In preparation for adding PV EOI support, disable PV EOI by default for
1.1 and older machine types, to avoid CPUID changing during migration.
PV EOI can still be enabled/disabled by specifying it explicitly.
Enable for 1.1
-M pc-1.1 -cpu kvm64,+kvm_pv_eoi
Disable for 1.2
-M pc-1.2 -cpu kvm64,-kvm_pv_eoi
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
hw/Makefile.objs | 2 +-
hw/cpu_flags.c | 32 ++++++++++++++++++++++++++++++++
hw/cpu_flags.h | 9 +++++++++
hw/pc_piix.c | 2 ++
target-i386/cpu.c | 8 ++++++++
5 files changed, 52 insertions(+), 1 deletion(-)
create mode 100644 hw/cpu_flags.c
create mode 100644 hw/cpu_flags.h
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 850b87b..3f2532a 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -1,5 +1,5 @@
hw-obj-y = usb/ ide/
-hw-obj-y += loader.o
+hw-obj-y += loader.o cpu_flags.o
hw-obj-$(CONFIG_VIRTIO) += virtio-console.o
hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
hw-obj-y += fw_cfg.o
diff --git a/hw/cpu_flags.c b/hw/cpu_flags.c
new file mode 100644
index 0000000..2422d20
--- /dev/null
+++ b/hw/cpu_flags.c
@@ -0,0 +1,32 @@
+/*
+ * CPU compatibility flags.
+ *
+ * Copyright (c) 2012 Red Hat Inc.
+ * Author: Michael S. Tsirkin.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "hw/cpu_flags.h"
+
+static bool __kvm_pv_eoi_disabled;
+
+void disable_kvm_pv_eoi(void)
+{
+ __kvm_pv_eoi_disabled = true;
+}
+
+bool kvm_pv_eoi_disabled(void)
+{
+ return __kvm_pv_eoi_disabled;
+}
diff --git a/hw/cpu_flags.h b/hw/cpu_flags.h
new file mode 100644
index 0000000..05777b6
--- /dev/null
+++ b/hw/cpu_flags.h
@@ -0,0 +1,9 @@
+#ifndef HW_CPU_FLAGS_H
+#define HW_CPU_FLAGS_H
+
+#include <stdbool.h>
+
+void disable_kvm_pv_eoi(void);
+bool kvm_pv_eoi_disabled(void);
+
+#endif
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 008d42f..bdbceda 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -46,6 +46,7 @@
#ifdef CONFIG_XEN
# include <xen/hvm/hvm_info_table.h>
#endif
+#include "cpu_flags.h"
#define MAX_IDE_BUS 2
@@ -371,6 +372,7 @@ static QEMUMachine pc_machine_v1_2 = {
static void pc_machine_v1_1_compat(void)
{
+ disable_kvm_pv_eoi();
}
static void pc_init_pci_v1_1(ram_addr_t ram_size,
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 120a2e3..0d02fd1 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -23,6 +23,7 @@
#include "cpu.h"
#include "kvm.h"
+#include "asm/kvm_para.h"
#include "qemu-option.h"
#include "qemu-config.h"
@@ -33,6 +34,7 @@
#include "hyperv.h"
#include "hw/hw.h"
+#include "hw/cpu_flags.h"
/* feature flags taken from "Intel Processor Identification and the CPUID
* Instruction" and AMD's "CPUID Specification". In cases of disagreement
@@ -889,6 +891,12 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
plus_kvm_features = ~0; /* not supported bits will be filtered out later */
+ /* Disable PV EOI for old machine types.
+ * Feature flags can still override. */
+ if (kvm_pv_eoi_disabled()) {
+ plus_kvm_features &= ~(0x1 << KVM_FEATURE_PV_EOI);
+ }
+
add_flagname_to_bitmaps("hypervisor", &plus_features,
&plus_ext_features, &plus_ext2_features, &plus_ext3_features,
&plus_kvm_features, &plus_svm_features);
--
MST
--
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