock */
- if (mm == &init_mm)
- preempt_disable();
+ ADD_STATS(set_pte_at, 1);
+// ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
+ ADD_STATS(set_pte_at_current, mm == current->mm);
+ ADD_STATS(set_pte_at_kernel, mm == &init_mm);
if (mm == current->mm || mm == &init_mm) {
if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
mcs = xen_mc_entry(0);
MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
+ ADD_STATS(set_pte_at_batched, 1);
xen_mc_issue(PARAVIRT_LAZY_MMU);
goto out;
} else
}
xen_set_pte(ptep, pteval);
-out:
- if (mm == &init_mm)
- preempt_enable();
+out: return;
}
-pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+pte_t xen_ptep_modify_prot_start(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
{
/* Just return the pte as-is. We preserve the bits on commit */
return *ptep;
xen_mc_batch();
- u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
+ u.ptr = arbitrary_virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
u.val = pte_val_ma(pte);
- extend_mmu_update(&u);
+ xen_extend_mmu_update(&u);
+
+ ADD_STATS(prot_commit, 1);
+ ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
static pteval_t pte_mfn_to_pfn(pteval_t val)
{
if (val & _PAGE_PRESENT) {
- unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT;
- pteval_t flags = val & ~PTE_MASK;
+ unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+ pteval_t flags = val & PTE_FLAGS_MASK;
val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
}
static pteval_t pte_pfn_to_mfn(pteval_t val)
{
if (val & _PAGE_PRESENT) {
- unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT;
- pteval_t flags = val & ~PTE_MASK;
+ unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+ pteval_t flags = val & PTE_FLAGS_MASK;
val = ((pteval_t)pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
}
{
return pte_mfn_to_pfn(pte.pte);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
pgdval_t xen_pgd_val(pgd_t pgd)
{
return pte_mfn_to_pfn(pgd.pgd);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
pte_t xen_make_pte(pteval_t pte)
{
pte = pte_pfn_to_mfn(pte);
return native_make_pte(pte);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
pgd_t xen_make_pgd(pgdval_t pgd)
{
pgd = pte_pfn_to_mfn(pgd);
return native_make_pgd(pgd);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd);
pmdval_t xen_pmd_val(pmd_t pmd)
{
return pte_mfn_to_pfn(pmd.pmd);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
void xen_set_pud_hyper(pud_t *ptr, pud_t val)
{
xen_mc_batch();
- u.ptr = virt_to_machine(ptr).maddr;
+ /* ptr may be ioremapped for 64-bit pagetable setup */
+ u.ptr = arbitrary_virt_to_machine(ptr).maddr;
u.val = pud_val_ma(val);
- extend_mmu_update(&u);
+ xen_extend_mmu_update(&u);
+
+ ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
xen_mc_issue(PARAVIRT_LAZY_MMU);
void xen_set_pud(pud_t *ptr, pud_t val)
{
+ ADD_STATS(pud_update, 1);
+
/* If page is not pinned, we can just update the entry
directly */
- if (!page_pinned(ptr)) {
+ if (!xen_page_pinned(ptr)) {
*ptr = val;
return;
}
+ ADD_STATS(pud_update_pinned, 1);
+
xen_set_pud_hyper(ptr, val);
}
void xen_set_pte(pte_t *ptep, pte_t pte)
{
+ ADD_STATS(pte_update, 1);
+// ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
+ ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
+#ifdef CONFIG_X86_PAE
ptep->pte_high = pte.pte_high;
smp_wmb();
ptep->pte_low = pte.pte_low;
+#else
+ *ptep = pte;
+#endif
}
+#ifdef CONFIG_X86_PAE
void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
{
- set_64bit((u64 *)ptep, pte_val_ma(pte));
+ set_64bit((u64 *)ptep, native_pte_val(pte));
}
void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
set_pmd(pmdp, __pmd(0));
}
+#endif /* CONFIG_X86_PAE */
pmd_t xen_make_pmd(pmdval_t pmd)
{
pmd = pte_pfn_to_mfn(pmd);
return native_make_pmd(pmd);
}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
+
+#if PAGETABLE_LEVELS == 4
+pudval_t xen_pud_val(pud_t pud)
+{
+ return pte_mfn_to_pfn(pud.pud);
+}
+PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
+
+pud_t xen_make_pud(pudval_t pud)
+{
+ pud = pte_pfn_to_mfn(pud);
+
+ return native_make_pud(pud);
+}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud);
+
+pgd_t *xen_get_user_pgd(pgd_t *pgd)
+{
+ pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
+ unsigned offset = pgd - pgd_page;
+ pgd_t *user_ptr = NULL;
+
+ if (offset < pgd_index(USER_LIMIT)) {
+ struct page *page = virt_to_page(pgd_page);
+ user_ptr = (pgd_t *)page->private;
+ if (user_ptr)
+ user_ptr += offset;
+ }
+
+ return user_ptr;
+}
+
+static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+ struct mmu_update u;
+
+ u.ptr = virt_to_machine(ptr).maddr;
+ u.val = pgd_val_ma(val);
+ xen_extend_mmu_update(&u);
+}
+
+/*
+ * Raw hypercall-based set_pgd, intended for in early boot before
+ * there's a page structure. This implies:
+ * 1. The only existing pagetable is the kernel's
+ * 2. It is always pinned
+ * 3. It has no user pagetable attached to it
+ */
+void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+ preempt_disable();
+
+ xen_mc_batch();
+
+ __xen_set_pgd_hyper(ptr, val);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ preempt_enable();
+}
+
+void xen_set_pgd(pgd_t *ptr, pgd_t val)
+{
+ pgd_t *user_ptr = xen_get_user_pgd(ptr);
+
+ ADD_STATS(pgd_update, 1);
+
+ /* If page is not pinned, we can just update the entry
+ directly */
+ if (!xen_page_pinned(ptr)) {
+ *ptr = val;
+ if (user_ptr) {
+ WARN_ON(xen_page_pinned(user_ptr));
+ *user_ptr = val;
+ }
+ return;
+ }
+
+ ADD_STATS(pgd_update_pinned, 1);
+ ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
+ /* If it's pinned, then we can at least batch the kernel and
+ user updates together. */
+ xen_mc_batch();
+
+ __xen_set_pgd_hyper(ptr, val);
+ if (user_ptr)
+ __xen_set_pgd_hyper(user_ptr, val);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+#endif /* PAGETABLE_LEVELS == 4 */
/*
- (Yet another) pagetable walker. This one is intended for pinning a
- pagetable. This means that it walks a pagetable and calls the
- callback function on each page it finds making up the page table,
- at every level. It walks the entire pagetable, but it only bothers
- pinning pte pages which are below pte_limit. In the normal case
- this will be TASK_SIZE, but at boot we need to pin up to
- FIXADDR_TOP. But the important bit is that we don't pin beyond
- there, because then we start getting into Xen's ptes.
-*/
-static int pgd_walk(pgd_t *pgd_base, int (*func)(struct page *, enum pt_level),
- unsigned long limit)
-{
- pgd_t *pgd = pgd_base;
+ * (Yet another) pagetable walker. This one is intended for pinning a
+ * pagetable. This means that it walks a pagetable and calls the
+ * callback function on each page it finds making up the page table,
+ * at every level. It walks the entire pagetable, but it only bothers
+ * pinning pte pages which are below limit. In the normal case this
+ * will be STACK_TOP_MAX, but at boot we need to pin up to
+ * FIXADDR_TOP.
+ *
+ * For 32-bit the important bit is that we don't pin beyond there,
+ * because then we start getting into Xen's ptes.
+ *
+ * For 64-bit, we must skip the Xen hole in the middle of the address
+ * space, just after the big x86-64 virtual hole.
+ */
+static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,
+ int (*func)(struct mm_struct *mm, struct page *,
+ enum pt_level),
+ unsigned long limit)
+{
int flush = 0;
- unsigned long addr = 0;
- unsigned long pgd_next;
+ unsigned hole_low, hole_high;
+ unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
+ unsigned pgdidx, pudidx, pmdidx;
- BUG_ON(limit > FIXADDR_TOP);
+ /* The limit is the last byte to be touched */
+ limit--;
+ BUG_ON(limit >= FIXADDR_TOP);
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
- for (; addr != FIXADDR_TOP; pgd++, addr = pgd_next) {
+ /*
+ * 64-bit has a great big hole in the middle of the address
+ * space, which contains the Xen mappings. On 32-bit these
+ * will end up making a zero-sized hole and so is a no-op.
+ */
+ hole_low = pgd_index(USER_LIMIT);
+ hole_high = pgd_index(PAGE_OFFSET);
+
+ pgdidx_limit = pgd_index(limit);
+#if PTRS_PER_PUD > 1
+ pudidx_limit = pud_index(limit);
+#else
+ pudidx_limit = 0;
+#endif
+#if PTRS_PER_PMD > 1
+ pmdidx_limit = pmd_index(limit);
+#else
+ pmdidx_limit = 0;
+#endif
+
+ for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
pud_t *pud;
- unsigned long pud_limit, pud_next;
- pgd_next = pud_limit = pgd_addr_end(addr, FIXADDR_TOP);
+ if (pgdidx >= hole_low && pgdidx < hole_high)
+ continue;
- if (!pgd_val(*pgd))
+ if (!pgd_val(pgd[pgdidx]))
continue;
- pud = pud_offset(pgd, 0);
+ pud = pud_offset(&pgd[pgdidx], 0);
if (PTRS_PER_PUD > 1) /* not folded */
- flush |= (*func)(virt_to_page(pud), PT_PUD);
+ flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
- for (; addr != pud_limit; pud++, addr = pud_next) {
+ for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
pmd_t *pmd;
- unsigned long pmd_limit;
-
- pud_next = pud_addr_end(addr, pud_limit);
- if (pud_next < limit)
- pmd_limit = pud_next;
- else
- pmd_limit = limit;
+ if (pgdidx == pgdidx_limit &&
+ pudidx > pudidx_limit)
+ goto out;
- if (pud_none(*pud))
+ if (pud_none(pud[pudidx]))
continue;
- pmd = pmd_offset(pud, 0);
+ pmd = pmd_offset(&pud[pudidx], 0);
if (PTRS_PER_PMD > 1) /* not folded */
- flush |= (*func)(virt_to_page(pmd), PT_PMD);
+ flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
+
+ for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
+ struct page *pte;
- for (; addr != pmd_limit; pmd++) {
- addr += (PAGE_SIZE * PTRS_PER_PTE);
- if ((pmd_limit-1) < (addr-1)) {
- addr = pmd_limit;
- break;
- }
+ if (pgdidx == pgdidx_limit &&
+ pudidx == pudidx_limit &&
+ pmdidx > pmdidx_limit)
+ goto out;
- if (pmd_none(*pmd))
+ if (pmd_none(pmd[pmdidx]))
continue;
- flush |= (*func)(pmd_page(*pmd), PT_PTE);
+ pte = pmd_page(pmd[pmdidx]);
+ flush |= (*func)(mm, pte, PT_PTE);
}
}
}
- flush |= (*func)(virt_to_page(pgd_base), PT_PGD);
+out:
+ /* Do the top level last, so that the callbacks can use it as
+ a cue to do final things like tlb flushes. */
+ flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);
return flush;
}
-static spinlock_t *lock_pte(struct page *page)
+static int xen_pgd_walk(struct mm_struct *mm,
+ int (*func)(struct mm_struct *mm, struct page *,
+ enum pt_level),
+ unsigned long limit)
+{
+ return __xen_pgd_walk(mm, mm->pgd, func, limit);
+}
+
+/* If we're using split pte locks, then take the page's lock and
+ return a pointer to it. Otherwise return NULL. */
+static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
{
spinlock_t *ptl = NULL;
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
ptl = __pte_lockptr(page);
- spin_lock(ptl);
+ spin_lock_nest_lock(ptl, &mm->page_table_lock);
#endif
return ptl;
}
-static void do_unlock(void *v)
+static void xen_pte_unlock(void *v)
{
spinlock_t *ptl = v;
spin_unlock(ptl);
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
}
-static int pin_page(struct page *page, enum pt_level level)
+static int xen_pin_page(struct mm_struct *mm, struct page *page,
+ enum pt_level level)
{
unsigned pgfl = TestSetPagePinned(page);
int flush;
flush = 0;
+ /*
+ * We need to hold the pagetable lock between the time
+ * we make the pagetable RO and when we actually pin
+ * it. If we don't, then other users may come in and
+ * attempt to update the pagetable by writing it,
+ * which will fail because the memory is RO but not
+ * pinned, so Xen won't do the trap'n'emulate.
+ *
+ * If we're using split pte locks, we can't hold the
+ * entire pagetable's worth of locks during the
+ * traverse, because we may wrap the preempt count (8
+ * bits). The solution is to mark RO and pin each PTE
+ * page while holding the lock. This means the number
+ * of locks we end up holding is never more than a
+ * batch size (~32 entries, at present).
+ *
+ * If we're not using split pte locks, we needn't pin
+ * the PTE pages independently, because we're
+ * protected by the overall pagetable lock.
+ */
ptl = NULL;
if (level == PT_PTE)
- ptl = lock_pte(page);
+ ptl = xen_pte_lock(page, mm);
MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
pfn_pte(pfn, PAGE_KERNEL_RO),
level == PT_PGD ? UVMF_TLB_FLUSH : 0);
- if (level == PT_PTE)
+ if (ptl) {
xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);
- if (ptl) {
/* Queue a deferred unlock for when this batch
is completed. */
- xen_mc_callback(do_unlock, ptl);
+ xen_mc_callback(xen_pte_unlock, ptl);
}
}
/* This is called just after a mm has been created, but it has not
been used yet. We need to make sure that its pagetable is all
read-only, and can be pinned. */
-void xen_pgd_pin(pgd_t *pgd)
+static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
{
+ vm_unmap_aliases();
+
xen_mc_batch();
- if (pgd_walk(pgd, pin_page, TASK_SIZE)) {
- /* re-enable interrupts for kmap_flush_unused */
+ if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) {
+ /* re-enable interrupts for flushing */
xen_mc_issue(0);
+
kmap_flush_unused();
+
xen_mc_batch();
}
+#ifdef CONFIG_X86_64
+ {
+ pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+ xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
+
+ if (user_pgd) {
+ xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
+ xen_do_pin(MMUEXT_PIN_L4_TABLE,
+ PFN_DOWN(__pa(user_pgd)));
+ }
+ }
+#else /* CONFIG_X86_32 */
+#ifdef CONFIG_X86_PAE
+ /* Need to make sure unshared kernel PMD is pinnable */
+ xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
+ PT_PMD);
+#endif
xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
+#endif /* CONFIG_X86_64 */
xen_mc_issue(0);
}
+static void xen_pgd_pin(struct mm_struct *mm)
+{
+ __xen_pgd_pin(mm, mm->pgd);
+}
+
/*
* On save, we need to pin all pagetables to make sure they get their
* mfns turned into pfns. Search the list for any unpinned pgds and pin
* them (unpinned pgds are not currently in use, probably because the
* process is under construction or destruction).
+ *
+ * Expected to be called in stop_machine() ("equivalent to taking
+ * every spinlock in the system"), so the locking doesn't really
+ * matter all that much.
*/
void xen_mm_pin_all(void)
{
list_for_each_entry(page, &pgd_list, lru) {
if (!PagePinned(page)) {
- xen_pgd_pin((pgd_t *)page_address(page));
+ __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
SetPageSavePinned(page);
}
}
* that's before we have page structures to store the bits. So do all
* the book-keeping now.
*/
-static __init int mark_pinned(struct page *page, enum pt_level level)
+static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
+ enum pt_level level)
{
SetPagePinned(page);
return 0;
}
-void __init xen_mark_init_mm_pinned(void)
+static void __init xen_mark_init_mm_pinned(void)
{
- pgd_walk(init_mm.pgd, mark_pinned, FIXADDR_TOP);
+ xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
}
-static int unpin_page(struct page *page, enum pt_level level)
+static int xen_unpin_page(struct mm_struct *mm, struct page *page,
+ enum pt_level level)
{
unsigned pgfl = TestClearPagePinned(page);
spinlock_t *ptl = NULL;
struct multicall_space mcs;
+ /*
+ * Do the converse to pin_page. If we're using split
+ * pte locks, we must be holding the lock for while
+ * the pte page is unpinned but still RO to prevent
+ * concurrent updates from seeing it in this
+ * partially-pinned state.
+ */
if (level == PT_PTE) {
- ptl = lock_pte(page);
+ ptl = xen_pte_lock(page, mm);
- xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
+ if (ptl)
+ xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
}
mcs = __xen_mc_entry(0);
if (ptl) {
/* unlock when batch completed */
- xen_mc_callback(do_unlock, ptl);
+ xen_mc_callback(xen_pte_unlock, ptl);
}
}
}
/* Release a pagetables pages back as normal RW */
-static void xen_pgd_unpin(pgd_t *pgd)
+static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
{
xen_mc_batch();
xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
- pgd_walk(pgd, unpin_page, TASK_SIZE);
+#ifdef CONFIG_X86_64
+ {
+ pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+ if (user_pgd) {
+ xen_do_pin(MMUEXT_UNPIN_TABLE,
+ PFN_DOWN(__pa(user_pgd)));
+ xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
+ }
+ }
+#endif
+
+#ifdef CONFIG_X86_PAE
+ /* Need to make sure unshared kernel PMD is unpinned */
+ xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
+ PT_PMD);
+#endif
+
+ __xen_pgd_walk(mm, pgd, xen_unpin_page, USER_LIMIT);
xen_mc_issue(0);
}
+static void xen_pgd_unpin(struct mm_struct *mm)
+{
+ __xen_pgd_unpin(mm, mm->pgd);
+}
+
/*
* On resume, undo any pinning done at save, so that the rest of the
* kernel doesn't see any unexpected pinned pagetables.
list_for_each_entry(page, &pgd_list, lru) {
if (PageSavePinned(page)) {
BUG_ON(!PagePinned(page));
- printk("unpinning pinned %p\n", page_address(page));
- xen_pgd_unpin((pgd_t *)page_address(page));
+ __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
ClearPageSavePinned(page);
}
}
void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
spin_lock(&next->page_table_lock);
- xen_pgd_pin(next->pgd);
+ xen_pgd_pin(next);
spin_unlock(&next->page_table_lock);
}
void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
{
spin_lock(&mm->page_table_lock);
- xen_pgd_pin(mm->pgd);
+ xen_pgd_pin(mm);
spin_unlock(&mm->page_table_lock);
}
static void drop_other_mm_ref(void *info)
{
struct mm_struct *mm = info;
+ struct mm_struct *active_mm;
+
+ active_mm = percpu_read(cpu_tlbstate.active_mm);
- if (__get_cpu_var(cpu_tlbstate).active_mm == mm)
+ if (active_mm == mm)
leave_mm(smp_processor_id());
/* If this cpu still has a stale cr3 reference, then make sure
it has been flushed. */
- if (x86_read_percpu(xen_current_cr3) == __pa(mm->pgd)) {
+ if (percpu_read(xen_current_cr3) == __pa(mm->pgd))
load_cr3(swapper_pg_dir);
- arch_flush_lazy_cpu_mode();
- }
}
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
{
- cpumask_t mask;
+ cpumask_var_t mask;
unsigned cpu;
if (current->active_mm == mm) {
load_cr3(swapper_pg_dir);
else
leave_mm(smp_processor_id());
- arch_flush_lazy_cpu_mode();
}
/* Get the "official" set of cpus referring to our pagetable. */
- mask = mm->cpu_vm_mask;
+ if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
+ for_each_online_cpu(cpu) {
+ if (!cpumask_test_cpu(cpu, mm_cpumask(mm))
+ && per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
+ continue;
+ smp_call_function_single(cpu, drop_other_mm_ref, mm, 1);
+ }
+ return;
+ }
+ cpumask_copy(mask, mm_cpumask(mm));
/* It's possible that a vcpu may have a stale reference to our
cr3, because its in lazy mode, and it hasn't yet flushed
if needed. */
for_each_online_cpu(cpu) {
if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
- cpu_set(cpu, mask);
+ cpumask_set_cpu(cpu, mask);
}
- if (!cpus_empty(mask))
- smp_call_function_mask(mask, drop_other_mm_ref, mm, 1);
+ if (!cpumask_empty(mask))
+ smp_call_function_many(mask, drop_other_mm_ref, mm, 1);
+ free_cpumask_var(mask);
}
#else
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
{
if (current->active_mm == mm)
load_cr3(swapper_pg_dir);
void xen_exit_mmap(struct mm_struct *mm)
{
get_cpu(); /* make sure we don't move around */
- drop_mm_ref(mm);
+ xen_drop_mm_ref(mm);
put_cpu();
spin_lock(&mm->page_table_lock);
/* pgd may not be pinned in the error exit path of execve */
- if (page_pinned(mm->pgd))
- xen_pgd_unpin(mm->pgd);
+ if (xen_page_pinned(mm->pgd))
+ xen_pgd_unpin(mm);
spin_unlock(&mm->page_table_lock);
}
+
+static __init void xen_pagetable_setup_start(pgd_t *base)
+{
+}
+
+static void xen_post_allocator_init(void);
+
+static __init void xen_pagetable_setup_done(pgd_t *base)
+{
+ xen_setup_shared_info();
+ xen_post_allocator_init();
+}
+
+static void xen_write_cr2(unsigned long cr2)
+{
+ percpu_read(xen_vcpu)->arch.cr2 = cr2;
+}
+
+static unsigned long xen_read_cr2(void)
+{
+ return percpu_read(xen_vcpu)->arch.cr2;
+}
+
+unsigned long xen_read_cr2_direct(void)
+{
+ return percpu_read(xen_vcpu_info.arch.cr2);
+}
+
+static void xen_flush_tlb(void)
+{
+ struct mmuext_op *op;
+ struct multicall_space mcs;
+
+ preempt_disable();
+
+ mcs = xen_mc_entry(sizeof(*op));
+
+ op = mcs.args;
+ op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
+ MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ preempt_enable();
+}
+
+static void xen_flush_tlb_single(unsigned long addr)
+{
+ struct mmuext_op *op;
+ struct multicall_space mcs;
+
+ preempt_disable();
+
+ mcs = xen_mc_entry(sizeof(*op));
+ op = mcs.args;
+ op->cmd = MMUEXT_INVLPG_LOCAL;
+ op->arg1.linear_addr = addr & PAGE_MASK;
+ MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ preempt_enable();
+}
+
+static void xen_flush_tlb_others(const struct cpumask *cpus,
+ struct mm_struct *mm, unsigned long va)
+{
+ struct {
+ struct mmuext_op op;
+ DECLARE_BITMAP(mask, NR_CPUS);
+ } *args;
+ struct multicall_space mcs;
+
+ if (cpumask_empty(cpus))
+ return; /* nothing to do */
+
+ mcs = xen_mc_entry(sizeof(*args));
+ args = mcs.args;
+ args->op.arg2.vcpumask = to_cpumask(args->mask);
+
+ /* Remove us, and any offline CPUS. */
+ cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
+
+ if (va == TLB_FLUSH_ALL) {
+ args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
+ } else {
+ args->op.cmd = MMUEXT_INVLPG_MULTI;
+ args->op.arg1.linear_addr = va;
+ }
+
+ MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+
+static unsigned long xen_read_cr3(void)
+{
+ return percpu_read(xen_cr3);
+}
+
+static void set_current_cr3(void *v)
+{
+ percpu_write(xen_current_cr3, (unsigned long)v);
+}
+
+static void __xen_write_cr3(bool kernel, unsigned long cr3)
+{
+ struct mmuext_op *op;
+ struct multicall_space mcs;
+ unsigned long mfn;
+
+ if (cr3)
+ mfn = pfn_to_mfn(PFN_DOWN(cr3));
+ else
+ mfn = 0;
+
+ WARN_ON(mfn == 0 && kernel);
+
+ mcs = __xen_mc_entry(sizeof(*op));
+
+ op = mcs.args;
+ op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
+ op->arg1.mfn = mfn;
+
+ MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+ if (kernel) {
+ percpu_write(xen_cr3, cr3);
+
+ /* Update xen_current_cr3 once the batch has actually
+ been submitted. */
+ xen_mc_callback(set_current_cr3, (void *)cr3);
+ }
+}
+
+static void xen_write_cr3(unsigned long cr3)
+{
+ BUG_ON(preemptible());
+
+ xen_mc_batch(); /* disables interrupts */
+
+ /* Update while interrupts are disabled, so its atomic with
+ respect to ipis */
+ percpu_write(xen_cr3, cr3);
+
+ __xen_write_cr3(true, cr3);
+
+#ifdef CONFIG_X86_64
+ {
+ pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
+ if (user_pgd)
+ __xen_write_cr3(false, __pa(user_pgd));
+ else
+ __xen_write_cr3(false, 0);
+ }
+#endif
+
+ xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */
+}
+
+static int xen_pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *pgd = mm->pgd;
+ int ret = 0;
+
+ BUG_ON(PagePinned(virt_to_page(pgd)));
+
+#ifdef CONFIG_X86_64
+ {
+ struct page *page = virt_to_page(pgd);
+ pgd_t *user_pgd;
+
+ BUG_ON(page->private != 0);
+
+ ret = -ENOMEM;
+
+ user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+ page->private = (unsigned long)user_pgd;
+
+ if (user_pgd != NULL) {
+ user_pgd[pgd_index(VSYSCALL_START)] =
+ __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
+ ret = 0;
+ }
+
+ BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
+ }
+#endif
+
+ return ret;
+}
+
+static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+#ifdef CONFIG_X86_64
+ pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+ if (user_pgd)
+ free_page((unsigned long)user_pgd);
+#endif
+}
+
+#ifdef CONFIG_X86_32
+static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
+{
+ /* If there's an existing pte, then don't allow _PAGE_RW to be set */
+ if (pte_val_ma(*ptep) & _PAGE_PRESENT)
+ pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
+ pte_val_ma(pte));
+
+ return pte;
+}
+
+/* Init-time set_pte while constructing initial pagetables, which
+ doesn't allow RO pagetable pages to be remapped RW */
+static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
+{
+ pte = mask_rw_pte(ptep, pte);
+
+ xen_set_pte(ptep, pte);
+}
+#endif
+
+static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
+{
+ struct mmuext_op op;
+ op.cmd = cmd;
+ op.arg1.mfn = pfn_to_mfn(pfn);
+ if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
+ BUG();
+}
+
+/* Early in boot, while setting up the initial pagetable, assume
+ everything is pinned. */
+static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
+{
+#ifdef CONFIG_FLATMEM
+ BUG_ON(mem_map); /* should only be used early */
+#endif
+ make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
+ pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
+}
+
+/* Used for pmd and pud */
+static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
+{
+#ifdef CONFIG_FLATMEM
+ BUG_ON(mem_map); /* should only be used early */
+#endif
+ make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
+}
+
+/* Early release_pte assumes that all pts are pinned, since there's
+ only init_mm and anything attached to that is pinned. */
+static __init void xen_release_pte_init(unsigned long pfn)
+{
+ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
+ make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
+}
+
+static __init void xen_release_pmd_init(unsigned long pfn)
+{
+ make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
+}
+
+/* This needs to make sure the new pte page is pinned iff its being
+ attached to a pinned pagetable. */
+static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)
+{
+ struct page *page = pfn_to_page(pfn);
+
+ if (PagePinned(virt_to_page(mm->pgd))) {
+ SetPagePinned(page);
+
+ vm_unmap_aliases();
+ if (!PageHighMem(page)) {
+ make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
+ if (level == PT_PTE && USE_SPLIT_PTLOCKS)
+ pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
+ } else {
+ /* make sure there are no stray mappings of
+ this page */
+ kmap_flush_unused();
+ }
+ }
+}
+
+static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn)
+{
+ xen_alloc_ptpage(mm, pfn, PT_PTE);
+}
+
+static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
+{
+ xen_alloc_ptpage(mm, pfn, PT_PMD);
+}
+
+/* This should never happen until we're OK to use struct page */
+static void xen_release_ptpage(unsigned long pfn, unsigned level)
+{
+ struct page *page = pfn_to_page(pfn);
+
+ if (PagePinned(page)) {
+ if (!PageHighMem(page)) {
+ if (level == PT_PTE && USE_SPLIT_PTLOCKS)
+ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
+ make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
+ }
+ ClearPagePinned(page);
+ }
+}
+
+static void xen_release_pte(unsigned long pfn)
+{
+ xen_release_ptpage(pfn, PT_PTE);
+}
+
+static void xen_release_pmd(unsigned long pfn)
+{
+ xen_release_ptpage(pfn, PT_PMD);
+}
+
+#if PAGETABLE_LEVELS == 4
+static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
+{
+ xen_alloc_ptpage(mm, pfn, PT_PUD);
+}
+
+static void xen_release_pud(unsigned long pfn)
+{
+ xen_release_ptpage(pfn, PT_PUD);
+}
+#endif
+
+void __init xen_reserve_top(void)
+{
+#ifdef CONFIG_X86_32
+ unsigned long top = HYPERVISOR_VIRT_START;
+ struct xen_platform_parameters pp;
+
+ if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
+ top = pp.virt_start;
+
+ reserve_top_address(-top);
+#endif /* CONFIG_X86_32 */
+}
+
+/*
+ * Like __va(), but returns address in the kernel mapping (which is
+ * all we have until the physical memory mapping has been set up.
+ */
+static void *__ka(phys_addr_t paddr)
+{
+#ifdef CONFIG_X86_64
+ return (void *)(paddr + __START_KERNEL_map);
+#else
+ return __va(paddr);
+#endif
+}
+
+/* Convert a machine address to physical address */
+static unsigned long m2p(phys_addr_t maddr)
+{
+ phys_addr_t paddr;
+
+ maddr &= PTE_PFN_MASK;
+ paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
+
+ return paddr;
+}
+
+/* Convert a machine address to kernel virtual */
+static void *m2v(phys_addr_t maddr)
+{
+ return __ka(m2p(maddr));
+}
+
+static void set_page_prot(void *addr, pgprot_t prot)
+{
+ unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
+ pte_t pte = pfn_pte(pfn, prot);
+
+ if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
+ BUG();
+}
+
+static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
+{
+ unsigned pmdidx, pteidx;
+ unsigned ident_pte;
+ unsigned long pfn;
+
+ ident_pte = 0;
+ pfn = 0;
+ for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
+ pte_t *pte_page;
+
+ /* Reuse or allocate a page of ptes */
+ if (pmd_present(pmd[pmdidx]))
+ pte_page = m2v(pmd[pmdidx].pmd);
+ else {
+ /* Check for free pte pages */
+ if (ident_pte == ARRAY_SIZE(level1_ident_pgt))
+ break;
+
+ pte_page = &level1_ident_pgt[ident_pte];
+ ident_pte += PTRS_PER_PTE;
+
+ pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
+ }
+
+ /* Install mappings */
+ for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
+ pte_t pte;
+
+ if (pfn > max_pfn_mapped)
+ max_pfn_mapped = pfn;
+
+ if (!pte_none(pte_page[pteidx]))
+ continue;
+
+ pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
+ pte_page[pteidx] = pte;
+ }
+ }
+
+ for (pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
+ set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
+
+ set_page_prot(pmd, PAGE_KERNEL_RO);
+}
+
+#ifdef CONFIG_X86_64
+static void convert_pfn_mfn(void *v)
+{
+ pte_t *pte = v;
+ int i;
+
+ /* All levels are converted the same way, so just treat them
+ as ptes. */
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ pte[i] = xen_make_pte(pte[i].pte);
+}
+
+/*
+ * Set up the inital kernel pagetable.
+ *
+ * We can construct this by grafting the Xen provided pagetable into
+ * head_64.S's preconstructed pagetables. We copy the Xen L2's into
+ * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt. This
+ * means that only the kernel has a physical mapping to start with -
+ * but that's enough to get __va working. We need to fill in the rest
+ * of the physical mapping once some sort of allocator has been set
+ * up.
+ */
+__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+ unsigned long max_pfn)
+{
+ pud_t *l3;
+ pmd_t *l2;
+
+ /* Zap identity mapping */
+ init_level4_pgt[0] = __pgd(0);
+
+ /* Pre-constructed entries are in pfn, so convert to mfn */
+ convert_pfn_mfn(init_level4_pgt);
+ convert_pfn_mfn(level3_ident_pgt);
+ convert_pfn_mfn(level3_kernel_pgt);
+
+ l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
+ l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);
+
+ memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+ memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+
+ l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd);
+ l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud);
+ memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+
+ /* Set up identity map */
+ xen_map_identity_early(level2_ident_pgt, max_pfn);
+
+ /* Make pagetable pieces RO */
+ set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
+ set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
+ set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
+ set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
+ set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
+ set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);
+
+ /* Pin down new L4 */
+ pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
+ PFN_DOWN(__pa_symbol(init_level4_pgt)));
+
+ /* Unpin Xen-provided one */
+ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+
+ /* Switch over */
+ pgd = init_level4_pgt;
+
+ /*
+ * At this stage there can be no user pgd, and no page
+ * structure to attach it to, so make sure we just set kernel
+ * pgd.
+ */
+ xen_mc_batch();
+ __xen_write_cr3(true, __pa(pgd));
+ xen_mc_issue(PARAVIRT_LAZY_CPU);
+
+ reserve_early(__pa(xen_start_info->pt_base),
+ __pa(xen_start_info->pt_base +
+ xen_start_info->nr_pt_frames * PAGE_SIZE),
+ "XEN PAGETABLES");
+
+ return pgd;
+}
+#else /* !CONFIG_X86_64 */
+static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss;
+
+__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+ unsigned long max_pfn)
+{
+ pmd_t *kernel_pmd;
+
+ max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) +
+ xen_start_info->nr_pt_frames * PAGE_SIZE +
+ 512*1024);
+
+ kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
+ memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
+
+ xen_map_identity_early(level2_kernel_pgt, max_pfn);
+
+ memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
+ set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],
+ __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));
+
+ set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
+ set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
+ set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
+
+ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+
+ xen_write_cr3(__pa(swapper_pg_dir));
+
+ pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
+
+ reserve_early(__pa(xen_start_info->pt_base),
+ __pa(xen_start_info->pt_base +
+ xen_start_info->nr_pt_frames * PAGE_SIZE),
+ "XEN PAGETABLES");
+
+ return swapper_pg_dir;
+}
+#endif /* CONFIG_X86_64 */
+
+static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
+{
+ pte_t pte;
+
+ phys >>= PAGE_SHIFT;
+
+ switch (idx) {
+ case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
+#ifdef CONFIG_X86_F00F_BUG
+ case FIX_F00F_IDT:
+#endif
+#ifdef CONFIG_X86_32
+ case FIX_WP_TEST:
+ case FIX_VDSO:
+# ifdef CONFIG_HIGHMEM
+ case FIX_KMAP_BEGIN ... FIX_KMAP_END:
+# endif
+#else
+ case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
+#endif
+#ifdef CONFIG_X86_LOCAL_APIC
+ case FIX_APIC_BASE: /* maps dummy local APIC */
+#endif
+ case FIX_TEXT_POKE0:
+ case FIX_TEXT_POKE1:
+ /* All local page mappings */
+ pte = pfn_pte(phys, prot);
+ break;
+
+ default:
+ pte = mfn_pte(phys, prot);
+ break;
+ }
+
+ __native_set_fixmap(idx, pte);
+
+#ifdef CONFIG_X86_64
+ /* Replicate changes to map the vsyscall page into the user
+ pagetable vsyscall mapping. */
+ if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
+ unsigned long vaddr = __fix_to_virt(idx);
+ set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
+ }
+#endif
+}
+
+static __init void xen_post_allocator_init(void)
+{
+ pv_mmu_ops.set_pte = xen_set_pte;
+ pv_mmu_ops.set_pmd = xen_set_pmd;
+ pv_mmu_ops.set_pud = xen_set_pud;
+#if PAGETABLE_LEVELS == 4
+ pv_mmu_ops.set_pgd = xen_set_pgd;
+#endif
+
+ /* This will work as long as patching hasn't happened yet
+ (which it hasn't) */
+ pv_mmu_ops.alloc_pte = xen_alloc_pte;
+ pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
+ pv_mmu_ops.release_pte = xen_release_pte;
+ pv_mmu_ops.release_pmd = xen_release_pmd;
+#if PAGETABLE_LEVELS == 4
+ pv_mmu_ops.alloc_pud = xen_alloc_pud;
+ pv_mmu_ops.release_pud = xen_release_pud;
+#endif
+
+#ifdef CONFIG_X86_64
+ SetPagePinned(virt_to_page(level3_user_vsyscall));
+#endif
+ xen_mark_init_mm_pinned();
+}
+
+static void xen_leave_lazy_mmu(void)
+{
+ preempt_disable();
+ xen_mc_flush();
+ paravirt_leave_lazy_mmu();
+ preempt_enable();
+}
+
+static const struct pv_mmu_ops xen_mmu_ops __initdata = {
+ .read_cr2 = xen_read_cr2,
+ .write_cr2 = xen_write_cr2,
+
+ .read_cr3 = xen_read_cr3,
+ .write_cr3 = xen_write_cr3,
+
+ .flush_tlb_user = xen_flush_tlb,
+ .flush_tlb_kernel = xen_flush_tlb,
+ .flush_tlb_single = xen_flush_tlb_single,
+ .flush_tlb_others = xen_flush_tlb_others,
+
+ .pte_update = paravirt_nop,
+ .pte_update_defer = paravirt_nop,
+
+ .pgd_alloc = xen_pgd_alloc,
+ .pgd_free = xen_pgd_free,
+
+ .alloc_pte = xen_alloc_pte_init,
+ .release_pte = xen_release_pte_init,
+ .alloc_pmd = xen_alloc_pmd_init,
+ .alloc_pmd_clone = paravirt_nop,
+ .release_pmd = xen_release_pmd_init,
+
+#ifdef CONFIG_X86_64
+ .set_pte = xen_set_pte,
+#else
+ .set_pte = xen_set_pte_init,
+#endif
+ .set_pte_at = xen_set_pte_at,
+ .set_pmd = xen_set_pmd_hyper,
+
+ .ptep_modify_prot_start = __ptep_modify_prot_start,
+ .ptep_modify_prot_commit = __ptep_modify_prot_commit,
+
+ .pte_val = PV_CALLEE_SAVE(xen_pte_val),
+ .pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
+
+ .make_pte = PV_CALLEE_SAVE(xen_make_pte),
+ .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
+
+#ifdef CONFIG_X86_PAE
+ .set_pte_atomic = xen_set_pte_atomic,
+ .pte_clear = xen_pte_clear,
+ .pmd_clear = xen_pmd_clear,
+#endif /* CONFIG_X86_PAE */
+ .set_pud = xen_set_pud_hyper,
+
+ .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
+ .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
+
+#if PAGETABLE_LEVELS == 4
+ .pud_val = PV_CALLEE_SAVE(xen_pud_val),
+ .make_pud = PV_CALLEE_SAVE(xen_make_pud),
+ .set_pgd = xen_set_pgd_hyper,
+
+ .alloc_pud = xen_alloc_pmd_init,
+ .release_pud = xen_release_pmd_init,
+#endif /* PAGETABLE_LEVELS == 4 */
+
+ .activate_mm = xen_activate_mm,
+ .dup_mmap = xen_dup_mmap,
+ .exit_mmap = xen_exit_mmap,
+
+ .lazy_mode = {
+ .enter = paravirt_enter_lazy_mmu,
+ .leave = xen_leave_lazy_mmu,
+ },
+
+ .set_fixmap = xen_set_fixmap,
+};
+
+void __init xen_init_mmu_ops(void)
+{
+ x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start;
+ x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done;
+ pv_mmu_ops = xen_mmu_ops;
+}
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct dentry *d_mmu_debug;
+
+static int __init xen_mmu_debugfs(void)
+{
+ struct dentry *d_xen = xen_init_debugfs();
+
+ if (d_xen == NULL)
+ return -ENOMEM;
+
+ d_mmu_debug = debugfs_create_dir("mmu", d_xen);
+
+ debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);
+
+ debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
+ debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
+ &mmu_stats.pgd_update_pinned);
+ debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
+ &mmu_stats.pgd_update_pinned);
+
+ debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
+ debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
+ &mmu_stats.pud_update_pinned);
+ debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
+ &mmu_stats.pud_update_pinned);
+
+ debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
+ debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
+ &mmu_stats.pmd_update_pinned);
+ debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
+ &mmu_stats.pmd_update_pinned);
+
+ debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
+// debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
+// &mmu_stats.pte_update_pinned);
+ debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
+ &mmu_stats.pte_update_pinned);
+
+ debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
+ debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
+ &mmu_stats.mmu_update_extended);
+ xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
+ mmu_stats.mmu_update_histo, 20);
+
+ debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
+ debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
+ &mmu_stats.set_pte_at_batched);
+ debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
+ &mmu_stats.set_pte_at_current);
+ debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
+ &mmu_stats.set_pte_at_kernel);
+
+ debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
+ debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
+ &mmu_stats.prot_commit_batched);
+
+ return 0;
+}
+fs_initcall(xen_mmu_debugfs);
+
+#endif /* CONFIG_XEN_DEBUG_FS */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff