[PATCH 2/2] KVM: nVMX: fix for disappearing L1->L2 event injection on L1 migration

From: Maxim Levitsky
Date: Wed Jan 06 2021 - 05:55:09 EST


If migration happens while L2 entry with an injected event to L2 is pending,
we weren't including the event in the migration state and it would be
lost leading to L2 hang.

Fix this by queueing the injected event in similar manner to how we queue
interrupted injections.

This can be reproduced by running an IO intense task in L2,
and repeatedly migrating the L1.

Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index e2f26564a12de..2ea0bb14f385f 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2355,12 +2355,12 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
* Interrupt/Exception Fields
*/
if (vmx->nested.nested_run_pending) {
- vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
- vmcs12->vm_entry_intr_info_field);
- vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
- vmcs12->vm_entry_exception_error_code);
- vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
- vmcs12->vm_entry_instruction_len);
+ if ((vmcs12->vm_entry_intr_info_field & VECTORING_INFO_VALID_MASK))
+ vmx_process_injected_event(&vmx->vcpu,
+ vmcs12->vm_entry_intr_info_field,
+ vmcs12->vm_entry_instruction_len,
+ vmcs12->vm_entry_exception_error_code);
+
vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
vmcs12->guest_interruptibility_info);
vmx->loaded_vmcs->nmi_known_unmasked =
--
2.26.2