From: Jay Zhou <jianjay.zhou@xxxxxxxxxx>
commit 1f7becf1b7e21794fc9d460765fe09679bc9b9e0 upstream.
The injection process of smi has two steps:
Qemu KVM
Step1:
cpu->interrupt_request &= \
~CPU_INTERRUPT_SMI;
kvm_vcpu_ioctl(cpu, KVM_SMI)
call kvm_vcpu_ioctl_smi() and
kvm_make_request(KVM_REQ_SMI, vcpu);
Step2:
kvm_vcpu_ioctl(cpu, KVM_RUN, 0)
call process_smi() if
kvm_check_request(KVM_REQ_SMI, vcpu) is
true, mark vcpu->arch.smi_pending = true;
The vcpu->arch.smi_pending will be set true in step2, unfortunately if
vcpu paused between step1 and step2, the kvm_run->immediate_exit will be
set and vcpu has to exit to Qemu immediately during step2 before mark
vcpu->arch.smi_pending true.
During VM migration, Qemu will get the smi pending status from KVM using
KVM_GET_VCPU_EVENTS ioctl at the downtime, then the smi pending status
will be lost.
Signed-off-by: Jay Zhou <jianjay.zhou@xxxxxxxxxx>
Signed-off-by: Shengen Zhuang <zhuangshengen@xxxxxxxxxx>
Message-Id: <20210118084720.1585-1-jianjay.zhou@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -97,6 +97,7 @@ static u64 __read_mostly efer_reserved_b
static void update_cr8_intercept(struct kvm_vcpu *vcpu);
static void process_nmi(struct kvm_vcpu *vcpu);
+static void process_smi(struct kvm_vcpu *vcpu);
static void enter_smm(struct kvm_vcpu *vcpu);
static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
@@ -3199,6 +3200,10 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_
struct kvm_vcpu_events *events)
{
process_nmi(vcpu);
+
+ if (kvm_check_request(KVM_REQ_SMI, vcpu))
+ process_smi(vcpu);
+
events->exception.injected =
vcpu->arch.exception.pending &&
!kvm_exception_is_soft(vcpu->arch.exception.nr);
