On 24/05/21 19:53, Marcelo Tosatti wrote:
On Mon, May 24, 2021 at 05:55:18PM +0200, Paolo Bonzini wrote:
On 10/05/21 19:26, Marcelo Tosatti wrote:
+void vmx_pi_start_assignment(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ if (!irq_remapping_cap(IRQ_POSTING_CAP))
+ return;
+
+ /*
+ * Wakeup will cause the vCPU to bail out of kvm_vcpu_block() and
+ * go back through vcpu_block().
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_vcpu_apicv_active(vcpu))
+ continue;
+
+ kvm_vcpu_wake_up(vcpu);
Would you still need the check_block callback, if you also added a
kvm_make_request(KVM_REQ_EVENT)?
In fact, since this is entirely not a hot path, can you just do
kvm_make_all_cpus_request(kvm, KVM_REQ_EVENT) instead of this loop?
Thanks,
Paolo
Hi Paolo,
Don't think so:
static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
{
int ret = -EINTR;
int idx = srcu_read_lock(&vcpu->kvm->srcu);
if (kvm_arch_vcpu_runnable(vcpu)) {
kvm_make_request(KVM_REQ_UNHALT, vcpu); <---- don't want KVM_REQ_UNHALT
UNHALT is incorrect indeed, but requests don't have to unhalt the vCPU.
This case is somewhat similar to signal_pending(), where the next
KVM_RUN ioctl resumes the halt. It's also similar to
KVM_REQ_PENDING_TIMER. So you can:
- rename KVM_REQ_PENDING_TIMER to KVM_REQ_UNBLOCK except in
arch/powerpc, where instead you add KVM_REQ_PENDING_TIMER to
arch/powerpc/include/asm/kvm_host.h
- here, you add
if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu))
goto out;
- then vmx_pi_start_assignment only needs to
if (!irq_remapping_cap(IRQ_POSTING_CAP))
return;
kvm_make_all_cpus_request(kvm, KVM_REQ_UNBLOCK);
kvm_arch_vcpu_runnable() would still return false, so the mp_state would
not change.
Paolo
