forked from Minki/linux
0cbe3e26ab
Patch series "NestMMU pte upgrade workaround for mprotect", v5.
We can upgrade pte access (R -> RW transition) via mprotect. We need to
make sure we follow the recommended pte update sequence as outlined in
commit bd5050e38a ("powerpc/mm/radix: Change pte relax sequence to
handle nest MMU hang") for such updates. This patch series does that.
This patch (of 5):
Some architectures may want to call flush_tlb_range from these helpers.
Link: http://lkml.kernel.org/r/20190116085035.29729-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1112 lines
28 KiB
C
1112 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2007, 2011
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/gfp.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/smp.h>
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/slab.h>
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#include <linux/swapops.h>
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#include <linux/sysctl.h>
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#include <linux/ksm.h>
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#include <linux/mman.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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#include <asm/page-states.h>
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static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, int nodat)
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{
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unsigned long opt, asce;
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if (MACHINE_HAS_TLB_GUEST) {
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opt = 0;
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asce = READ_ONCE(mm->context.gmap_asce);
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if (asce == 0UL || nodat)
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opt |= IPTE_NODAT;
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if (asce != -1UL) {
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asce = asce ? : mm->context.asce;
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opt |= IPTE_GUEST_ASCE;
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}
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__ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
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} else {
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__ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
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}
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}
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static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, int nodat)
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{
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unsigned long opt, asce;
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if (MACHINE_HAS_TLB_GUEST) {
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opt = 0;
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asce = READ_ONCE(mm->context.gmap_asce);
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if (asce == 0UL || nodat)
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opt |= IPTE_NODAT;
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if (asce != -1UL) {
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asce = asce ? : mm->context.asce;
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opt |= IPTE_GUEST_ASCE;
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}
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__ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
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} else {
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__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
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}
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}
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static inline pte_t ptep_flush_direct(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep,
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int nodat)
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{
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pte_t old;
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old = *ptep;
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if (unlikely(pte_val(old) & _PAGE_INVALID))
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return old;
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atomic_inc(&mm->context.flush_count);
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if (MACHINE_HAS_TLB_LC &&
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cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
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ptep_ipte_local(mm, addr, ptep, nodat);
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else
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ptep_ipte_global(mm, addr, ptep, nodat);
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atomic_dec(&mm->context.flush_count);
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return old;
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}
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static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep,
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int nodat)
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{
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pte_t old;
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old = *ptep;
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if (unlikely(pte_val(old) & _PAGE_INVALID))
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return old;
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atomic_inc(&mm->context.flush_count);
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if (cpumask_equal(&mm->context.cpu_attach_mask,
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cpumask_of(smp_processor_id()))) {
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pte_val(*ptep) |= _PAGE_INVALID;
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mm->context.flush_mm = 1;
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} else
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ptep_ipte_global(mm, addr, ptep, nodat);
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atomic_dec(&mm->context.flush_count);
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return old;
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}
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static inline pgste_t pgste_get_lock(pte_t *ptep)
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{
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unsigned long new = 0;
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#ifdef CONFIG_PGSTE
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unsigned long old;
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asm(
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" lg %0,%2\n"
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"0: lgr %1,%0\n"
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" nihh %0,0xff7f\n" /* clear PCL bit in old */
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" oihh %1,0x0080\n" /* set PCL bit in new */
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" csg %0,%1,%2\n"
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" jl 0b\n"
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: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
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: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
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#endif
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return __pgste(new);
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}
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static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
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{
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#ifdef CONFIG_PGSTE
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asm(
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" nihh %1,0xff7f\n" /* clear PCL bit */
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" stg %1,%0\n"
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: "=Q" (ptep[PTRS_PER_PTE])
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: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
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: "cc", "memory");
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#endif
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}
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static inline pgste_t pgste_get(pte_t *ptep)
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{
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unsigned long pgste = 0;
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#ifdef CONFIG_PGSTE
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pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
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#endif
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return __pgste(pgste);
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}
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static inline void pgste_set(pte_t *ptep, pgste_t pgste)
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{
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#ifdef CONFIG_PGSTE
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*(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
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#endif
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}
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static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
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struct mm_struct *mm)
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{
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#ifdef CONFIG_PGSTE
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unsigned long address, bits, skey;
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if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
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return pgste;
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address = pte_val(pte) & PAGE_MASK;
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skey = (unsigned long) page_get_storage_key(address);
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bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
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/* Transfer page changed & referenced bit to guest bits in pgste */
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pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
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/* Copy page access key and fetch protection bit to pgste */
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pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
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pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
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#endif
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return pgste;
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}
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static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
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struct mm_struct *mm)
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{
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#ifdef CONFIG_PGSTE
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unsigned long address;
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unsigned long nkey;
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if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
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return;
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VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
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address = pte_val(entry) & PAGE_MASK;
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/*
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* Set page access key and fetch protection bit from pgste.
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* The guest C/R information is still in the PGSTE, set real
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* key C/R to 0.
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*/
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nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
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nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
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page_set_storage_key(address, nkey, 0);
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#endif
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}
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static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
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{
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#ifdef CONFIG_PGSTE
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if ((pte_val(entry) & _PAGE_PRESENT) &&
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(pte_val(entry) & _PAGE_WRITE) &&
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!(pte_val(entry) & _PAGE_INVALID)) {
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if (!MACHINE_HAS_ESOP) {
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/*
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* Without enhanced suppression-on-protection force
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* the dirty bit on for all writable ptes.
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*/
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pte_val(entry) |= _PAGE_DIRTY;
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pte_val(entry) &= ~_PAGE_PROTECT;
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}
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if (!(pte_val(entry) & _PAGE_PROTECT))
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/* This pte allows write access, set user-dirty */
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pgste_val(pgste) |= PGSTE_UC_BIT;
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}
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#endif
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*ptep = entry;
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return pgste;
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}
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static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
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unsigned long addr,
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pte_t *ptep, pgste_t pgste)
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{
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#ifdef CONFIG_PGSTE
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unsigned long bits;
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bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
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if (bits) {
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pgste_val(pgste) ^= bits;
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ptep_notify(mm, addr, ptep, bits);
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}
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#endif
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return pgste;
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}
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static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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pgste_t pgste = __pgste(0);
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if (mm_has_pgste(mm)) {
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pgste = pgste_get_lock(ptep);
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pgste = pgste_pte_notify(mm, addr, ptep, pgste);
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}
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return pgste;
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}
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static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep,
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pgste_t pgste, pte_t old, pte_t new)
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{
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if (mm_has_pgste(mm)) {
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if (pte_val(old) & _PAGE_INVALID)
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pgste_set_key(ptep, pgste, new, mm);
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if (pte_val(new) & _PAGE_INVALID) {
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pgste = pgste_update_all(old, pgste, mm);
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if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
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_PGSTE_GPS_USAGE_UNUSED)
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pte_val(old) |= _PAGE_UNUSED;
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}
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pgste = pgste_set_pte(ptep, pgste, new);
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pgste_set_unlock(ptep, pgste);
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} else {
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*ptep = new;
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}
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return old;
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}
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pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t new)
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{
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pgste_t pgste;
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pte_t old;
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int nodat;
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preempt_disable();
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pgste = ptep_xchg_start(mm, addr, ptep);
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nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
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old = ptep_flush_direct(mm, addr, ptep, nodat);
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old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
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preempt_enable();
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return old;
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}
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EXPORT_SYMBOL(ptep_xchg_direct);
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pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t new)
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{
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pgste_t pgste;
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pte_t old;
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int nodat;
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preempt_disable();
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pgste = ptep_xchg_start(mm, addr, ptep);
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nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
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old = ptep_flush_lazy(mm, addr, ptep, nodat);
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old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
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preempt_enable();
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return old;
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}
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EXPORT_SYMBOL(ptep_xchg_lazy);
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pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
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pte_t *ptep)
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{
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pgste_t pgste;
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pte_t old;
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int nodat;
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struct mm_struct *mm = vma->vm_mm;
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preempt_disable();
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pgste = ptep_xchg_start(mm, addr, ptep);
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nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
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old = ptep_flush_lazy(mm, addr, ptep, nodat);
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if (mm_has_pgste(mm)) {
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pgste = pgste_update_all(old, pgste, mm);
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pgste_set(ptep, pgste);
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}
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return old;
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}
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void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
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pte_t *ptep, pte_t pte)
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{
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pgste_t pgste;
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struct mm_struct *mm = vma->vm_mm;
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if (!MACHINE_HAS_NX)
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pte_val(pte) &= ~_PAGE_NOEXEC;
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if (mm_has_pgste(mm)) {
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pgste = pgste_get(ptep);
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pgste_set_key(ptep, pgste, pte, mm);
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pgste = pgste_set_pte(ptep, pgste, pte);
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pgste_set_unlock(ptep, pgste);
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} else {
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*ptep = pte;
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}
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preempt_enable();
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}
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static inline void pmdp_idte_local(struct mm_struct *mm,
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unsigned long addr, pmd_t *pmdp)
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{
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if (MACHINE_HAS_TLB_GUEST)
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__pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
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mm->context.asce, IDTE_LOCAL);
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else
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__pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
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if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
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gmap_pmdp_idte_local(mm, addr);
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}
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static inline void pmdp_idte_global(struct mm_struct *mm,
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unsigned long addr, pmd_t *pmdp)
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{
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if (MACHINE_HAS_TLB_GUEST) {
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__pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
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mm->context.asce, IDTE_GLOBAL);
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if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
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gmap_pmdp_idte_global(mm, addr);
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} else if (MACHINE_HAS_IDTE) {
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__pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
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if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
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gmap_pmdp_idte_global(mm, addr);
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} else {
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__pmdp_csp(pmdp);
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if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
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gmap_pmdp_csp(mm, addr);
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}
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}
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static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
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unsigned long addr, pmd_t *pmdp)
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{
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pmd_t old;
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old = *pmdp;
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if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
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return old;
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atomic_inc(&mm->context.flush_count);
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if (MACHINE_HAS_TLB_LC &&
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cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
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pmdp_idte_local(mm, addr, pmdp);
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else
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pmdp_idte_global(mm, addr, pmdp);
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atomic_dec(&mm->context.flush_count);
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return old;
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}
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static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
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unsigned long addr, pmd_t *pmdp)
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{
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pmd_t old;
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old = *pmdp;
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if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
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return old;
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atomic_inc(&mm->context.flush_count);
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if (cpumask_equal(&mm->context.cpu_attach_mask,
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cpumask_of(smp_processor_id()))) {
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pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
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mm->context.flush_mm = 1;
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if (mm_has_pgste(mm))
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gmap_pmdp_invalidate(mm, addr);
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} else {
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pmdp_idte_global(mm, addr, pmdp);
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}
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atomic_dec(&mm->context.flush_count);
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return old;
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}
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static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
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{
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pgd_t *pgd;
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p4d_t *p4d;
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pud_t *pud;
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pmd_t *pmd;
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pgd = pgd_offset(mm, addr);
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p4d = p4d_alloc(mm, pgd, addr);
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if (!p4d)
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return NULL;
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pud = pud_alloc(mm, p4d, addr);
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if (!pud)
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return NULL;
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pmd = pmd_alloc(mm, pud, addr);
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return pmd;
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}
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pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
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pmd_t *pmdp, pmd_t new)
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{
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pmd_t old;
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preempt_disable();
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old = pmdp_flush_direct(mm, addr, pmdp);
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*pmdp = new;
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preempt_enable();
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return old;
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}
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EXPORT_SYMBOL(pmdp_xchg_direct);
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|
|
pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, pmd_t new)
|
|
{
|
|
pmd_t old;
|
|
|
|
preempt_disable();
|
|
old = pmdp_flush_lazy(mm, addr, pmdp);
|
|
*pmdp = new;
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(pmdp_xchg_lazy);
|
|
|
|
static inline void pudp_idte_local(struct mm_struct *mm,
|
|
unsigned long addr, pud_t *pudp)
|
|
{
|
|
if (MACHINE_HAS_TLB_GUEST)
|
|
__pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
|
|
mm->context.asce, IDTE_LOCAL);
|
|
else
|
|
__pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
|
|
}
|
|
|
|
static inline void pudp_idte_global(struct mm_struct *mm,
|
|
unsigned long addr, pud_t *pudp)
|
|
{
|
|
if (MACHINE_HAS_TLB_GUEST)
|
|
__pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
|
|
mm->context.asce, IDTE_GLOBAL);
|
|
else if (MACHINE_HAS_IDTE)
|
|
__pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
|
|
else
|
|
/*
|
|
* Invalid bit position is the same for pmd and pud, so we can
|
|
* re-use _pmd_csp() here
|
|
*/
|
|
__pmdp_csp((pmd_t *) pudp);
|
|
}
|
|
|
|
static inline pud_t pudp_flush_direct(struct mm_struct *mm,
|
|
unsigned long addr, pud_t *pudp)
|
|
{
|
|
pud_t old;
|
|
|
|
old = *pudp;
|
|
if (pud_val(old) & _REGION_ENTRY_INVALID)
|
|
return old;
|
|
atomic_inc(&mm->context.flush_count);
|
|
if (MACHINE_HAS_TLB_LC &&
|
|
cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
|
|
pudp_idte_local(mm, addr, pudp);
|
|
else
|
|
pudp_idte_global(mm, addr, pudp);
|
|
atomic_dec(&mm->context.flush_count);
|
|
return old;
|
|
}
|
|
|
|
pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
|
|
pud_t *pudp, pud_t new)
|
|
{
|
|
pud_t old;
|
|
|
|
preempt_disable();
|
|
old = pudp_flush_direct(mm, addr, pudp);
|
|
*pudp = new;
|
|
preempt_enable();
|
|
return old;
|
|
}
|
|
EXPORT_SYMBOL(pudp_xchg_direct);
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
|
|
pgtable_t pgtable)
|
|
{
|
|
struct list_head *lh = (struct list_head *) pgtable;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
|
|
/* FIFO */
|
|
if (!pmd_huge_pte(mm, pmdp))
|
|
INIT_LIST_HEAD(lh);
|
|
else
|
|
list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
|
|
pmd_huge_pte(mm, pmdp) = pgtable;
|
|
}
|
|
|
|
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
|
|
{
|
|
struct list_head *lh;
|
|
pgtable_t pgtable;
|
|
pte_t *ptep;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
|
|
/* FIFO */
|
|
pgtable = pmd_huge_pte(mm, pmdp);
|
|
lh = (struct list_head *) pgtable;
|
|
if (list_empty(lh))
|
|
pmd_huge_pte(mm, pmdp) = NULL;
|
|
else {
|
|
pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
|
|
list_del(lh);
|
|
}
|
|
ptep = (pte_t *) pgtable;
|
|
pte_val(*ptep) = _PAGE_INVALID;
|
|
ptep++;
|
|
pte_val(*ptep) = _PAGE_INVALID;
|
|
return pgtable;
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
#ifdef CONFIG_PGSTE
|
|
void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t entry)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
/* the mm_has_pgste() check is done in set_pte_at() */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
|
|
pgste_set_key(ptep, pgste, entry, mm);
|
|
pgste = pgste_set_pte(ptep, pgste, entry);
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) |= PGSTE_IN_BIT;
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
/**
|
|
* ptep_force_prot - change access rights of a locked pte
|
|
* @mm: pointer to the process mm_struct
|
|
* @addr: virtual address in the guest address space
|
|
* @ptep: pointer to the page table entry
|
|
* @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
|
|
* @bit: pgste bit to set (e.g. for notification)
|
|
*
|
|
* Returns 0 if the access rights were changed and -EAGAIN if the current
|
|
* and requested access rights are incompatible.
|
|
*/
|
|
int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, int prot, unsigned long bit)
|
|
{
|
|
pte_t entry;
|
|
pgste_t pgste;
|
|
int pte_i, pte_p, nodat;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
entry = *ptep;
|
|
/* Check pte entry after all locks have been acquired */
|
|
pte_i = pte_val(entry) & _PAGE_INVALID;
|
|
pte_p = pte_val(entry) & _PAGE_PROTECT;
|
|
if ((pte_i && (prot != PROT_NONE)) ||
|
|
(pte_p && (prot & PROT_WRITE))) {
|
|
pgste_set_unlock(ptep, pgste);
|
|
return -EAGAIN;
|
|
}
|
|
/* Change access rights and set pgste bit */
|
|
nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
|
|
if (prot == PROT_NONE && !pte_i) {
|
|
ptep_flush_direct(mm, addr, ptep, nodat);
|
|
pgste = pgste_update_all(entry, pgste, mm);
|
|
pte_val(entry) |= _PAGE_INVALID;
|
|
}
|
|
if (prot == PROT_READ && !pte_p) {
|
|
ptep_flush_direct(mm, addr, ptep, nodat);
|
|
pte_val(entry) &= ~_PAGE_INVALID;
|
|
pte_val(entry) |= _PAGE_PROTECT;
|
|
}
|
|
pgste_val(pgste) |= bit;
|
|
pgste = pgste_set_pte(ptep, pgste, entry);
|
|
pgste_set_unlock(ptep, pgste);
|
|
return 0;
|
|
}
|
|
|
|
int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
|
|
pte_t *sptep, pte_t *tptep, pte_t pte)
|
|
{
|
|
pgste_t spgste, tpgste;
|
|
pte_t spte, tpte;
|
|
int rc = -EAGAIN;
|
|
|
|
if (!(pte_val(*tptep) & _PAGE_INVALID))
|
|
return 0; /* already shadowed */
|
|
spgste = pgste_get_lock(sptep);
|
|
spte = *sptep;
|
|
if (!(pte_val(spte) & _PAGE_INVALID) &&
|
|
!((pte_val(spte) & _PAGE_PROTECT) &&
|
|
!(pte_val(pte) & _PAGE_PROTECT))) {
|
|
pgste_val(spgste) |= PGSTE_VSIE_BIT;
|
|
tpgste = pgste_get_lock(tptep);
|
|
pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
|
|
(pte_val(pte) & _PAGE_PROTECT);
|
|
/* don't touch the storage key - it belongs to parent pgste */
|
|
tpgste = pgste_set_pte(tptep, tpgste, tpte);
|
|
pgste_set_unlock(tptep, tpgste);
|
|
rc = 1;
|
|
}
|
|
pgste_set_unlock(sptep, spgste);
|
|
return rc;
|
|
}
|
|
|
|
void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
int nodat;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
/* notifier is called by the caller */
|
|
nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
|
|
ptep_flush_direct(mm, saddr, ptep, nodat);
|
|
/* don't touch the storage key - it belongs to parent pgste */
|
|
pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
|
|
pgste_set_unlock(ptep, pgste);
|
|
}
|
|
|
|
static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
|
|
{
|
|
if (!non_swap_entry(entry))
|
|
dec_mm_counter(mm, MM_SWAPENTS);
|
|
else if (is_migration_entry(entry)) {
|
|
struct page *page = migration_entry_to_page(entry);
|
|
|
|
dec_mm_counter(mm, mm_counter(page));
|
|
}
|
|
free_swap_and_cache(entry);
|
|
}
|
|
|
|
void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, int reset)
|
|
{
|
|
unsigned long pgstev;
|
|
pgste_t pgste;
|
|
pte_t pte;
|
|
|
|
/* Zap unused and logically-zero pages */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgstev = pgste_val(pgste);
|
|
pte = *ptep;
|
|
if (!reset && pte_swap(pte) &&
|
|
((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
|
|
(pgstev & _PGSTE_GPS_ZERO))) {
|
|
ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
|
|
pte_clear(mm, addr, ptep);
|
|
}
|
|
if (reset)
|
|
pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
|
|
{
|
|
unsigned long ptev;
|
|
pgste_t pgste;
|
|
|
|
/* Clear storage key ACC and F, but set R/C */
|
|
preempt_disable();
|
|
pgste = pgste_get_lock(ptep);
|
|
pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
|
|
pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
|
|
ptev = pte_val(*ptep);
|
|
if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
|
|
page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
|
|
pgste_set_unlock(ptep, pgste);
|
|
preempt_enable();
|
|
}
|
|
|
|
/*
|
|
* Test and reset if a guest page is dirty
|
|
*/
|
|
bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
pgste_t pgste;
|
|
pte_t pte;
|
|
bool dirty;
|
|
int nodat;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
|
|
pgste_val(pgste) &= ~PGSTE_UC_BIT;
|
|
pte = *ptep;
|
|
if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
|
|
pgste = pgste_pte_notify(mm, addr, ptep, pgste);
|
|
nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
|
|
ptep_ipte_global(mm, addr, ptep, nodat);
|
|
if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
|
|
pte_val(pte) |= _PAGE_PROTECT;
|
|
else
|
|
pte_val(pte) |= _PAGE_INVALID;
|
|
*ptep = pte;
|
|
}
|
|
pgste_set_unlock(ptep, pgste);
|
|
return dirty;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
|
|
|
|
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char key, bool nq)
|
|
{
|
|
unsigned long keyul, paddr;
|
|
spinlock_t *ptl;
|
|
pgste_t old, new;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep;
|
|
|
|
pmdp = pmd_alloc_map(mm, addr);
|
|
if (unlikely(!pmdp))
|
|
return -EFAULT;
|
|
|
|
ptl = pmd_lock(mm, pmdp);
|
|
if (!pmd_present(*pmdp)) {
|
|
spin_unlock(ptl);
|
|
return -EFAULT;
|
|
}
|
|
|
|
if (pmd_large(*pmdp)) {
|
|
paddr = pmd_val(*pmdp) & HPAGE_MASK;
|
|
paddr |= addr & ~HPAGE_MASK;
|
|
/*
|
|
* Huge pmds need quiescing operations, they are
|
|
* always mapped.
|
|
*/
|
|
page_set_storage_key(paddr, key, 1);
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
spin_unlock(ptl);
|
|
|
|
ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
new = old = pgste_get_lock(ptep);
|
|
pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
|
|
PGSTE_ACC_BITS | PGSTE_FP_BIT);
|
|
keyul = (unsigned long) key;
|
|
pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
|
|
pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
unsigned long bits, skey;
|
|
|
|
paddr = pte_val(*ptep) & PAGE_MASK;
|
|
skey = (unsigned long) page_get_storage_key(paddr);
|
|
bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
|
|
skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
|
|
/* Set storage key ACC and FP */
|
|
page_set_storage_key(paddr, skey, !nq);
|
|
/* Merge host changed & referenced into pgste */
|
|
pgste_val(new) |= bits << 52;
|
|
}
|
|
/* changing the guest storage key is considered a change of the page */
|
|
if ((pgste_val(new) ^ pgste_val(old)) &
|
|
(PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
|
|
pgste_val(new) |= PGSTE_UC_BIT;
|
|
|
|
pgste_set_unlock(ptep, new);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(set_guest_storage_key);
|
|
|
|
/**
|
|
* Conditionally set a guest storage key (handling csske).
|
|
* oldkey will be updated when either mr or mc is set and a pointer is given.
|
|
*
|
|
* Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
|
|
* storage key was updated and -EFAULT on access errors.
|
|
*/
|
|
int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char key, unsigned char *oldkey,
|
|
bool nq, bool mr, bool mc)
|
|
{
|
|
unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
|
|
int rc;
|
|
|
|
/* we can drop the pgste lock between getting and setting the key */
|
|
if (mr | mc) {
|
|
rc = get_guest_storage_key(current->mm, addr, &tmp);
|
|
if (rc)
|
|
return rc;
|
|
if (oldkey)
|
|
*oldkey = tmp;
|
|
if (!mr)
|
|
mask |= _PAGE_REFERENCED;
|
|
if (!mc)
|
|
mask |= _PAGE_CHANGED;
|
|
if (!((tmp ^ key) & mask))
|
|
return 0;
|
|
}
|
|
rc = set_guest_storage_key(current->mm, addr, key, nq);
|
|
return rc < 0 ? rc : 1;
|
|
}
|
|
EXPORT_SYMBOL(cond_set_guest_storage_key);
|
|
|
|
/**
|
|
* Reset a guest reference bit (rrbe), returning the reference and changed bit.
|
|
*
|
|
* Returns < 0 in case of error, otherwise the cc to be reported to the guest.
|
|
*/
|
|
int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
spinlock_t *ptl;
|
|
unsigned long paddr;
|
|
pgste_t old, new;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep;
|
|
int cc = 0;
|
|
|
|
pmdp = pmd_alloc_map(mm, addr);
|
|
if (unlikely(!pmdp))
|
|
return -EFAULT;
|
|
|
|
ptl = pmd_lock(mm, pmdp);
|
|
if (!pmd_present(*pmdp)) {
|
|
spin_unlock(ptl);
|
|
return -EFAULT;
|
|
}
|
|
|
|
if (pmd_large(*pmdp)) {
|
|
paddr = pmd_val(*pmdp) & HPAGE_MASK;
|
|
paddr |= addr & ~HPAGE_MASK;
|
|
cc = page_reset_referenced(paddr);
|
|
spin_unlock(ptl);
|
|
return cc;
|
|
}
|
|
spin_unlock(ptl);
|
|
|
|
ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
new = old = pgste_get_lock(ptep);
|
|
/* Reset guest reference bit only */
|
|
pgste_val(new) &= ~PGSTE_GR_BIT;
|
|
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
paddr = pte_val(*ptep) & PAGE_MASK;
|
|
cc = page_reset_referenced(paddr);
|
|
/* Merge real referenced bit into host-set */
|
|
pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
|
|
}
|
|
/* Reflect guest's logical view, not physical */
|
|
cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
|
|
/* Changing the guest storage key is considered a change of the page */
|
|
if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
|
|
pgste_val(new) |= PGSTE_UC_BIT;
|
|
|
|
pgste_set_unlock(ptep, new);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return cc;
|
|
}
|
|
EXPORT_SYMBOL(reset_guest_reference_bit);
|
|
|
|
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
|
|
unsigned char *key)
|
|
{
|
|
unsigned long paddr;
|
|
spinlock_t *ptl;
|
|
pgste_t pgste;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep;
|
|
|
|
pmdp = pmd_alloc_map(mm, addr);
|
|
if (unlikely(!pmdp))
|
|
return -EFAULT;
|
|
|
|
ptl = pmd_lock(mm, pmdp);
|
|
if (!pmd_present(*pmdp)) {
|
|
/* Not yet mapped memory has a zero key */
|
|
spin_unlock(ptl);
|
|
*key = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_large(*pmdp)) {
|
|
paddr = pmd_val(*pmdp) & HPAGE_MASK;
|
|
paddr |= addr & ~HPAGE_MASK;
|
|
*key = page_get_storage_key(paddr);
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
spin_unlock(ptl);
|
|
|
|
ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
|
|
pgste = pgste_get_lock(ptep);
|
|
*key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
|
|
paddr = pte_val(*ptep) & PAGE_MASK;
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID))
|
|
*key = page_get_storage_key(paddr);
|
|
/* Reflect guest's logical view, not physical */
|
|
*key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
|
|
pgste_set_unlock(ptep, pgste);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(get_guest_storage_key);
|
|
|
|
/**
|
|
* pgste_perform_essa - perform ESSA actions on the PGSTE.
|
|
* @mm: the memory context. It must have PGSTEs, no check is performed here!
|
|
* @hva: the host virtual address of the page whose PGSTE is to be processed
|
|
* @orc: the specific action to perform, see the ESSA_SET_* macros.
|
|
* @oldpte: the PTE will be saved there if the pointer is not NULL.
|
|
* @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
|
|
*
|
|
* Return: 1 if the page is to be added to the CBRL, otherwise 0,
|
|
* or < 0 in case of error. -EINVAL is returned for invalid values
|
|
* of orc, -EFAULT for invalid addresses.
|
|
*/
|
|
int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
|
|
unsigned long *oldpte, unsigned long *oldpgste)
|
|
{
|
|
unsigned long pgstev;
|
|
spinlock_t *ptl;
|
|
pgste_t pgste;
|
|
pte_t *ptep;
|
|
int res = 0;
|
|
|
|
WARN_ON_ONCE(orc > ESSA_MAX);
|
|
if (unlikely(orc > ESSA_MAX))
|
|
return -EINVAL;
|
|
ptep = get_locked_pte(mm, hva, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
pgste = pgste_get_lock(ptep);
|
|
pgstev = pgste_val(pgste);
|
|
if (oldpte)
|
|
*oldpte = pte_val(*ptep);
|
|
if (oldpgste)
|
|
*oldpgste = pgstev;
|
|
|
|
switch (orc) {
|
|
case ESSA_GET_STATE:
|
|
break;
|
|
case ESSA_SET_STABLE:
|
|
pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
|
|
pgstev |= _PGSTE_GPS_USAGE_STABLE;
|
|
break;
|
|
case ESSA_SET_UNUSED:
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgstev |= _PGSTE_GPS_USAGE_UNUSED;
|
|
if (pte_val(*ptep) & _PAGE_INVALID)
|
|
res = 1;
|
|
break;
|
|
case ESSA_SET_VOLATILE:
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
|
|
if (pte_val(*ptep) & _PAGE_INVALID)
|
|
res = 1;
|
|
break;
|
|
case ESSA_SET_POT_VOLATILE:
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
|
|
break;
|
|
}
|
|
if (pgstev & _PGSTE_GPS_ZERO) {
|
|
pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
|
|
break;
|
|
}
|
|
if (!(pgstev & PGSTE_GC_BIT)) {
|
|
pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
|
|
res = 1;
|
|
break;
|
|
}
|
|
break;
|
|
case ESSA_SET_STABLE_RESIDENT:
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgstev |= _PGSTE_GPS_USAGE_STABLE;
|
|
/*
|
|
* Since the resident state can go away any time after this
|
|
* call, we will not make this page resident. We can revisit
|
|
* this decision if a guest will ever start using this.
|
|
*/
|
|
break;
|
|
case ESSA_SET_STABLE_IF_RESIDENT:
|
|
if (!(pte_val(*ptep) & _PAGE_INVALID)) {
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgstev |= _PGSTE_GPS_USAGE_STABLE;
|
|
}
|
|
break;
|
|
case ESSA_SET_STABLE_NODAT:
|
|
pgstev &= ~_PGSTE_GPS_USAGE_MASK;
|
|
pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
|
|
break;
|
|
default:
|
|
/* we should never get here! */
|
|
break;
|
|
}
|
|
/* If we are discarding a page, set it to logical zero */
|
|
if (res)
|
|
pgstev |= _PGSTE_GPS_ZERO;
|
|
|
|
pgste_val(pgste) = pgstev;
|
|
pgste_set_unlock(ptep, pgste);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(pgste_perform_essa);
|
|
|
|
/**
|
|
* set_pgste_bits - set specific PGSTE bits.
|
|
* @mm: the memory context. It must have PGSTEs, no check is performed here!
|
|
* @hva: the host virtual address of the page whose PGSTE is to be processed
|
|
* @bits: a bitmask representing the bits that will be touched
|
|
* @value: the values of the bits to be written. Only the bits in the mask
|
|
* will be written.
|
|
*
|
|
* Return: 0 on success, < 0 in case of error.
|
|
*/
|
|
int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
|
|
unsigned long bits, unsigned long value)
|
|
{
|
|
spinlock_t *ptl;
|
|
pgste_t new;
|
|
pte_t *ptep;
|
|
|
|
ptep = get_locked_pte(mm, hva, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
new = pgste_get_lock(ptep);
|
|
|
|
pgste_val(new) &= ~bits;
|
|
pgste_val(new) |= value & bits;
|
|
|
|
pgste_set_unlock(ptep, new);
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(set_pgste_bits);
|
|
|
|
/**
|
|
* get_pgste - get the current PGSTE for the given address.
|
|
* @mm: the memory context. It must have PGSTEs, no check is performed here!
|
|
* @hva: the host virtual address of the page whose PGSTE is to be processed
|
|
* @pgstep: will be written with the current PGSTE for the given address.
|
|
*
|
|
* Return: 0 on success, < 0 in case of error.
|
|
*/
|
|
int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
|
|
{
|
|
spinlock_t *ptl;
|
|
pte_t *ptep;
|
|
|
|
ptep = get_locked_pte(mm, hva, &ptl);
|
|
if (unlikely(!ptep))
|
|
return -EFAULT;
|
|
*pgstep = pgste_val(pgste_get(ptep));
|
|
pte_unmap_unlock(ptep, ptl);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(get_pgste);
|
|
#endif
|