linux/arch/powerpc/include/asm/kvm_book3s_64.h
Paul Mackerras a1b4a0f606 KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes
At present, the code that determines whether a HPT entry has changed,
and thus needs to be sent to userspace when it is copying the HPT,
doesn't consider a hardware update to the reference and change bits
(R and C) in the HPT entries to constitute a change that needs to
be sent to userspace.  This adds code to check for changes in R and C
when we are scanning the HPT to find changed entries, and adds code
to set the changed flag for the HPTE when we update the R and C bits
in the guest view of the HPTE.

Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c
as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification()
function into kvm_book3s_64.h.

Current Linux guest kernels don't use the hardware updates of R and C
in the HPT, so this change won't affect them.  Linux (or other) kernels
might in future want to use the R and C bits and have them correctly
transferred across when a guest is migrated, so it is better to correct
this deficiency.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26 20:27:12 +02:00

285 lines
7.1 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2010
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#ifndef __ASM_KVM_BOOK3S_64_H__
#define __ASM_KVM_BOOK3S_64_H__
#ifdef CONFIG_KVM_BOOK3S_PR
static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)
{
preempt_disable();
return &get_paca()->shadow_vcpu;
}
static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
{
preempt_enable();
}
#endif
#define SPAPR_TCE_SHIFT 12
#ifdef CONFIG_KVM_BOOK3S_64_HV
#define KVM_DEFAULT_HPT_ORDER 24 /* 16MB HPT by default */
extern int kvm_hpt_order; /* order of preallocated HPTs */
#endif
#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
/*
* We use a lock bit in HPTE dword 0 to synchronize updates and
* accesses to each HPTE, and another bit to indicate non-present
* HPTEs.
*/
#define HPTE_V_HVLOCK 0x40UL
#define HPTE_V_ABSENT 0x20UL
/*
* We use this bit in the guest_rpte field of the revmap entry
* to indicate a modified HPTE.
*/
#define HPTE_GR_MODIFIED (1ul << 62)
/* These bits are reserved in the guest view of the HPTE */
#define HPTE_GR_RESERVED HPTE_GR_MODIFIED
static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
{
unsigned long tmp, old;
asm volatile(" ldarx %0,0,%2\n"
" and. %1,%0,%3\n"
" bne 2f\n"
" ori %0,%0,%4\n"
" stdcx. %0,0,%2\n"
" beq+ 2f\n"
" mr %1,%3\n"
"2: isync"
: "=&r" (tmp), "=&r" (old)
: "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK)
: "cc", "memory");
return old == 0;
}
static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
unsigned long pte_index)
{
unsigned long rb, va_low;
rb = (v & ~0x7fUL) << 16; /* AVA field */
va_low = pte_index >> 3;
if (v & HPTE_V_SECONDARY)
va_low = ~va_low;
/* xor vsid from AVA */
if (!(v & HPTE_V_1TB_SEG))
va_low ^= v >> 12;
else
va_low ^= v >> 24;
va_low &= 0x7ff;
if (v & HPTE_V_LARGE) {
rb |= 1; /* L field */
if (cpu_has_feature(CPU_FTR_ARCH_206) &&
(r & 0xff000)) {
/* non-16MB large page, must be 64k */
/* (masks depend on page size) */
rb |= 0x1000; /* page encoding in LP field */
rb |= (va_low & 0x7f) << 16; /* 7b of VA in AVA/LP field */
rb |= (va_low & 0xfe); /* AVAL field (P7 doesn't seem to care) */
}
} else {
/* 4kB page */
rb |= (va_low & 0x7ff) << 12; /* remaining 11b of VA */
}
rb |= (v >> 54) & 0x300; /* B field */
return rb;
}
static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
{
/* only handle 4k, 64k and 16M pages for now */
if (!(h & HPTE_V_LARGE))
return 1ul << 12; /* 4k page */
if ((l & 0xf000) == 0x1000 && cpu_has_feature(CPU_FTR_ARCH_206))
return 1ul << 16; /* 64k page */
if ((l & 0xff000) == 0)
return 1ul << 24; /* 16M page */
return 0; /* error */
}
static inline unsigned long hpte_rpn(unsigned long ptel, unsigned long psize)
{
return ((ptel & HPTE_R_RPN) & ~(psize - 1)) >> PAGE_SHIFT;
}
static inline int hpte_is_writable(unsigned long ptel)
{
unsigned long pp = ptel & (HPTE_R_PP0 | HPTE_R_PP);
return pp != PP_RXRX && pp != PP_RXXX;
}
static inline unsigned long hpte_make_readonly(unsigned long ptel)
{
if ((ptel & HPTE_R_PP0) || (ptel & HPTE_R_PP) == PP_RWXX)
ptel = (ptel & ~HPTE_R_PP) | PP_RXXX;
else
ptel |= PP_RXRX;
return ptel;
}
static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
{
unsigned int wimg = ptel & HPTE_R_WIMG;
/* Handle SAO */
if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) &&
cpu_has_feature(CPU_FTR_ARCH_206))
wimg = HPTE_R_M;
if (!io_type)
return wimg == HPTE_R_M;
return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type;
}
/*
* Lock and read a linux PTE. If it's present and writable, atomically
* set dirty and referenced bits and return the PTE, otherwise return 0.
*/
static inline pte_t kvmppc_read_update_linux_pte(pte_t *p, int writing)
{
pte_t pte, tmp;
/* wait until _PAGE_BUSY is clear then set it atomically */
__asm__ __volatile__ (
"1: ldarx %0,0,%3\n"
" andi. %1,%0,%4\n"
" bne- 1b\n"
" ori %1,%0,%4\n"
" stdcx. %1,0,%3\n"
" bne- 1b"
: "=&r" (pte), "=&r" (tmp), "=m" (*p)
: "r" (p), "i" (_PAGE_BUSY)
: "cc");
if (pte_present(pte)) {
pte = pte_mkyoung(pte);
if (writing && pte_write(pte))
pte = pte_mkdirty(pte);
}
*p = pte; /* clears _PAGE_BUSY */
return pte;
}
/* Return HPTE cache control bits corresponding to Linux pte bits */
static inline unsigned long hpte_cache_bits(unsigned long pte_val)
{
#if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W
return pte_val & (HPTE_R_W | HPTE_R_I);
#else
return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) +
((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0);
#endif
}
static inline bool hpte_read_permission(unsigned long pp, unsigned long key)
{
if (key)
return PP_RWRX <= pp && pp <= PP_RXRX;
return 1;
}
static inline bool hpte_write_permission(unsigned long pp, unsigned long key)
{
if (key)
return pp == PP_RWRW;
return pp <= PP_RWRW;
}
static inline int hpte_get_skey_perm(unsigned long hpte_r, unsigned long amr)
{
unsigned long skey;
skey = ((hpte_r & HPTE_R_KEY_HI) >> 57) |
((hpte_r & HPTE_R_KEY_LO) >> 9);
return (amr >> (62 - 2 * skey)) & 3;
}
static inline void lock_rmap(unsigned long *rmap)
{
do {
while (test_bit(KVMPPC_RMAP_LOCK_BIT, rmap))
cpu_relax();
} while (test_and_set_bit_lock(KVMPPC_RMAP_LOCK_BIT, rmap));
}
static inline void unlock_rmap(unsigned long *rmap)
{
__clear_bit_unlock(KVMPPC_RMAP_LOCK_BIT, rmap);
}
static inline bool slot_is_aligned(struct kvm_memory_slot *memslot,
unsigned long pagesize)
{
unsigned long mask = (pagesize >> PAGE_SHIFT) - 1;
if (pagesize <= PAGE_SIZE)
return 1;
return !(memslot->base_gfn & mask) && !(memslot->npages & mask);
}
/*
* This works for 4k, 64k and 16M pages on POWER7,
* and 4k and 16M pages on PPC970.
*/
static inline unsigned long slb_pgsize_encoding(unsigned long psize)
{
unsigned long senc = 0;
if (psize > 0x1000) {
senc = SLB_VSID_L;
if (psize == 0x10000)
senc |= SLB_VSID_LP_01;
}
return senc;
}
static inline int is_vrma_hpte(unsigned long hpte_v)
{
return (hpte_v & ~0xffffffUL) ==
(HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)));
}
#ifdef CONFIG_KVM_BOOK3S_64_HV
/*
* Note modification of an HPTE; set the HPTE modified bit
* if anyone is interested.
*/
static inline void note_hpte_modification(struct kvm *kvm,
struct revmap_entry *rev)
{
if (atomic_read(&kvm->arch.hpte_mod_interest))
rev->guest_rpte |= HPTE_GR_MODIFIED;
}
#endif /* CONFIG_KVM_BOOK3S_64_HV */
#endif /* __ASM_KVM_BOOK3S_64_H__ */