From: Oliver Upton <oupton@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm list <kvm@vger.kernel.org>, Jim Mattson <jmattson@google.com>,
Peter Shier <pshier@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Subject: Re: [PATCH v3 0/5] Handle monitor trap flag during instruction emulation
Date: Thu, 27 Feb 2020 01:11:53 -0800 [thread overview]
Message-ID: <CAOQ_QsgbDUNxKgqEnQUs_sHShrRREpqwJ_=Cg9bjdo9-sBBH9A@mail.gmail.com> (raw)
In-Reply-To: <74650413-5cbc-6dd7-498e-22e89f1f6732@redhat.com>
On Wed, Feb 26, 2020 at 10:38 PM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 27/02/20 01:22, Oliver Upton wrote:
> > Are there any strong opinions about how the newly introduced nested
> > state should be handled across live migrations? When applying this
> > patch set internally I realized live migration would be busted in the
> > case of a kernel rollback (i.e. a kernel with this patchset emits the
> > nested state, kernel w/o receives it + refuses).
>
> Only if you use MTF + emulation. In this case it's a pure bugfix so
> it's okay to break backwards migration. If it's really a new feature,
> it should support KVM_ENABLE_CAP to enable it.
>
> Paolo
>
True. I suppose I've conflated the pure bugfix here with the fact that
MTF is new to us.
Thanks Paolo!
--
Best,
Oliver
> > Easy fix is to only turn on the feature once it is rollback-proof, but
> > I wonder if there is any room for improvement on this topic..
>
prev parent reply other threads:[~2020-02-27 9:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-07 10:36 [PATCH v3 0/5] Handle monitor trap flag during instruction emulation Oliver Upton
2020-02-07 10:36 ` [PATCH v3 1/5] KVM: x86: Mask off reserved bit from #DB exception payload Oliver Upton
2020-02-07 10:36 ` [PATCH v3 2/5] KVM: nVMX: Handle pending #DB when injecting INIT VM-exit Oliver Upton
2020-02-07 10:36 ` [PATCH v3 3/5] KVM: x86: Deliver exception payload on KVM_GET_VCPU_EVENTS Oliver Upton
2020-02-07 10:36 ` [PATCH v3 4/5] KVM: nVMX: Emulate MTF when performing instruction emulation Oliver Upton
2020-02-07 10:36 ` [kvm-unit-tests PATCH v3 5/5] x86: VMX: Add tests for monitor trap flag Oliver Upton
2020-02-25 0:09 ` Oliver Upton
2020-02-25 7:36 ` Paolo Bonzini
2020-02-25 7:52 ` Oliver Upton
2020-02-26 0:13 ` Krish Sadhukhan
2020-02-26 0:55 ` Oliver Upton
2020-02-12 11:34 ` [PATCH v3 0/5] Handle monitor trap flag during instruction emulation Paolo Bonzini
2020-02-27 0:22 ` Oliver Upton
2020-02-27 6:37 ` Paolo Bonzini
2020-02-27 9:11 ` Oliver Upton [this message]
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