- 根目录:
- arch
- powerpc
- kvm
- 44x_tlb.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 IBM Corp. 2007
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <asm/tlbflush.h>
#include <asm/mmu-44x.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_44x.h>
#include "timing.h"
#include "44x_tlb.h"
#include "trace.h"
#ifndef PPC44x_TLBE_SIZE
#define PPC44x_TLBE_SIZE PPC44x_TLB_4K
#endif
#define PAGE_SIZE_4K (1<<12)
#define PAGE_MASK_4K (~(PAGE_SIZE_4K - 1))
#define PPC44x_TLB_UATTR_MASK \
(PPC44x_TLB_U0|PPC44x_TLB_U1|PPC44x_TLB_U2|PPC44x_TLB_U3)
#define PPC44x_TLB_USER_PERM_MASK (PPC44x_TLB_UX|PPC44x_TLB_UR|PPC44x_TLB_UW)
#define PPC44x_TLB_SUPER_PERM_MASK (PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW)
#ifdef DEBUG
void kvmppc_dump_tlbs(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *tlbe;
int i;
printk("vcpu %d TLB dump:\n", vcpu->vcpu_id);
printk("| %2s | %3s | %8s | %8s | %8s |\n",
"nr", "tid", "word0", "word1", "word2");
for (i = 0; i < ARRAY_SIZE(vcpu_44x->guest_tlb); i++) {
tlbe = &vcpu_44x->guest_tlb[i];
if (tlbe->word0 & PPC44x_TLB_VALID)
printk(" G%2d | %02X | %08X | %08X | %08X |\n",
i, tlbe->tid, tlbe->word0, tlbe->word1,
tlbe->word2);
}
}
#endif
static inline void kvmppc_44x_tlbie(unsigned int index)
{
/* 0 <= index < 64, so the V bit is clear and we can use the index as
* word0. */
asm volatile(
"tlbwe %[index], %[index], 0\n"
:
: [index] "r"(index)
);
}
static inline void kvmppc_44x_tlbre(unsigned int index,
struct kvmppc_44x_tlbe *tlbe)
{
asm volatile(
"tlbre %[word0], %[index], 0\n"
"mfspr %[tid], %[sprn_mmucr]\n"
"andi. %[tid], %[tid], 0xff\n"
"tlbre %[word1], %[index], 1\n"
"tlbre %[word2], %[index], 2\n"
: [word0] "=r"(tlbe->word0),
[word1] "=r"(tlbe->word1),
[word2] "=r"(tlbe->word2),
[tid] "=r"(tlbe->tid)
: [index] "r"(index),
[sprn_mmucr] "i"(SPRN_MMUCR)
: "cc"
);
}
static inline void kvmppc_44x_tlbwe(unsigned int index,
struct kvmppc_44x_tlbe *stlbe)
{
unsigned long tmp;
asm volatile(
"mfspr %[tmp], %[sprn_mmucr]\n"
"rlwimi %[tmp], %[tid], 0, 0xff\n"
"mtspr %[sprn_mmucr], %[tmp]\n"
"tlbwe %[word0], %[index], 0\n"
"tlbwe %[word1], %[index], 1\n"
"tlbwe %[word2], %[index], 2\n"
: [tmp] "=&r"(tmp)
: [word0] "r"(stlbe->word0),
[word1] "r"(stlbe->word1),
[word2] "r"(stlbe->word2),
[tid] "r"(stlbe->tid),
[index] "r"(index),
[sprn_mmucr] "i"(SPRN_MMUCR)
);
}
static u32 kvmppc_44x_tlb_shadow_attrib(u32 attrib, int usermode)
{
/* We only care about the guest's permission and user bits. */
attrib &= PPC44x_TLB_PERM_MASK|PPC44x_TLB_UATTR_MASK;
if (!usermode) {
/* Guest is in supervisor mode, so we need to translate guest
* supervisor permissions into user permissions. */
attrib &= ~PPC44x_TLB_USER_PERM_MASK;
attrib |= (attrib & PPC44x_TLB_SUPER_PERM_MASK) << 3;
}
/* Make sure host can always access this memory. */
attrib |= PPC44x_TLB_SX|PPC44x_TLB_SR|PPC44x_TLB_SW;
/* WIMGE = 0b00100 */
attrib |= PPC44x_TLB_M;
return attrib;
}
/* Load shadow TLB back into hardware. */
void kvmppc_44x_tlb_load(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
for (i = 0; i <= tlb_44x_hwater; i++) {
struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
kvmppc_44x_tlbwe(i, stlbe);
}
}
static void kvmppc_44x_tlbe_set_modified(struct kvmppc_vcpu_44x *vcpu_44x,
unsigned int i)
{
vcpu_44x->shadow_tlb_mod[i] = 1;
}
/* Save hardware TLB to the vcpu, and invalidate all guest mappings. */
void kvmppc_44x_tlb_put(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
for (i = 0; i <= tlb_44x_hwater; i++) {
struct kvmppc_44x_tlbe *stlbe = &vcpu_44x->shadow_tlb[i];
if (vcpu_44x->shadow_tlb_mod[i])
kvmppc_44x_tlbre(i, stlbe);
if (get_tlb_v(stlbe) && get_tlb_ts(stlbe))
kvmppc_44x_tlbie(i);
}
}
/* Search the guest TLB for a matching entry. */
int kvmppc_44x_tlb_index(struct kvm_vcpu *vcpu, gva_t eaddr, unsigned int pid,
unsigned int as)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
/* XXX Replace loop with fancy data structures. */
for (i = 0; i < ARRAY_SIZE(vcpu_44x->guest_tlb); i++) {
struct kvmppc_44x_tlbe *tlbe = &vcpu_44x->guest_tlb[i];
unsigned int tid;
if (eaddr < get_tlb_eaddr(tlbe))
continue;
if (eaddr > get_tlb_end(tlbe))
continue;
tid = get_tlb_tid(tlbe);
if (tid && (tid != pid))
continue;
if (!get_tlb_v(tlbe))
continue;
if (get_tlb_ts(tlbe) != as)
continue;
return i;
}
return -1;
}
gpa_t kvmppc_mmu_xlate(struct kvm_vcpu *vcpu, unsigned int gtlb_index,
gva_t eaddr)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *gtlbe = &vcpu_44x->guest_tlb[gtlb_index];
unsigned int pgmask = get_tlb_bytes(gtlbe) - 1;
return get_tlb_raddr(gtlbe) | (eaddr & pgmask);
}
int kvmppc_mmu_itlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
{
unsigned int as = !!(vcpu->arch.shared->msr & MSR_IS);
return kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
}
int kvmppc_mmu_dtlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
{
unsigned int as = !!(vcpu->arch.shared->msr & MSR_DS);
return kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
}
void kvmppc_mmu_itlb_miss(struct kvm_vcpu *vcpu)
{
}
void kvmppc_mmu_dtlb_miss(struct kvm_vcpu *vcpu)
{
}
static void kvmppc_44x_shadow_release(struct kvmppc_vcpu_44x *vcpu_44x,
unsigned int stlb_index)
{
struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[stlb_index];
if (!ref->page)
return;
/* Discard from the TLB. */
/* Note: we could actually invalidate a host mapping, if the host overwrote
* this TLB entry since we inserted a guest mapping. */
kvmppc_44x_tlbie(stlb_index);
/* Now release the page. */
if (ref->writeable)
kvm_release_page_dirty(ref->page);
else
kvm_release_page_clean(ref->page);
ref->page = NULL;
/* XXX set tlb_44x_index to stlb_index? */
trace_kvm_stlb_inval(stlb_index);
}
void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
for (i = 0; i <= tlb_44x_hwater; i++)
kvmppc_44x_shadow_release(vcpu_44x, i);
}
/**
* kvmppc_mmu_map -- create a host mapping for guest memory
*
* If the guest wanted a larger page than the host supports, only the first
* host page is mapped here and the rest are demand faulted.
*
* If the guest wanted a smaller page than the host page size, we map only the
* guest-size page (i.e. not a full host page mapping).
*
* Caller must ensure that the specified guest TLB entry is safe to insert into
* the shadow TLB.
*/
void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gpa_t gpaddr,
unsigned int gtlb_index)
{
struct kvmppc_44x_tlbe stlbe;
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *gtlbe = &vcpu_44x->guest_tlb[gtlb_index];
struct kvmppc_44x_shadow_ref *ref;
struct page *new_page;
hpa_t hpaddr;
gfn_t gfn;
u32 asid = gtlbe->tid;
u32 flags = gtlbe->word2;
u32 max_bytes = get_tlb_bytes(gtlbe);
unsigned int victim;
/* Select TLB entry to clobber. Indirectly guard against races with the TLB
* miss handler by disabling interrupts. */
local_irq_disable();
victim = ++tlb_44x_index;
if (victim > tlb_44x_hwater)
victim = 0;
tlb_44x_index = victim;
local_irq_enable();
/* Get reference to new page. */
gfn = gpaddr >> PAGE_SHIFT;
new_page = gfn_to_page(vcpu->kvm, gfn);
if (is_error_page(new_page)) {
printk(KERN_ERR "Couldn't get guest page for gfn %llx!\n",
(unsigned long long)gfn);
return;
}
hpaddr = page_to_phys(new_page);
/* Invalidate any previous shadow mappings. */
kvmppc_44x_shadow_release(vcpu_44x, victim);
/* XXX Make sure (va, size) doesn't overlap any other
* entries. 440x6 user manual says the result would be
* "undefined." */
/* XXX what about AS? */
/* Force TS=1 for all guest mappings. */
stlbe.word0 = PPC44x_TLB_VALID | PPC44x_TLB_TS;
if (max_bytes >= PAGE_SIZE) {
/* Guest mapping is larger than or equal to host page size. We can use
* a "native" host mapping. */
stlbe.word0 |= (gvaddr & PAGE_MASK) | PPC44x_TLBE_SIZE;
} else {
/* Guest mapping is smaller than host page size. We must restrict the
* size of the mapping to be at most the smaller of the two, but for
* simplicity we fall back to a 4K mapping (this is probably what the
* guest is using anyways). */
stlbe.word0 |= (gvaddr & PAGE_MASK_4K) | PPC44x_TLB_4K;
/* 'hpaddr' is a host page, which is larger than the mapping we're
* inserting here. To compensate, we must add the in-page offset to the
* sub-page. */
hpaddr |= gpaddr & (PAGE_MASK ^ PAGE_MASK_4K);
}
stlbe.word1 = (hpaddr & 0xfffffc00) | ((hpaddr >> 32) & 0xf);
stlbe.word2 = kvmppc_44x_tlb_shadow_attrib(flags,
vcpu->arch.shared->msr & MSR_PR);
stlbe.tid = !(asid & 0xff);
/* Keep track of the reference so we can properly release it later. */
ref = &vcpu_44x->shadow_refs[victim];
ref->page = new_page;
ref->gtlb_index = gtlb_index;
ref->writeable = !!(stlbe.word2 & PPC44x_TLB_UW);
ref->tid = stlbe.tid;
/* Insert shadow mapping into hardware TLB. */
kvmppc_44x_tlbe_set_modified(vcpu_44x, victim);
kvmppc_44x_tlbwe(victim, &stlbe);
trace_kvm_stlb_write(victim, stlbe.tid, stlbe.word0, stlbe.word1,
stlbe.word2);
}
/* For a particular guest TLB entry, invalidate the corresponding host TLB
* mappings and release the host pages. */
static void kvmppc_44x_invalidate(struct kvm_vcpu *vcpu,
unsigned int gtlb_index)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_refs); i++) {
struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[i];
if (ref->gtlb_index == gtlb_index)
kvmppc_44x_shadow_release(vcpu_44x, i);
}
}
void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
int usermode = vcpu->arch.shared->msr & MSR_PR;
vcpu->arch.shadow_pid = !usermode;
}
void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
int i;
if (unlikely(vcpu->arch.pid == new_pid))
return;
vcpu->arch.pid = new_pid;
/* Guest userspace runs with TID=0 mappings and PID=0, to make sure it
* can't access guest kernel mappings (TID=1). When we switch to a new
* guest PID, which will also use host PID=0, we must discard the old guest
* userspace mappings. */
for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_refs); i++) {
struct kvmppc_44x_shadow_ref *ref = &vcpu_44x->shadow_refs[i];
if (ref->tid == 0)
kvmppc_44x_shadow_release(vcpu_44x, i);
}
}
static int tlbe_is_host_safe(const struct kvm_vcpu *vcpu,
const struct kvmppc_44x_tlbe *tlbe)
{
gpa_t gpa;
if (!get_tlb_v(tlbe))
return 0;
/* Does it match current guest AS? */
/* XXX what about IS != DS? */
if (get_tlb_ts(tlbe) != !!(vcpu->arch.shared->msr & MSR_IS))
return 0;
gpa = get_tlb_raddr(tlbe);
if (!gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT))
/* Mapping is not for RAM. */
return 0;
return 1;
}
int kvmppc_44x_emul_tlbwe(struct kvm_vcpu *vcpu, u8 ra, u8 rs, u8 ws)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *tlbe;
unsigned int gtlb_index;
int idx;
gtlb_index = kvmppc_get_gpr(vcpu, ra);
if (gtlb_index >= KVM44x_GUEST_TLB_SIZE) {
printk("%s: index %d\n", __func__, gtlb_index);
kvmppc_dump_vcpu(vcpu);
return EMULATE_FAIL;
}
tlbe = &vcpu_44x->guest_tlb[gtlb_index];
/* Invalidate shadow mappings for the about-to-be-clobbered TLB entry. */
if (tlbe->word0 & PPC44x_TLB_VALID)
kvmppc_44x_invalidate(vcpu, gtlb_index);
switch (ws) {
case PPC44x_TLB_PAGEID:
tlbe->tid = get_mmucr_stid(vcpu);
tlbe->word0 = kvmppc_get_gpr(vcpu, rs);
break;
case PPC44x_TLB_XLAT:
tlbe->word1 = kvmppc_get_gpr(vcpu, rs);
break;
case PPC44x_TLB_ATTRIB:
tlbe->word2 = kvmppc_get_gpr(vcpu, rs);
break;
default:
return EMULATE_FAIL;
}
idx = srcu_read_lock(&vcpu->kvm->srcu);
if (tlbe_is_host_safe(vcpu, tlbe)) {
gva_t eaddr;
gpa_t gpaddr;
u32 bytes;
eaddr = get_tlb_eaddr(tlbe);
gpaddr = get_tlb_raddr(tlbe);
/* Use the advertised page size to mask effective and real addrs. */
bytes = get_tlb_bytes(tlbe);
eaddr &= ~(bytes - 1);
gpaddr &= ~(bytes - 1);
kvmppc_mmu_map(vcpu, eaddr, gpaddr, gtlb_index);
}
srcu_read_unlock(&vcpu->kvm->srcu, idx);
trace_kvm_gtlb_write(gtlb_index, tlbe->tid, tlbe->word0, tlbe->word1,
tlbe->word2);
kvmppc_set_exit_type(vcpu, EMULATED_TLBWE_EXITS);
return EMULATE_DONE;
}
int kvmppc_44x_emul_tlbsx(struct kvm_vcpu *vcpu, u8 rt, u8 ra, u8 rb, u8 rc)
{
u32 ea;
int gtlb_index;
unsigned int as = get_mmucr_sts(vcpu);
unsigned int pid = get_mmucr_stid(vcpu);
ea = kvmppc_get_gpr(vcpu, rb);
if (ra)
ea += kvmppc_get_gpr(vcpu, ra);
gtlb_index = kvmppc_44x_tlb_index(vcpu, ea, pid, as);
if (rc) {
u32 cr = kvmppc_get_cr(vcpu);
if (gtlb_index < 0)
kvmppc_set_cr(vcpu, cr & ~0x20000000);
else
kvmppc_set_cr(vcpu, cr | 0x20000000);
}
kvmppc_set_gpr(vcpu, rt, gtlb_index);
kvmppc_set_exit_type(vcpu, EMULATED_TLBSX_EXITS);
return EMULATE_DONE;
}