From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH 2/2] KVM: VMX: Fix guest debugging while in L2 Date: Tue, 9 Feb 2016 20:15:18 +0100 Message-ID: <56BA3AC6.6000104@web.de> References: <56BA3A8D.7020106@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm To: Paolo Bonzini Return-path: Received: from mout.web.de ([212.227.17.11]:52555 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932359AbcBITPY (ORCPT ); Tue, 9 Feb 2016 14:15:24 -0500 In-Reply-To: <56BA3A8D.7020106@web.de> Sender: kvm-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 From: Jan Kiszka When we take a #DB or #BP vmexit while in guest mode, we first of all need to check if there is ongoing guest debugging that might be interested in the event. Currently, we unconditionally leave L2 and inject the event into L1 if it is intercepting the exceptions. That breaks things marvelously. Signed-off-by: Jan Kiszka - --- arch/x86/kvm/vmx.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7852092..cb501d3 100644 - --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -968,6 +968,16 @@ static inline bool is_exception_n(u32 intr_info, u8 vector) (INTR_TYPE_HARD_EXCEPTION | vector | INTR_INFO_VALID_MASK); } +static inline bool is_debug(u32 intr_info) +{ + return is_exception_n(intr_info, DB_VECTOR); +} + +static inline bool is_breakpoint(u32 intr_info) +{ + return is_exception_n(intr_info, BP_VECTOR); +} + static inline bool is_page_fault(u32 intr_info) { return is_exception_n(intr_info, PF_VECTOR); @@ -7753,6 +7763,13 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu) else if (is_no_device(intr_info) && !(vmcs12->guest_cr0 & X86_CR0_TS)) return false; + else if (is_debug(intr_info) && + vcpu->guest_debug & + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) + return false; + else if (is_breakpoint(intr_info) && + vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) + return false; return vmcs12->exception_bitmap & (1u << (intr_info & INTR_INFO_VECTOR_MASK)); case EXIT_REASON_EXTERNAL_INTERRUPT: - -- 2.1.4 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAla6OsYACgkQitSsb3rl5xSzCACffw3KGJi4oXaT2WM6ec5puJNe 4bUAn012m9dYnUkkRBC7iHNENFbKs1y2 =abYj -----END PGP SIGNATURE-----