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[Qemu-devel] [PATCH 3/7] target/i386: Use global variables to control KV
From: |
Eduardo Habkost |
Subject: |
[Qemu-devel] [PATCH 3/7] target/i386: Use global variables to control KVM defaults |
Date: |
Fri, 6 Oct 2017 18:52:40 -0300 |
The compatibility rules for KVM defaults are implemented today
using x86_cpu_change_kvm_default(), and representing the
arguments to x86_cpu_change_kvm_default() inside compat_props
would be a challenge.
But the compat system doesn't need to be that complex. From the
10 entries at kvm_default_props, only 3 of them need to be
affected by machine-type compat code. It's much simpler and
obvious to just have 3 boolean properties that will control
compatibility mode, and handle them manually at the same place
where kvm_default_props is applied to the CPU object.
This introduces 3 global properties to control the KVM defaults
for x2apic, kvm-pv-eoi, and svm. The global variables are just
an intermediate step to convert this to 3 X86CPU properties to be
controlled using MachineClass::compat_props.
Signed-off-by: Eduardo Habkost <address@hidden>
---
target/i386/cpu.h | 14 ++++++--------
hw/i386/pc_piix.c | 6 +++---
target/i386/cpu.c | 37 +++++++++++++++++--------------------
3 files changed, 26 insertions(+), 31 deletions(-)
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index b086b1528b..0184f98241 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1700,15 +1700,13 @@ void apic_handle_tpr_access_report(DeviceState *d,
target_ulong ip,
TPRAccess access);
-/* Change the value of a KVM-specific default
- *
- * If value is NULL, no default will be set and the original
- * value from the CPU model table will be kept.
- *
- * It is valid to call this function only for properties that
- * are already present in the kvm_default_props table.
+/*
+ * Compat globals to control features automatically enabled/disabled by KVM.
+ * TODO: convert them to X86CPU fields set by MachineClass::compat_props
*/
-void x86_cpu_change_kvm_default(const char *prop, const char *value);
+extern bool kvm_auto_disable_svm;
+extern bool kvm_auto_enable_x2apic;
+extern bool kvm_auto_enable_pv_eoi;
/* mpx_helper.c */
void cpu_sync_bndcs_hflags(CPUX86State *env);
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 31646e63c4..3e466b3896 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -328,7 +328,7 @@ static void pc_compat_2_2(MachineState *machine)
static void pc_compat_2_1(MachineState *machine)
{
pc_compat_2_2(machine);
- x86_cpu_change_kvm_default("svm", NULL);
+ kvm_auto_disable_svm = false;
}
static void pc_compat_2_0(MachineState *machine)
@@ -339,7 +339,7 @@ static void pc_compat_2_0(MachineState *machine)
static void pc_compat_1_7(MachineState *machine)
{
pc_compat_2_0(machine);
- x86_cpu_change_kvm_default("x2apic", NULL);
+ kvm_auto_enable_x2apic = false;
}
static void pc_compat_1_6(MachineState *machine)
@@ -367,7 +367,7 @@ static void pc_compat_1_3(MachineState *machine)
static void pc_compat_1_2(MachineState *machine)
{
pc_compat_1_3(machine);
- x86_cpu_change_kvm_default("kvm-pv-eoi", NULL);
+ kvm_auto_enable_pv_eoi = false;
}
/* PC compat function for pc-0.10 to pc-0.13 */
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 90c969363e..f8d317f1f9 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1577,15 +1577,16 @@ static PropValue kvm_default_props[] = {
{ "kvm-nopiodelay", "on" },
{ "kvm-asyncpf", "on" },
{ "kvm-steal-time", "on" },
- { "kvm-pv-eoi", "on" },
{ "kvmclock-stable-bit", "on" },
- { "x2apic", "on" },
{ "acpi", "off" },
{ "monitor", "off" },
- { "svm", "off" },
{ NULL, NULL },
};
+bool kvm_auto_disable_svm = true;
+bool kvm_auto_enable_x2apic = true;
+bool kvm_auto_enable_pv_eoi = true;
+
/* TCG-specific defaults that override all CPU models when using TCG
*/
static PropValue tcg_default_props[] = {
@@ -1594,22 +1595,6 @@ static PropValue tcg_default_props[] = {
};
-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 uint32_t x86_cpu_get_supported_feature_word(FeatureWord w,
bool migratable_only);
@@ -2439,7 +2424,19 @@ static void x86_cpu_load_def(X86CPU *cpu,
X86CPUDefinition *def, Error **errp)
/* Special cases not set in the X86CPUDefinition structs: */
if (kvm_enabled()) {
if (!kvm_irqchip_in_kernel()) {
- x86_cpu_change_kvm_default("x2apic", "off");
+ object_property_set_bool(OBJECT(cpu), false, "x2apic",
+ &error_abort);
+ } else if (kvm_auto_enable_x2apic) {
+ object_property_set_bool(OBJECT(cpu), true, "x2apic",
+ &error_abort);
+ }
+ if (kvm_auto_disable_svm) {
+ object_property_set_bool(OBJECT(cpu), false, "svm",
+ &error_abort);
+ }
+ if (kvm_auto_enable_pv_eoi) {
+ object_property_set_bool(OBJECT(cpu), true, "kvm-pv-eoi",
+ &error_abort);
}
x86_cpu_apply_props(cpu, kvm_default_props);
--
2.13.6
- [Qemu-devel] [PATCH 0/7] x86: Rework KVM-defaults compat code, enable kvm_pv_unhalt by default, Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 1/7] qemu-doc: Document minimum kernel version for KVM in x86_64, Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 2/7] target/i386: x86_cpu_expand_feature() helper, Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 3/7] target/i386: Use global variables to control KVM defaults,
Eduardo Habkost <=
- [Qemu-devel] [PATCH 4/7] kvm: Define KVM_FEAT_* even if CONFIG_KVM is not defined, Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 5/7] target/i386: Handle kvm_auto_* compat in x86_cpu_expand_features(), Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 6/7] pc: Use compat_props to control KVM defaults compatibility, Eduardo Habkost, 2017/10/06
- [Qemu-devel] [PATCH 7/7] target/i386: Enable kvm_pv_unhalt by default, Eduardo Habkost, 2017/10/06
- Re: [Qemu-devel] [PATCH 0/7] x86: Rework KVM-defaults compat code, enable kvm_pv_unhalt by default, Paolo Bonzini, 2017/10/09