| Message ID | 1479706302-2251-4-git-send-email-david@gibson.dropbear.id.au |
|---|---|
| State | New |
| Headers | show |
* David Gibson (david@gibson.dropbear.id.au) wrote: > Until very recently, the vmstate for ppc cpus included some poorly > thought out VMSTATE_EQUAL() components, that can easily break > migration compatibility, and did so between qemu-2.6 and later > versions. A hack was recently added which fixes this migration > breakage, but it leaves the unhelpful cruft of these fields in the > migration stream. > > dThis patch adds a new cpu property allowing these fields to be > removed from the stream entirely. This property is enabled by default > for the pseries-2.8 machine type - which comes after the fix - and for > all non-pseries machine types - which aren't mature enough to care > about cross-version migration. > > The migration hack remains in place for pseries-2.7 and earlier > machine types, allowing backwards and forwards migration with the > older machine types. > > This restricts the migration compatibility cruft to older machine > types, and at least opens the possibility of eventually deprecating > and removing it entirely. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > hw/ppc/spapr.c | 5 +++++ > target-ppc/cpu.h | 3 ++- > target-ppc/machine.c | 26 ++++++++++++++++++-------- > target-ppc/translate_init.c | 6 ++++++ > 4 files changed, 31 insertions(+), 9 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 54b88d3..775ad2e 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2767,6 +2767,11 @@ DEFINE_SPAPR_MACHINE(2_8, "2.8", true); > .driver = TYPE_SPAPR_PCI_HOST_BRIDGE, \ > .property = "mem64_win_size", \ > .value = "0", \ > + }, \ > + { \ > + .driver = TYPE_POWERPC_CPU, \ > + .property = "pre-2.8-migration", \ > + .value = "on", \ > }, > > static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index, > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h > index 7798b2e..2a50c43 100644 > --- a/target-ppc/cpu.h > +++ b/target-ppc/cpu.h > @@ -1167,7 +1167,8 @@ struct PowerPCCPU { > uint32_t max_compat; > uint32_t cpu_version; > > - /* fields used only during migration for compatibility hacks */ > + /* Fields related to migration compatibility hacks */ > + bool pre_2_8_migration; > target_ulong mig_msr_mask; > uint64_t mig_insns_flags; > uint64_t mig_insns_flags2; > diff --git a/target-ppc/machine.c b/target-ppc/machine.c > index fcac263..18c16d2 100644 > --- a/target-ppc/machine.c > +++ b/target-ppc/machine.c > @@ -135,6 +135,13 @@ static const VMStateInfo vmstate_info_avr = { > #define VMSTATE_AVR_ARRAY(_f, _s, _n) \ > VMSTATE_AVR_ARRAY_V(_f, _s, _n, 0) > > +static bool cpu_pre_2_8_migration(void *opaque, int version_id) > +{ > + PowerPCCPU *cpu = opaque; > + > + return cpu->pre_2_8_migration; > +} > + > static void cpu_pre_save(void *opaque) > { > PowerPCCPU *cpu = opaque; > @@ -178,10 +185,12 @@ static void cpu_pre_save(void *opaque) > } > > /* Hacks for migration compatibility between 2.6, 2.7 & 2.8 */ > - cpu->mig_msr_mask = env->msr_mask; > - cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > - cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > - cpu->mig_nb_BATs = env->nb_BATs; > + if (cpu->pre_2_8_migration) { > + cpu->mig_msr_mask = env->msr_mask; > + cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > + cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > + cpu->mig_nb_BATs = env->nb_BATs; > + } > } > > static int cpu_post_load(void *opaque, int version_id) > @@ -582,10 +591,11 @@ const VMStateDescription vmstate_ppc_cpu = { > /* FIXME: access_type? */ > > /* Sanity checking */ > - VMSTATE_UINTTL(mig_msr_mask, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags2, PowerPCCPU), > - VMSTATE_UINT32(mig_nb_BATs, PowerPCCPU), > + VMSTATE_UINTTL_TEST(mig_msr_mask, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags2, PowerPCCPU, > + cpu_pre_2_8_migration), > + VMSTATE_UINT32_TEST(mig_nb_BATs, PowerPCCPU, cpu_pre_2_8_migration), > VMSTATE_END_OF_LIST() > }, > .subsections = (const VMStateDescription*[]) { > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c > index 208fa1e..626e031 100644 > --- a/target-ppc/translate_init.c > +++ b/target-ppc/translate_init.c > @@ -10520,6 +10520,11 @@ static gchar *ppc_gdb_arch_name(CPUState *cs) > #endif > } > > +static Property ppc_cpu_properties[] = { > + DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false), > + DEFINE_PROP_END_OF_LIST(), > +}; > + > static void ppc_cpu_class_init(ObjectClass *oc, void *data) > { > PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc); > @@ -10532,6 +10537,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data) > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_always; > dc->realize = ppc_cpu_realizefn; > dc->unrealize = ppc_cpu_unrealizefn; > + dc->props = ppc_cpu_properties; > > pcc->parent_reset = cc->reset; > cc->reset = ppc_cpu_reset; > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 21.11.2016 06:31, David Gibson wrote: > Until very recently, the vmstate for ppc cpus included some poorly > thought out VMSTATE_EQUAL() components, that can easily break > migration compatibility, and did so between qemu-2.6 and later > versions. A hack was recently added which fixes this migration > breakage, but it leaves the unhelpful cruft of these fields in the > migration stream. > > dThis patch adds a new cpu property allowing these fields to be > removed from the stream entirely. This property is enabled by default > for the pseries-2.8 machine type - which comes after the fix - and for > all non-pseries machine types - which aren't mature enough to care > about cross-version migration. > > The migration hack remains in place for pseries-2.7 and earlier > machine types, allowing backwards and forwards migration with the > older machine types. > > This restricts the migration compatibility cruft to older machine > types, and at least opens the possibility of eventually deprecating > and removing it entirely. I like that idea! Patch looks fine, too, so: Reviewed-by: Thomas Huth <thuth@redhat.com>
On Mon, 21 Nov 2016 16:31:40 +1100 David Gibson <david@gibson.dropbear.id.au> wrote: > Until very recently, the vmstate for ppc cpus included some poorly > thought out VMSTATE_EQUAL() components, that can easily break > migration compatibility, and did so between qemu-2.6 and later > versions. A hack was recently added which fixes this migration > breakage, but it leaves the unhelpful cruft of these fields in the > migration stream. > > dThis patch adds a new cpu property allowing these fields to be ^ typo > removed from the stream entirely. This property is enabled by default > for the pseries-2.8 machine type - which comes after the fix - and for > all non-pseries machine types - which aren't mature enough to care > about cross-version migration. > It is a bit confusing (at least for me) that "property is enabled" means it is actually set to off. No big deal though. > The migration hack remains in place for pseries-2.7 and earlier > machine types, allowing backwards and forwards migration with the > older machine types. > > This restricts the migration compatibility cruft to older machine > types, and at least opens the possibility of eventually deprecating > and removing it entirely. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- Reviewed-by: Greg Kurz <groug@kaod.org> > hw/ppc/spapr.c | 5 +++++ > target-ppc/cpu.h | 3 ++- > target-ppc/machine.c | 26 ++++++++++++++++++-------- > target-ppc/translate_init.c | 6 ++++++ > 4 files changed, 31 insertions(+), 9 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 54b88d3..775ad2e 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2767,6 +2767,11 @@ DEFINE_SPAPR_MACHINE(2_8, "2.8", true); > .driver = TYPE_SPAPR_PCI_HOST_BRIDGE, \ > .property = "mem64_win_size", \ > .value = "0", \ > + }, \ > + { \ > + .driver = TYPE_POWERPC_CPU, \ > + .property = "pre-2.8-migration", \ > + .value = "on", \ > }, > > static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index, > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h > index 7798b2e..2a50c43 100644 > --- a/target-ppc/cpu.h > +++ b/target-ppc/cpu.h > @@ -1167,7 +1167,8 @@ struct PowerPCCPU { > uint32_t max_compat; > uint32_t cpu_version; > > - /* fields used only during migration for compatibility hacks */ > + /* Fields related to migration compatibility hacks */ > + bool pre_2_8_migration; > target_ulong mig_msr_mask; > uint64_t mig_insns_flags; > uint64_t mig_insns_flags2; > diff --git a/target-ppc/machine.c b/target-ppc/machine.c > index fcac263..18c16d2 100644 > --- a/target-ppc/machine.c > +++ b/target-ppc/machine.c > @@ -135,6 +135,13 @@ static const VMStateInfo vmstate_info_avr = { > #define VMSTATE_AVR_ARRAY(_f, _s, _n) \ > VMSTATE_AVR_ARRAY_V(_f, _s, _n, 0) > > +static bool cpu_pre_2_8_migration(void *opaque, int version_id) > +{ > + PowerPCCPU *cpu = opaque; > + > + return cpu->pre_2_8_migration; > +} > + > static void cpu_pre_save(void *opaque) > { > PowerPCCPU *cpu = opaque; > @@ -178,10 +185,12 @@ static void cpu_pre_save(void *opaque) > } > > /* Hacks for migration compatibility between 2.6, 2.7 & 2.8 */ > - cpu->mig_msr_mask = env->msr_mask; > - cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > - cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > - cpu->mig_nb_BATs = env->nb_BATs; > + if (cpu->pre_2_8_migration) { > + cpu->mig_msr_mask = env->msr_mask; > + cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > + cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > + cpu->mig_nb_BATs = env->nb_BATs; > + } > } > > static int cpu_post_load(void *opaque, int version_id) > @@ -582,10 +591,11 @@ const VMStateDescription vmstate_ppc_cpu = { > /* FIXME: access_type? */ > > /* Sanity checking */ > - VMSTATE_UINTTL(mig_msr_mask, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags2, PowerPCCPU), > - VMSTATE_UINT32(mig_nb_BATs, PowerPCCPU), > + VMSTATE_UINTTL_TEST(mig_msr_mask, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags2, PowerPCCPU, > + cpu_pre_2_8_migration), > + VMSTATE_UINT32_TEST(mig_nb_BATs, PowerPCCPU, cpu_pre_2_8_migration), > VMSTATE_END_OF_LIST() > }, > .subsections = (const VMStateDescription*[]) { > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c > index 208fa1e..626e031 100644 > --- a/target-ppc/translate_init.c > +++ b/target-ppc/translate_init.c > @@ -10520,6 +10520,11 @@ static gchar *ppc_gdb_arch_name(CPUState *cs) > #endif > } > > +static Property ppc_cpu_properties[] = { > + DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false), > + DEFINE_PROP_END_OF_LIST(), > +}; > + > static void ppc_cpu_class_init(ObjectClass *oc, void *data) > { > PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc); > @@ -10532,6 +10537,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data) > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_always; > dc->realize = ppc_cpu_realizefn; > dc->unrealize = ppc_cpu_unrealizefn; > + dc->props = ppc_cpu_properties; > > pcc->parent_reset = cc->reset; > cc->reset = ppc_cpu_reset;
On Mon, Nov 21, 2016 at 04:26:10PM +0100, Greg Kurz wrote: > On Mon, 21 Nov 2016 16:31:40 +1100 > David Gibson <david@gibson.dropbear.id.au> wrote: > > > Until very recently, the vmstate for ppc cpus included some poorly > > thought out VMSTATE_EQUAL() components, that can easily break > > migration compatibility, and did so between qemu-2.6 and later > > versions. A hack was recently added which fixes this migration > > breakage, but it leaves the unhelpful cruft of these fields in the > > migration stream. > > > > dThis patch adds a new cpu property allowing these fields to be > ^ > typo Oops, fixed. > > removed from the stream entirely. This property is enabled by default > > for the pseries-2.8 machine type - which comes after the fix - and for > > all non-pseries machine types - which aren't mature enough to care > > about cross-version migration. > > > > It is a bit confusing (at least for me) that "property is enabled" means it is > actually set to off. No big deal though. Uh, yes, I've reworded this a bit. > > > The migration hack remains in place for pseries-2.7 and earlier > > machine types, allowing backwards and forwards migration with the > > older machine types. > > > > This restricts the migration compatibility cruft to older machine > > types, and at least opens the possibility of eventually deprecating > > and removing it entirely. > > > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > > --- > > Reviewed-by: Greg Kurz <groug@kaod.org> > > > hw/ppc/spapr.c | 5 +++++ > > target-ppc/cpu.h | 3 ++- > > target-ppc/machine.c | 26 ++++++++++++++++++-------- > > target-ppc/translate_init.c | 6 ++++++ > > 4 files changed, 31 insertions(+), 9 deletions(-) > > > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 54b88d3..775ad2e 100644 > > --- a/hw/ppc/spapr.c > > +++ b/hw/ppc/spapr.c > > @@ -2767,6 +2767,11 @@ DEFINE_SPAPR_MACHINE(2_8, "2.8", true); > > .driver = TYPE_SPAPR_PCI_HOST_BRIDGE, \ > > .property = "mem64_win_size", \ > > .value = "0", \ > > + }, \ > > + { \ > > + .driver = TYPE_POWERPC_CPU, \ > > + .property = "pre-2.8-migration", \ > > + .value = "on", \ > > }, > > > > static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index, > > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h > > index 7798b2e..2a50c43 100644 > > --- a/target-ppc/cpu.h > > +++ b/target-ppc/cpu.h > > @@ -1167,7 +1167,8 @@ struct PowerPCCPU { > > uint32_t max_compat; > > uint32_t cpu_version; > > > > - /* fields used only during migration for compatibility hacks */ > > + /* Fields related to migration compatibility hacks */ > > + bool pre_2_8_migration; > > target_ulong mig_msr_mask; > > uint64_t mig_insns_flags; > > uint64_t mig_insns_flags2; > > diff --git a/target-ppc/machine.c b/target-ppc/machine.c > > index fcac263..18c16d2 100644 > > --- a/target-ppc/machine.c > > +++ b/target-ppc/machine.c > > @@ -135,6 +135,13 @@ static const VMStateInfo vmstate_info_avr = { > > #define VMSTATE_AVR_ARRAY(_f, _s, _n) \ > > VMSTATE_AVR_ARRAY_V(_f, _s, _n, 0) > > > > +static bool cpu_pre_2_8_migration(void *opaque, int version_id) > > +{ > > + PowerPCCPU *cpu = opaque; > > + > > + return cpu->pre_2_8_migration; > > +} > > + > > static void cpu_pre_save(void *opaque) > > { > > PowerPCCPU *cpu = opaque; > > @@ -178,10 +185,12 @@ static void cpu_pre_save(void *opaque) > > } > > > > /* Hacks for migration compatibility between 2.6, 2.7 & 2.8 */ > > - cpu->mig_msr_mask = env->msr_mask; > > - cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > > - cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > > - cpu->mig_nb_BATs = env->nb_BATs; > > + if (cpu->pre_2_8_migration) { > > + cpu->mig_msr_mask = env->msr_mask; > > + cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > > + cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > > + cpu->mig_nb_BATs = env->nb_BATs; > > + } > > } > > > > static int cpu_post_load(void *opaque, int version_id) > > @@ -582,10 +591,11 @@ const VMStateDescription vmstate_ppc_cpu = { > > /* FIXME: access_type? */ > > > > /* Sanity checking */ > > - VMSTATE_UINTTL(mig_msr_mask, PowerPCCPU), > > - VMSTATE_UINT64(mig_insns_flags, PowerPCCPU), > > - VMSTATE_UINT64(mig_insns_flags2, PowerPCCPU), > > - VMSTATE_UINT32(mig_nb_BATs, PowerPCCPU), > > + VMSTATE_UINTTL_TEST(mig_msr_mask, PowerPCCPU, cpu_pre_2_8_migration), > > + VMSTATE_UINT64_TEST(mig_insns_flags, PowerPCCPU, cpu_pre_2_8_migration), > > + VMSTATE_UINT64_TEST(mig_insns_flags2, PowerPCCPU, > > + cpu_pre_2_8_migration), > > + VMSTATE_UINT32_TEST(mig_nb_BATs, PowerPCCPU, cpu_pre_2_8_migration), > > VMSTATE_END_OF_LIST() > > }, > > .subsections = (const VMStateDescription*[]) { > > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c > > index 208fa1e..626e031 100644 > > --- a/target-ppc/translate_init.c > > +++ b/target-ppc/translate_init.c > > @@ -10520,6 +10520,11 @@ static gchar *ppc_gdb_arch_name(CPUState *cs) > > #endif > > } > > > > +static Property ppc_cpu_properties[] = { > > + DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false), > > + DEFINE_PROP_END_OF_LIST(), > > +}; > > + > > static void ppc_cpu_class_init(ObjectClass *oc, void *data) > > { > > PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc); > > @@ -10532,6 +10537,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data) > > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_always; > > dc->realize = ppc_cpu_realizefn; > > dc->unrealize = ppc_cpu_unrealizefn; > > + dc->props = ppc_cpu_properties; > > > > pcc->parent_reset = cc->reset; > > cc->reset = ppc_cpu_reset; >
On 21/11/16 16:31, David Gibson wrote: > Until very recently, the vmstate for ppc cpus included some poorly > thought out VMSTATE_EQUAL() components, that can easily break > migration compatibility, and did so between qemu-2.6 and later > versions. A hack was recently added which fixes this migration > breakage, but it leaves the unhelpful cruft of these fields in the > migration stream. > > dThis patch adds a new cpu property allowing these fields to be > removed from the stream entirely. This property is enabled by default > for the pseries-2.8 machine type - which comes after the fix - and for > all non-pseries machine types - which aren't mature enough to care > about cross-version migration. > > The migration hack remains in place for pseries-2.7 and earlier > machine types, allowing backwards and forwards migration with the > older machine types. > > This restricts the migration compatibility cruft to older machine > types, and at least opens the possibility of eventually deprecating > and removing it entirely. > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > hw/ppc/spapr.c | 5 +++++ > target-ppc/cpu.h | 3 ++- > target-ppc/machine.c | 26 ++++++++++++++++++-------- > target-ppc/translate_init.c | 6 ++++++ > 4 files changed, 31 insertions(+), 9 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 54b88d3..775ad2e 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2767,6 +2767,11 @@ DEFINE_SPAPR_MACHINE(2_8, "2.8", true); > .driver = TYPE_SPAPR_PCI_HOST_BRIDGE, \ > .property = "mem64_win_size", \ > .value = "0", \ > + }, \ > + { \ > + .driver = TYPE_POWERPC_CPU, \ > + .property = "pre-2.8-migration", \ > + .value = "on", \ > }, > > static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index, > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h > index 7798b2e..2a50c43 100644 > --- a/target-ppc/cpu.h > +++ b/target-ppc/cpu.h > @@ -1167,7 +1167,8 @@ struct PowerPCCPU { > uint32_t max_compat; > uint32_t cpu_version; > > - /* fields used only during migration for compatibility hacks */ > + /* Fields related to migration compatibility hacks */ > + bool pre_2_8_migration; > target_ulong mig_msr_mask; > uint64_t mig_insns_flags; > uint64_t mig_insns_flags2; > diff --git a/target-ppc/machine.c b/target-ppc/machine.c > index fcac263..18c16d2 100644 > --- a/target-ppc/machine.c > +++ b/target-ppc/machine.c > @@ -135,6 +135,13 @@ static const VMStateInfo vmstate_info_avr = { > #define VMSTATE_AVR_ARRAY(_f, _s, _n) \ > VMSTATE_AVR_ARRAY_V(_f, _s, _n, 0) > > +static bool cpu_pre_2_8_migration(void *opaque, int version_id) > +{ > + PowerPCCPU *cpu = opaque; > + > + return cpu->pre_2_8_migration; > +} > + > static void cpu_pre_save(void *opaque) > { > PowerPCCPU *cpu = opaque; > @@ -178,10 +185,12 @@ static void cpu_pre_save(void *opaque) > } > > /* Hacks for migration compatibility between 2.6, 2.7 & 2.8 */ > - cpu->mig_msr_mask = env->msr_mask; > - cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > - cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > - cpu->mig_nb_BATs = env->nb_BATs; > + if (cpu->pre_2_8_migration) { > + cpu->mig_msr_mask = env->msr_mask; > + cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; > + cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; > + cpu->mig_nb_BATs = env->nb_BATs; > + } > } > > static int cpu_post_load(void *opaque, int version_id) > @@ -582,10 +591,11 @@ const VMStateDescription vmstate_ppc_cpu = { > /* FIXME: access_type? */ > > /* Sanity checking */ > - VMSTATE_UINTTL(mig_msr_mask, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags, PowerPCCPU), > - VMSTATE_UINT64(mig_insns_flags2, PowerPCCPU), > - VMSTATE_UINT32(mig_nb_BATs, PowerPCCPU), > + VMSTATE_UINTTL_TEST(mig_msr_mask, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags, PowerPCCPU, cpu_pre_2_8_migration), > + VMSTATE_UINT64_TEST(mig_insns_flags2, PowerPCCPU, > + cpu_pre_2_8_migration), > + VMSTATE_UINT32_TEST(mig_nb_BATs, PowerPCCPU, cpu_pre_2_8_migration), > VMSTATE_END_OF_LIST() > }, > .subsections = (const VMStateDescription*[]) { > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c > index 208fa1e..626e031 100644 > --- a/target-ppc/translate_init.c > +++ b/target-ppc/translate_init.c > @@ -10520,6 +10520,11 @@ static gchar *ppc_gdb_arch_name(CPUState *cs) > #endif > } > > +static Property ppc_cpu_properties[] = { > + DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false), > + DEFINE_PROP_END_OF_LIST(), > +}; > + > static void ppc_cpu_class_init(ObjectClass *oc, void *data) > { > PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc); > @@ -10532,6 +10537,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data) > pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_always; > dc->realize = ppc_cpu_realizefn; > dc->unrealize = ppc_cpu_unrealizefn; > + dc->props = ppc_cpu_properties; > > pcc->parent_reset = cc->reset; > cc->reset = ppc_cpu_reset; >
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 54b88d3..775ad2e 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2767,6 +2767,11 @@ DEFINE_SPAPR_MACHINE(2_8, "2.8", true); .driver = TYPE_SPAPR_PCI_HOST_BRIDGE, \ .property = "mem64_win_size", \ .value = "0", \ + }, \ + { \ + .driver = TYPE_POWERPC_CPU, \ + .property = "pre-2.8-migration", \ + .value = "on", \ }, static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index, diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h index 7798b2e..2a50c43 100644 --- a/target-ppc/cpu.h +++ b/target-ppc/cpu.h @@ -1167,7 +1167,8 @@ struct PowerPCCPU { uint32_t max_compat; uint32_t cpu_version; - /* fields used only during migration for compatibility hacks */ + /* Fields related to migration compatibility hacks */ + bool pre_2_8_migration; target_ulong mig_msr_mask; uint64_t mig_insns_flags; uint64_t mig_insns_flags2; diff --git a/target-ppc/machine.c b/target-ppc/machine.c index fcac263..18c16d2 100644 --- a/target-ppc/machine.c +++ b/target-ppc/machine.c @@ -135,6 +135,13 @@ static const VMStateInfo vmstate_info_avr = { #define VMSTATE_AVR_ARRAY(_f, _s, _n) \ VMSTATE_AVR_ARRAY_V(_f, _s, _n, 0) +static bool cpu_pre_2_8_migration(void *opaque, int version_id) +{ + PowerPCCPU *cpu = opaque; + + return cpu->pre_2_8_migration; +} + static void cpu_pre_save(void *opaque) { PowerPCCPU *cpu = opaque; @@ -178,10 +185,12 @@ static void cpu_pre_save(void *opaque) } /* Hacks for migration compatibility between 2.6, 2.7 & 2.8 */ - cpu->mig_msr_mask = env->msr_mask; - cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; - cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; - cpu->mig_nb_BATs = env->nb_BATs; + if (cpu->pre_2_8_migration) { + cpu->mig_msr_mask = env->msr_mask; + cpu->mig_insns_flags = env->insns_flags & insns_compat_mask; + cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2; + cpu->mig_nb_BATs = env->nb_BATs; + } } static int cpu_post_load(void *opaque, int version_id) @@ -582,10 +591,11 @@ const VMStateDescription vmstate_ppc_cpu = { /* FIXME: access_type? */ /* Sanity checking */ - VMSTATE_UINTTL(mig_msr_mask, PowerPCCPU), - VMSTATE_UINT64(mig_insns_flags, PowerPCCPU), - VMSTATE_UINT64(mig_insns_flags2, PowerPCCPU), - VMSTATE_UINT32(mig_nb_BATs, PowerPCCPU), + VMSTATE_UINTTL_TEST(mig_msr_mask, PowerPCCPU, cpu_pre_2_8_migration), + VMSTATE_UINT64_TEST(mig_insns_flags, PowerPCCPU, cpu_pre_2_8_migration), + VMSTATE_UINT64_TEST(mig_insns_flags2, PowerPCCPU, + cpu_pre_2_8_migration), + VMSTATE_UINT32_TEST(mig_nb_BATs, PowerPCCPU, cpu_pre_2_8_migration), VMSTATE_END_OF_LIST() }, .subsections = (const VMStateDescription*[]) { diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c index 208fa1e..626e031 100644 --- a/target-ppc/translate_init.c +++ b/target-ppc/translate_init.c @@ -10520,6 +10520,11 @@ static gchar *ppc_gdb_arch_name(CPUState *cs) #endif } +static Property ppc_cpu_properties[] = { + DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false), + DEFINE_PROP_END_OF_LIST(), +}; + static void ppc_cpu_class_init(ObjectClass *oc, void *data) { PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc); @@ -10532,6 +10537,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data) pcc->interrupts_big_endian = ppc_cpu_interrupts_big_endian_always; dc->realize = ppc_cpu_realizefn; dc->unrealize = ppc_cpu_unrealizefn; + dc->props = ppc_cpu_properties; pcc->parent_reset = cc->reset; cc->reset = ppc_cpu_reset;
Until very recently, the vmstate for ppc cpus included some poorly thought out VMSTATE_EQUAL() components, that can easily break migration compatibility, and did so between qemu-2.6 and later versions. A hack was recently added which fixes this migration breakage, but it leaves the unhelpful cruft of these fields in the migration stream. dThis patch adds a new cpu property allowing these fields to be removed from the stream entirely. This property is enabled by default for the pseries-2.8 machine type - which comes after the fix - and for all non-pseries machine types - which aren't mature enough to care about cross-version migration. The migration hack remains in place for pseries-2.7 and earlier machine types, allowing backwards and forwards migration with the older machine types. This restricts the migration compatibility cruft to older machine types, and at least opens the possibility of eventually deprecating and removing it entirely. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- hw/ppc/spapr.c | 5 +++++ target-ppc/cpu.h | 3 ++- target-ppc/machine.c | 26 ++++++++++++++++++-------- target-ppc/translate_init.c | 6 ++++++ 4 files changed, 31 insertions(+), 9 deletions(-)