qemu/target/i386/kvm/kvm-cpu.c
Claudio Fontana 662175b91f i386: reorder call to cpu_exec_realizefn
i386 realizefn code is sensitive to ordering, and recent commits
aimed at refactoring it, splitting accelerator-specific code,
broke assumptions which need to be fixed.

We need to:

* process hyper-v enlightements first, as they assume features
  not to be expanded

* only then, expand features

* after expanding features, attempt to check them and modify them in the
  accel-specific realizefn code called by cpu_exec_realizefn().

* after the framework has been called via cpu_exec_realizefn,
  the code can check for what has or hasn't been set by accel-specific
  code, or extend its results, ie:

  - check and evenually set code_urev default
  - modify cpu->mwait after potentially being set from host CPUID.
  - finally check for phys_bits assuming all user and accel-specific
    adjustments have already been taken into account.

Fixes: f5cc5a5c ("i386: split cpu accelerators from cpu.c"...)
Fixes: 30565f10 ("cpu: call AccelCPUClass::cpu_realizefn in"...)
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210603123001.17843-2-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-04 13:47:08 +02:00

165 lines
4.4 KiB
C

/*
* x86 KVM CPU type initialization
*
* Copyright 2021 SUSE LLC
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "host-cpu.h"
#include "kvm-cpu.h"
#include "qapi/error.h"
#include "sysemu/sysemu.h"
#include "hw/boards.h"
#include "kvm_i386.h"
#include "hw/core/accel-cpu.h"
static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
/*
* The realize order is important, since x86_cpu_realize() checks if
* nothing else has been set by the user (or by accelerators) in
* cpu->ucode_rev and cpu->phys_bits, and updates the CPUID results in
* mwait.ecx.
* This accel realization code also assumes cpu features are already expanded.
*
* realize order:
*
* x86_cpu_realize():
* -> x86_cpu_expand_features()
* -> cpu_exec_realizefn():
* -> accel_cpu_realizefn()
* kvm_cpu_realizefn() -> host_cpu_realizefn()
* -> check/update ucode_rev, phys_bits, mwait
*/
if (cpu->max_features) {
if (enable_cpu_pm && kvm_has_waitpkg()) {
env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
}
if (cpu->ucode_rev == 0) {
cpu->ucode_rev =
kvm_arch_get_supported_msr_feature(kvm_state,
MSR_IA32_UCODE_REV);
}
}
return host_cpu_realizefn(cs, errp);
}
/*
* KVM-specific features that are automatically added/removed
* from all CPU models when KVM is enabled.
*
* NOTE: features can be enabled by default only if they were
* already available in the oldest kernel version supported
* by the KVM accelerator (see "OS requirements" section at
* docs/system/target-i386.rst)
*/
static PropValue kvm_default_props[] = {
{ "kvmclock", "on" },
{ "kvm-nopiodelay", "on" },
{ "kvm-asyncpf", "on" },
{ "kvm-steal-time", "on" },
{ "kvm-pv-eoi", "on" },
{ "kvmclock-stable-bit", "on" },
{ "x2apic", "on" },
{ "kvm-msi-ext-dest-id", "off" },
{ "acpi", "off" },
{ "monitor", "off" },
{ "svm", "off" },
{ NULL, NULL },
};
void x86_cpu_change_kvm_default(const char *prop, const char *value)
{
PropValue *pv;
for (pv = kvm_default_props; pv->prop; pv++) {
if (!strcmp(pv->prop, prop)) {
pv->value = value;
break;
}
}
/*
* It is valid to call this function only for properties that
* are already present in the kvm_default_props table.
*/
assert(pv->prop);
}
static bool lmce_supported(void)
{
uint64_t mce_cap = 0;
if (kvm_ioctl(kvm_state, KVM_X86_GET_MCE_CAP_SUPPORTED, &mce_cap) < 0) {
return false;
}
return !!(mce_cap & MCG_LMCE_P);
}
static void kvm_cpu_max_instance_init(X86CPU *cpu)
{
CPUX86State *env = &cpu->env;
KVMState *s = kvm_state;
host_cpu_max_instance_init(cpu);
if (lmce_supported()) {
object_property_set_bool(OBJECT(cpu), "lmce", true, &error_abort);
}
env->cpuid_min_level =
kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
env->cpuid_min_xlevel =
kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
env->cpuid_min_xlevel2 =
kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
}
static void kvm_cpu_instance_init(CPUState *cs)
{
X86CPU *cpu = X86_CPU(cs);
host_cpu_instance_init(cpu);
if (!kvm_irqchip_in_kernel()) {
x86_cpu_change_kvm_default("x2apic", "off");
} else if (kvm_irqchip_is_split() && kvm_enable_x2apic()) {
x86_cpu_change_kvm_default("kvm-msi-ext-dest-id", "on");
}
/* Special cases not set in the X86CPUDefinition structs: */
x86_cpu_apply_props(cpu, kvm_default_props);
if (cpu->max_features) {
kvm_cpu_max_instance_init(cpu);
}
}
static void kvm_cpu_accel_class_init(ObjectClass *oc, void *data)
{
AccelCPUClass *acc = ACCEL_CPU_CLASS(oc);
acc->cpu_realizefn = kvm_cpu_realizefn;
acc->cpu_instance_init = kvm_cpu_instance_init;
}
static const TypeInfo kvm_cpu_accel_type_info = {
.name = ACCEL_CPU_NAME("kvm"),
.parent = TYPE_ACCEL_CPU,
.class_init = kvm_cpu_accel_class_init,
.abstract = true,
};
static void kvm_cpu_accel_register_types(void)
{
type_register_static(&kvm_cpu_accel_type_info);
}
type_init(kvm_cpu_accel_register_types);