From: Jan Kiszka Date: Fri, 30 Oct 2009 11:46:59 +0000 (+0100) Subject: KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4f926bf291863c237188bd2e27222ed801f12094;p=linux-beck.git KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG Decouple KVM_GUESTDBG_INJECT_DB and KVM_GUESTDBG_INJECT_BP from KVM_GUESTDBG_ENABLE, their are actually orthogonal. At this chance, avoid triggering the WARN_ON in kvm_queue_exception if there is already an exception pending and reject such invalid requests. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cd6fe0a5797f..ba8958dca3c4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4656,10 +4656,20 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) { unsigned long rflags; - int i; + int i, r; vcpu_load(vcpu); + if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) { + r = -EBUSY; + if (vcpu->arch.exception.pending) + goto unlock_out; + if (dbg->control & KVM_GUESTDBG_INJECT_DB) + kvm_queue_exception(vcpu, DB_VECTOR); + else + kvm_queue_exception(vcpu, BP_VECTOR); + } + /* * Read rflags as long as potentially injected trace flags are still * filtered out. @@ -4695,14 +4705,12 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_x86_ops->set_guest_debug(vcpu, dbg); - if (vcpu->guest_debug & KVM_GUESTDBG_INJECT_DB) - kvm_queue_exception(vcpu, DB_VECTOR); - else if (vcpu->guest_debug & KVM_GUESTDBG_INJECT_BP) - kvm_queue_exception(vcpu, BP_VECTOR); + r = 0; +unlock_out: vcpu_put(vcpu); - return 0; + return r; } /*