qemu/target/ppc/mmu-radix64.c
Benjamin Herrenschmidt 24b5e0a5ce target/ppc: Don't check UPRT in radix mode when in HV real mode
It appears that during kexec, we run for a while in hypervisor
real mode with LPCR:HR set and LPCR:UPRT clear, which trips
the assertion in ppc_radix64_handle_mmu_fault().

First this shouldn't be an assertion, it's a guest error.

Then we shouldn't be checking these things in hypervisor real
mode (or in virtual hypervisor guest real mode which is similar)
as the real HW won't use those LPCR bits in those cases anyway,
so technically it's ok to have this discrepancy.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-2-clg@kaod.org>
[dwg: Fix for 32-bit builds]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2019-04-26 11:37:57 +10:00

367 lines
12 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 "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)
{
if (msr_hv) { /* MSR[HV] -> Hypervisor/bare metal */
switch (eaddr & R_EADDR_QUADRANT) {
case R_EADDR_QUADRANT0:
*lpid = 0;
*pid = env->spr[SPR_BOOKS_PID];
break;
case R_EADDR_QUADRANT1:
*lpid = env->spr[SPR_LPIDR];
*pid = env->spr[SPR_BOOKS_PID];
break;
case R_EADDR_QUADRANT2:
*lpid = env->spr[SPR_LPIDR];
*pid = 0;
break;
case R_EADDR_QUADRANT3:
*lpid = 0;
*pid = 0;
break;
}
} else { /* !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);
}
static bool validate_pate(PowerPCCPU *cpu, uint64_t lpid, ppc_v3_pate_t *pate)
{
CPUPPCState *env = &cpu->env;
if (!(pate->dw0 & PATE0_HR)) {
return false;
}
if (lpid == 0 && !msr_hv) {
return false;
}
/* More checks ... */
return true;
}
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;
hwaddr raddr, pte_addr;
uint64_t lpid = 0, pid = 0, offset, size, prtbe0, pte;
int page_size, prot, fault_cause = 0;
ppc_v3_pate_t pate;
assert((rwx == 0) || (rwx == 1) || (rwx == 2));
/* HV or virtual hypervisor Real Mode Access */
if ((msr_hv || cpu->vhyp) &&
(((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;
}
/*
* Check UPRT (we avoid the check in real mode to deal with
* transitional states during kexec.
*/
if (!ppc64_use_proc_tbl(cpu)) {
qemu_log_mask(LOG_GUEST_ERROR,
"LPCR:UPRT not set in radix mode ! LPCR="
TARGET_FMT_lx "\n", env->spr[SPR_LPCR]);
}
/* 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 */
if (cpu->vhyp) {
vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
vhc->get_pate(cpu->vhyp, &pate);
} else {
if (!ppc64_v3_get_pate(cpu, lpid, &pate)) {
ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_NOPTE);
return 1;
}
if (!validate_pate(cpu, lpid, &pate)) {
ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_R_BADCONFIG);
}
/* We don't support guest mode yet */
if (lpid != 0) {
error_report("PowerNV guest support Unimplemented");
exit(1);
}
}
/* Index Process Table by PID to Find Corresponding Process Table Entry */
offset = pid * sizeof(struct prtb_entry);
size = 1ULL << ((pate.dw1 & PATE1_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, (pate.dw1 & PATE1_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;
hwaddr raddr, pte_addr;
uint64_t lpid = 0, pid = 0, offset, size, prtbe0, pte;
int page_size, fault_cause = 0;
ppc_v3_pate_t pate;
/* 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 */
if (cpu->vhyp) {
vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
vhc->get_pate(cpu->vhyp, &pate);
} else {
if (!ppc64_v3_get_pate(cpu, lpid, &pate)) {
return -1;
}
if (!validate_pate(cpu, lpid, &pate)) {
return -1;
}
/* We don't support guest mode yet */
if (lpid != 0) {
error_report("PowerNV guest support Unimplemented");
exit(1);
}
}
/* Index Process Table by PID to Find Corresponding Process Table Entry */
offset = pid * sizeof(struct prtb_entry);
size = 1ULL << ((pate.dw1 & PATE1_R_PRTS) + 12);
if (offset >= size) {
/* offset exceeds size of the process table */
return -1;
}
prtbe0 = ldq_phys(cs->as, (pate.dw1 & PATE1_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;
}