qemu/target/ppc/compat.c
Greg Kurz e4f0c6bb1a ppc: fix setting of compat mode
While trying to make KVM PR usable again, commit 5dfaa532ae introduced a
regression: the current compat_pvr value is passed to KVM instead of the
new one. This means that we always pass 0 instead of the max-cpu-compat
PVR during the initial machine reset. And at CAS time, we either pass
the PVR from the command line or even don't call kvmppc_set_compat() at
all, ie, the PCR will not be set as expected.

For example if we start a big endian fedora26 guest in power7 compat
mode on a POWER8 host, we get this in the guest:

$ cat /proc/cpuinfo
processor       : 0
cpu             : POWER7 (architected), altivec supported
clock           : 4024.000000MHz
revision        : 2.0 (pvr 004d 0200)

timebase        : 512000000
platform        : pSeries
model           : IBM pSeries (emulated by qemu)
machine         : CHRP IBM pSeries (emulated by qemu)
MMU             : Hash

but the guest can still execute POWER8 instructions, and the following
program succeeds:

int main()
{
        asm("vncipher 0,0,0"); // ISA 2.07 instruction
}

Let's pass the new compat_pvr to kvmppc_set_compat() and the program fails
with SIGILL as expected.

Reported-by: Nageswara R Sastry <rnsastry@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-11-08 13:21:37 +11:00

295 lines
7.8 KiB
C

/*
* PowerPC CPU initialization for qemu.
*
* Copyright 2016, David Gibson, Red Hat Inc. <dgibson@redhat.com>
*
* 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 "sysemu/hw_accel.h"
#include "sysemu/kvm.h"
#include "kvm_ppc.h"
#include "sysemu/cpus.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "cpu-models.h"
typedef struct {
const char *name;
uint32_t pvr;
uint64_t pcr;
uint64_t pcr_level;
int max_threads;
} CompatInfo;
static const CompatInfo compat_table[] = {
/*
* Ordered from oldest to newest - the code relies on this
*/
{ /* POWER6, ISA2.05 */
.name = "power6",
.pvr = CPU_POWERPC_LOGICAL_2_05,
.pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 |
PCR_COMPAT_2_05 | PCR_TM_DIS | PCR_VSX_DIS,
.pcr_level = PCR_COMPAT_2_05,
.max_threads = 2,
},
{ /* POWER7, ISA2.06 */
.name = "power7",
.pvr = CPU_POWERPC_LOGICAL_2_06,
.pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
.pcr_level = PCR_COMPAT_2_06,
.max_threads = 4,
},
{
.name = "power7+",
.pvr = CPU_POWERPC_LOGICAL_2_06_PLUS,
.pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
.pcr_level = PCR_COMPAT_2_06,
.max_threads = 4,
},
{ /* POWER8, ISA2.07 */
.name = "power8",
.pvr = CPU_POWERPC_LOGICAL_2_07,
.pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07,
.pcr_level = PCR_COMPAT_2_07,
.max_threads = 8,
},
{ /* POWER9, ISA3.00 */
.name = "power9",
.pvr = CPU_POWERPC_LOGICAL_3_00,
.pcr = PCR_COMPAT_3_00,
.pcr_level = PCR_COMPAT_3_00,
.max_threads = 4,
},
};
static const CompatInfo *compat_by_pvr(uint32_t pvr)
{
int i;
for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
if (compat_table[i].pvr == pvr) {
return &compat_table[i];
}
}
return NULL;
}
bool ppc_check_compat(PowerPCCPU *cpu, uint32_t compat_pvr,
uint32_t min_compat_pvr, uint32_t max_compat_pvr)
{
PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
const CompatInfo *compat = compat_by_pvr(compat_pvr);
const CompatInfo *min = compat_by_pvr(min_compat_pvr);
const CompatInfo *max = compat_by_pvr(max_compat_pvr);
#if !defined(CONFIG_USER_ONLY)
g_assert(cpu->vhyp);
#endif
g_assert(!min_compat_pvr || min);
g_assert(!max_compat_pvr || max);
if (!compat) {
/* Not a recognized logical PVR */
return false;
}
if ((min && (compat < min)) || (max && (compat > max))) {
/* Outside specified range */
return false;
}
if (!(pcc->pcr_supported & compat->pcr_level)) {
/* Not supported by this CPU */
return false;
}
return true;
}
void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
{
const CompatInfo *compat = compat_by_pvr(compat_pvr);
CPUPPCState *env = &cpu->env;
PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
uint64_t pcr;
if (!compat_pvr) {
pcr = 0;
} else if (!compat) {
error_setg(errp, "Unknown compatibility PVR 0x%08"PRIx32, compat_pvr);
return;
} else if (!ppc_check_compat(cpu, compat_pvr, 0, 0)) {
error_setg(errp, "Compatibility PVR 0x%08"PRIx32" not valid for CPU",
compat_pvr);
return;
} else {
pcr = compat->pcr;
}
cpu_synchronize_state(CPU(cpu));
if (kvm_enabled() && cpu->compat_pvr != compat_pvr) {
int ret = kvmppc_set_compat(cpu, compat_pvr);
if (ret < 0) {
error_setg_errno(errp, -ret,
"Unable to set CPU compatibility mode in KVM");
return;
}
}
cpu->compat_pvr = compat_pvr;
env->spr[SPR_PCR] = pcr & pcc->pcr_mask;
}
typedef struct {
uint32_t compat_pvr;
Error *err;
} SetCompatState;
static void do_set_compat(CPUState *cs, run_on_cpu_data arg)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
SetCompatState *s = arg.host_ptr;
ppc_set_compat(cpu, s->compat_pvr, &s->err);
}
void ppc_set_compat_all(uint32_t compat_pvr, Error **errp)
{
CPUState *cs;
CPU_FOREACH(cs) {
SetCompatState s = {
.compat_pvr = compat_pvr,
.err = NULL,
};
run_on_cpu(cs, do_set_compat, RUN_ON_CPU_HOST_PTR(&s));
if (s.err) {
error_propagate(errp, s.err);
return;
}
}
}
int ppc_compat_max_threads(PowerPCCPU *cpu)
{
const CompatInfo *compat = compat_by_pvr(cpu->compat_pvr);
int n_threads = CPU(cpu)->nr_threads;
if (cpu->compat_pvr) {
g_assert(compat);
n_threads = MIN(n_threads, compat->max_threads);
}
return n_threads;
}
static void ppc_compat_prop_get(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
uint32_t compat_pvr = *((uint32_t *)opaque);
const char *value;
if (!compat_pvr) {
value = "";
} else {
const CompatInfo *compat = compat_by_pvr(compat_pvr);
g_assert(compat);
value = compat->name;
}
visit_type_str(v, name, (char **)&value, errp);
}
static void ppc_compat_prop_set(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
Error *local_err = NULL;
char *value;
uint32_t compat_pvr;
visit_type_str(v, name, &value, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (strcmp(value, "") == 0) {
compat_pvr = 0;
} else {
int i;
const CompatInfo *compat = NULL;
for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
if (strcmp(value, compat_table[i].name) == 0) {
compat = &compat_table[i];
break;
}
}
if (!compat) {
error_setg(errp, "Invalid compatibility mode \"%s\"", value);
goto out;
}
compat_pvr = compat->pvr;
}
*((uint32_t *)opaque) = compat_pvr;
out:
g_free(value);
}
void ppc_compat_add_property(Object *obj, const char *name,
uint32_t *compat_pvr, const char *basedesc,
Error **errp)
{
Error *local_err = NULL;
gchar *namesv[ARRAY_SIZE(compat_table) + 1];
gchar *names, *desc;
int i;
object_property_add(obj, name, "string",
ppc_compat_prop_get, ppc_compat_prop_set, NULL,
compat_pvr, &local_err);
if (local_err) {
goto out;
}
for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
/*
* Have to discard const here, because g_strjoinv() takes
* (gchar **), not (const gchar **) :(
*/
namesv[i] = (gchar *)compat_table[i].name;
}
namesv[ARRAY_SIZE(compat_table)] = NULL;
names = g_strjoinv(", ", namesv);
desc = g_strdup_printf("%s. Valid values are %s.", basedesc, names);
object_property_set_description(obj, name, desc, &local_err);
g_free(names);
g_free(desc);
out:
error_propagate(errp, local_err);
}