KVM: Update Posted-Interrupts Descriptor when vCPU is blocked

This patch updates the Posted-Interrupts Descriptor when vCPU
is blocked.

pre-block:
- Add the vCPU to the blocked per-CPU list
- Set 'NV' to POSTED_INTR_WAKEUP_VECTOR

post-block:
- Remove the vCPU from the per-CPU list

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 15664994b6f3..cdbdb559ecd2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -899,6 +899,17 @@ struct kvm_x86_ops {
 	/* pmu operations of sub-arch */
 	const struct kvm_pmu_ops *pmu_ops;
 
+	/*
+	 * Architecture specific hooks for vCPU blocking due to
+	 * HLT instruction.
+	 * Returns for .pre_block():
+	 *    - 0 means continue to block the vCPU.
+	 *    - 1 means we cannot block the vCPU since some event
+	 *        happens during this period, such as, 'ON' bit in
+	 *        posted-interrupts descriptor is set.
+	 */
+	int (*pre_block)(struct kvm_vcpu *vcpu);
+	void (*post_block)(struct kvm_vcpu *vcpu);
 	int (*update_pi_irte)(struct kvm *kvm, unsigned int host_irq,
 			      uint32_t guest_irq, bool set);
 };