/*
* PowerPC Radix MMU mulation helpers for QEMU.
*
* Copyright (c) 2016 Suraj Jitindar Singh, IBM Corporation
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
#include "qemu/error-report.h"
#include "sysemu/kvm.h"
#include "kvm_ppc.h"
#include "exec/log.h"
#include "mmu-radix64.h"
#include "mmu-book3s-v3.h"
static bool ppc_radix64_get_fully_qualified_addr(CPUPPCState *env, vaddr eaddr,
uint64_t *lpid, uint64_t *pid)
{
/* We don't have HV support yet and shouldn't get here with it set anyway */
assert(!msr_hv);
if (!msr_hv) { /* !MSR[HV] -> Guest */
switch (eaddr & R_EADDR_QUADRANT) {
case R_EADDR_QUADRANT0: /* Guest application */
*lpid = env->spr[SPR_LPIDR];
*pid = env->spr[SPR_BOOKS_PID];
break;
case R_EADDR_QUADRANT1: /* Illegal */
case R_EADDR_QUADRANT2:
return false;
case R_EADDR_QUADRANT3: /* Guest OS */
*lpid = env->spr[SPR_LPIDR];
*pid = 0; /* pid set to 0 -> addresses guest operating system */
break;
}
}
return true;
}
static void ppc_radix64_raise_segi(PowerPCCPU *cpu, int rwx, vaddr eaddr)
{
CPUState *cs = CPU(cpu);
CPUPPCState *env = &cpu->env;
if (rwx == 2) { /* Instruction Segment Interrupt */
cs->exception_index = POWERPC_EXCP_ISEG;
} else { /* Data Segment Interrupt */
cs->exception_index = POWERPC_EXCP_DSEG;
env->spr[SPR_DAR] = eaddr;
}
env->error_code = 0;
}
static void ppc_radix64_raise_si(PowerPCCPU *cpu, int rwx, vaddr eaddr,
uint32_t cause)
{
CPUState *cs = CPU(cpu);
CPUPPCState *env = &cpu->env;
if (rwx == 2) { /* Instruction Storage Interrupt */
cs->exception_index = POWERPC_EXCP_ISI;
env->error_code = cause;
} else { /* Data Storage Interrupt */
cs->exception_index = POWERPC_EXCP_DSI;
if (rwx == 1) { /* Write -> Store */
cause |= DSISR_ISSTORE;
}
env->spr[SPR_DSISR] = cause;
env->spr[SPR_DAR] = eaddr;
env->error_code = 0;
}
}
static bool ppc_radix64_check_prot(PowerPCCPU *cpu, int rwx, uint64_t pte,
int *fault_cause, int *prot)
{
CPUPPCState *env = &cpu->env;
const int need_prot[] = { PAGE_READ, PAGE_WRITE, PAGE_EXEC };
/* Check Page Attributes (pte58:59) */
if (((pte & R_PTE_ATT) == R_PTE_ATT_NI_IO) && (rwx == 2)) {
/*
* Radix PTE entries with the non-idempotent I/O attribute are treated
* as guarded storage
*/
*fault_cause |= SRR1_NOEXEC_GUARD;
return true;
}
/* Determine permissions allowed by Encoded Access Authority */
if ((pte & R_PTE_EAA_PRIV) && msr_pr) { /* Insufficient Privilege */
*prot = 0;
} else if (msr_pr || (pte & R_PTE_EAA_PRIV)) {
*prot = ppc_radix64_get_prot_eaa(pte);
} else { /* !msr_pr && !(pte & R_PTE_EAA_PRIV) */
*prot = ppc_radix64_get_prot_eaa(pte);
*prot &= ppc_radix64_get_prot_amr(cpu); /* Least combined permissions */
}
/* Check if requested access type is allowed */
if (need_prot[rwx] & ~(*prot)) { /* Page Protected for that Access */
*fault_cause |= DSISR_PROTFAULT;
return true;
}
return false;
}
static void ppc_radix64_set_rc(PowerPCCPU *cpu, int rwx, uint64_t pte,
hwaddr pte_addr, int *prot)
{
CPUState *cs = CPU(cpu);
uint64_t npte;
npte = pte | R_PTE_R; /* Always set reference bit */
if (rwx == 1) { /* Store/Write */
npte |= R_PTE_C; /* Set change bit */
} else {
/*
* Treat the page as read-only for now, so that a later write
* will pass through this function again to set the C bit.
*/
*prot &= ~PAGE_WRITE;
}
if (pte ^ npte) { /* If pte has changed then write it back */
stq_phys(cs->as, pte_addr, npte);
}
}
static uint64_t ppc_radix64_walk_tree(PowerPCCPU *cpu, vaddr eaddr,
uint64_t base_addr, uint64_t nls,
hwaddr *raddr, int *psize,
int *fault_cause, hwaddr *pte_addr)
{
CPUState *cs = CPU(cpu);
uint64_t index, pde;
if (nls < 5) { /* Directory maps less than 2**5 entries */
*fault_cause |= DSISR_R_BADCONFIG;
return 0;
}
/* Read page <directory/table> entry from guest address space */
index = eaddr >> (*psize - nls); /* Shift */
index &= ((1UL << nls) - 1); /* Mask */
pde = ldq_phys(cs->as, base_addr + (index * sizeof(pde)));
if (!(pde & R_PTE_VALID)) { /* Invalid Entry */
*fault_cause |= DSISR_NOPTE;
return 0;
}
*psize -= nls;
/* Check if Leaf Entry -> Page Table Entry -> Stop the Search */
if (pde & R_PTE_LEAF) {
uint64_t rpn = pde & R_PTE_RPN;
uint64_t mask = (1UL << *psize) - 1;
/* Or high bits of rpn and low bits to ea to form whole real addr */
*raddr = (rpn & ~mask) | (eaddr & mask);
*pte_addr = base_addr + (index * sizeof(pde));
return pde;
}
/* Next Level of Radix Tree */
return ppc_radix64_walk_tree(cpu, eaddr, pde & R_PDE_NLB, pde & R_PDE_NLS,
raddr, psize, fault_cause, pte_addr);
}
int ppc_radix64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
int mmu_idx)
{
CPUState *cs = CPU(cpu);
CPUPPCState *env = &cpu->env;
PPCVirtualHypervisorClass *vhc =
PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
hwaddr raddr, pte_addr;
uint64_t lpid = 0, pid = 0, offset, size, patbe, prtbe0, pte;
int page_size, prot, fault_cause = 0;
assert((rwx == 0) || (rwx == 1) || (rwx == 2));
assert(!msr_hv); /* For now there is no Radix PowerNV Support */
assert(cpu->vhyp);
assert(ppc64_use_proc_tbl(cpu));
/* Real Mode Access */
if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
/* In real mode top 4 effective addr bits (mostly) ignored */
raddr = eaddr & 0x0FFFFFFFFFFFFFFFULL;
tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
PAGE_READ | PAGE_WRITE | PAGE_EXEC, mmu_idx,
TARGET_PAGE_SIZE);
return 0;
}
/* Virtual Mode Access - get the fully qualified address */
if (!ppc_radix64_get_fully_qualified_addr(env, eaddr, &lpid, &pid)) {
ppc_radix64_raise_segi(cpu, rwx, eaddr);
return 1;
}
/* Get Process Table */
patbe = vhc->get_patbe(cpu->vhyp);
/* Index Process Table by PID to Find Corresponding Process Table Entry */
offset = pid * sizeof(struct prtb_entry);
size = 1ULL << ((patbe & PATBE1_R_PRTS) + 12);
if (offset >= size) {
/* offset exceeds size of the process table */
ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_NOPTE);
return 1;
}
prtbe0 = ldq_phys(cs->as, (patbe & PATBE1_R_PRTB) + offset);
/* Walk Radix Tree from Process Table Entry to Convert EA to RA */
page_size = PRTBE_R_GET_RTS(prtbe0);
pte = ppc_radix64_walk_tree(cpu, eaddr & R_EADDR_MASK,
prtbe0 & PRTBE_R_RPDB, prtbe0 & PRTBE_R_RPDS,
&raddr, &page_size, &fault_cause, &pte_addr);
if (!pte || ppc_radix64_check_prot(cpu, rwx, pte, &fault_cause, &prot)) {
/* Couldn't get pte or access denied due to protection */
ppc_radix64_raise_si(cpu, rwx, eaddr, fault_cause);
return 1;
}
/* Update Reference and Change Bits */
ppc_radix64_set_rc(cpu, rwx, pte, pte_addr, &prot);
tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
prot, mmu_idx, 1UL << page_size);
return 0;
}
