[Devel] [PATCH RHEL7 COMMIT] ms/KVM: nVMX: Don't halt vcpu when L1 is injecting events to L2

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.21.1.vz7.46.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.21.1.vz7.46.4
------>
commit afd8e4208c1da64732bb5c15e395c432285bef35
Author: Chao Gao <chao.gao at intel.com>
Date:   Fri Apr 6 18:44:48 2018 +0300

    ms/KVM: nVMX: Don't halt vcpu when L1 is injecting events to L2
    
    Although L2 is in halt state, it will be in the active state after
    VM entry if the VM entry is vectoring according to SDM 26.6.2 Activity
    State. Halting the vcpu here means the event won't be injected to L2
    and this decision isn't reported to L1. Thus L0 drops an event that
    should be injected to L2.
    
    Cc: Liran Alon <liran.alon at oracle.com>
    Reviewed-by: Liran Alon <liran.alon at oracle.com>
    Signed-off-by: Chao Gao <chao.gao at intel.com>
    Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
    
    https://jira.sw.ru/browse/PSBM-83005
    (cherry picked from commit 135a06c3a515bbd17729eb04f4f26316d48363d7)
    Signed-off-by: Jan Dakinevich <jan.dakinevich at virtuozzo.com>
    
    ==========================================
    Patchset description:
    kernel fixes after kvm-unit-tests
    
    https://jira.sw.ru/browse/PSBM-83005
    
    patch 1
      Chao Gao (1):
        KVM: nVMX: Don't halt vcpu when L1 is injecting events to L2
      fixes 'vmx_cr_load_test':
        FAIL: Test return 3 code: FAIL: x86/vmx_tests.c:3912: Assertion failed:
            !write_cr4_checking(cr4 | X86_CR4_MCE)
    
    patch 2
      Haozhong Zhang (1):
        KVM: nVMX: Don't halt vcpu when L1 is injecting events to L2
      fixes 'vmx_interrupt'
        FAIL: QEMU command timed out
---
 arch/x86/kvm/vmx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7d7f0fae475b..7a566de088de 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10116,7 +10116,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 
 	vmcs12->launch_state = 1;
 
-	if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT)
+	/*
+	 * If we're entering a halted L2 vcpu and the L2 vcpu won't be woken
+	 * by event injection, halt vcpu.
+	 */
+	if ((vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) &&
+	    !(vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK))
 		return kvm_vcpu_halt(vcpu);
 
 	vmx->nested.nested_run_pending = 1;