Re: [PATCH 0/6] Save state error handling (kill off no_migrate)

Alex Williamson
2010-10-07T16:55:44Z

[-- Attachment #1: Type: text/plain, Size: 4783 bytes --]

Avi, Marcelo,

Assuming this gets merged to qemu.git, you'll need the attached trivial
updates for the qemu-kvm.git merge. Thanks,

Alex

On Wed, 2010-10-06 at 14:58 -0600, Alex Williamson wrote:
> Our code paths for saving or migrating a VM are full of functions that
> return void, leaving no opportunity for a device to cancel a migration,
> either from error or incompatibility. The ivshmem driver attempted to
> solve this with a no_migrate flag on the save state entry. I think the
> more generic and flexible way to solve this is to allow driver save
> functions to fail. This series implements that and converts ivshmem
> to uses a set_params function to NAK migration much earlier in the
> processes. This touches a lot of files, but bulk of those changes are
> simply s/void/int/ and tacking a "return 0" to the end of functions.
> Thanks,
>
> Alex
>
> ---
>
> Alex Williamson (6):
> savevm: Remove register_device_unmigratable()
> savevm: Allow set_params and save_live_state to error
> virtio: Allow virtio_save() errors
> pci: Allow pci_device_save() to return error
> savevm: Allow vmsd->pre_save to return error
> savevm: Allow SaveStateHandler() to return error
>
>
> block-migration.c | 4 +-
> hw/adb.c | 8 +++-
> hw/ads7846.c | 4 +-
> hw/arm_gic.c | 4 +-
> hw/arm_timer.c | 6 ++-
> hw/armv7m_nvic.c | 4 +-
> hw/cuda.c | 4 +-
> hw/fdc.c | 3 +
> hw/g364fb.c | 4 +-
> hw/grackle_pci.c | 4 +-
> hw/gt64xxx.c | 4 +-
> hw/heathrow_pic.c | 4 +-
> hw/hpet.c | 3 +
> hw/hw.h | 12 ++----
> hw/i2c.c | 3 +
> hw/ide/core.c | 4 +-
> hw/ivshmem.c | 30 +++++++++++----
> hw/lsi53c895a.c | 4 +-
> hw/m48t59.c | 4 +-
> hw/mac_dbdma.c | 4 +-
> hw/mac_nvram.c | 4 +-
> hw/max111x.c | 4 +-
> hw/mipsnet.c | 4 +-
> hw/mst_fpga.c | 3 +
> hw/nand.c | 3 +
> hw/openpic.c | 4 +-
> hw/pci.c | 9 +++-
> hw/pci.h | 2 -
> hw/piix4.c | 4 +-
> hw/pl011.c | 4 +-
> hw/pl022.c | 4 +-
> hw/pl061.c | 4 +-
> hw/ppc4xx_pci.c | 11 ++++-
> hw/ppce500_pci.c | 11 ++++-
> hw/pxa2xx.c | 28 ++++++++++----
> hw/pxa2xx_dma.c | 4 +-
> hw/pxa2xx_gpio.c | 4 +-
> hw/pxa2xx_keypad.c | 3 +
> hw/pxa2xx_lcd.c | 4 +-
> hw/pxa2xx_mmci.c | 4 +-
> hw/pxa2xx_pic.c | 4 +-
> hw/pxa2xx_timer.c | 4 +-
> hw/rc4030.c | 4 +-
> hw/rtl8139.c | 4 +-
> hw/serial.c | 3 +
> hw/spitz.c | 14 +++++--
> hw/ssd0323.c | 4 +-
> hw/ssi-sd.c | 4 +-
> hw/stellaris.c | 20 +++++++---
> hw/stellaris_enet.c | 4 +-
> hw/stellaris_input.c | 4 +-
> hw/syborg_fb.c | 4 +-
> hw/syborg_interrupt.c | 3 +
> hw/syborg_keyboard.c | 3 +
> hw/syborg_pointer.c | 3 +
> hw/syborg_rtc.c | 4 +-
> hw/syborg_serial.c | 4 +-
> hw/syborg_timer.c | 4 +-
> hw/tsc2005.c | 4 +-
> hw/tsc210x.c | 4 +-
> hw/twl92230.c | 3 +
> hw/unin_pci.c | 4 +-
> hw/usb-uhci.c | 3 +
> hw/virtio-balloon.c | 9 +++-
> hw/virtio-blk.c | 10 ++++-
> hw/virtio-net.c | 11 ++++-
> hw/virtio-pci.c | 10 ++++-
> hw/virtio-serial-bus.c | 10 ++++-
> hw/virtio.c | 14 +++++--
> hw/virtio.h | 4 +-
> hw/wm8750.c | 3 +
> hw/zaurus.c | 4 +-
> qemu-common.h | 2 -
> savevm.c | 88 +++++++++++++++++++------------------------
> slirp/slirp.c | 6 ++-
> target-arm/machine.c | 3 +
> target-cris/machine.c | 3 +
> target-i386/machine.c | 7 ++-
> target-microblaze/machine.c | 3 +
> target-mips/machine.c | 3 +
> target-ppc/machine.c | 3 +
> target-s390x/machine.c | 3 +
> target-sparc/machine.c | 3 +
> 83 files changed, 365 insertions(+), 181 deletions(-)

[-- Attachment #2: kvm-1.patch --]
[-- Type: text/x-patch, Size: 868 bytes --]

kvm: update for: savevm: Allow SaveStateHandler() to return error

From: Alex Williamson <alex.williamson@redhat.com>

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

kvm-tpr-opt.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/kvm-tpr-opt.c b/kvm-tpr-opt.c
index 46890e2..632b6d6 100644
--- a/kvm-tpr-opt.c
+++ b/kvm-tpr-opt.c
@@ -296,7 +296,7 @@ void kvm_tpr_access_report(CPUState *env, uint64_t rip, int is_write)
patch_instruction(env, rip);
}

-static void tpr_save(QEMUFile *f, void *s)
+static int tpr_save(QEMUFile *f, void *s)
{
int i;

@@ -307,6 +307,8 @@ static void tpr_save(QEMUFile *f, void *s)
qemu_put_be32s(f, &bios_addr);
qemu_put_be32s(f, &vapic_phys);
qemu_put_be32s(f, &vbios_desc_phys);
+
+ return 0;
}

static int tpr_load(QEMUFile *f, void *s, int version_id)

[-- Attachment #3: kvm-2.patch --]
[-- Type: text/x-patch, Size: 2542 bytes --]

kvm: update for: savevm: Allow vmsd->pre_save to return error

From: Alex Williamson <alex.williamson@redhat.com>

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

hw/i8254-kvm.c | 3 ++-
hw/i8259.c | 3 ++-
hw/ioapic.c | 3 ++-
qemu-kvm-x86.c | 4 +++-
4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/hw/i8254-kvm.c b/hw/i8254-kvm.c
index 6125213..9c62b87 100644
--- a/hw/i8254-kvm.c
+++ b/hw/i8254-kvm.c
@@ -32,7 +32,7 @@ extern VMStateDescription vmstate_pit;

static PITState pit_state;

-static void kvm_pit_pre_save(void *opaque)
+static int kvm_pit_pre_save(void *opaque)
{
PITState *s = (void *)opaque;
struct kvm_pit_state2 pit2;
@@ -64,6 +64,7 @@ static void kvm_pit_pre_save(void *opaque)
sc->gate = c->gate;
sc->count_load_time = c->count_load_time;
}
+ return 0;
}

static int kvm_pit_post_load(void *opaque, int version_id)
diff --git a/hw/i8259.c b/hw/i8259.c
index 986dcf5..fc06c44 100644
--- a/hw/i8259.c
+++ b/hw/i8259.c
@@ -470,13 +470,14 @@ static uint32_t elcr_ioport_read(void *opaque, uint32_t addr1)
static void kvm_kernel_pic_save_to_user(PicState *s);
static int kvm_kernel_pic_load_from_user(PicState *s);

-static void pic_pre_save(void *opaque)
+static int pic_pre_save(void *opaque)
{
PicState *s = opaque;

if (kvm_enabled() && kvm_irqchip_in_kernel()) {
kvm_kernel_pic_save_to_user(s);
}
+ return 0;
}

static int pic_post_load(void *opaque, int version_id)
diff --git a/hw/ioapic.c b/hw/ioapic.c
index 276c72e..4f71027 100644
--- a/hw/ioapic.c
+++ b/hw/ioapic.c
@@ -249,13 +249,14 @@ static void kvm_kernel_ioapic_load_from_user(IOAPICState *s)
#endif
}

-static void ioapic_pre_save(void *opaque)
+static int ioapic_pre_save(void *opaque)
{
IOAPICState *s = (void *)opaque;

if (kvm_enabled() && kvm_irqchip_in_kernel()) {
kvm_kernel_ioapic_save_to_user(s);
}
+ return 0;
}

static int ioapic_pre_load(void *opaque)
diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index fd974b3..1dcea38 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -561,11 +561,13 @@ static int kvm_enable_tpr_access_reporting(CPUState *env)
#ifdef KVM_CAP_ADJUST_CLOCK
static struct kvm_clock_data kvmclock_data;

-static void kvmclock_pre_save(void *opaque)
+static int kvmclock_pre_save(void *opaque)
{
struct kvm_clock_data *cl = opaque;

kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, cl);
+
+ return 0;
}

static int kvmclock_post_load(void *opaque, int version_id)