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| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-11-02 11:54:45 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-11-07 15:44:04 +0100 |
| commit | 82b32774c2d00c0a12ab182c67e32e0b5e5e580a (patch) | |
| tree | 4952f26cbee010060c1b447216cc60961b9edee5 /arch/x86/kvm/x86.c | |
| parent | 7305eb5d8cf147ce4178e723c95de15e2f001429 (diff) | |
| download | lwn-82b32774c2d00c0a12ab182c67e32e0b5e5e580a.tar.gz lwn-82b32774c2d00c0a12ab182c67e32e0b5e5e580a.zip | |
KVM: x86: Breakpoints do not consider CS.base
x86 debug registers hold a linear address. Therefore, breakpoints detection
should consider CS.base, and check whether instruction linear address equals
(CS.base + RIP). This patch introduces a function to evaluate RIP linear
address and uses it for breakpoints detection.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e8850295031f..773c17ec42dd 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5207,21 +5207,17 @@ static void kvm_vcpu_check_singlestep(struct kvm_vcpu *vcpu, unsigned long rflag static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r) { - struct kvm_run *kvm_run = vcpu->run; - unsigned long eip = vcpu->arch.emulate_ctxt.eip; - u32 dr6 = 0; - if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) && (vcpu->arch.guest_debug_dr7 & DR7_BP_EN_MASK)) { - dr6 = kvm_vcpu_check_hw_bp(eip, 0, + struct kvm_run *kvm_run = vcpu->run; + unsigned long eip = kvm_get_linear_rip(vcpu); + u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0, vcpu->arch.guest_debug_dr7, vcpu->arch.eff_db); if (dr6 != 0) { kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1 | DR6_RTM; - kvm_run->debug.arch.pc = kvm_rip_read(vcpu) + - get_segment_base(vcpu, VCPU_SREG_CS); - + kvm_run->debug.arch.pc = eip; kvm_run->debug.arch.exception = DB_VECTOR; kvm_run->exit_reason = KVM_EXIT_DEBUG; *r = EMULATE_USER_EXIT; @@ -5231,7 +5227,8 @@ static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r) if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK) && !(kvm_get_rflags(vcpu) & X86_EFLAGS_RF)) { - dr6 = kvm_vcpu_check_hw_bp(eip, 0, + unsigned long eip = kvm_get_linear_rip(vcpu); + u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0, vcpu->arch.dr7, vcpu->arch.db); @@ -7538,12 +7535,18 @@ int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu) return kvm_x86_ops->interrupt_allowed(vcpu); } -bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip) +unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu) { - unsigned long current_rip = kvm_rip_read(vcpu) + - get_segment_base(vcpu, VCPU_SREG_CS); + if (is_64_bit_mode(vcpu)) + return kvm_rip_read(vcpu); + return (u32)(get_segment_base(vcpu, VCPU_SREG_CS) + + kvm_rip_read(vcpu)); +} +EXPORT_SYMBOL_GPL(kvm_get_linear_rip); - return current_rip == linear_rip; +bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip) +{ + return kvm_get_linear_rip(vcpu) == linear_rip; } EXPORT_SYMBOL_GPL(kvm_is_linear_rip); |