[RFC PATCH 18/67] KVM: x86: Add per-VM flag to disable direct IRQ injection

From: isaku . yamahata
Date: Mon Nov 16 2020 - 13:28:16 EST


From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

Add a flag to disable IRQ injection, which is not supported by TDX.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e687a8bd46ad..e8180a1fe610 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -995,6 +995,7 @@ struct kvm_arch {
} msr_filter;

bool guest_state_protected;
+ bool irq_injection_disallowed;

struct kvm_pmu_event_filter *pmu_event_filter;
struct task_struct *nx_lpage_recovery_thread;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6154abecd546..ec66d5d53a1a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4041,7 +4041,8 @@ static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
struct kvm_interrupt *irq)
{
- if (irq->irq >= KVM_NR_INTERRUPTS)
+ if (irq->irq >= KVM_NR_INTERRUPTS ||
+ vcpu->kvm->arch.irq_injection_disallowed)
return -EINVAL;

if (!irqchip_in_kernel(vcpu->kvm)) {
@@ -8170,6 +8171,7 @@ static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
{
return vcpu->run->request_interrupt_window &&
+ !vcpu->kvm->arch.irq_injection_disallowed &&
likely(!pic_in_kernel(vcpu->kvm));
}

--
2.17.1