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authorMaxim Levitsky <mlevitsk@redhat.com>2021-11-08 11:02:45 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2021-11-11 10:56:20 -0500
commitcae72dcc3b219c6f85f543ab34452d7c7fe664c0 (patch)
tree9b16f7a9608012029394ae21e5564c04461987f9
parente6cd31f1a8ce2f1150225ae176a08d12119e2444 (diff)
KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active
KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using standard kvm's inject_pending_event, and not via APICv/AVIC. Since this is a debug feature, just inhibit APICv/AVIC while KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU. Fixes: 61e5f69ef0837 ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ") Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Tested-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/include/asm/kvm_host.h1
-rw-r--r--arch/x86/kvm/svm/avic.c3
-rw-r--r--arch/x86/kvm/vmx/vmx.c3
-rw-r--r--arch/x86/kvm/x86.c20
4 files changed, 25 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 32345241e620..b71023c64b83 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1034,6 +1034,7 @@ struct kvm_x86_msr_filter {
#define APICV_INHIBIT_REASON_IRQWIN 3
#define APICV_INHIBIT_REASON_PIT_REINJ 4
#define APICV_INHIBIT_REASON_X2APIC 5
+#define APICV_INHIBIT_REASON_BLOCKIRQ 6
struct kvm_arch {
unsigned long n_used_mmu_pages;
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 8052d92069e0..affc0ea98d30 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -904,7 +904,8 @@ bool svm_check_apicv_inhibit_reasons(ulong bit)
BIT(APICV_INHIBIT_REASON_NESTED) |
BIT(APICV_INHIBIT_REASON_IRQWIN) |
BIT(APICV_INHIBIT_REASON_PIT_REINJ) |
- BIT(APICV_INHIBIT_REASON_X2APIC);
+ BIT(APICV_INHIBIT_REASON_X2APIC) |
+ BIT(APICV_INHIBIT_REASON_BLOCKIRQ);
return supported & BIT(bit);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 71f54d85f104..e4fc9ff7cd94 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7565,7 +7565,8 @@ static void hardware_unsetup(void)
static bool vmx_check_apicv_inhibit_reasons(ulong bit)
{
ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) |
- BIT(APICV_INHIBIT_REASON_HYPERV);
+ BIT(APICV_INHIBIT_REASON_HYPERV) |
+ BIT(APICV_INHIBIT_REASON_BLOCKIRQ);
return supported & BIT(bit);
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6bfef1d70ce1..d7d2f1bbd83f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10753,6 +10753,24 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
return ret;
}
+static void kvm_arch_vcpu_guestdbg_update_apicv_inhibit(struct kvm *kvm)
+{
+ bool inhibit = false;
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ down_write(&kvm->arch.apicv_update_lock);
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (vcpu->guest_debug & KVM_GUESTDBG_BLOCKIRQ) {
+ inhibit = true;
+ break;
+ }
+ }
+ __kvm_request_apicv_update(kvm, !inhibit, APICV_INHIBIT_REASON_BLOCKIRQ);
+ up_write(&kvm->arch.apicv_update_lock);
+}
+
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg)
{
@@ -10805,6 +10823,8 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
static_call(kvm_x86_update_exception_bitmap)(vcpu);
+ kvm_arch_vcpu_guestdbg_update_apicv_inhibit(vcpu->kvm);
+
r = 0;
out: