/*
|
* Xen mmu operations
|
*
|
* This file contains the various mmu fetch and update operations.
|
* The most important job they must perform is the mapping between the
|
* domain's pfn and the overall machine mfns.
|
*
|
* Xen allows guests to directly update the pagetable, in a controlled
|
* fashion. In other words, the guest modifies the same pagetable
|
* that the CPU actually uses, which eliminates the overhead of having
|
* a separate shadow pagetable.
|
*
|
* In order to allow this, it falls on the guest domain to map its
|
* notion of a "physical" pfn - which is just a domain-local linear
|
* address - into a real "machine address" which the CPU's MMU can
|
* use.
|
*
|
* A pgd_t/pmd_t/pte_t will typically contain an mfn, and so can be
|
* inserted directly into the pagetable. When creating a new
|
* pte/pmd/pgd, it converts the passed pfn into an mfn. Conversely,
|
* when reading the content back with __(pgd|pmd|pte)_val, it converts
|
* the mfn back into a pfn.
|
*
|
* The other constraint is that all pages which make up a pagetable
|
* must be mapped read-only in the guest. This prevents uncontrolled
|
* guest updates to the pagetable. Xen strictly enforces this, and
|
* will disallow any pagetable update which will end up mapping a
|
* pagetable page RW, and will disallow using any writable page as a
|
* pagetable.
|
*
|
* Naively, when loading %cr3 with the base of a new pagetable, Xen
|
* would need to validate the whole pagetable before going on.
|
* Naturally, this is quite slow. The solution is to "pin" a
|
* pagetable, which enforces all the constraints on the pagetable even
|
* when it is not actively in use. This menas that Xen can be assured
|
* that it is still valid when you do load it into %cr3, and doesn't
|
* need to revalidate it.
|
*
|
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
|
*/
|
#include <linux/sched/mm.h>
|
#include <linux/highmem.h>
|
#include <linux/debugfs.h>
|
#include <linux/bug.h>
|
#include <linux/vmalloc.h>
|
#include <linux/export.h>
|
#include <linux/init.h>
|
#include <linux/gfp.h>
|
#include <linux/memblock.h>
|
#include <linux/seq_file.h>
|
#include <linux/crash_dump.h>
|
#ifdef CONFIG_KEXEC_CORE
|
#include <linux/kexec.h>
|
#endif
|
|
#include <trace/events/xen.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/e820/api.h>
|
#include <asm/linkage.h>
|
#include <asm/page.h>
|
#include <asm/init.h>
|
#include <asm/pat.h>
|
#include <asm/smp.h>
|
#include <asm/tlb.h>
|
|
#include <asm/xen/hypercall.h>
|
#include <asm/xen/hypervisor.h>
|
|
#include <xen/xen.h>
|
#include <xen/page.h>
|
#include <xen/interface/xen.h>
|
#include <xen/interface/hvm/hvm_op.h>
|
#include <xen/interface/version.h>
|
#include <xen/interface/memory.h>
|
#include <xen/hvc-console.h>
|
|
#include "multicalls.h"
|
#include "mmu.h"
|
#include "debugfs.h"
|
|
#ifdef CONFIG_X86_32
|
/*
|
* 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.
|
*/
|
#define LEVEL1_IDENT_ENTRIES (PTRS_PER_PTE * 4)
|
static RESERVE_BRK_ARRAY(pte_t, level1_ident_pgt, LEVEL1_IDENT_ENTRIES);
|
#endif
|
#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 */
|
|
static phys_addr_t xen_pt_base, xen_pt_size __initdata;
|
|
static DEFINE_STATIC_KEY_FALSE(xen_struct_pages_ready);
|
|
/*
|
* 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)
|
|
void make_lowmem_page_readonly(void *vaddr)
|
{
|
pte_t *pte, ptev;
|
unsigned long address = (unsigned long)vaddr;
|
unsigned int level;
|
|
pte = lookup_address(address, &level);
|
if (pte == NULL)
|
return; /* vaddr missing */
|
|
ptev = pte_wrprotect(*pte);
|
|
if (HYPERVISOR_update_va_mapping(address, ptev, 0))
|
BUG();
|
}
|
|
void make_lowmem_page_readwrite(void *vaddr)
|
{
|
pte_t *pte, ptev;
|
unsigned long address = (unsigned long)vaddr;
|
unsigned int level;
|
|
pte = lookup_address(address, &level);
|
if (pte == NULL)
|
return; /* vaddr missing */
|
|
ptev = pte_mkwrite(*pte);
|
|
if (HYPERVISOR_update_va_mapping(address, ptev, 0))
|
BUG();
|
}
|
|
|
/*
|
* During early boot all page table pages are pinned, but we do not have struct
|
* pages, so return true until struct pages are ready.
|
*/
|
static bool xen_page_pinned(void *ptr)
|
{
|
if (static_branch_likely(&xen_struct_pages_ready)) {
|
struct page *page = virt_to_page(ptr);
|
|
return PagePinned(page);
|
}
|
return true;
|
}
|
|
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) {
|
mcs.mc->args[1]++;
|
} else {
|
mcs = __xen_mc_entry(sizeof(*u));
|
MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
|
}
|
|
u = mcs.args;
|
*u = *update;
|
}
|
|
static void xen_extend_mmuext_op(const struct mmuext_op *op)
|
{
|
struct multicall_space mcs;
|
struct mmuext_op *u;
|
|
mcs = xen_mc_extend_args(__HYPERVISOR_mmuext_op, sizeof(*u));
|
|
if (mcs.mc != NULL) {
|
mcs.mc->args[1]++;
|
} else {
|
mcs = __xen_mc_entry(sizeof(*u));
|
MULTI_mmuext_op(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
|
}
|
|
u = mcs.args;
|
*u = *op;
|
}
|
|
static void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
|
{
|
struct mmu_update u;
|
|
preempt_disable();
|
|
xen_mc_batch();
|
|
/* ptr may be ioremapped for 64-bit pagetable setup */
|
u.ptr = arbitrary_virt_to_machine(ptr).maddr;
|
u.val = pmd_val_ma(val);
|
xen_extend_mmu_update(&u);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
preempt_enable();
|
}
|
|
static void xen_set_pmd(pmd_t *ptr, pmd_t val)
|
{
|
trace_xen_mmu_set_pmd(ptr, val);
|
|
/* If page is not pinned, we can just update the entry
|
directly */
|
if (!xen_page_pinned(ptr)) {
|
*ptr = val;
|
return;
|
}
|
|
xen_set_pmd_hyper(ptr, val);
|
}
|
|
/*
|
* Associate a virtual page frame with a given physical page frame
|
* and protection flags for that frame.
|
*/
|
void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
|
{
|
set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
|
}
|
|
static bool xen_batched_set_pte(pte_t *ptep, pte_t pteval)
|
{
|
struct mmu_update u;
|
|
if (paravirt_get_lazy_mode() != PARAVIRT_LAZY_MMU)
|
return false;
|
|
xen_mc_batch();
|
|
u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE;
|
u.val = pte_val_ma(pteval);
|
xen_extend_mmu_update(&u);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
return true;
|
}
|
|
static inline void __xen_set_pte(pte_t *ptep, pte_t pteval)
|
{
|
if (!xen_batched_set_pte(ptep, pteval)) {
|
/*
|
* Could call native_set_pte() here and trap and
|
* emulate the PTE write but with 32-bit guests this
|
* needs two traps (one for each of the two 32-bit
|
* words in the PTE) so do one hypercall directly
|
* instead.
|
*/
|
struct mmu_update u;
|
|
u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE;
|
u.val = pte_val_ma(pteval);
|
HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF);
|
}
|
}
|
|
static void xen_set_pte(pte_t *ptep, pte_t pteval)
|
{
|
trace_xen_mmu_set_pte(ptep, pteval);
|
__xen_set_pte(ptep, pteval);
|
}
|
|
static void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
|
pte_t *ptep, pte_t pteval)
|
{
|
trace_xen_mmu_set_pte_at(mm, addr, ptep, pteval);
|
__xen_set_pte(ptep, pteval);
|
}
|
|
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 */
|
trace_xen_mmu_ptep_modify_prot_start(mm, addr, ptep, *ptep);
|
return *ptep;
|
}
|
|
void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
|
pte_t *ptep, pte_t pte)
|
{
|
struct mmu_update u;
|
|
trace_xen_mmu_ptep_modify_prot_commit(mm, addr, ptep, pte);
|
xen_mc_batch();
|
|
u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
|
u.val = pte_val_ma(pte);
|
xen_extend_mmu_update(&u);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
}
|
|
/* Assume pteval_t is equivalent to all the other *val_t types. */
|
static pteval_t pte_mfn_to_pfn(pteval_t val)
|
{
|
if (val & _PAGE_PRESENT) {
|
unsigned long mfn = (val & XEN_PTE_MFN_MASK) >> PAGE_SHIFT;
|
unsigned long pfn = mfn_to_pfn(mfn);
|
|
pteval_t flags = val & PTE_FLAGS_MASK;
|
if (unlikely(pfn == ~0))
|
val = flags & ~_PAGE_PRESENT;
|
else
|
val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
|
}
|
|
return val;
|
}
|
|
static pteval_t pte_pfn_to_mfn(pteval_t val)
|
{
|
if (val & _PAGE_PRESENT) {
|
unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
|
pteval_t flags = val & PTE_FLAGS_MASK;
|
unsigned long mfn;
|
|
mfn = __pfn_to_mfn(pfn);
|
|
/*
|
* If there's no mfn for the pfn, then just create an
|
* empty non-present pte. Unfortunately this loses
|
* information about the original pfn, so
|
* pte_mfn_to_pfn is asymmetric.
|
*/
|
if (unlikely(mfn == INVALID_P2M_ENTRY)) {
|
mfn = 0;
|
flags = 0;
|
} else
|
mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
|
val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
|
}
|
|
return val;
|
}
|
|
__visible pteval_t xen_pte_val(pte_t pte)
|
{
|
pteval_t pteval = pte.pte;
|
|
return pte_mfn_to_pfn(pteval);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
|
|
__visible pgdval_t xen_pgd_val(pgd_t pgd)
|
{
|
return pte_mfn_to_pfn(pgd.pgd);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
|
|
__visible 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);
|
|
__visible 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);
|
|
__visible pmdval_t xen_pmd_val(pmd_t pmd)
|
{
|
return pte_mfn_to_pfn(pmd.pmd);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
|
|
static void xen_set_pud_hyper(pud_t *ptr, pud_t val)
|
{
|
struct mmu_update u;
|
|
preempt_disable();
|
|
xen_mc_batch();
|
|
/* ptr may be ioremapped for 64-bit pagetable setup */
|
u.ptr = arbitrary_virt_to_machine(ptr).maddr;
|
u.val = pud_val_ma(val);
|
xen_extend_mmu_update(&u);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
preempt_enable();
|
}
|
|
static void xen_set_pud(pud_t *ptr, pud_t val)
|
{
|
trace_xen_mmu_set_pud(ptr, val);
|
|
/* If page is not pinned, we can just update the entry
|
directly */
|
if (!xen_page_pinned(ptr)) {
|
*ptr = val;
|
return;
|
}
|
|
xen_set_pud_hyper(ptr, val);
|
}
|
|
#ifdef CONFIG_X86_PAE
|
static void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
|
{
|
trace_xen_mmu_set_pte_atomic(ptep, pte);
|
__xen_set_pte(ptep, pte);
|
}
|
|
static void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
|
{
|
trace_xen_mmu_pte_clear(mm, addr, ptep);
|
__xen_set_pte(ptep, native_make_pte(0));
|
}
|
|
static void xen_pmd_clear(pmd_t *pmdp)
|
{
|
trace_xen_mmu_pmd_clear(pmdp);
|
set_pmd(pmdp, __pmd(0));
|
}
|
#endif /* CONFIG_X86_PAE */
|
|
__visible 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);
|
|
#ifdef CONFIG_X86_64
|
__visible pudval_t xen_pud_val(pud_t pud)
|
{
|
return pte_mfn_to_pfn(pud.pud);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
|
|
__visible 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);
|
|
static 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_p4d_hyper(p4d_t *ptr, p4d_t val)
|
{
|
struct mmu_update u;
|
|
u.ptr = virt_to_machine(ptr).maddr;
|
u.val = p4d_val_ma(val);
|
xen_extend_mmu_update(&u);
|
}
|
|
/*
|
* Raw hypercall-based set_p4d, 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
|
*/
|
static void __init xen_set_p4d_hyper(p4d_t *ptr, p4d_t val)
|
{
|
preempt_disable();
|
|
xen_mc_batch();
|
|
__xen_set_p4d_hyper(ptr, val);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
|
preempt_enable();
|
}
|
|
static void xen_set_p4d(p4d_t *ptr, p4d_t val)
|
{
|
pgd_t *user_ptr = xen_get_user_pgd((pgd_t *)ptr);
|
pgd_t pgd_val;
|
|
trace_xen_mmu_set_p4d(ptr, (p4d_t *)user_ptr, val);
|
|
/* 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));
|
pgd_val.pgd = p4d_val_ma(val);
|
*user_ptr = pgd_val;
|
}
|
return;
|
}
|
|
/* If it's pinned, then we can at least batch the kernel and
|
user updates together. */
|
xen_mc_batch();
|
|
__xen_set_p4d_hyper(ptr, val);
|
if (user_ptr)
|
__xen_set_p4d_hyper((p4d_t *)user_ptr, val);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
}
|
|
#if CONFIG_PGTABLE_LEVELS >= 5
|
__visible p4dval_t xen_p4d_val(p4d_t p4d)
|
{
|
return pte_mfn_to_pfn(p4d.p4d);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_p4d_val);
|
|
__visible p4d_t xen_make_p4d(p4dval_t p4d)
|
{
|
p4d = pte_pfn_to_mfn(p4d);
|
|
return native_make_p4d(p4d);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d);
|
#endif /* CONFIG_PGTABLE_LEVELS >= 5 */
|
#endif /* CONFIG_X86_64 */
|
|
static int xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd,
|
int (*func)(struct mm_struct *mm, struct page *, enum pt_level),
|
bool last, unsigned long limit)
|
{
|
int i, nr, flush = 0;
|
|
nr = last ? pmd_index(limit) + 1 : PTRS_PER_PMD;
|
for (i = 0; i < nr; i++) {
|
if (!pmd_none(pmd[i]))
|
flush |= (*func)(mm, pmd_page(pmd[i]), PT_PTE);
|
}
|
return flush;
|
}
|
|
static int xen_pud_walk(struct mm_struct *mm, pud_t *pud,
|
int (*func)(struct mm_struct *mm, struct page *, enum pt_level),
|
bool last, unsigned long limit)
|
{
|
int i, nr, flush = 0;
|
|
nr = last ? pud_index(limit) + 1 : PTRS_PER_PUD;
|
for (i = 0; i < nr; i++) {
|
pmd_t *pmd;
|
|
if (pud_none(pud[i]))
|
continue;
|
|
pmd = pmd_offset(&pud[i], 0);
|
if (PTRS_PER_PMD > 1)
|
flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
|
flush |= xen_pmd_walk(mm, pmd, func,
|
last && i == nr - 1, limit);
|
}
|
return flush;
|
}
|
|
static int xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d,
|
int (*func)(struct mm_struct *mm, struct page *, enum pt_level),
|
bool last, unsigned long limit)
|
{
|
int flush = 0;
|
pud_t *pud;
|
|
|
if (p4d_none(*p4d))
|
return flush;
|
|
pud = pud_offset(p4d, 0);
|
if (PTRS_PER_PUD > 1)
|
flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
|
flush |= xen_pud_walk(mm, pud, func, last, limit);
|
return flush;
|
}
|
|
/*
|
* (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 i, nr, flush = 0;
|
unsigned hole_low = 0, hole_high = 0;
|
|
/* The limit is the last byte to be touched */
|
limit--;
|
BUG_ON(limit >= FIXADDR_TOP);
|
|
#ifdef CONFIG_X86_64
|
/*
|
* 64-bit has a great big hole in the middle of the address
|
* space, which contains the Xen mappings.
|
*/
|
hole_low = pgd_index(GUARD_HOLE_BASE_ADDR);
|
hole_high = pgd_index(GUARD_HOLE_END_ADDR);
|
#endif
|
|
nr = pgd_index(limit) + 1;
|
for (i = 0; i < nr; i++) {
|
p4d_t *p4d;
|
|
if (i >= hole_low && i < hole_high)
|
continue;
|
|
if (pgd_none(pgd[i]))
|
continue;
|
|
p4d = p4d_offset(&pgd[i], 0);
|
flush |= xen_p4d_walk(mm, p4d, func, i == nr - 1, limit);
|
}
|
|
/* 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 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 USE_SPLIT_PTE_PTLOCKS
|
ptl = ptlock_ptr(page);
|
spin_lock_nest_lock(ptl, &mm->page_table_lock);
|
#endif
|
|
return ptl;
|
}
|
|
static void xen_pte_unlock(void *v)
|
{
|
spinlock_t *ptl = v;
|
spin_unlock(ptl);
|
}
|
|
static void xen_do_pin(unsigned level, unsigned long pfn)
|
{
|
struct mmuext_op op;
|
|
op.cmd = level;
|
op.arg1.mfn = pfn_to_mfn(pfn);
|
|
xen_extend_mmuext_op(&op);
|
}
|
|
static int xen_pin_page(struct mm_struct *mm, struct page *page,
|
enum pt_level level)
|
{
|
unsigned pgfl = TestSetPagePinned(page);
|
int flush;
|
|
if (pgfl)
|
flush = 0; /* already pinned */
|
else if (PageHighMem(page))
|
/* kmaps need flushing if we found an unpinned
|
highpage */
|
flush = 1;
|
else {
|
void *pt = lowmem_page_address(page);
|
unsigned long pfn = page_to_pfn(page);
|
struct multicall_space mcs = __xen_mc_entry(0);
|
spinlock_t *ptl;
|
|
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 = 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 (ptl) {
|
xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);
|
|
/* Queue a deferred unlock for when this batch
|
is completed. */
|
xen_mc_callback(xen_pte_unlock, ptl);
|
}
|
}
|
|
return flush;
|
}
|
|
/* 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. */
|
static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
|
{
|
trace_xen_mmu_pgd_pin(mm, pgd);
|
|
xen_mc_batch();
|
|
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)
|
{
|
struct page *page;
|
|
spin_lock(&pgd_lock);
|
|
list_for_each_entry(page, &pgd_list, lru) {
|
if (!PagePinned(page)) {
|
__xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
|
SetPageSavePinned(page);
|
}
|
}
|
|
spin_unlock(&pgd_lock);
|
}
|
|
static int __init xen_mark_pinned(struct mm_struct *mm, struct page *page,
|
enum pt_level level)
|
{
|
SetPagePinned(page);
|
return 0;
|
}
|
|
/*
|
* The init_mm pagetable is really pinned as soon as its created, but
|
* that's before we have page structures to store the bits. So do all
|
* the book-keeping now once struct pages for allocated pages are
|
* initialized. This happens only after free_all_bootmem() is called.
|
*/
|
static void __init xen_after_bootmem(void)
|
{
|
static_branch_enable(&xen_struct_pages_ready);
|
#ifdef CONFIG_X86_64
|
SetPagePinned(virt_to_page(level3_user_vsyscall));
|
#endif
|
xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
|
}
|
|
static int xen_unpin_page(struct mm_struct *mm, struct page *page,
|
enum pt_level level)
|
{
|
unsigned pgfl = TestClearPagePinned(page);
|
|
if (pgfl && !PageHighMem(page)) {
|
void *pt = lowmem_page_address(page);
|
unsigned long pfn = page_to_pfn(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 = xen_pte_lock(page, mm);
|
|
if (ptl)
|
xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
|
}
|
|
mcs = __xen_mc_entry(0);
|
|
MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
|
pfn_pte(pfn, PAGE_KERNEL),
|
level == PT_PGD ? UVMF_TLB_FLUSH : 0);
|
|
if (ptl) {
|
/* unlock when batch completed */
|
xen_mc_callback(xen_pte_unlock, ptl);
|
}
|
}
|
|
return 0; /* never need to flush on unpin */
|
}
|
|
/* Release a pagetables pages back as normal RW */
|
static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
|
{
|
trace_xen_mmu_pgd_unpin(mm, pgd);
|
|
xen_mc_batch();
|
|
xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
|
|
#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.
|
*/
|
void xen_mm_unpin_all(void)
|
{
|
struct page *page;
|
|
spin_lock(&pgd_lock);
|
|
list_for_each_entry(page, &pgd_list, lru) {
|
if (PageSavePinned(page)) {
|
BUG_ON(!PagePinned(page));
|
__xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
|
ClearPageSavePinned(page);
|
}
|
}
|
|
spin_unlock(&pgd_lock);
|
}
|
|
static void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
|
{
|
spin_lock(&next->page_table_lock);
|
xen_pgd_pin(next);
|
spin_unlock(&next->page_table_lock);
|
}
|
|
static void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
|
{
|
spin_lock(&mm->page_table_lock);
|
xen_pgd_pin(mm);
|
spin_unlock(&mm->page_table_lock);
|
}
|
|
static void drop_mm_ref_this_cpu(void *info)
|
{
|
struct mm_struct *mm = info;
|
|
if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm)
|
leave_mm(smp_processor_id());
|
|
/*
|
* If this cpu still has a stale cr3 reference, then make sure
|
* it has been flushed.
|
*/
|
if (this_cpu_read(xen_current_cr3) == __pa(mm->pgd))
|
xen_mc_flush();
|
}
|
|
#ifdef CONFIG_SMP
|
/*
|
* Another cpu may still have their %cr3 pointing at the pagetable, so
|
* we need to repoint it somewhere else before we can unpin it.
|
*/
|
static void xen_drop_mm_ref(struct mm_struct *mm)
|
{
|
cpumask_var_t mask;
|
unsigned cpu;
|
|
drop_mm_ref_this_cpu(mm);
|
|
/* Get the "official" set of cpus referring to our pagetable. */
|
if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
|
for_each_online_cpu(cpu) {
|
if (per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
|
continue;
|
smp_call_function_single(cpu, drop_mm_ref_this_cpu, mm, 1);
|
}
|
return;
|
}
|
|
/*
|
* 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
|
* its set of pending hypercalls yet. In this case, we can
|
* look at its actual current cr3 value, and force it to flush
|
* if needed.
|
*/
|
cpumask_clear(mask);
|
for_each_online_cpu(cpu) {
|
if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
|
cpumask_set_cpu(cpu, mask);
|
}
|
|
smp_call_function_many(mask, drop_mm_ref_this_cpu, mm, 1);
|
free_cpumask_var(mask);
|
}
|
#else
|
static void xen_drop_mm_ref(struct mm_struct *mm)
|
{
|
drop_mm_ref_this_cpu(mm);
|
}
|
#endif
|
|
/*
|
* While a process runs, Xen pins its pagetables, which means that the
|
* hypervisor forces it to be read-only, and it controls all updates
|
* to it. This means that all pagetable updates have to go via the
|
* hypervisor, which is moderately expensive.
|
*
|
* Since we're pulling the pagetable down, we switch to use init_mm,
|
* unpin old process pagetable and mark it all read-write, which
|
* allows further operations on it to be simple memory accesses.
|
*
|
* The only subtle point is that another CPU may be still using the
|
* pagetable because of lazy tlb flushing. This means we need need to
|
* switch all CPUs off this pagetable before we can unpin it.
|
*/
|
static void xen_exit_mmap(struct mm_struct *mm)
|
{
|
get_cpu(); /* make sure we don't move around */
|
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 (xen_page_pinned(mm->pgd))
|
xen_pgd_unpin(mm);
|
|
spin_unlock(&mm->page_table_lock);
|
}
|
|
static void xen_post_allocator_init(void);
|
|
static void __init 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();
|
}
|
|
#ifdef CONFIG_X86_64
|
static void __init xen_cleanhighmap(unsigned long vaddr,
|
unsigned long vaddr_end)
|
{
|
unsigned long kernel_end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
|
pmd_t *pmd = level2_kernel_pgt + pmd_index(vaddr);
|
|
/* NOTE: The loop is more greedy than the cleanup_highmap variant.
|
* We include the PMD passed in on _both_ boundaries. */
|
for (; vaddr <= vaddr_end && (pmd < (level2_kernel_pgt + PTRS_PER_PMD));
|
pmd++, vaddr += PMD_SIZE) {
|
if (pmd_none(*pmd))
|
continue;
|
if (vaddr < (unsigned long) _text || vaddr > kernel_end)
|
set_pmd(pmd, __pmd(0));
|
}
|
/* In case we did something silly, we should crash in this function
|
* instead of somewhere later and be confusing. */
|
xen_mc_flush();
|
}
|
|
/*
|
* Make a page range writeable and free it.
|
*/
|
static void __init xen_free_ro_pages(unsigned long paddr, unsigned long size)
|
{
|
void *vaddr = __va(paddr);
|
void *vaddr_end = vaddr + size;
|
|
for (; vaddr < vaddr_end; vaddr += PAGE_SIZE)
|
make_lowmem_page_readwrite(vaddr);
|
|
memblock_free(paddr, size);
|
}
|
|
static void __init xen_cleanmfnmap_free_pgtbl(void *pgtbl, bool unpin)
|
{
|
unsigned long pa = __pa(pgtbl) & PHYSICAL_PAGE_MASK;
|
|
if (unpin)
|
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(pa));
|
ClearPagePinned(virt_to_page(__va(pa)));
|
xen_free_ro_pages(pa, PAGE_SIZE);
|
}
|
|
static void __init xen_cleanmfnmap_pmd(pmd_t *pmd, bool unpin)
|
{
|
unsigned long pa;
|
pte_t *pte_tbl;
|
int i;
|
|
if (pmd_large(*pmd)) {
|
pa = pmd_val(*pmd) & PHYSICAL_PAGE_MASK;
|
xen_free_ro_pages(pa, PMD_SIZE);
|
return;
|
}
|
|
pte_tbl = pte_offset_kernel(pmd, 0);
|
for (i = 0; i < PTRS_PER_PTE; i++) {
|
if (pte_none(pte_tbl[i]))
|
continue;
|
pa = pte_pfn(pte_tbl[i]) << PAGE_SHIFT;
|
xen_free_ro_pages(pa, PAGE_SIZE);
|
}
|
set_pmd(pmd, __pmd(0));
|
xen_cleanmfnmap_free_pgtbl(pte_tbl, unpin);
|
}
|
|
static void __init xen_cleanmfnmap_pud(pud_t *pud, bool unpin)
|
{
|
unsigned long pa;
|
pmd_t *pmd_tbl;
|
int i;
|
|
if (pud_large(*pud)) {
|
pa = pud_val(*pud) & PHYSICAL_PAGE_MASK;
|
xen_free_ro_pages(pa, PUD_SIZE);
|
return;
|
}
|
|
pmd_tbl = pmd_offset(pud, 0);
|
for (i = 0; i < PTRS_PER_PMD; i++) {
|
if (pmd_none(pmd_tbl[i]))
|
continue;
|
xen_cleanmfnmap_pmd(pmd_tbl + i, unpin);
|
}
|
set_pud(pud, __pud(0));
|
xen_cleanmfnmap_free_pgtbl(pmd_tbl, unpin);
|
}
|
|
static void __init xen_cleanmfnmap_p4d(p4d_t *p4d, bool unpin)
|
{
|
unsigned long pa;
|
pud_t *pud_tbl;
|
int i;
|
|
if (p4d_large(*p4d)) {
|
pa = p4d_val(*p4d) & PHYSICAL_PAGE_MASK;
|
xen_free_ro_pages(pa, P4D_SIZE);
|
return;
|
}
|
|
pud_tbl = pud_offset(p4d, 0);
|
for (i = 0; i < PTRS_PER_PUD; i++) {
|
if (pud_none(pud_tbl[i]))
|
continue;
|
xen_cleanmfnmap_pud(pud_tbl + i, unpin);
|
}
|
set_p4d(p4d, __p4d(0));
|
xen_cleanmfnmap_free_pgtbl(pud_tbl, unpin);
|
}
|
|
/*
|
* Since it is well isolated we can (and since it is perhaps large we should)
|
* also free the page tables mapping the initial P->M table.
|
*/
|
static void __init xen_cleanmfnmap(unsigned long vaddr)
|
{
|
pgd_t *pgd;
|
p4d_t *p4d;
|
bool unpin;
|
|
unpin = (vaddr == 2 * PGDIR_SIZE);
|
vaddr &= PMD_MASK;
|
pgd = pgd_offset_k(vaddr);
|
p4d = p4d_offset(pgd, 0);
|
if (!p4d_none(*p4d))
|
xen_cleanmfnmap_p4d(p4d, unpin);
|
}
|
|
static void __init xen_pagetable_p2m_free(void)
|
{
|
unsigned long size;
|
unsigned long addr;
|
|
size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
|
|
/* No memory or already called. */
|
if ((unsigned long)xen_p2m_addr == xen_start_info->mfn_list)
|
return;
|
|
/* using __ka address and sticking INVALID_P2M_ENTRY! */
|
memset((void *)xen_start_info->mfn_list, 0xff, size);
|
|
addr = xen_start_info->mfn_list;
|
/*
|
* We could be in __ka space.
|
* We roundup to the PMD, which means that if anybody at this stage is
|
* using the __ka address of xen_start_info or
|
* xen_start_info->shared_info they are in going to crash. Fortunatly
|
* we have already revectored in xen_setup_kernel_pagetable.
|
*/
|
size = roundup(size, PMD_SIZE);
|
|
if (addr >= __START_KERNEL_map) {
|
xen_cleanhighmap(addr, addr + size);
|
size = PAGE_ALIGN(xen_start_info->nr_pages *
|
sizeof(unsigned long));
|
memblock_free(__pa(addr), size);
|
} else {
|
xen_cleanmfnmap(addr);
|
}
|
}
|
|
static void __init xen_pagetable_cleanhighmap(void)
|
{
|
unsigned long size;
|
unsigned long addr;
|
|
/* At this stage, cleanup_highmap has already cleaned __ka space
|
* from _brk_limit way up to the max_pfn_mapped (which is the end of
|
* the ramdisk). We continue on, erasing PMD entries that point to page
|
* tables - do note that they are accessible at this stage via __va.
|
* As Xen is aligning the memory end to a 4MB boundary, for good
|
* measure we also round up to PMD_SIZE * 2 - which means that if
|
* anybody is using __ka address to the initial boot-stack - and try
|
* to use it - they are going to crash. The xen_start_info has been
|
* taken care of already in xen_setup_kernel_pagetable. */
|
addr = xen_start_info->pt_base;
|
size = xen_start_info->nr_pt_frames * PAGE_SIZE;
|
|
xen_cleanhighmap(addr, roundup(addr + size, PMD_SIZE * 2));
|
xen_start_info->pt_base = (unsigned long)__va(__pa(xen_start_info->pt_base));
|
}
|
#endif
|
|
static void __init xen_pagetable_p2m_setup(void)
|
{
|
xen_vmalloc_p2m_tree();
|
|
#ifdef CONFIG_X86_64
|
xen_pagetable_p2m_free();
|
|
xen_pagetable_cleanhighmap();
|
#endif
|
/* And revector! Bye bye old array */
|
xen_start_info->mfn_list = (unsigned long)xen_p2m_addr;
|
}
|
|
static void __init xen_pagetable_init(void)
|
{
|
paging_init();
|
xen_post_allocator_init();
|
|
xen_pagetable_p2m_setup();
|
|
/* Allocate and initialize top and mid mfn levels for p2m structure */
|
xen_build_mfn_list_list();
|
|
/* Remap memory freed due to conflicts with E820 map */
|
xen_remap_memory();
|
xen_setup_mfn_list_list();
|
}
|
static void xen_write_cr2(unsigned long cr2)
|
{
|
this_cpu_read(xen_vcpu)->arch.cr2 = cr2;
|
}
|
|
static unsigned long xen_read_cr2(void)
|
{
|
return this_cpu_read(xen_vcpu)->arch.cr2;
|
}
|
|
unsigned long xen_read_cr2_direct(void)
|
{
|
return this_cpu_read(xen_vcpu_info.arch.cr2);
|
}
|
|
static noinline 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_one_user(unsigned long addr)
|
{
|
struct mmuext_op *op;
|
struct multicall_space mcs;
|
|
trace_xen_mmu_flush_tlb_one_user(addr);
|
|
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,
|
const struct flush_tlb_info *info)
|
{
|
struct {
|
struct mmuext_op op;
|
DECLARE_BITMAP(mask, NR_CPUS);
|
} *args;
|
struct multicall_space mcs;
|
const size_t mc_entry_size = sizeof(args->op) +
|
sizeof(args->mask[0]) * BITS_TO_LONGS(num_possible_cpus());
|
|
trace_xen_mmu_flush_tlb_others(cpus, info->mm, info->start, info->end);
|
|
if (cpumask_empty(cpus))
|
return; /* nothing to do */
|
|
mcs = xen_mc_entry(mc_entry_size);
|
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));
|
|
args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
|
if (info->end != TLB_FLUSH_ALL &&
|
(info->end - info->start) <= PAGE_SIZE) {
|
args->op.cmd = MMUEXT_INVLPG_MULTI;
|
args->op.arg1.linear_addr = info->start;
|
}
|
|
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 this_cpu_read(xen_cr3);
|
}
|
|
static void set_current_cr3(void *v)
|
{
|
this_cpu_write(xen_current_cr3, (unsigned long)v);
|
}
|
|
static void __xen_write_cr3(bool kernel, unsigned long cr3)
|
{
|
struct mmuext_op op;
|
unsigned long mfn;
|
|
trace_xen_mmu_write_cr3(kernel, cr3);
|
|
if (cr3)
|
mfn = pfn_to_mfn(PFN_DOWN(cr3));
|
else
|
mfn = 0;
|
|
WARN_ON(mfn == 0 && kernel);
|
|
op.cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
|
op.arg1.mfn = mfn;
|
|
xen_extend_mmuext_op(&op);
|
|
if (kernel) {
|
this_cpu_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 */
|
this_cpu_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 */
|
}
|
|
#ifdef CONFIG_X86_64
|
/*
|
* At the start of the day - when Xen launches a guest, it has already
|
* built pagetables for the guest. We diligently look over them
|
* in xen_setup_kernel_pagetable and graft as appropriate them in the
|
* init_top_pgt and its friends. Then when we are happy we load
|
* the new init_top_pgt - and continue on.
|
*
|
* The generic code starts (start_kernel) and 'init_mem_mapping' sets
|
* up the rest of the pagetables. When it has completed it loads the cr3.
|
* N.B. that baremetal would start at 'start_kernel' (and the early
|
* #PF handler would create bootstrap pagetables) - so we are running
|
* with the same assumptions as what to do when write_cr3 is executed
|
* at this point.
|
*
|
* Since there are no user-page tables at all, we have two variants
|
* of xen_write_cr3 - the early bootup (this one), and the late one
|
* (xen_write_cr3). The reason we have to do that is that in 64-bit
|
* the Linux kernel and user-space are both in ring 3 while the
|
* hypervisor is in ring 0.
|
*/
|
static void __init xen_write_cr3_init(unsigned long cr3)
|
{
|
BUG_ON(preemptible());
|
|
xen_mc_batch(); /* disables interrupts */
|
|
/* Update while interrupts are disabled, so its atomic with
|
respect to ipis */
|
this_cpu_write(xen_cr3, cr3);
|
|
__xen_write_cr3(true, cr3);
|
|
xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */
|
}
|
#endif
|
|
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) {
|
#ifdef CONFIG_X86_VSYSCALL_EMULATION
|
user_pgd[pgd_index(VSYSCALL_ADDR)] =
|
__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
|
#endif
|
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
|
}
|
|
/*
|
* Init-time set_pte while constructing initial pagetables, which
|
* doesn't allow RO page table pages to be remapped RW.
|
*
|
* If there is no MFN for this PFN then this page is initially
|
* ballooned out so clear the PTE (as in decrease_reservation() in
|
* drivers/xen/balloon.c).
|
*
|
* Many of these PTE updates are done on unpinned and writable pages
|
* and doing a hypercall for these is unnecessary and expensive. At
|
* this point it is not possible to tell if a page is pinned or not,
|
* so always write the PTE directly and rely on Xen trapping and
|
* emulating any updates as necessary.
|
*/
|
__visible pte_t xen_make_pte_init(pteval_t pte)
|
{
|
#ifdef CONFIG_X86_64
|
unsigned long pfn;
|
|
/*
|
* Pages belonging to the initial p2m list mapped outside the default
|
* address range must be mapped read-only. This region contains the
|
* page tables for mapping the p2m list, too, and page tables MUST be
|
* mapped read-only.
|
*/
|
pfn = (pte & PTE_PFN_MASK) >> PAGE_SHIFT;
|
if (xen_start_info->mfn_list < __START_KERNEL_map &&
|
pfn >= xen_start_info->first_p2m_pfn &&
|
pfn < xen_start_info->first_p2m_pfn + xen_start_info->nr_p2m_frames)
|
pte &= ~_PAGE_RW;
|
#endif
|
pte = pte_pfn_to_mfn(pte);
|
return native_make_pte(pte);
|
}
|
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_init);
|
|
static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
|
{
|
#ifdef CONFIG_X86_32
|
/* If there's an existing pte, then don't allow _PAGE_RW to be set */
|
if (pte_mfn(pte) != INVALID_P2M_ENTRY
|
&& pte_val_ma(*ptep) & _PAGE_PRESENT)
|
pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
|
pte_val_ma(pte));
|
#endif
|
__xen_set_pte(ptep, pte);
|
}
|
|
/* Early in boot, while setting up the initial pagetable, assume
|
everything is pinned. */
|
static void __init 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 void __init 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 void __init xen_release_pte_init(unsigned long pfn)
|
{
|
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
|
make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
|
}
|
|
static void __init xen_release_pmd_init(unsigned long pfn)
|
{
|
make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
|
}
|
|
static inline void __pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
|
{
|
struct multicall_space mcs;
|
struct mmuext_op *op;
|
|
mcs = __xen_mc_entry(sizeof(*op));
|
op = mcs.args;
|
op->cmd = cmd;
|
op->arg1.mfn = pfn_to_mfn(pfn);
|
|
MULTI_mmuext_op(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
|
}
|
|
static inline void __set_pfn_prot(unsigned long pfn, pgprot_t prot)
|
{
|
struct multicall_space mcs;
|
unsigned long addr = (unsigned long)__va(pfn << PAGE_SHIFT);
|
|
mcs = __xen_mc_entry(0);
|
MULTI_update_va_mapping(mcs.mc, (unsigned long)addr,
|
pfn_pte(pfn, prot), 0);
|
}
|
|
/* This needs to make sure the new pte page is pinned iff its being
|
attached to a pinned pagetable. */
|
static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn,
|
unsigned level)
|
{
|
bool pinned = xen_page_pinned(mm->pgd);
|
|
trace_xen_mmu_alloc_ptpage(mm, pfn, level, pinned);
|
|
if (pinned) {
|
struct page *page = pfn_to_page(pfn);
|
|
if (static_branch_likely(&xen_struct_pages_ready))
|
SetPagePinned(page);
|
|
if (!PageHighMem(page)) {
|
xen_mc_batch();
|
|
__set_pfn_prot(pfn, PAGE_KERNEL_RO);
|
|
if (level == PT_PTE && USE_SPLIT_PTE_PTLOCKS)
|
__pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
} 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 inline void xen_release_ptpage(unsigned long pfn, unsigned level)
|
{
|
struct page *page = pfn_to_page(pfn);
|
bool pinned = PagePinned(page);
|
|
trace_xen_mmu_release_ptpage(pfn, level, pinned);
|
|
if (pinned) {
|
if (!PageHighMem(page)) {
|
xen_mc_batch();
|
|
if (level == PT_PTE && USE_SPLIT_PTE_PTLOCKS)
|
__pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
|
|
__set_pfn_prot(pfn, PAGE_KERNEL);
|
|
xen_mc_issue(PARAVIRT_LAZY_MMU);
|
}
|
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);
|
}
|
|
#ifdef CONFIG_X86_64
|
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 * __init __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 __init m2p(phys_addr_t maddr)
|
{
|
phys_addr_t paddr;
|
|
maddr &= XEN_PTE_MFN_MASK;
|
paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
|
|
return paddr;
|
}
|
|
/* Convert a machine address to kernel virtual */
|
static void * __init m2v(phys_addr_t maddr)
|
{
|
return __ka(m2p(maddr));
|
}
|
|
/* Set the page permissions on an identity-mapped pages */
|
static void __init set_page_prot_flags(void *addr, pgprot_t prot,
|
unsigned long flags)
|
{
|
unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
|
pte_t pte = pfn_pte(pfn, prot);
|
|
if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, flags))
|
BUG();
|
}
|
static void __init set_page_prot(void *addr, pgprot_t prot)
|
{
|
return set_page_prot_flags(addr, prot, UVMF_NONE);
|
}
|
#ifdef CONFIG_X86_32
|
static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
|
{
|
unsigned pmdidx, pteidx;
|
unsigned ident_pte;
|
unsigned long pfn;
|
|
level1_ident_pgt = extend_brk(sizeof(pte_t) * LEVEL1_IDENT_ENTRIES,
|
PAGE_SIZE);
|
|
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 == LEVEL1_IDENT_ENTRIES)
|
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);
|
}
|
#endif
|
void __init xen_setup_machphys_mapping(void)
|
{
|
struct xen_machphys_mapping mapping;
|
|
if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
|
machine_to_phys_mapping = (unsigned long *)mapping.v_start;
|
machine_to_phys_nr = mapping.max_mfn + 1;
|
} else {
|
machine_to_phys_nr = MACH2PHYS_NR_ENTRIES;
|
}
|
#ifdef CONFIG_X86_32
|
WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
|
< machine_to_phys_mapping);
|
#endif
|
}
|
|
#ifdef CONFIG_X86_64
|
static void __init 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);
|
}
|
static void __init check_pt_base(unsigned long *pt_base, unsigned long *pt_end,
|
unsigned long addr)
|
{
|
if (*pt_base == PFN_DOWN(__pa(addr))) {
|
set_page_prot_flags((void *)addr, PAGE_KERNEL, UVMF_INVLPG);
|
clear_page((void *)addr);
|
(*pt_base)++;
|
}
|
if (*pt_end == PFN_DOWN(__pa(addr))) {
|
set_page_prot_flags((void *)addr, PAGE_KERNEL, UVMF_INVLPG);
|
clear_page((void *)addr);
|
(*pt_end)--;
|
}
|
}
|
/*
|
* Set up the initial 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, and level2_kernel_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.
|
*/
|
void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
|
{
|
pud_t *l3;
|
pmd_t *l2;
|
unsigned long addr[3];
|
unsigned long pt_base, pt_end;
|
unsigned i;
|
|
/* max_pfn_mapped is the last pfn mapped in the initial memory
|
* mappings. Considering that on Xen after the kernel mappings we
|
* have the mappings of some pages that don't exist in pfn space, we
|
* set max_pfn_mapped to the last real pfn mapped. */
|
if (xen_start_info->mfn_list < __START_KERNEL_map)
|
max_pfn_mapped = xen_start_info->first_p2m_pfn;
|
else
|
max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->mfn_list));
|
|
pt_base = PFN_DOWN(__pa(xen_start_info->pt_base));
|
pt_end = pt_base + xen_start_info->nr_pt_frames;
|
|
/* Zap identity mapping */
|
init_top_pgt[0] = __pgd(0);
|
|
/* Pre-constructed entries are in pfn, so convert to mfn */
|
/* L4[273] -> level3_ident_pgt */
|
/* L4[511] -> level3_kernel_pgt */
|
convert_pfn_mfn(init_top_pgt);
|
|
/* L3_i[0] -> level2_ident_pgt */
|
convert_pfn_mfn(level3_ident_pgt);
|
/* L3_k[510] -> level2_kernel_pgt */
|
/* L3_k[511] -> level2_fixmap_pgt */
|
convert_pfn_mfn(level3_kernel_pgt);
|
|
/* L3_k[511][508-FIXMAP_PMD_NUM ... 507] -> level1_fixmap_pgt */
|
convert_pfn_mfn(level2_fixmap_pgt);
|
|
/* We get [511][511] and have Xen's version of level2_kernel_pgt */
|
l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
|
l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);
|
|
addr[0] = (unsigned long)pgd;
|
addr[1] = (unsigned long)l3;
|
addr[2] = (unsigned long)l2;
|
/* Graft it onto L4[273][0]. Note that we creating an aliasing problem:
|
* Both L4[273][0] and L4[511][510] have entries that point to the same
|
* L2 (PMD) tables. Meaning that if you modify it in __va space
|
* it will be also modified in the __ka space! (But if you just
|
* modify the PMD table to point to other PTE's or none, then you
|
* are OK - which is what cleanup_highmap does) */
|
copy_page(level2_ident_pgt, l2);
|
/* Graft it onto L4[511][510] */
|
copy_page(level2_kernel_pgt, l2);
|
|
/*
|
* Zap execute permission from the ident map. Due to the sharing of
|
* L1 entries we need to do this in the L2.
|
*/
|
if (__supported_pte_mask & _PAGE_NX) {
|
for (i = 0; i < PTRS_PER_PMD; ++i) {
|
if (pmd_none(level2_ident_pgt[i]))
|
continue;
|
level2_ident_pgt[i] = pmd_set_flags(level2_ident_pgt[i], _PAGE_NX);
|
}
|
}
|
|
/* Copy the initial P->M table mappings if necessary. */
|
i = pgd_index(xen_start_info->mfn_list);
|
if (i && i < pgd_index(__START_KERNEL_map))
|
init_top_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i];
|
|
/* Make pagetable pieces RO */
|
set_page_prot(init_top_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_ident_pgt, PAGE_KERNEL_RO);
|
set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
|
set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);
|
|
for (i = 0; i < FIXMAP_PMD_NUM; i++) {
|
set_page_prot(level1_fixmap_pgt + i * PTRS_PER_PTE,
|
PAGE_KERNEL_RO);
|
}
|
|
/* Pin down new L4 */
|
pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
|
PFN_DOWN(__pa_symbol(init_top_pgt)));
|
|
/* Unpin Xen-provided one */
|
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
|
|
/*
|
* 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(init_top_pgt));
|
xen_mc_issue(PARAVIRT_LAZY_CPU);
|
|
/* We can't that easily rip out L3 and L2, as the Xen pagetables are
|
* set out this way: [L4], [L1], [L2], [L3], [L1], [L1] ... for
|
* the initial domain. For guests using the toolstack, they are in:
|
* [L4], [L3], [L2], [L1], [L1], order .. So for dom0 we can only
|
* rip out the [L4] (pgd), but for guests we shave off three pages.
|
*/
|
for (i = 0; i < ARRAY_SIZE(addr); i++)
|
check_pt_base(&pt_base, &pt_end, addr[i]);
|
|
/* Our (by three pages) smaller Xen pagetable that we are using */
|
xen_pt_base = PFN_PHYS(pt_base);
|
xen_pt_size = (pt_end - pt_base) * PAGE_SIZE;
|
memblock_reserve(xen_pt_base, xen_pt_size);
|
|
/* Revector the xen_start_info */
|
xen_start_info = (struct start_info *)__va(__pa(xen_start_info));
|
}
|
|
/*
|
* Read a value from a physical address.
|
*/
|
static unsigned long __init xen_read_phys_ulong(phys_addr_t addr)
|
{
|
unsigned long *vaddr;
|
unsigned long val;
|
|
vaddr = early_memremap_ro(addr, sizeof(val));
|
val = *vaddr;
|
early_memunmap(vaddr, sizeof(val));
|
return val;
|
}
|
|
/*
|
* Translate a virtual address to a physical one without relying on mapped
|
* page tables. Don't rely on big pages being aligned in (guest) physical
|
* space!
|
*/
|
static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
|
{
|
phys_addr_t pa;
|
pgd_t pgd;
|
pud_t pud;
|
pmd_t pmd;
|
pte_t pte;
|
|
pa = read_cr3_pa();
|
pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) *
|
sizeof(pgd)));
|
if (!pgd_present(pgd))
|
return 0;
|
|
pa = pgd_val(pgd) & PTE_PFN_MASK;
|
pud = native_make_pud(xen_read_phys_ulong(pa + pud_index(vaddr) *
|
sizeof(pud)));
|
if (!pud_present(pud))
|
return 0;
|
pa = pud_val(pud) & PTE_PFN_MASK;
|
if (pud_large(pud))
|
return pa + (vaddr & ~PUD_MASK);
|
|
pmd = native_make_pmd(xen_read_phys_ulong(pa + pmd_index(vaddr) *
|
sizeof(pmd)));
|
if (!pmd_present(pmd))
|
return 0;
|
pa = pmd_val(pmd) & PTE_PFN_MASK;
|
if (pmd_large(pmd))
|
return pa + (vaddr & ~PMD_MASK);
|
|
pte = native_make_pte(xen_read_phys_ulong(pa + pte_index(vaddr) *
|
sizeof(pte)));
|
if (!pte_present(pte))
|
return 0;
|
pa = pte_pfn(pte) << PAGE_SHIFT;
|
|
return pa | (vaddr & ~PAGE_MASK);
|
}
|
|
/*
|
* Find a new area for the hypervisor supplied p2m list and relocate the p2m to
|
* this area.
|
*/
|
void __init xen_relocate_p2m(void)
|
{
|
phys_addr_t size, new_area, pt_phys, pmd_phys, pud_phys;
|
unsigned long p2m_pfn, p2m_pfn_end, n_frames, pfn, pfn_end;
|
int n_pte, n_pt, n_pmd, n_pud, idx_pte, idx_pt, idx_pmd, idx_pud;
|
pte_t *pt;
|
pmd_t *pmd;
|
pud_t *pud;
|
pgd_t *pgd;
|
unsigned long *new_p2m;
|
|
size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
|
n_pte = roundup(size, PAGE_SIZE) >> PAGE_SHIFT;
|
n_pt = roundup(size, PMD_SIZE) >> PMD_SHIFT;
|
n_pmd = roundup(size, PUD_SIZE) >> PUD_SHIFT;
|
n_pud = roundup(size, P4D_SIZE) >> P4D_SHIFT;
|
n_frames = n_pte + n_pt + n_pmd + n_pud;
|
|
new_area = xen_find_free_area(PFN_PHYS(n_frames));
|
if (!new_area) {
|
xen_raw_console_write("Can't find new memory area for p2m needed due to E820 map conflict\n");
|
BUG();
|
}
|
|
/*
|
* Setup the page tables for addressing the new p2m list.
|
* We have asked the hypervisor to map the p2m list at the user address
|
* PUD_SIZE. It may have done so, or it may have used a kernel space
|
* address depending on the Xen version.
|
* To avoid any possible virtual address collision, just use
|
* 2 * PUD_SIZE for the new area.
|
*/
|
pud_phys = new_area;
|
pmd_phys = pud_phys + PFN_PHYS(n_pud);
|
pt_phys = pmd_phys + PFN_PHYS(n_pmd);
|
p2m_pfn = PFN_DOWN(pt_phys) + n_pt;
|
|
pgd = __va(read_cr3_pa());
|
new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
|
for (idx_pud = 0; idx_pud < n_pud; idx_pud++) {
|
pud = early_memremap(pud_phys, PAGE_SIZE);
|
clear_page(pud);
|
for (idx_pmd = 0; idx_pmd < min(n_pmd, PTRS_PER_PUD);
|
idx_pmd++) {
|
pmd = early_memremap(pmd_phys, PAGE_SIZE);
|
clear_page(pmd);
|
for (idx_pt = 0; idx_pt < min(n_pt, PTRS_PER_PMD);
|
idx_pt++) {
|
pt = early_memremap(pt_phys, PAGE_SIZE);
|
clear_page(pt);
|
for (idx_pte = 0;
|
idx_pte < min(n_pte, PTRS_PER_PTE);
|
idx_pte++) {
|
pt[idx_pte] = pfn_pte(p2m_pfn,
|
PAGE_KERNEL);
|
p2m_pfn++;
|
}
|
n_pte -= PTRS_PER_PTE;
|
early_memunmap(pt, PAGE_SIZE);
|
make_lowmem_page_readonly(__va(pt_phys));
|
pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE,
|
PFN_DOWN(pt_phys));
|
pmd[idx_pt] = __pmd(_PAGE_TABLE | pt_phys);
|
pt_phys += PAGE_SIZE;
|
}
|
n_pt -= PTRS_PER_PMD;
|
early_memunmap(pmd, PAGE_SIZE);
|
make_lowmem_page_readonly(__va(pmd_phys));
|
pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE,
|
PFN_DOWN(pmd_phys));
|
pud[idx_pmd] = __pud(_PAGE_TABLE | pmd_phys);
|
pmd_phys += PAGE_SIZE;
|
}
|
n_pmd -= PTRS_PER_PUD;
|
early_memunmap(pud, PAGE_SIZE);
|
make_lowmem_page_readonly(__va(pud_phys));
|
pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(pud_phys));
|
set_pgd(pgd + 2 + idx_pud, __pgd(_PAGE_TABLE | pud_phys));
|
pud_phys += PAGE_SIZE;
|
}
|
|
/* Now copy the old p2m info to the new area. */
|
memcpy(new_p2m, xen_p2m_addr, size);
|
xen_p2m_addr = new_p2m;
|
|
/* Release the old p2m list and set new list info. */
|
p2m_pfn = PFN_DOWN(xen_early_virt_to_phys(xen_start_info->mfn_list));
|
BUG_ON(!p2m_pfn);
|
p2m_pfn_end = p2m_pfn + PFN_DOWN(size);
|
|
if (xen_start_info->mfn_list < __START_KERNEL_map) {
|
pfn = xen_start_info->first_p2m_pfn;
|
pfn_end = xen_start_info->first_p2m_pfn +
|
xen_start_info->nr_p2m_frames;
|
set_pgd(pgd + 1, __pgd(0));
|
} else {
|
pfn = p2m_pfn;
|
pfn_end = p2m_pfn_end;
|
}
|
|
memblock_free(PFN_PHYS(pfn), PAGE_SIZE * (pfn_end - pfn));
|
while (pfn < pfn_end) {
|
if (pfn == p2m_pfn) {
|
pfn = p2m_pfn_end;
|
continue;
|
}
|
make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
|
pfn++;
|
}
|
|
xen_start_info->mfn_list = (unsigned long)xen_p2m_addr;
|
xen_start_info->first_p2m_pfn = PFN_DOWN(new_area);
|
xen_start_info->nr_p2m_frames = n_frames;
|
}
|
|
#else /* !CONFIG_X86_64 */
|
static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
|
static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);
|
RESERVE_BRK(fixup_kernel_pmd, PAGE_SIZE);
|
RESERVE_BRK(fixup_kernel_pte, PAGE_SIZE);
|
|
static void __init xen_write_cr3_init(unsigned long cr3)
|
{
|
unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
|
|
BUG_ON(read_cr3_pa() != __pa(initial_page_table));
|
BUG_ON(cr3 != __pa(swapper_pg_dir));
|
|
/*
|
* We are switching to swapper_pg_dir for the first time (from
|
* initial_page_table) and therefore need to mark that page
|
* read-only and then pin it.
|
*
|
* Xen disallows sharing of kernel PMDs for PAE
|
* guests. Therefore we must copy the kernel PMD from
|
* initial_page_table into a new kernel PMD to be used in
|
* swapper_pg_dir.
|
*/
|
swapper_kernel_pmd =
|
extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
|
copy_page(swapper_kernel_pmd, initial_kernel_pmd);
|
swapper_pg_dir[KERNEL_PGD_BOUNDARY] =
|
__pgd(__pa(swapper_kernel_pmd) | _PAGE_PRESENT);
|
set_page_prot(swapper_kernel_pmd, PAGE_KERNEL_RO);
|
|
set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
|
xen_write_cr3(cr3);
|
pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, pfn);
|
|
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,
|
PFN_DOWN(__pa(initial_page_table)));
|
set_page_prot(initial_page_table, PAGE_KERNEL);
|
set_page_prot(initial_kernel_pmd, PAGE_KERNEL);
|
|
pv_mmu_ops.write_cr3 = &xen_write_cr3;
|
}
|
|
/*
|
* For 32 bit domains xen_start_info->pt_base is the pgd address which might be
|
* not the first page table in the page table pool.
|
* Iterate through the initial page tables to find the real page table base.
|
*/
|
static phys_addr_t __init xen_find_pt_base(pmd_t *pmd)
|
{
|
phys_addr_t pt_base, paddr;
|
unsigned pmdidx;
|
|
pt_base = min(__pa(xen_start_info->pt_base), __pa(pmd));
|
|
for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++)
|
if (pmd_present(pmd[pmdidx]) && !pmd_large(pmd[pmdidx])) {
|
paddr = m2p(pmd[pmdidx].pmd);
|
pt_base = min(pt_base, paddr);
|
}
|
|
return pt_base;
|
}
|
|
void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
|
{
|
pmd_t *kernel_pmd;
|
|
kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
|
|
xen_pt_base = xen_find_pt_base(kernel_pmd);
|
xen_pt_size = xen_start_info->nr_pt_frames * PAGE_SIZE;
|
|
initial_kernel_pmd =
|
extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
|
|
max_pfn_mapped = PFN_DOWN(xen_pt_base + xen_pt_size + 512 * 1024);
|
|
copy_page(initial_kernel_pmd, kernel_pmd);
|
|
xen_map_identity_early(initial_kernel_pmd, max_pfn);
|
|
copy_page(initial_page_table, pgd);
|
initial_page_table[KERNEL_PGD_BOUNDARY] =
|
__pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
|
|
set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
|
set_page_prot(initial_page_table, PAGE_KERNEL_RO);
|
set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
|
|
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
|
|
pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
|
PFN_DOWN(__pa(initial_page_table)));
|
xen_write_cr3(__pa(initial_page_table));
|
|
memblock_reserve(xen_pt_base, xen_pt_size);
|
}
|
#endif /* CONFIG_X86_64 */
|
|
void __init xen_reserve_special_pages(void)
|
{
|
phys_addr_t paddr;
|
|
memblock_reserve(__pa(xen_start_info), PAGE_SIZE);
|
if (xen_start_info->store_mfn) {
|
paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->store_mfn));
|
memblock_reserve(paddr, PAGE_SIZE);
|
}
|
if (!xen_initial_domain()) {
|
paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->console.domU.mfn));
|
memblock_reserve(paddr, PAGE_SIZE);
|
}
|
}
|
|
void __init xen_pt_check_e820(void)
|
{
|
if (xen_is_e820_reserved(xen_pt_base, xen_pt_size)) {
|
xen_raw_console_write("Xen hypervisor allocated page table memory conflicts with E820 map\n");
|
BUG();
|
}
|
}
|
|
static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss;
|
|
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_32
|
case FIX_WP_TEST:
|
# ifdef CONFIG_HIGHMEM
|
case FIX_KMAP_BEGIN ... FIX_KMAP_END:
|
# endif
|
#elif defined(CONFIG_X86_VSYSCALL_EMULATION)
|
case VSYSCALL_PAGE:
|
#endif
|
case FIX_TEXT_POKE0:
|
case FIX_TEXT_POKE1:
|
/* All local page mappings */
|
pte = pfn_pte(phys, prot);
|
break;
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
case FIX_APIC_BASE: /* maps dummy local APIC */
|
pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
|
break;
|
#endif
|
|
#ifdef CONFIG_X86_IO_APIC
|
case FIX_IO_APIC_BASE_0 ... FIX_IO_APIC_BASE_END:
|
/*
|
* We just don't map the IO APIC - all access is via
|
* hypercalls. Keep the address in the pte for reference.
|
*/
|
pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
|
break;
|
#endif
|
|
case FIX_PARAVIRT_BOOTMAP:
|
/* This is an MFN, but it isn't an IO mapping from the
|
IO domain */
|
pte = mfn_pte(phys, prot);
|
break;
|
|
default:
|
/* By default, set_fixmap is used for hardware mappings */
|
pte = mfn_pte(phys, prot);
|
break;
|
}
|
|
__native_set_fixmap(idx, pte);
|
|
#ifdef CONFIG_X86_VSYSCALL_EMULATION
|
/* Replicate changes to map the vsyscall page into the user
|
pagetable vsyscall mapping. */
|
if (idx == VSYSCALL_PAGE) {
|
unsigned long vaddr = __fix_to_virt(idx);
|
set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
|
}
|
#endif
|
}
|
|
static void __init 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;
|
#ifdef CONFIG_X86_64
|
pv_mmu_ops.set_p4d = xen_set_p4d;
|
#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;
|
#ifdef CONFIG_X86_64
|
pv_mmu_ops.alloc_pud = xen_alloc_pud;
|
pv_mmu_ops.release_pud = xen_release_pud;
|
#endif
|
pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte);
|
|
#ifdef CONFIG_X86_64
|
pv_mmu_ops.write_cr3 = &xen_write_cr3;
|
#endif
|
}
|
|
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 __initconst = {
|
.read_cr2 = xen_read_cr2,
|
.write_cr2 = xen_write_cr2,
|
|
.read_cr3 = xen_read_cr3,
|
.write_cr3 = xen_write_cr3_init,
|
|
.flush_tlb_user = xen_flush_tlb,
|
.flush_tlb_kernel = xen_flush_tlb,
|
.flush_tlb_one_user = xen_flush_tlb_one_user,
|
.flush_tlb_others = xen_flush_tlb_others,
|
.tlb_remove_table = tlb_remove_table,
|
|
.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,
|
.release_pmd = xen_release_pmd_init,
|
|
.set_pte = xen_set_pte_init,
|
.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_init),
|
.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),
|
|
#ifdef CONFIG_X86_64
|
.pud_val = PV_CALLEE_SAVE(xen_pud_val),
|
.make_pud = PV_CALLEE_SAVE(xen_make_pud),
|
.set_p4d = xen_set_p4d_hyper,
|
|
.alloc_pud = xen_alloc_pmd_init,
|
.release_pud = xen_release_pmd_init,
|
|
#if CONFIG_PGTABLE_LEVELS >= 5
|
.p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
|
.make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
|
#endif
|
#endif /* CONFIG_X86_64 */
|
|
.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,
|
.flush = paravirt_flush_lazy_mmu,
|
},
|
|
.set_fixmap = xen_set_fixmap,
|
};
|
|
void __init xen_init_mmu_ops(void)
|
{
|
x86_init.paging.pagetable_init = xen_pagetable_init;
|
x86_init.hyper.init_after_bootmem = xen_after_bootmem;
|
|
pv_mmu_ops = xen_mmu_ops;
|
|
memset(dummy_mapping, 0xff, PAGE_SIZE);
|
}
|
|
/* Protected by xen_reservation_lock. */
|
#define MAX_CONTIG_ORDER 9 /* 2MB */
|
static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER];
|
|
#define VOID_PTE (mfn_pte(0, __pgprot(0)))
|
static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
|
unsigned long *in_frames,
|
unsigned long *out_frames)
|
{
|
int i;
|
struct multicall_space mcs;
|
|
xen_mc_batch();
|
for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) {
|
mcs = __xen_mc_entry(0);
|
|
if (in_frames)
|
in_frames[i] = virt_to_mfn(vaddr);
|
|
MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
|
__set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
|
|
if (out_frames)
|
out_frames[i] = virt_to_pfn(vaddr);
|
}
|
xen_mc_issue(0);
|
}
|
|
/*
|
* Update the pfn-to-mfn mappings for a virtual address range, either to
|
* point to an array of mfns, or contiguously from a single starting
|
* mfn.
|
*/
|
static void xen_remap_exchanged_ptes(unsigned long vaddr, int order,
|
unsigned long *mfns,
|
unsigned long first_mfn)
|
{
|
unsigned i, limit;
|
unsigned long mfn;
|
|
xen_mc_batch();
|
|
limit = 1u << order;
|
for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) {
|
struct multicall_space mcs;
|
unsigned flags;
|
|
mcs = __xen_mc_entry(0);
|
if (mfns)
|
mfn = mfns[i];
|
else
|
mfn = first_mfn + i;
|
|
if (i < (limit - 1))
|
flags = 0;
|
else {
|
if (order == 0)
|
flags = UVMF_INVLPG | UVMF_ALL;
|
else
|
flags = UVMF_TLB_FLUSH | UVMF_ALL;
|
}
|
|
MULTI_update_va_mapping(mcs.mc, vaddr,
|
mfn_pte(mfn, PAGE_KERNEL), flags);
|
|
set_phys_to_machine(virt_to_pfn(vaddr), mfn);
|
}
|
|
xen_mc_issue(0);
|
}
|
|
/*
|
* Perform the hypercall to exchange a region of our pfns to point to
|
* memory with the required contiguous alignment. Takes the pfns as
|
* input, and populates mfns as output.
|
*
|
* Returns a success code indicating whether the hypervisor was able to
|
* satisfy the request or not.
|
*/
|
static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
|
unsigned long *pfns_in,
|
unsigned long extents_out,
|
unsigned int order_out,
|
unsigned long *mfns_out,
|
unsigned int address_bits)
|
{
|
long rc;
|
int success;
|
|
struct xen_memory_exchange exchange = {
|
.in = {
|
.nr_extents = extents_in,
|
.extent_order = order_in,
|
.extent_start = pfns_in,
|
.domid = DOMID_SELF
|
},
|
.out = {
|
.nr_extents = extents_out,
|
.extent_order = order_out,
|
.extent_start = mfns_out,
|
.address_bits = address_bits,
|
.domid = DOMID_SELF
|
}
|
};
|
|
BUG_ON(extents_in << order_in != extents_out << order_out);
|
|
rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
|
success = (exchange.nr_exchanged == extents_in);
|
|
BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0)));
|
BUG_ON(success && (rc != 0));
|
|
return success;
|
}
|
|
int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
|
unsigned int address_bits,
|
dma_addr_t *dma_handle)
|
{
|
unsigned long *in_frames = discontig_frames, out_frame;
|
unsigned long flags;
|
int success;
|
unsigned long vstart = (unsigned long)phys_to_virt(pstart);
|
|
/*
|
* Currently an auto-translated guest will not perform I/O, nor will
|
* it require PAE page directories below 4GB. Therefore any calls to
|
* this function are redundant and can be ignored.
|
*/
|
|
if (unlikely(order > MAX_CONTIG_ORDER))
|
return -ENOMEM;
|
|
memset((void *) vstart, 0, PAGE_SIZE << order);
|
|
spin_lock_irqsave(&xen_reservation_lock, flags);
|
|
/* 1. Zap current PTEs, remembering MFNs. */
|
xen_zap_pfn_range(vstart, order, in_frames, NULL);
|
|
/* 2. Get a new contiguous memory extent. */
|
out_frame = virt_to_pfn(vstart);
|
success = xen_exchange_memory(1UL << order, 0, in_frames,
|
1, order, &out_frame,
|
address_bits);
|
|
/* 3. Map the new extent in place of old pages. */
|
if (success)
|
xen_remap_exchanged_ptes(vstart, order, NULL, out_frame);
|
else
|
xen_remap_exchanged_ptes(vstart, order, in_frames, 0);
|
|
spin_unlock_irqrestore(&xen_reservation_lock, flags);
|
|
*dma_handle = virt_to_machine(vstart).maddr;
|
return success ? 0 : -ENOMEM;
|
}
|
EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
|
|
void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
|
{
|
unsigned long *out_frames = discontig_frames, in_frame;
|
unsigned long flags;
|
int success;
|
unsigned long vstart;
|
|
if (unlikely(order > MAX_CONTIG_ORDER))
|
return;
|
|
vstart = (unsigned long)phys_to_virt(pstart);
|
memset((void *) vstart, 0, PAGE_SIZE << order);
|
|
spin_lock_irqsave(&xen_reservation_lock, flags);
|
|
/* 1. Find start MFN of contiguous extent. */
|
in_frame = virt_to_mfn(vstart);
|
|
/* 2. Zap current PTEs. */
|
xen_zap_pfn_range(vstart, order, NULL, out_frames);
|
|
/* 3. Do the exchange for non-contiguous MFNs. */
|
success = xen_exchange_memory(1, order, &in_frame, 1UL << order,
|
0, out_frames, 0);
|
|
/* 4. Map new pages in place of old pages. */
|
if (success)
|
xen_remap_exchanged_ptes(vstart, order, out_frames, 0);
|
else
|
xen_remap_exchanged_ptes(vstart, order, NULL, in_frame);
|
|
spin_unlock_irqrestore(&xen_reservation_lock, flags);
|
}
|
EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
|
|
#ifdef CONFIG_KEXEC_CORE
|
phys_addr_t paddr_vmcoreinfo_note(void)
|
{
|
if (xen_pv_domain())
|
return virt_to_machine(vmcoreinfo_note).maddr;
|
else
|
return __pa(vmcoreinfo_note);
|
}
|
#endif /* CONFIG_KEXEC_CORE */
|
