Hello Marcelo, cc:qemu,
Sorry for re-using this old thread, but I have a problem loading some
saved state from qemu-kvm-1.1.2, which fails for piix4_pm.
You following patch was committed as
<http://git.qemu-project.org/?p=qemu.git;a=commitdiff;h=b0b873a07872f7ab7f66f259c73fb9dd42aa66a9>:
Am 15.11.2012 um 01:11 schrieb Marcelo Tosatti:
> Migrate 16 bytes for en/sts fields (which is the correct size),
> increase version to 3, and document how to support incoming
> migration from qemu-kvm 1.2.
I my case qemu-kvm-1.1.2/hw/acpi_piix4.c:284
| VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
only saves 4 bytes, not 16 bytes.
> Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
> ---
> hw/acpi_piix4.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
> 1 files changed, 46 insertions(+), 4 deletions(-)
>
> diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
> index 15275cf..519269a 100644
> --- a/hw/acpi_piix4.c
> +++ b/hw/acpi_piix4.c
> @@ -235,10 +235,9 @@ static int vmstate_acpi_post_load(void *opaque, int version_id)
> { \
> .name = (stringify(_field)), \
> .version_id = 0, \
> - .num = GPE_LEN, \
> .info = &vmstate_info_uint16, \
> .size = sizeof(uint16_t), \
> - .flags = VMS_ARRAY | VMS_POINTER, \
> + .flags = VMS_SINGLE | VMS_POINTER, \
> .offset = vmstate_offset_pointer(_state, _field, uint8_t), \
> }
>
> @@ -267,11 +266,54 @@ static const VMStateDescription vmstate_pci_status = {
> }
> };
On load qemu-2.8 uses this function
> +static int acpi_load_old(QEMUFile *f, void *opaque, int version_id)
> +{
> + PIIX4PMState *s = opaque;
> + int ret, i;
> + uint16_t temp;
> +
> + ret = pci_device_load(&s->dev, f);
> + if (ret < 0) {
> + return ret;
> + }
> + qemu_get_be16s(f, &s->ar.pm1.evt.sts);
> + qemu_get_be16s(f, &s->ar.pm1.evt.en);
> + qemu_get_be16s(f, &s->ar.pm1.cnt.cnt);
> +
> + ret = vmstate_load_state(f, &vmstate_apm, opaque, 1);
> + if (ret) {
> + return ret;
> + }
> +
> + qemu_get_timer(f, s->ar.tmr.timer);
> + qemu_get_sbe64s(f, &s->ar.tmr.overflow_time);
> +
> + qemu_get_be16s(f, (uint16_t *)s->ar.gpe.sts);
> + for (i = 0; i < 3; i++) {
> + qemu_get_be16s(f, &temp);
> + }
and the loop loads 6 extra bytes here
> +
> + qemu_get_be16s(f, (uint16_t *)s->ar.gpe.en);
> + for (i = 0; i < 3; i++) {
> + qemu_get_be16s(f, &temp);
> + }
and 6 here.
So in total 12 bytes are read too much and qemu_loadvm_state() ends
somewhere in the middle of the next device state section. (patch 0001
helped me to identify that offset)
If I apply the attached 0002 patch, I can load the old VM state.
> +
> + ret = vmstate_load_state(f, &vmstate_pci_status, opaque, 1);
> + return ret;
> +}
> +
> +/* qemu-kvm 1.2 uses version 3 but advertised as 2
> + * To support incoming qemu-kvm 1.2 migration, change version_id
> + * and minimum_version_id to 2 below (which breaks migration from
> + * qemu 1.2).
> + *
> + */
> static const VMStateDescription vmstate_acpi = {
> .name = "piix4_pm",
> - .version_id = 2,
> - .minimum_version_id = 1,
> + .version_id = 3,
> + .minimum_version_id = 3,
> .minimum_version_id_old = 1,
> + .load_state_old = acpi_load_old,
> .post_load = vmstate_acpi_post_load,
> .fields = (VMStateField []) {
> VMSTATE_PCI_DEVICE(dev, PIIX4PMState),
>
Do you remember why 16 bytes were saved in your case?
Thank you in advance.
Philipp
From 4e43999b0f56975dbbd528e4956231b2ee64c071 Mon Sep 17 00:00:00 2001
Message-Id: <4e43999b0f56975dbbd528e4956231b2ee64c071.1490011194.git.hahn@xxxxxxxxxxxxx>
In-Reply-To: <1313efdc0ac664169c5c271f832264efe6659743.1490011194.git.hahn@xxxxxxxxxxxxx>
References: <1313efdc0ac664169c5c271f832264efe6659743.1490011194.git.hahn@xxxxxxxxxxxxx>
From: Philipp Hahn <hahn@xxxxxxxxxxxxx>
Date: Mon, 20 Mar 2017 12:36:53 +0100
Subject: [PATCH 2/2] 0007-Bug-38877-fix-qemu-kvm-1.1-piix4_pm-incompatibility
Organization: Univention GmbH, Bremen, Germany
To: qemu-devel@xxxxxxxxxx
qemu-kvm-1.1 only saves 2*uint16, but qemu-2.8 tries to load 2*4*uint16.
The code was added by b0b873a07872f7ab7f66f259c73fb9dd42aa66a9 and the
commit message claims 16 bytes are the supposed size, but as UCS never
used qemu-kvm-1.2, fix the case for qemu-kvm-1.1
Gbp: Topic UCS
Signed-off-by: Philipp Hahn <hahn@xxxxxxxxxxxxx>
---
hw/acpi/piix4.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 17d36bd..c756d18 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -232,14 +232,18 @@ static int acpi_load_old(QEMUFile *f, void *opaque, int version_id)
qemu_get_sbe64s(f, &s->ar.tmr.overflow_time);
qemu_get_be16s(f, (uint16_t *)s->ar.gpe.sts);
+#if 0 // Bug #38877
for (i = 0; i < 3; i++) {
qemu_get_be16s(f, &temp);
}
+#endif
qemu_get_be16s(f, (uint16_t *)s->ar.gpe.en);
+#if 0 // Bug #38877
for (i = 0; i < 3; i++) {
qemu_get_be16s(f, &temp);
}
+#endif
ret = vmstate_load_state(f, &vmstate_pci_status,
&s->acpi_pci_hotplug.acpi_pcihp_pci_status[ACPI_PCIHP_BSEL_DEFAULT], 1);
--
2.1.4
From 1313efdc0ac664169c5c271f832264efe6659743 Mon Sep 17 00:00:00 2001
Message-Id: <1313efdc0ac664169c5c271f832264efe6659743.1490011194.git.hahn@xxxxxxxxxxxxx>
From: Philipp Hahn <hahn@xxxxxxxxxxxxx>
Date: Fri, 17 Mar 2017 12:51:01 +0100
Subject: [PATCH 1/2] 0006-Bug-38877-debug-loadvm-offset
Organization: Univention GmbH, Bremen, Germany
To: qemu-devel@xxxxxxxxxx
debug: Print offset on section error:
30143@1489751176.344102:qemu_loadvm_state_section 48@0x364da2
Gbp: Topic debug
Signed-off-by: Philipp Hahn <hahn@xxxxxxxxxxxxx>
---
include/migration/qemu-file.h | 1 +
migration/qemu-file.c | 5 +++++
migration/savevm.c | 2 +-
migration/trace-events | 2 +-
4 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index abedd46..a570836 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -126,6 +126,7 @@ int qemu_get_fd(QEMUFile *f);
int qemu_fclose(QEMUFile *f);
int64_t qemu_ftell(QEMUFile *f);
int64_t qemu_ftell_fast(QEMUFile *f);
+int64_t qemu_ftell_internal(QEMUFile *f);
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
void qemu_put_byte(QEMUFile *f, int v);
/*
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index e9fae31..862b8c7 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -543,6 +543,11 @@ int64_t qemu_ftell(QEMUFile *f)
return f->pos;
}
+int64_t qemu_ftell_internal(QEMUFile *f)
+{
+ return f->pos - f->buf_size + f->buf_index;
+}
+
int qemu_file_rate_limit(QEMUFile *f)
{
if (qemu_file_get_error(f)) {
diff --git a/migration/savevm.c b/migration/savevm.c
index 0363372..da2a98b 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1882,7 +1882,7 @@ static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
ret = 0;
- trace_qemu_loadvm_state_section(section_type);
+ trace_qemu_loadvm_state_section(section_type, qemu_ftell_internal(f) - 1);
switch (section_type) {
case QEMU_VM_SECTION_START:
case QEMU_VM_SECTION_FULL:
diff --git a/migration/trace-events b/migration/trace-events
index 94134f7..49f8458 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -1,7 +1,7 @@
# See docs/tracing.txt for syntax documentation.
# migration/savevm.c
-qemu_loadvm_state_section(unsigned int section_type) "%d"
+qemu_loadvm_state_section(unsigned int section_type, uint64_t offset) "%d@0x%" PRIx64
qemu_loadvm_state_section_command(int ret) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
qemu_loadvm_state_main(void) ""
--
2.1.4
