Michael S. Tsirkin writes:
> On Thu, Dec 02, 2010 at 10:19:55PM +0800, Jason Wang wrote:
> > Michael S. Tsirkin writes:
> > > On Thu, Dec 02, 2010 at 08:56:30PM +0800, Jason Wang wrote:
> > > > Michael S. Tsirkin writes:
> > > > > On Wed, Dec 01, 2010 at 01:45:09PM +0800, Jason Wang wrote:
> > > > > > Michael S. Tsirkin writes:
> > > > > > > Avoid sending out packets, and modifying
> > > > > > > device state, when VM is stopped.
> > > > > > > Add assert statements to verify this does not happen.
> > > > > > >
> > > > > > > Avoid scheduling bh when vhost-net is started.
> > > > > > >
> > > > > > > Stop bh when driver disabled bus mastering
> > > > > > > (we must not access memory after this).
> > > > > > >
> > > > > > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> > > > > > >
> > > > > >
> > > > > > There's no need to disable it bh we call qemu_aio_flush() after
> > > > > > vm_state_notify() in do_vm_stop(). And for timer, looks like
> > every device should
> > > > > > stop its timer in vm state change handler, not only for
> > virtio-net?
> > > > >
> > > > > BTW I fixed some typos. Here a fixed version.
> > > > > Jason, could you review/test please?
> > > > >
> > > >
> > > > Have done the test, it's more stable than before but still get small
> > deltas in
> > > > cpu section.
> > >
> > > And just to clarify: no more deltas in the memory section?
> > >
> >
> > Yes.
> >
> > And the offset for cpu section is 1161-1165
>
> As far as I can say the state is in
> target-i386/machine.c
> static const VMStateDescription vmstate_cpu.
> Need to do some math to find this:
>
> I think this is mtrr_var, but maybe my math is off.
> I would sugest printing out the state and see
> what is changed exactly.
>
Try printing CPUX86State through gdb and the filed used to do the save/restore
are the same. Have done the check for mtrr_var and the value are same for both
src and dst. And looks like it was never used by kvm.
>
> > and sometimes I get deltas for ide
> > section at offset 295 and 314.
>
> I see that ide has some bh processing. Most likely that starts io after
> vmstop? I suggest adding a vm state handler and checking vm status in
> ide_dma_restart_bh.
>
> Start with an assert, just for debug.
>
> Also, what if we use virtio-blk?
>
One byte delta for virtio-blk section at offset 377. And also get delta for ide
section ( so I didn't try your patch of stopping bh of ide becuse for virtio-blk
we even do not use ide ).
>
> > > > I didn't find any interesting difference by checking the
> > > > CPUX86State in the dest in kvm_arch_load_regs(), any thought on this?
> > > >
> > > > BTW, looks like the error_code was missed in saving the cpu state:
> > > >
> > > > diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> > > > index 35a1a51..145bb38 100644
> > > > --- a/target-i386/cpu.h
> > > > +++ b/target-i386/cpu.h
> > > > @@ -687,7 +687,7 @@ typedef struct CPUX86State {
> > > > uint64_t pat;
> > > >
> > > > /* exception/interrupt handling */
> > > > - int error_code;
> > > > + uint32_t error_code;
> > > > int exception_is_int;
> > > > target_ulong exception_next_eip;
> > > > target_ulong dr[8]; /* debug registers */
> > > > @@ -935,7 +935,7 @@ CPUState *pc_new_cpu(const char *cpu_model);
> > > > #define cpu_list_id x86_cpu_list
> > > > #define cpudef_setup x86_cpudef_setup
> > > >
> > > > -#define CPU_SAVE_VERSION 12
> > > > +#define CPU_SAVE_VERSION 13
> > > >
> > > > /* MMU modes definitions */
> > > > #define MMU_MODE0_SUFFIX _kernel
> > > > diff --git a/target-i386/machine.c b/target-i386/machine.c
> > > > index 4398801..fa231d8 100644
> > > > --- a/target-i386/machine.c
> > > > +++ b/target-i386/machine.c
> > > > @@ -474,6 +474,8 @@ static const VMStateDescription vmstate_cpu = {
> > > > VMSTATE_UINT64_V(xcr0, CPUState, 12),
> > > > VMSTATE_UINT64_V(xstate_bv, CPUState, 12),
> > > > VMSTATE_YMMH_REGS_VARS(ymmh_regs, CPUState, CPU_NB_REGS, 12),
> > > > +
> > > > + VMSTATE_UINT32_V(error_code, CPUState, 13),
> > > > VMSTATE_END_OF_LIST()
> > > > /* The above list is not sorted /wrt version numbers, watch
> > out! */
> > > > }
