From 6f43ed01e87c8a8dbd8c826eaf0f714c1342c039 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Tue, 15 Jul 2014 17:37:46 +0300 Subject: KVM: x86: DR6/7.RTM cannot be written Haswell and newer Intel CPUs have support for RTM, and in that case DR6.RTM is not fixed to 1 and DR7.RTM is not fixed to zero. That is not the case in the current KVM implementation. This bug is apparent only if the MOV-DR instruction is emulated or the host also debugs the guest. This patch is a partial fix which enables DR6.RTM and DR7.RTM to be cleared and set respectively. It also sets DR6.RTM upon every debug exception. Obviously, it is not a complete fix, as debugging of RTM is still unsupported. Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b8a4480176b9..a84eaf7ba33f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -152,14 +152,16 @@ enum { #define DR6_BD (1 << 13) #define DR6_BS (1 << 14) -#define DR6_FIXED_1 0xffff0ff0 -#define DR6_VOLATILE 0x0000e00f +#define DR6_RTM (1 << 16) +#define DR6_FIXED_1 0xfffe0ff0 +#define DR6_INIT 0xffff0ff0 +#define DR6_VOLATILE 0x0001e00f #define DR7_BP_EN_MASK 0x000000ff #define DR7_GE (1 << 9) #define DR7_GD (1 << 13) #define DR7_FIXED_1 0x00000400 -#define DR7_VOLATILE 0xffff23ff +#define DR7_VOLATILE 0xffff2bff /* apic attention bits */ #define KVM_APIC_CHECK_VAPIC 0 -- cgit v1.2.3