| Message ID | 56BA3A8D.7020106@web.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 From: Jan Kiszka <jan.kiszka@siemens.com> 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 <jan.kiszka@siemens.com> - --- 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----- -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 09/02/2016 20:15, Jan Kiszka wrote: > From: Jan Kiszka <jan.kiszka@siemens.com> > > 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 <jan.kiszka@siemens.com> > --- > 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: > Thanks, I'll apply both patches shortly to kvm/queue. However, next time please do not sign the patches. git send-email doesn't like the way PGP signed messages escape "-" at the beginning of the line. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 164eb9e..7852092 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -961,25 +961,26 @@ static const u32 vmx_msr_index[] = { MSR_EFER, MSR_TSC_AUX, MSR_STAR, }; -static inline bool is_page_fault(u32 intr_info) +static inline bool is_exception_n(u32 intr_info, u8 vector) { return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK | INTR_INFO_VALID_MASK)) == - (INTR_TYPE_HARD_EXCEPTION | PF_VECTOR | INTR_INFO_VALID_MASK); + (INTR_TYPE_HARD_EXCEPTION | vector | INTR_INFO_VALID_MASK); +} + +static inline bool is_page_fault(u32 intr_info) +{ + return is_exception_n(intr_info, PF_VECTOR); } static inline bool is_no_device(u32 intr_info) { - return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK | - INTR_INFO_VALID_MASK)) == - (INTR_TYPE_HARD_EXCEPTION | NM_VECTOR | INTR_INFO_VALID_MASK); + return is_exception_n(intr_info, NM_VECTOR); } static inline bool is_invalid_opcode(u32 intr_info) { - return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK | - INTR_INFO_VALID_MASK)) == - (INTR_TYPE_HARD_EXCEPTION | UD_VECTOR | INTR_INFO_VALID_MASK); + return is_exception_n(intr_info, UD_VECTOR); } static inline bool is_external_interrupt(u32 intr_info)