[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 9/9] qemu/kvm: kvm hyper-v based guest crash eve
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 9/9] qemu/kvm: kvm hyper-v based guest crash event handling |
Date: |
Thu, 2 Jul 2015 15:30:26 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 |
On 02/07/2015 15:19, Andrey Smetanin wrote:
>>> > > + if (has_msr_hv_crash) {
>>> > > + env->msr_hv_crash_ctl = HV_X64_MSR_CRASH_CTL_NOTIFY;
>> >
>> > The value is always host-defined, so I think it doesn't need a field in
>> > CPUX86State. On the other hand, this:
> Kernel just works with that value, kernel doesn't setup it.
> The user space is allowed to setup this msr if qemu option "hv-crash" is
> on. So the code "env->msr_hv_crash_ctl = HV_X64_MSR_CRASH_CTL_NOTIFY;"
> setups msr in user space at cpu reset. When cpu setup it's registers
> these msr's values are uploaded into kernel.
>
> Anyway we need a code that initially set up crash ctl msr with value
> HV_X64_MSR_CRASH_CTL_NOTIFY. And I think that code should be user space.
> Any objections ?
Yes, that's correct.
What I'm saying, is that the value can be hard-coded and doesn't need a
field in CPUX86State. If you want to leave the field that's also okay,
but even then it should not be part of the migration state.
Paolo