[Qemu-devel] [PATCHv3 0/4] migrate PV EOI MSR

[Qemu-devel] [PATCHv3 0/4] migrate PV EOI MSR

[Michael S. Tsirkin]

It turns out PV EOI gets disabled after migration -
until next guest reset.
This is because we are missing code to actually migrate it.
This patch fixes it up: it applies cleanly to qemu.git
as well as qemu-kvm.git, so I think it's cleaner
to apply it in qemu.git to keep diff to minimum.

Note: there's talk about adding infrastructure for
CPUID whitelisting which thinkably could be used
for migration compat support. I am guessing this won't be
1.2 material - when it's ready we can easily replace
a simple flag that this patchset adds with something else.

So this just adds minimal code to avoid regressing
cross-version migration.

Note: there's a kernel bug in linux 3.6-rc3 - apply
my patch 'kvm: fix KVM_GET_MSR for PV EOI' in order to
use this patchset on it.

Needed for 1.2.

Changes from v2:
    Fix HACKING rules violation (Blue Swirl)
Changes from v1:
    Update all headers from 3.6-rc3 to keep them in sync (Jan)
    Disable cpuid flag for qemu 1.2 and older (Orit)

Michael S. Tsirkin (4):
  linux-headers: update to 3.6-rc3
  pc: refactor compat code
  cpuid: disable pv eoi for 1.1 and older compat types
  kvm: get/set PV EOI MSR

 hw/Makefile.objs                  |  2 +-
 hw/cpu_flags.c                    | 32 +++++++++++++++++++++++++++
 hw/cpu_flags.h                    |  9 ++++++++
 hw/pc_piix.c                      | 46 ++++++++++++++++++++++++++++++++-------
 linux-headers/asm-s390/kvm.h      |  2 +-
 linux-headers/asm-s390/kvm_para.h |  2 +-
 linux-headers/asm-x86/kvm.h       |  1 +
 linux-headers/asm-x86/kvm_para.h  |  7 ++++++
 linux-headers/linux/kvm.h         |  3 +++
 target-i386/cpu.c                 |  8 +++++++
 target-i386/cpu.h                 |  1 +
 target-i386/kvm.c                 | 13 +++++++++++
 target-i386/machine.c             | 21 ++++++++++++++++++
 13 files changed, 136 insertions(+), 11 deletions(-)
 create mode 100644 hw/cpu_flags.c
 create mode 100644 hw/cpu_flags.h

-- 
MST

[Qemu-devel] [PATCHv3 1/4] linux-headers: update to 3.6-rc3

[Michael S. Tsirkin]

Update linux-headers to version present in Linux 3.6-rc3.
Header asm-x96_64/kvm_para.h update is needed for the new PV EOI
feature.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 linux-headers/asm-s390/kvm.h      | 2 +-
 linux-headers/asm-s390/kvm_para.h | 2 +-
 linux-headers/asm-x86/kvm.h       | 1 +
 linux-headers/asm-x86/kvm_para.h  | 7 +++++++
 linux-headers/linux/kvm.h         | 3 +++
 5 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/linux-headers/asm-s390/kvm.h b/linux-headers/asm-s390/kvm.h
index bdcbe0f..d25da59 100644
--- a/linux-headers/asm-s390/kvm.h
+++ b/linux-headers/asm-s390/kvm.h
@@ -1,7 +1,7 @@
 #ifndef __LINUX_KVM_S390_H
 #define __LINUX_KVM_S390_H
 /*
- * asm-s390/kvm.h - KVM s390 specific structures and definitions
+ * KVM s390 specific structures and definitions
  *
  * Copyright IBM Corp. 2008
  *
diff --git a/linux-headers/asm-s390/kvm_para.h b/linux-headers/asm-s390/kvm_para.h
index 8e2dd67..870051f 100644
--- a/linux-headers/asm-s390/kvm_para.h
+++ b/linux-headers/asm-s390/kvm_para.h
@@ -1,5 +1,5 @@
 /*
- * asm-s390/kvm_para.h - definition for paravirtual devices on s390
+ * definition for paravirtual devices on s390
  *
  * Copyright IBM Corp. 2008
  *
diff --git a/linux-headers/asm-x86/kvm.h b/linux-headers/asm-x86/kvm.h
index e7d1c19..246617e 100644
--- a/linux-headers/asm-x86/kvm.h
+++ b/linux-headers/asm-x86/kvm.h
@@ -12,6 +12,7 @@
 /* Select x86 specific features in <linux/kvm.h> */
 #define __KVM_HAVE_PIT
 #define __KVM_HAVE_IOAPIC
+#define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_DEVICE_ASSIGNMENT
 #define __KVM_HAVE_MSI
 #define __KVM_HAVE_USER_NMI
diff --git a/linux-headers/asm-x86/kvm_para.h b/linux-headers/asm-x86/kvm_para.h
index f2ac46a..a1c3d72 100644
--- a/linux-headers/asm-x86/kvm_para.h
+++ b/linux-headers/asm-x86/kvm_para.h
@@ -22,6 +22,7 @@
 #define KVM_FEATURE_CLOCKSOURCE2        3
 #define KVM_FEATURE_ASYNC_PF		4
 #define KVM_FEATURE_STEAL_TIME		5
+#define KVM_FEATURE_PV_EOI		6
 
 /* The last 8 bits are used to indicate how to interpret the flags field
  * in pvclock structure. If no bits are set, all flags are ignored.
@@ -37,6 +38,7 @@
 #define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01
 #define MSR_KVM_ASYNC_PF_EN 0x4b564d02
 #define MSR_KVM_STEAL_TIME  0x4b564d03
+#define MSR_KVM_PV_EOI_EN      0x4b564d04
 
 struct kvm_steal_time {
 	__u64 steal;
@@ -89,5 +91,10 @@ struct kvm_vcpu_pv_apf_data {
 	__u32 enabled;
 };
 
+#define KVM_PV_EOI_BIT 0
+#define KVM_PV_EOI_MASK (0x1 << KVM_PV_EOI_BIT)
+#define KVM_PV_EOI_ENABLED KVM_PV_EOI_MASK
+#define KVM_PV_EOI_DISABLED 0x0
+
 
 #endif /* _ASM_X86_KVM_PARA_H */
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 5a9d4e3..4b9e575 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -617,6 +617,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_SIGNAL_MSI 77
 #define KVM_CAP_PPC_GET_SMMU_INFO 78
 #define KVM_CAP_S390_COW 79
+#define KVM_CAP_PPC_ALLOC_HTAB 80
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -828,6 +829,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_SIGNAL_MSI            _IOW(KVMIO,  0xa5, struct kvm_msi)
 /* Available with KVM_CAP_PPC_GET_SMMU_INFO */
 #define KVM_PPC_GET_SMMU_INFO	  _IOR(KVMIO,  0xa6, struct kvm_ppc_smmu_info)
+/* Available with KVM_CAP_PPC_ALLOC_HTAB */
+#define KVM_PPC_ALLOCATE_HTAB	  _IOWR(KVMIO, 0xa7, __u32)
 
 /*
  * ioctls for vcpu fds
-- 
MST

[Qemu-devel] [PATCHv3 2/4] pc: refactor compat code

[Michael S. Tsirkin]

In preparation to adding PV EOI migration for 1.2,
trivially refactor some some compat code
to make it easier to add version specific
cpuid tweaks.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/pc_piix.c | 44 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index a771d79..008d42f 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -369,6 +369,22 @@ static QEMUMachine pc_machine_v1_2 = {
     .default_machine_opts = KVM_MACHINE_OPTIONS,
 };
 
+static void pc_machine_v1_1_compat(void)
+{
+}
+
+static void pc_init_pci_v1_1(ram_addr_t ram_size,
+                             const char *boot_device,
+                             const char *kernel_filename,
+                             const char *kernel_cmdline,
+                             const char *initrd_filename,
+                             const char *cpu_model)
+{
+    pc_machine_v1_1_compat();
+    pc_init_pci(ram_size, boot_device, kernel_filename,
+                kernel_cmdline, initrd_filename, cpu_model);
+}
+
 #define PC_COMPAT_1_1 \
         {\
             .driver   = "virtio-scsi-pci",\
@@ -403,7 +419,7 @@ static QEMUMachine pc_machine_v1_2 = {
 static QEMUMachine pc_machine_v1_1 = {
     .name = "pc-1.1",
     .desc = "Standard PC",
-    .init = pc_init_pci,
+    .init = pc_init_pci_v1_1,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -439,7 +455,7 @@ static QEMUMachine pc_machine_v1_1 = {
 static QEMUMachine pc_machine_v1_0 = {
     .name = "pc-1.0",
     .desc = "Standard PC",
-    .init = pc_init_pci,
+    .init = pc_init_pci_v1_1,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -455,7 +471,7 @@ static QEMUMachine pc_machine_v1_0 = {
 static QEMUMachine pc_machine_v0_15 = {
     .name = "pc-0.15",
     .desc = "Standard PC",
-    .init = pc_init_pci,
+    .init = pc_init_pci_v1_1,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -488,7 +504,7 @@ static QEMUMachine pc_machine_v0_15 = {
 static QEMUMachine pc_machine_v0_14 = {
     .name = "pc-0.14",
     .desc = "Standard PC",
-    .init = pc_init_pci,
+    .init = pc_init_pci_v1_1,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -519,10 +535,22 @@ static QEMUMachine pc_machine_v0_14 = {
             .value    = stringify(1),\
         }
 
+static void pc_init_pci_v0_13(ram_addr_t ram_size,
+                             const char *boot_device,
+                             const char *kernel_filename,
+                             const char *kernel_cmdline,
+                             const char *initrd_filename,
+                             const char *cpu_model)
+{
+    pc_machine_v1_1_compat();
+    pc_init_pci_no_kvmclock(ram_size, boot_device, kernel_filename,
+                            kernel_cmdline, initrd_filename, cpu_model);
+}
+
 static QEMUMachine pc_machine_v0_13 = {
     .name = "pc-0.13",
     .desc = "Standard PC",
-    .init = pc_init_pci_no_kvmclock,
+    .init = pc_init_pci_v0_13,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -560,7 +588,7 @@ static QEMUMachine pc_machine_v0_13 = {
 static QEMUMachine pc_machine_v0_12 = {
     .name = "pc-0.12",
     .desc = "Standard PC",
-    .init = pc_init_pci_no_kvmclock,
+    .init = pc_init_pci_v0_13,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -594,7 +622,7 @@ static QEMUMachine pc_machine_v0_12 = {
 static QEMUMachine pc_machine_v0_11 = {
     .name = "pc-0.11",
     .desc = "Standard PC, qemu 0.11",
-    .init = pc_init_pci_no_kvmclock,
+    .init = pc_init_pci_v0_13,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
@@ -616,7 +644,7 @@ static QEMUMachine pc_machine_v0_11 = {
 static QEMUMachine pc_machine_v0_10 = {
     .name = "pc-0.10",
     .desc = "Standard PC, qemu 0.10",
-    .init = pc_init_pci_no_kvmclock,
+    .init = pc_init_pci_v0_13,
     .max_cpus = 255,
     .default_machine_opts = KVM_MACHINE_OPTIONS,
     .compat_props = (GlobalProperty[]) {
-- 
MST

[Qemu-devel] [PATCHv3 3/4] cpuid: disable pv eoi for 1.1 and older compat types

[Michael S. Tsirkin]

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@redhat.com>
---
 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..d821d8c
--- /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

[Qemu-devel] [PATCHv3 4/4] kvm: get/set PV EOI MSR

[Michael S. Tsirkin]

Support get/set of new PV EOI MSR, for migration.
Add an optional section for MSR value - send it
out in case MSR was changed from the default value (0).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 target-i386/cpu.h     |  1 +
 target-i386/kvm.c     | 13 +++++++++++++
 target-i386/machine.c | 21 +++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index aabf993..3c57d8b 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -699,6 +699,7 @@ typedef struct CPUX86State {
     uint64_t system_time_msr;
     uint64_t wall_clock_msr;
     uint64_t async_pf_en_msr;
+    uint64_t pv_eoi_en_msr;
 
     uint64_t tsc;
     uint64_t tsc_deadline;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 5e2d4f5..6790180 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -64,6 +64,7 @@ static bool has_msr_star;
 static bool has_msr_hsave_pa;
 static bool has_msr_tsc_deadline;
 static bool has_msr_async_pf_en;
+static bool has_msr_pv_eoi_en;
 static bool has_msr_misc_enable;
 static int lm_capable_kernel;
 
@@ -456,6 +457,8 @@ int kvm_arch_init_vcpu(CPUX86State *env)
 
     has_msr_async_pf_en = c->eax & (1 << KVM_FEATURE_ASYNC_PF);
 
+    has_msr_pv_eoi_en = c->eax & (1 << KVM_FEATURE_PV_EOI);
+
     cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0; i <= limit; i++) {
@@ -1018,6 +1021,10 @@ static int kvm_put_msrs(CPUX86State *env, int level)
             kvm_msr_entry_set(&msrs[n++], MSR_KVM_ASYNC_PF_EN,
                               env->async_pf_en_msr);
         }
+        if (has_msr_pv_eoi_en) {
+            kvm_msr_entry_set(&msrs[n++], MSR_KVM_PV_EOI_EN,
+                              env->pv_eoi_en_msr);
+        }
         if (hyperv_hypercall_available()) {
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_GUEST_OS_ID, 0);
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_HYPERCALL, 0);
@@ -1260,6 +1267,9 @@ static int kvm_get_msrs(CPUX86State *env)
     if (has_msr_async_pf_en) {
         msrs[n++].index = MSR_KVM_ASYNC_PF_EN;
     }
+    if (has_msr_pv_eoi_en) {
+        msrs[n++].index = MSR_KVM_PV_EOI_EN;
+    }
 
     if (env->mcg_cap) {
         msrs[n++].index = MSR_MCG_STATUS;
@@ -1339,6 +1349,9 @@ static int kvm_get_msrs(CPUX86State *env)
         case MSR_KVM_ASYNC_PF_EN:
             env->async_pf_en_msr = msrs[i].data;
             break;
+        case MSR_KVM_PV_EOI_EN:
+            env->pv_eoi_en_msr = msrs[i].data;
+            break;
         }
     }
 
diff --git a/target-i386/machine.c b/target-i386/machine.c
index a8be058..4771508 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -279,6 +279,13 @@ static bool async_pf_msr_needed(void *opaque)
     return cpu->async_pf_en_msr != 0;
 }
 
+static bool pv_eoi_msr_needed(void *opaque)
+{
+    CPUX86State *cpu = opaque;
+
+    return cpu->pv_eoi_en_msr != 0;
+}
+
 static const VMStateDescription vmstate_async_pf_msr = {
     .name = "cpu/async_pf_msr",
     .version_id = 1,
@@ -290,6 +297,17 @@ static const VMStateDescription vmstate_async_pf_msr = {
     }
 };
 
+static const VMStateDescription vmstate_pv_eoi_msr = {
+    .name = "cpu/async_pv_eoi_msr",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT64(pv_eoi_en_msr, CPUX86State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static bool fpop_ip_dp_needed(void *opaque)
 {
     CPUX86State *env = opaque;
@@ -454,6 +472,9 @@ static const VMStateDescription vmstate_cpu = {
             .vmsd = &vmstate_async_pf_msr,
             .needed = async_pf_msr_needed,
         } , {
+            .vmsd = &vmstate_pv_eoi_msr,
+            .needed = pv_eoi_msr_needed,
+        } , {
             .vmsd = &vmstate_fpop_ip_dp,
             .needed = fpop_ip_dp_needed,
         }, {
-- 
MST

Re: [Qemu-devel] [PATCHv3 3/4] cpuid: disable pv eoi for 1.1 and older compat types

[Blue Swirl]

On Tue, Aug 28, 2012 at 1:22 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> 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@redhat.com>
> ---
>  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..d821d8c
> --- /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;

NACK. I find your lack of compliance disturbing.

> +
> +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
>
>

Re: [Qemu-devel] [PATCHv3 3/4] cpuid: disable pv eoi for 1.1 and older compat types

[Michael S. Tsirkin]

On Tue, Aug 28, 2012 at 05:05:25PM +0000, Blue Swirl wrote:
> > +static bool _kvm_pv_eoi_disabled;
> 
> NACK. I find your lack of compliance disturbing.

Compliance with what? Could you please add some
motivation for the NACK?

-- 
MST

Re: [Qemu-devel] [PATCHv3 3/4] cpuid: disable pv eoi for 1.1 and older compat types

[Blue Swirl]

On Tue, Aug 28, 2012 at 5:22 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Tue, Aug 28, 2012 at 05:05:25PM +0000, Blue Swirl wrote:
>> > +static bool _kvm_pv_eoi_disabled;
>>
>> NACK. I find your lack of compliance disturbing.
>
> Compliance with what? Could you please add some
> motivation for the NACK?

You did not respect my review comments.

>
> --
> MST

Re: [Qemu-devel] [PATCHv3 3/4] cpuid: disable pv eoi for 1.1 and older compat types

[Michael S. Tsirkin]

On Tue, Aug 28, 2012 at 05:28:22PM +0000, Blue Swirl wrote:
> On Tue, Aug 28, 2012 at 5:22 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> > On Tue, Aug 28, 2012 at 05:05:25PM +0000, Blue Swirl wrote:
> >> > +static bool _kvm_pv_eoi_disabled;
> >>
> >> NACK. I find your lack of compliance disturbing.
> >
> > Compliance with what? Could you please add some
> > motivation for the NACK?
> 
> You did not respect my review comments.

I merely asking for motivation for the comments.
Anyway, malc explained it to me so I got it now.
Thanks for the review will post soon.

> >
> > --
> > MST