/*
* 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/mmu-44x.h>
#include <asm/kvm_ppc.h>
#include "44x_tlb.h"
#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)
static unsigned int kvmppc_tlb_44x_pos;
#ifdef DEBUG
void kvmppc_dump_tlbs(struct kvm_vcpu *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 < PPC44x_TLB_SIZE; i++) {
tlbe = &vcpu->arch.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);
}
for (i = 0; i < PPC44x_TLB_SIZE; i++) {
tlbe = &vcpu->arch.shadow_tlb[i];
if (tlbe->word0 & PPC44x_TLB_VALID)
printk(" S%2d | %02X | %08X | %08X | %08X |\n",
i, tlbe->tid, tlbe->word0, tlbe->word1,
tlbe->word2);
}
}
#endif
static u32 kvmppc_44x_tlb_shadow_attrib(u32 attrib, int usermode)
{
/* Mask off reserved bits. */
attrib &= PPC44x_TLB_PERM_MASK|PPC44x_TLB_ATTR_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;
return attrib;
}
/* 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)
{
int i;
/* XXX Replace loop with fancy data structures. */
for (i = 0; i < PPC44x_TLB_SIZE; i++) {
struct kvmppc_44x_tlbe *tlbe = &vcpu->arch.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;
}
struct kvmppc_44x_tlbe *kvmppc_44x_itlb_search(struct kvm_vcpu *vcpu,
gva_t eaddr)
{
unsigned int as = !!(vcpu->arch.msr & MSR_IS);
unsigned int index;
index = kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
if (index == -1)
return NULL;
return &vcpu->arch.guest_tlb[index];
}
struct kvmppc_44x_tlbe *kvmppc_44x_dtlb_search(struct kvm_vcpu *vcpu,
gva_t eaddr)
{
unsigned int as = !!(vcpu->arch.msr & MSR_DS);
unsigned int index;
index = kvmppc_44x_tlb_index(vcpu, eaddr, vcpu->arch.pid, as);
if (index == -1)
return NULL;
return &vcpu->arch.guest_tlb[index];
}
static int kvmppc_44x_tlbe_is_writable(struct kvmppc_44x_tlbe *tlbe)
{
return tlbe->word2 & (PPC44x_TLB_SW|PPC44x_TLB_UW);
}
static void kvmppc_44x_shadow_release(struct kvm_vcpu *vcpu,
unsigned int index)
{
struct kvmppc_44x_tlbe *stlbe = &vcpu->arch.shadow_tlb[index];
struct page *page = vcpu->arch.shadow_pages[index];
if (get_tlb_v(stlbe)) {
if (kvmppc_44x_tlbe_is_writable(stlbe))
kvm_release_page_dirty(page);
else
kvm_release_page_clean(page);
}
}
void kvmppc_core_destroy_mmu(struct kvm_vcpu *vcpu)
{
int i;
for (i = 0; i <= tlb_44x_hwater; i++)
kvmppc_44x_shadow_release(vcpu, i);
}
void kvmppc_tlbe_set_modified(struct kvm_vcpu *vcpu, unsigned int i)
{
vcpu->arch.shadow_tlb_mod[i] = 1;
}
/* 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, gfn_t gfn, u64 asid,
u32 flags)
{
struct page *new_page;
struct kvmppc_44x_tlbe *stlbe;
hpa_t hpaddr;
unsigned int victim;
/* Future optimization: don't overwrite the TLB entry containing the
* current PC (or stack?). */
victim = kvmppc_tlb_44x_pos++;
if (kvmppc_tlb_44x_pos > tlb_44x_hwater)
kvmppc_tlb_44x_pos = 0;
stlbe = &vcpu->arch.shadow_tlb[victim];
/* Get reference to new page. */
new_page = gfn_to_page(vcpu->kvm, gfn);
if (is_error_page(new_page)) {
printk(KERN_ERR "Couldn't get guest page for gfn %lx!\n", gfn);
kvm_release_page_clean(new_page);
return;
}
hpaddr = page_to_phys(new_page);
/* Drop reference to old page. */
kvmppc_44x_shadow_release(vcpu, victim);
vcpu->arch.shadow_pages[victim] = new_page;
/* XXX Make sure (va, size) doesn't overlap any other
* entries. 440x6 user manual says the result would be
* "undefined." */
/* XXX what about AS? */
stlbe->tid = !(asid & 0xff);
/* Force TS=1 for all guest mappings. */
/* For now we hardcode 4KB mappings, but it will be important to
* use host large pages in the future. */
stlbe->word0 = (gvaddr & PAGE_MASK) | PPC44x_TLB_VALID | PPC44x_TLB_TS
| PPC44x_TLB_4K;
stlbe->word1 = (hpaddr & 0xfffffc00) | ((hpaddr >> 32) & 0xf);
stlbe->word2 = kvmppc_44x_tlb_shadow_attrib(flags,
vcpu->arch.msr & MSR_PR);
kvmppc_tlbe_set_modified(vcpu, victim);
KVMTRACE_5D(STLB_WRITE, vcpu, victim,
stlbe->tid, stlbe->word0, stlbe->word1, stlbe->word2,
handler);
}
static void kvmppc_mmu_invalidate(struct kvm_vcpu *vcpu, gva_t eaddr,
gva_t eend, u32 asid)
{
unsigned int pid = !(asid & 0xff);
int i;
/* XXX Replace loop with fancy data structures. */
for (i = 0; i <= tlb_44x_hwater; i++) {
struct kvmppc_44x_tlbe *stlbe = &vcpu->arch.shadow_tlb[i];
unsigned int tid;
if (!get_tlb_v(stlbe))
continue;
if (eend < get_tlb_eaddr(stlbe))
continue;
if (eaddr > get_tlb_end(stlbe))
continue;
tid = get_tlb_tid(stlbe);
if (tid && (tid != pid))
continue;
kvmppc_44x_shadow_release(vcpu, i);
stlbe->word0 = 0;
kvmppc_tlbe_set_modified(vcpu, i);
KVMTRACE_5D(STLB_INVAL, vcpu, i,
stlbe->tid, stlbe->word0, stlbe->word1,
stlbe->word2, handler);
}
}
/* Invalidate all mappings on the privilege switch after PID has been changed.
* The guest always runs with PID=1, so we must clear the entire TLB when
* switching address spaces. */
void kvmppc_mmu_priv_switch(struct kvm_vcpu *vcpu, int usermode)
{
int i;
if (vcpu->arch.swap_pid) {
/* XXX Replace loop with fancy data structures. */
for (i = 0; i <= tlb_44x_hwater; i++) {
struct kvmppc_44x_tlbe *stlbe = &vcpu->arch.shadow_tlb[i];
/* Future optimization: clear only userspace mappings. */
kvmppc_44x_shadow_release(vcpu, i);
stlbe->word0 = 0;
kvmppc_tlbe_set_modified(vcpu, i);
KVMTRACE_5D(STLB_INVAL, vcpu, i,
stlbe->tid, stlbe->word0, stlbe->word1,
stlbe->word2, handler);
}
vcpu->arch.swap_pid = 0;
}
vcpu->arch.shadow_pid = !usermode;
}
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.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_emul_tlbwe(struct kvm_vcpu *vcpu, u8 ra, u8 rs, u8 ws)
{
u64 eaddr;
u64 raddr;
u64 asid;
u32 flags;
struct kvmppc_44x_tlbe *tlbe;
unsigned int index;
index = vcpu->arch.gpr[ra];
if (index > PPC44x_TLB_SIZE) {
printk("%s: index %d\n", __func__, index);
kvmppc_dump_vcpu(vcpu);
return EMULATE_FAIL;
}
tlbe = &vcpu->arch.guest_tlb[index];
/* Invalidate shadow mappings for the about-to-be-clobbered TLBE. */
if (tlbe->word0 & PPC44x_TLB_VALID) {
eaddr = get_tlb_eaddr(tlbe);
asid = (tlbe->word0 & PPC44x_TLB_TS) | tlbe->tid;
kvmppc_mmu_invalidate(vcpu, eaddr, get_tlb_end(tlbe), asid);
}
switch (ws) {
case PPC44x_TLB_PAGEID:
tlbe->tid = vcpu->arch.mmucr & 0xff;
tlbe->word0 = vcpu->arch.gpr[rs];
break;
case PPC44x_TLB_XLAT:
tlbe->word1 = vcpu->arch.gpr[rs];
break;
case PPC44x_TLB_ATTRIB:
tlbe->word2 = vcpu->arch.gpr[rs];
break;
default:
return EMULATE_FAIL;
}
if (tlbe_is_host_safe(vcpu, tlbe)) {
eaddr = get_tlb_eaddr(tlbe);
raddr = get_tlb_raddr(tlbe);
asid = (tlbe->word0 & PPC44x_TLB_TS) | tlbe->tid;
flags = tlbe->word2 & 0xffff;
/* Create a 4KB mapping on the host. If the guest wanted a
* large page, only the first 4KB is mapped here and the rest
* are mapped on the fly. */
kvmppc_mmu_map(vcpu, eaddr, raddr >> PAGE_SHIFT, asid, flags);
}
KVMTRACE_5D(GTLB_WRITE, vcpu, index,
tlbe->tid, tlbe->word0, tlbe->word1, tlbe->word2,
handler);
return EMULATE_DONE;
}
int kvmppc_emul_tlbsx(struct kvm_vcpu *vcpu, u8 rt, u8 ra, u8 rb, u8 rc)
{
u32 ea;
int index;
unsigned int as = get_mmucr_sts(vcpu);
unsigned int pid = get_mmucr_stid(vcpu);
ea = vcpu->arch.gpr[rb];
if (ra)
ea += vcpu->arch.gpr[ra];
index = kvmppc_44x_tlb_index(vcpu, ea, pid, as);
if (rc) {
if (index < 0)
vcpu->arch.cr &= ~0x20000000;
else
vcpu->arch.cr |= 0x20000000;
}
vcpu->arch.gpr[rt] = index;
return EMULATE_DONE;
}
