On Tue, Jun 16, 2015 at 07:54:09PM +0100, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > Older QEMUs dont understand the new (sub)sections that > may be generated in the serial device. Limit their generation > to newer machine types. > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
I don't see a problem with this, but the specific interface is unfortunate: this spreads versioning info around which we don't normally do. Instead, please add specific flags, e.g. serial_has_recv_fifo Also, is it really enough to just skip a bunch of stuff on load? For example, I notice that before 7385b275d9ae8bdf3c012bc4e2ae9779fcea6312 we used to generate interrupts on loadvm - isn't that needed in this compat mode? > --- > hw/char/serial.c | 19 +++++++++++++------ > hw/i386/pc_piix.c | 2 ++ > hw/i386/pc_q35.c | 2 ++ > hw/ppc/spapr.c | 2 ++ > include/hw/char/serial.h | 3 +++ > 5 files changed, 22 insertions(+), 6 deletions(-) > > diff --git a/hw/char/serial.c b/hw/char/serial.c > index 513d73c..ef31df3 100644 > --- a/hw/char/serial.c > +++ b/hw/char/serial.c > @@ -103,6 +103,9 @@ do { fprintf(stderr, "serial: " fmt , ## __VA_ARGS__); } > while (0) > do {} while (0) > #endif > > +/* Force migration compatibility of pre-2.2 machine types */ > +bool serial_migrate_pre_2_2; > + > static void serial_receive1(void *opaque, const uint8_t *buf, int size); > > static inline void recv_fifo_put(SerialState *s, uint8_t chr) > @@ -646,6 +649,10 @@ static bool serial_thr_ipending_needed(void *opaque) > { > SerialState *s = opaque; > > + if (serial_migrate_pre_2_2) { > + return false; > + } > + > if (s->ier & UART_IER_THRI) { > bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI); > return s->thr_ipending != expected_value; > @@ -672,7 +679,7 @@ static const VMStateDescription > vmstate_serial_thr_ipending = { > static bool serial_tsr_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return s->tsr_retry != 0; > + return !serial_migrate_pre_2_2 && s->tsr_retry != 0; > } > > static const VMStateDescription vmstate_serial_tsr = { > @@ -691,7 +698,7 @@ static const VMStateDescription vmstate_serial_tsr = { > static bool serial_recv_fifo_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return !fifo8_is_empty(&s->recv_fifo); > + return !serial_migrate_pre_2_2 && !fifo8_is_empty(&s->recv_fifo); > > } > > @@ -709,7 +716,7 @@ static const VMStateDescription vmstate_serial_recv_fifo > = { > static bool serial_xmit_fifo_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return !fifo8_is_empty(&s->xmit_fifo); > + return !serial_migrate_pre_2_2 && !fifo8_is_empty(&s->xmit_fifo); > } > > static const VMStateDescription vmstate_serial_xmit_fifo = { > @@ -726,7 +733,7 @@ static const VMStateDescription vmstate_serial_xmit_fifo > = { > static bool serial_fifo_timeout_timer_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return timer_pending(s->fifo_timeout_timer); > + return !serial_migrate_pre_2_2 && timer_pending(s->fifo_timeout_timer); > } > > static const VMStateDescription vmstate_serial_fifo_timeout_timer = { > @@ -743,7 +750,7 @@ static const VMStateDescription > vmstate_serial_fifo_timeout_timer = { > static bool serial_timeout_ipending_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return s->timeout_ipending != 0; > + return !serial_migrate_pre_2_2 && s->timeout_ipending != 0; > } > > static const VMStateDescription vmstate_serial_timeout_ipending = { > @@ -760,7 +767,7 @@ static const VMStateDescription > vmstate_serial_timeout_ipending = { > static bool serial_poll_needed(void *opaque) > { > SerialState *s = (SerialState *)opaque; > - return s->poll_msl >= 0; > + return !serial_migrate_pre_2_2 && s->poll_msl >= 0; > } > > static const VMStateDescription vmstate_serial_poll = { > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index e142f75..d6d596c 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -39,6 +39,7 @@ > #include "hw/kvm/clock.h" > #include "sysemu/sysemu.h" > #include "hw/sysbus.h" > +#include "hw/char/serial.h" > #include "hw/cpu/icc_bus.h" > #include "sysemu/arch_init.h" > #include "sysemu/block-backend.h" > @@ -344,6 +345,7 @@ static void pc_compat_2_1(MachineState *machine) > x86_cpu_compat_set_features("core2duo", FEAT_1_ECX, CPUID_EXT_VMX, 0); > x86_cpu_compat_kvm_no_autodisable(FEAT_8000_0001_ECX, CPUID_EXT3_SVM); > pcms->enforce_aligned_dimm = false; > + serial_migrate_pre_2_2 = true; > } > > static void pc_compat_2_0(MachineState *machine) > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index b68263d..a211f21 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -32,6 +32,7 @@ > #include "sysemu/arch_init.h" > #include "hw/i2c/smbus.h" > #include "hw/boards.h" > +#include "hw/char/serial.h" > #include "hw/timer/mc146818rtc.h" > #include "hw/xen/xen.h" > #include "sysemu/kvm.h" > @@ -328,6 +329,7 @@ static void pc_compat_2_1(MachineState *machine) > x86_cpu_compat_set_features("coreduo", FEAT_1_ECX, CPUID_EXT_VMX, 0); > x86_cpu_compat_set_features("core2duo", FEAT_1_ECX, CPUID_EXT_VMX, 0); > x86_cpu_compat_kvm_no_autodisable(FEAT_8000_0001_ECX, CPUID_EXT3_SVM); > + serial_migrate_pre_2_2 = true; > } > > static void pc_compat_2_0(MachineState *machine) > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 01f8da8..f2673da 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -39,6 +39,7 @@ > #include "qom/cpu.h" > > #include "hw/boards.h" > +#include "hw/char/serial.h" > #include "hw/ppc/ppc.h" > #include "hw/loader.h" > > @@ -1863,6 +1864,7 @@ static void spapr_compat_2_2(Object *obj) > static void spapr_compat_2_1(Object *obj) > { > spapr_compat_2_2(obj); > + serial_migrate_pre_2_2 = true; > } > > static void spapr_machine_2_3_instance_init(Object *obj) > diff --git a/include/hw/char/serial.h b/include/hw/char/serial.h > index 15beb6b..527d728 100644 > --- a/include/hw/char/serial.h > +++ b/include/hw/char/serial.h > @@ -94,4 +94,7 @@ SerialState *serial_mm_init(MemoryRegion *address_space, > #define TYPE_ISA_SERIAL "isa-serial" > void serial_hds_isa_init(ISABus *bus, int n); > > +/* Force migration compatibility of pre-2.2 machine types */ > +extern bool serial_migrate_pre_2_2; > + > #endif > -- > 2.4.3