On 26/02/2017 09:46, Wanpeng Li wrote:
> From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
>
> L2 fails to boot on a non-APICv box dues to 'commit 0ad3bed6c5ec
> ("kvm: nVMX: move nested events check to kvm_vcpu_running")'
>
> KVM internal error. Suberror: 3
> extra data[0]: 800000ef
> extra data[1]: 1
> RAX=0000000000000000 RBX=ffffffff81f36140 RCX=0000000000000000 RDX=0000000000000000
> RSI=0000000000000000 RDI=0000000000000000 RBP=ffff88007c92fe90 RSP=ffff88007c92fe90
> R8 =ffff88007fccdca0 R9 =0000000000000000 R10=00000000fffedb3d R11=0000000000000000
> R12=0000000000000003 R13=0000000000000000 R14=0000000000000000 R15=ffff88007c92c000
> RIP=ffffffff810645e6 RFL=00000246 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =0000 0000000000000000 ffffffff 00c00000
> CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
> SS =0000 0000000000000000 ffffffff 00c00000
> DS =0000 0000000000000000 ffffffff 00c00000
> FS =0000 0000000000000000 ffffffff 00c00000
> GS =0000 ffff88007fcc0000 ffffffff 00c00000
> LDT=0000 0000000000000000 ffffffff 00c00000
> TR =0040 ffff88007fcd4200 00002087 00008b00 DPL=0 TSS64-busy
> GDT= ffff88007fcc9000 0000007f
> IDT= ffffffffff578000 00000fff
> CR0=80050033 CR2=00000000ffffffff CR3=0000000001e0a000 CR4=003406e0
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
> DR6=00000000fffe0ff0 DR7=0000000000000400
> EFER=0000000000000d01
>
> We should try to reinject previous events if any before trying to inject
> new event if pending. If vmexit is triggered by L2 guest and L0 interested
> in, we should reinject IDT-vectoring info to L2 through vmcs02 if any,
> otherwise, we can consider new IRQs/NMIs which can be injected and call
> nested events callback to switch from L2 to L1 if needed and inject the
> proper vmexit events. However, 'commit 0ad3bed6c5ec ("kvm: nVMX: move
> nested events check to kvm_vcpu_running")' results in the handle events
> order reversely on non-APICv box. This patch fixes it by checking nested
> events if there is no KVM_REQ_EVENT since APICv interrupt injection doesn't
> use KVM_REQ_EVENT any more.
>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
I need to understand this better. I would hope that something like
@@ -10668,7 +10598,8 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
if ((kvm_cpu_has_interrupt(vcpu) || external_intr) &&
nested_exit_on_intr(vcpu)) {
- if (vmx->nested.nested_run_pending)
+ if (vmx->nested.nested_run_pending ||
+ vcpu->arch.interrupt.pending)
return -EBUSY;
nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
return 0;
does it instead.
Paolo
> ---
> arch/x86/kvm/x86.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index b2a4b11..74fc47b 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6843,7 +6843,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
> update_cr8_intercept(vcpu);
> kvm_lapic_sync_to_vapic(vcpu);
> }
> - }
> + } else if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events)
> + kvm_x86_ops->check_nested_events(vcpu, false);
>
> r = kvm_mmu_reload(vcpu);
> if (unlikely(r)) {
> @@ -7025,9 +7026,6 @@ static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
>
> static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu)
> {
> - if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events)
> - kvm_x86_ops->check_nested_events(vcpu, false);
> -
> return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
> !vcpu->arch.apf.halted);
> }
> @@ -8397,6 +8395,9 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
>
> int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
> {
> + if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events)
> + kvm_x86_ops->check_nested_events(vcpu, false);
> +
> return kvm_vcpu_running(vcpu) || kvm_vcpu_has_events(vcpu);
> }
>
>
