diff options
| author |   Sean Christopherson <seanjc@google.com> | 2021-10-08 19:12:13 -0700 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2021-12-08 04:24:54 -0500 |
| commit | 057aa61bc992f2d27218b6558b0115d5623f1a7b (patch) | |
| tree | 0dde27d3e15a2d8c52627606aa6dc82880248370 /arch/x86/kvm/vmx/posted_intr.c | |
| parent | KVM: Add helpers to wake/query blocking vCPU (diff) | |
| download | wireguard-linux-057aa61bc992f2d27218b6558b0115d5623f1a7b.tar.xz wireguard-linux-057aa61bc992f2d27218b6558b0115d5623f1a7b.zip | |
KVM: VMX: Skip Posted Interrupt updates if APICv is hard disabled
Explicitly skip posted interrupt updates if APICv is disabled in all of
KVM, or if the guest doesn't have an in-kernel APIC. The PI descriptor
is kept up-to-date if APICv is inhibited, e.g. so that re-enabling APICv
doesn't require a bunch of updates, but neither the module param nor the
APIC type can be changed on-the-fly.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-21-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/posted_intr.c')
| -rw-r--r-- | arch/x86/kvm/vmx/posted_intr.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index 41f946e2123e..ee4ddc6e268b 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -29,11 +29,14 @@ void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu) unsigned int dest; /* - * In case of hot-plug or hot-unplug, we may have to undo - * vmx_vcpu_pi_put even if there is no assigned device. And we - * always keep PI.NDST up to date for simplicity: it makes the - * code easier, and CPU migration is not a fast path. + * To simplify hot-plug and dynamic toggling of APICv, keep PI.NDST and + * PI.SN up-to-date even if there is no assigned device or if APICv is + * deactivated due to a dynamic inhibit bit, e.g. for Hyper-V's SyncIC. */ + if (!enable_apicv || !lapic_in_kernel(vcpu)) + return; + + /* Nothing to do if PI.SN and PI.NDST both have the desired value. */ if (!pi_test_sn(pi_desc) && vcpu->cpu == cpu) return; |