linux-kernel - Re: [PATCH] KVM: vmx: DR7 masking on task switch emulation is wrong

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Message-ID: <5379E43E.9070502@redhat.com>
Date:	Mon, 19 May 2014 13:00:14 +0200
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Nadav Amit <namit@...technion.ac.il>
CC:	gleb@...nel.org, tglx@...utronix.de, mingo@...hat.com,
	hpa@...or.com, x86@...nel.org, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] KVM: vmx: DR7 masking on task switch emulation is wrong

Il 19/05/2014 08:50, Nadav Amit ha scritto:
> The DR7 masking which is done on task switch emulation should be in hex format
> (clearing the local breakpoints enable bits 0,2,4 and 6).
>
> Signed-off-by: Nadav Amit <namit@...technion.ac.il>
> ---
>  arch/x86/kvm/vmx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 138ceff..286d510 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5439,7 +5439,7 @@ static int handle_task_switch(struct kvm_vcpu *vcpu)
>  	}
>
>  	/* clear all local breakpoint enable flags */
> -	vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~55);
> +	vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~0x55);
>
>  	/*
>  	 * TODO: What about debug traps on tss switch?
>

Thanks, applying to kvm/queue.

Paolo
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