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

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Message-Id: <1400482250-16631-1-git-send-email-namit@cs.technion.ac.il>
Date:	Mon, 19 May 2014 09:50:50 +0300
From:	Nadav Amit <namit@...technion.ac.il>
To:	pbonzini@...hat.com
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, Nadav Amit <namit@...technion.ac.il>
Subject: [PATCH] KVM: vmx: DR7 masking on task switch emulation is wrong

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?
-- 
1.9.1

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