From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
------------[ cut here ]------------
WARNING: CPU: 7 PID: 3861 at /home/kernel/ssd/kvm/arch/x86/kvm//vmx.c:11299 nested_vmx_vmexit+0x176e/0x1980 [kvm_intel]
CPU: 7 PID: 3861 Comm: qemu-system-x86 Tainted: G W OE 4.13.0-rc4+ #11
RIP: 0010:nested_vmx_vmexit+0x176e/0x1980 [kvm_intel]
Call Trace:
? kvm_multiple_exception+0x149/0x170 [kvm]
? handle_emulation_failure+0x79/0x230 [kvm]
? load_vmcs12_host_state+0xa80/0xa80 [kvm_intel]
? check_chain_key+0x137/0x1e0
? reexecute_instruction.part.168+0x130/0x130 [kvm]
nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel]
? nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel]
vmx_queue_exception+0x197/0x300 [kvm_intel]
kvm_arch_vcpu_ioctl_run+0x1b0c/0x2c90 [kvm]
? kvm_arch_vcpu_runnable+0x220/0x220 [kvm]
? preempt_count_sub+0x18/0xc0
? restart_apic_timer+0x17d/0x300 [kvm]
? kvm_lapic_restart_hv_timer+0x37/0x50 [kvm]
? kvm_arch_vcpu_load+0x1d8/0x350 [kvm]
kvm_vcpu_ioctl+0x4e4/0x910 [kvm]
? kvm_vcpu_ioctl+0x4e4/0x910 [kvm]
? kvm_dev_ioctl+0xbe0/0xbe0 [kvm]
The flag "nested_run_pending", which can override the decision of which should run
next, L1 or L2. nested_run_pending=1 means that we *must* run L2 next, not L1. This
is necessary in particular when L1 did a VMLAUNCH of L2 and therefore expects L2 to
be run (and perhaps be injected with an event it specified, etc.). Nested_run_pending
is especially intended to avoid switching to L1 in the injection decision-point.
I catch this in the queue exception path, this patch fixes it by running L2 next
instead of L1 in the queue exception path.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e398946..3e64a9b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2466,6 +2466,9 @@ static int nested_vmx_check_exception(struct kvm_vcpu *vcpu)
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
unsigned int nr = vcpu->arch.exception.nr;
+ if (to_vmx(vcpu)->nested.nested_run_pending)
+ return 0;
+
if (nr == PF_VECTOR) {
if (vcpu->arch.exception.nested_apf) {
nested_vmx_inject_exception_vmexit(vcpu,
--
2.7.4
