qemu/target/ppc/mmu-radix64.c
Suraj Jitindar Singh 95cb065776 target/ppc: Add debug function for radix mmu translation
In target/ppc/mmu-hash64.c there already exists the function
ppc_hash64_get_phys_page_debug() to get the physical (real) address for
a given effective address in hash mode.

Implement the function ppc_radix64_get_phys_page_debug() to allow a real
address to be obtained for a given effective address in radix mode.
This is used when a debugger is attached to qemu.

Previously we just had a comment saying this is unimplemented which then
fell through to the default case and caused an abort due to
unrecognised mmu model as the default had no case for the V3 mmu, which
was misleading at best.

We reuse ppc_radix64_walk_tree() which is used by the radix fault
handler since the process of walking the radix tree is identical.

Reported-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-07-11 11:04:02 +10:00

299 lines
10 KiB
C

/*
* 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;
}
hwaddr ppc_radix64_get_phys_page_debug(PowerPCCPU *cpu, target_ulong eaddr)
{
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, fault_cause = 0;
/* Handle Real Mode */
if (msr_dr == 0) {
/* In real mode top 4 effective addr bits (mostly) ignored */
return eaddr & 0x0FFFFFFFFFFFFFFFULL;
}
/* Virtual Mode Access - get the fully qualified address */
if (!ppc_radix64_get_fully_qualified_addr(env, eaddr, &lpid, &pid)) {
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 */
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) {
return -1;
}
return raddr & TARGET_PAGE_MASK;
}