From: Paolo Bonzini <pbonzini@redhat.com>
To: "Radim Krčmář" <rkrcmar@redhat.com>, "Nadav Amit" <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@cs.technion.ac.il>,
joro@8bytes.org, kvm@vger.kernel.org
Subject: Re: [PATCH 5/5] KVM: x86: Using TSC deadline may cause multiple interrupts by user writes
Date: Wed, 08 Oct 2014 12:07:47 +0200 [thread overview]
Message-ID: <54350CF3.80403@redhat.com> (raw)
In-Reply-To: <20141008100619.GA20422@potion.brq.redhat.com>
Il 08/10/2014 12:06, Radim Krčmář ha scritto:
> > > - why is host_initiated required?
>
> > Since if the guest writes to the MSR, it means it wants to rearm the TSC deadline. Even if the deadline passed, interrupt should be triggered.
>
> MSR isn't 0, so the deadline hasn't passed for the guest yet.
>
> > If the guest writes the same value on the deadline MSR twice, it might expect two interrupts.
>
> When guest writes to it without getting an interrupt first, it might
> expect just one. (Which it better IMO.)
Indeed that was my doubt as well.
Paolo
next prev parent reply other threads:[~2014-10-08 10:08 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-02 22:10 [PATCH 0/5] KVM: x86: Various bug fixes Nadav Amit
2014-10-02 22:10 ` [PATCH 1/5] KVM: x86: Clear DR7.LE during task-switch Nadav Amit
2014-10-06 19:45 ` Radim Krčmář
2014-10-02 22:10 ` [PATCH 2/5] KVM: x86: Emulator performs code segment checks on read access Nadav Amit
2014-10-06 20:32 ` Radim Krčmář
2014-10-10 2:07 ` [PATCH v2 " Nadav Amit
2014-10-10 15:54 ` Radim Krčmář
2014-10-11 9:39 ` Paolo Bonzini
2014-10-12 6:57 ` Nadav Amit
2014-10-12 12:12 ` Paolo Bonzini
2014-10-12 23:15 ` Nadav Amit
2014-10-13 4:29 ` Paolo Bonzini
2014-10-13 11:31 ` Gleb Natapov
2014-10-19 16:07 ` Nadav Amit
2014-10-02 22:10 ` [PATCH 3/5] KVM: x86: Decoding guest instructions which cross page boundary may fail Nadav Amit
2014-10-06 20:50 ` Radim Krčmář
2014-10-07 9:15 ` Nadav Amit
2014-10-08 9:02 ` Paolo Bonzini
2014-10-02 22:10 ` [PATCH 4/5] KVM: vmx: Unavailable DR4/5 is checked before CPL Nadav Amit
2014-10-06 19:33 ` Radim Krčmář
2014-10-02 22:10 ` [PATCH 5/5] KVM: x86: Using TSC deadline may cause multiple interrupts by user writes Nadav Amit
2014-10-06 20:57 ` Radim Krčmář
2014-10-07 9:35 ` Nadav Amit
2014-10-08 10:06 ` Radim Krčmář
2014-10-08 10:07 ` Paolo Bonzini [this message]
2014-10-10 1:55 ` Nadav Amit
2014-10-10 9:45 ` Paolo Bonzini
2014-10-10 12:50 ` Radim Krčmář
2014-10-10 12:51 ` Nadav Amit
2014-10-10 13:55 ` Paolo Bonzini
2014-10-10 14:02 ` Paolo Bonzini
2014-10-08 9:29 ` Paolo Bonzini
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