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linux/arch/powerpc/kvm/44x_tlb.c
Aneesh Kumar K.V 3a167beac0 kvm: powerpc: Add kvmppc_ops callback
This patch add a new callback kvmppc_ops. This will help us in enabling
both HV and PR KVM together in the same kernel. The actual change to
enable them together is done in the later patch in the series.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[agraf: squash in booke changes]
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-17 15:24:26 +02:00

529 lines
14 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 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_44x(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;
}