linux-kernel - Re: [PATCH 1/3] KVM: x86: handle 0 write to TSC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 7 Oct 2017 08:26:39 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     Radim Krčmář <rkrcmar@...hat.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        kvm <kvm@...r.kernel.org>, Paolo Bonzini <pbonzini@...hat.com>
Subject: Re: [PATCH 1/3] KVM: x86: handle 0 write to TSC_DEADLINE MSR

2017-10-07 1:25 GMT+08:00 Radim Krčmář <rkrcmar@...hat.com>:
> 0 should disable the timer, but start_hv_timer will recognize it as an
> expired timer instead.
>
> Signed-off-by: Radim Krčmář <rkrcmar@...hat.com>

Reviewed-by: Wanpeng Li <wanpeng.li@...mail.com>

> ---
>  arch/x86/kvm/lapic.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 2c9e88a82738..39c1ae11ce1d 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1549,6 +1549,9 @@ static bool start_hv_timer(struct kvm_lapic *apic)
>         if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
>                 return false;
>
> +       if (!ktimer->tscdeadline)
> +               return false;
> +
>         r = kvm_x86_ops->set_hv_timer(apic->vcpu, ktimer->tscdeadline);
>         if (r < 0)
>                 return false;
> --
> 2.14.2
>