| Message ID | 5319F7FE.50106@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2014-03-07 17:46, Paolo Bonzini wrote: > Il 07/03/2014 17:29, Jan Kiszka ha scritto: >> On 2014-03-07 16:44, Paolo Bonzini wrote: >>> With this patch do we still need >>> >>> if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>> /* >>> * We get here if vmx_interrupt_allowed() said we can't >>> * inject to L1 now because L2 must run. The caller will have >>> * to make L2 exit right after entry, so we can inject to L1 >>> * more promptly. >>> */ >>> return -EBUSY; >>> >>> in enable_irq_window? If not, enable_nmi_window and enable_irq_window >>> can both return void. >> >> I don't see right now why this should have changed. We still cannot >> interrupt vmlaunch/vmresume. > > But then shouldn't the ame be true for enable_nmi_window? It doesn't > check is_guest_mode(vcpu) && nested_exit_on_nmi(vcpu). Yes, that seems wrong now. But I need to think this through again, why we may have excluded NMIs from this test so far. > > Since check_nested_events has already returned -EBUSY, perhaps the > following: > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index fda1028..df320e9 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) > { > u32 cpu_based_vm_exec_control; > > - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) > - /* > - * We get here if vmx_interrupt_allowed() said we can't > - * inject to L1 now because L2 must run. The caller will have > - * to make L2 exit right after entry, so we can inject to L1 > - * more promptly. > - */ > - return -EBUSY; > - > cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); > cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; > vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index a03d611..83c2df5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > > inject_pending_event(vcpu); > > - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) > - req_immediate_exit |= > - kvm_x86_ops->check_nested_events(vcpu, > - req_int_win) != 0; > + if (is_guest_mode(vcpu) && > + kvm_x86_ops->check_nested_events && > + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) > + req_immediate_exit = true; > > /* enable NMI/IRQ window open exits if needed */ > - if (vcpu->arch.nmi_pending) > + else if (vcpu->arch.nmi_pending) > req_immediate_exit |= > kvm_x86_ops->enable_nmi_window(vcpu) != 0; > else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) > Hmm, looks reasonable. Jan
On 2014-03-07 18:28, Jan Kiszka wrote: > On 2014-03-07 17:46, Paolo Bonzini wrote: >> Il 07/03/2014 17:29, Jan Kiszka ha scritto: >>> On 2014-03-07 16:44, Paolo Bonzini wrote: >>>> With this patch do we still need >>>> >>>> if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>>> /* >>>> * We get here if vmx_interrupt_allowed() said we can't >>>> * inject to L1 now because L2 must run. The caller will have >>>> * to make L2 exit right after entry, so we can inject to L1 >>>> * more promptly. >>>> */ >>>> return -EBUSY; >>>> >>>> in enable_irq_window? If not, enable_nmi_window and enable_irq_window >>>> can both return void. >>> >>> I don't see right now why this should have changed. We still cannot >>> interrupt vmlaunch/vmresume. >> >> But then shouldn't the ame be true for enable_nmi_window? It doesn't >> check is_guest_mode(vcpu) && nested_exit_on_nmi(vcpu). > > Yes, that seems wrong now. But I need to think this through again, why > we may have excluded NMIs from this test so far. > >> >> Since check_nested_events has already returned -EBUSY, perhaps the >> following: >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index fda1028..df320e9 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) >> { >> u32 cpu_based_vm_exec_control; >> >> - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >> - /* >> - * We get here if vmx_interrupt_allowed() said we can't >> - * inject to L1 now because L2 must run. The caller will have >> - * to make L2 exit right after entry, so we can inject to L1 >> - * more promptly. >> - */ >> - return -EBUSY; >> - >> cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); >> cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; >> vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index a03d611..83c2df5 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) >> >> inject_pending_event(vcpu); >> >> - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) >> - req_immediate_exit |= >> - kvm_x86_ops->check_nested_events(vcpu, >> - req_int_win) != 0; >> + if (is_guest_mode(vcpu) && >> + kvm_x86_ops->check_nested_events && >> + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) >> + req_immediate_exit = true; >> >> /* enable NMI/IRQ window open exits if needed */ >> - if (vcpu->arch.nmi_pending) >> + else if (vcpu->arch.nmi_pending) >> req_immediate_exit |= >> kvm_x86_ops->enable_nmi_window(vcpu) != 0; >> else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) >> > > Hmm, looks reasonable. Also on second thought. I can give this hunk some test cycles here, just in case. Reading through my code again, I'm now wondering why I added check_nested_events to both inject_pending_event and vcpu_enter_guest. The former seems redundant, only vcpu_enter_guest calls inject_pending_event. I guess I forgot a cleanup here. I can fold in your changes when I resend for the other cleanup. Jan
Il 07/03/2014 19:19, Jan Kiszka ha scritto: > On 2014-03-07 18:28, Jan Kiszka wrote: >> On 2014-03-07 17:46, Paolo Bonzini wrote: >>> Il 07/03/2014 17:29, Jan Kiszka ha scritto: >>>> On 2014-03-07 16:44, Paolo Bonzini wrote: >>>>> With this patch do we still need >>>>> >>>>> if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>>>> /* >>>>> * We get here if vmx_interrupt_allowed() said we can't >>>>> * inject to L1 now because L2 must run. The caller will have >>>>> * to make L2 exit right after entry, so we can inject to L1 >>>>> * more promptly. >>>>> */ >>>>> return -EBUSY; >>>>> >>>>> in enable_irq_window? If not, enable_nmi_window and enable_irq_window >>>>> can both return void. >>>> >>>> I don't see right now why this should have changed. We still cannot >>>> interrupt vmlaunch/vmresume. >>> >>> But then shouldn't the ame be true for enable_nmi_window? It doesn't >>> check is_guest_mode(vcpu) && nested_exit_on_nmi(vcpu). >> >> Yes, that seems wrong now. But I need to think this through again, why >> we may have excluded NMIs from this test so far. >> >>> >>> Since check_nested_events has already returned -EBUSY, perhaps the >>> following: >>> >>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >>> index fda1028..df320e9 100644 >>> --- a/arch/x86/kvm/vmx.c >>> +++ b/arch/x86/kvm/vmx.c >>> @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) >>> { >>> u32 cpu_based_vm_exec_control; >>> >>> - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>> - /* >>> - * We get here if vmx_interrupt_allowed() said we can't >>> - * inject to L1 now because L2 must run. The caller will have >>> - * to make L2 exit right after entry, so we can inject to L1 >>> - * more promptly. >>> - */ >>> - return -EBUSY; >>> - >>> cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); >>> cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; >>> vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); >>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >>> index a03d611..83c2df5 100644 >>> --- a/arch/x86/kvm/x86.c >>> +++ b/arch/x86/kvm/x86.c >>> @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) >>> >>> inject_pending_event(vcpu); >>> >>> - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) >>> - req_immediate_exit |= >>> - kvm_x86_ops->check_nested_events(vcpu, >>> - req_int_win) != 0; >>> + if (is_guest_mode(vcpu) && >>> + kvm_x86_ops->check_nested_events && >>> + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) >>> + req_immediate_exit = true; >>> >>> /* enable NMI/IRQ window open exits if needed */ >>> - if (vcpu->arch.nmi_pending) >>> + else if (vcpu->arch.nmi_pending) >>> req_immediate_exit |= >>> kvm_x86_ops->enable_nmi_window(vcpu) != 0; >>> else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) >>> >> >> Hmm, looks reasonable. > > Also on second thought. I can give this hunk some test cycles here, just > in case. Thanks. > Reading through my code again, I'm now wondering why I added > check_nested_events to both inject_pending_event and vcpu_enter_guest. > The former seems redundant, only vcpu_enter_guest calls > inject_pending_event. I guess I forgot a cleanup here. > > I can fold in your changes when I resend for the other cleanup. As you prefer, I can also post it as a separate patch (my changes above do not have the int->void change). I had pushed your patches already to kvm/queue. You can post v4 relative to kvm/next. 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
On 2014-03-07 19:19, Jan Kiszka wrote: > On 2014-03-07 18:28, Jan Kiszka wrote: >> On 2014-03-07 17:46, Paolo Bonzini wrote: >>> Il 07/03/2014 17:29, Jan Kiszka ha scritto: >>>> On 2014-03-07 16:44, Paolo Bonzini wrote: >>>>> With this patch do we still need >>>>> >>>>> if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>>>> /* >>>>> * We get here if vmx_interrupt_allowed() said we can't >>>>> * inject to L1 now because L2 must run. The caller will have >>>>> * to make L2 exit right after entry, so we can inject to L1 >>>>> * more promptly. >>>>> */ >>>>> return -EBUSY; >>>>> >>>>> in enable_irq_window? If not, enable_nmi_window and enable_irq_window >>>>> can both return void. >>>> >>>> I don't see right now why this should have changed. We still cannot >>>> interrupt vmlaunch/vmresume. >>> >>> But then shouldn't the ame be true for enable_nmi_window? It doesn't >>> check is_guest_mode(vcpu) && nested_exit_on_nmi(vcpu). >> >> Yes, that seems wrong now. But I need to think this through again, why >> we may have excluded NMIs from this test so far. >> >>> >>> Since check_nested_events has already returned -EBUSY, perhaps the >>> following: >>> >>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >>> index fda1028..df320e9 100644 >>> --- a/arch/x86/kvm/vmx.c >>> +++ b/arch/x86/kvm/vmx.c >>> @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) >>> { >>> u32 cpu_based_vm_exec_control; >>> >>> - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) >>> - /* >>> - * We get here if vmx_interrupt_allowed() said we can't >>> - * inject to L1 now because L2 must run. The caller will have >>> - * to make L2 exit right after entry, so we can inject to L1 >>> - * more promptly. >>> - */ >>> - return -EBUSY; >>> - >>> cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); >>> cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; >>> vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); >>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >>> index a03d611..83c2df5 100644 >>> --- a/arch/x86/kvm/x86.c >>> +++ b/arch/x86/kvm/x86.c >>> @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) >>> >>> inject_pending_event(vcpu); >>> >>> - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) >>> - req_immediate_exit |= >>> - kvm_x86_ops->check_nested_events(vcpu, >>> - req_int_win) != 0; >>> + if (is_guest_mode(vcpu) && >>> + kvm_x86_ops->check_nested_events && >>> + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) >>> + req_immediate_exit = true; >>> >>> /* enable NMI/IRQ window open exits if needed */ >>> - if (vcpu->arch.nmi_pending) >>> + else if (vcpu->arch.nmi_pending) >>> req_immediate_exit |= >>> kvm_x86_ops->enable_nmi_window(vcpu) != 0; >>> else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) >>> >> >> Hmm, looks reasonable. > > Also on second thought. I can give this hunk some test cycles here, just > in case. > > Reading through my code again, I'm now wondering why I added > check_nested_events to both inject_pending_event and vcpu_enter_guest. > The former seems redundant, only vcpu_enter_guest calls > inject_pending_event. I guess I forgot a cleanup here. Nah, it's not redundant, we need to check for potential L2->L2 switches *before* trying deliver events to L2. But think I can (and probably should) get rid of the second test in vcpu_enter_guest. Jan > > I can fold in your changes when I resend for the other cleanup. > > Jan >
Il 07/03/2014 19:26, Jan Kiszka ha scritto: >> > Reading through my code again, I'm now wondering why I added >> > check_nested_events to both inject_pending_event and vcpu_enter_guest. >> > The former seems redundant, only vcpu_enter_guest calls >> > inject_pending_event. I guess I forgot a cleanup here. > Nah, it's not redundant, we need to check for potential L2->L2 switches > *before* trying deliver events to L2. Yeah, and after the call in inject_pending_event you can similarly have an "else if" since vmx_nmi/interrupt_allowed will check nested_run_pending and never return true. > But think I can (and probably > should) get rid of the second test in vcpu_enter_guest. If so inject_pending_event would return true to request an immediate exit, right? 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 fda1028..df320e9 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4522,15 +4522,6 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) { u32 cpu_based_vm_exec_control; - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) - /* - * We get here if vmx_interrupt_allowed() said we can't - * inject to L1 now because L2 must run. The caller will have - * to make L2 exit right after entry, so we can inject to L1 - * more promptly. - */ - return -EBUSY; - cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a03d611..83c2df5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5970,13 +5970,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) inject_pending_event(vcpu); - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) - req_immediate_exit |= - kvm_x86_ops->check_nested_events(vcpu, - req_int_win) != 0; + if (is_guest_mode(vcpu) && + kvm_x86_ops->check_nested_events && + kvm_x86_ops->check_nested_events(vcpu, req_int_win) != 0) + req_immediate_exit = true; /* enable NMI/IRQ window open exits if needed */ - if (vcpu->arch.nmi_pending) + else if (vcpu->arch.nmi_pending) req_immediate_exit |= kvm_x86_ops->enable_nmi_window(vcpu) != 0; else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)