KVM: PPC: Book3S HV P9: Use kvm_arch_vcpu_get_wait() to get rcuwait object

Use kvm_arch_vcpu_get_wait() to get a vCPU's rcuwait object instead of
using vcpu->wait directly in kvmhv_run_single_vcpu().  Functionally, this
is a nop as vcpu->arch.waitp is guaranteed to point at vcpu->wait.  But
that is not obvious at first glance, and a future change coming in via
the KVM tree, commit 510958e99721 ("KVM: Force PPC to define its own
rcuwait object"), will hide vcpu->wait from architectures that define
__KVM_HAVE_ARCH_WQP to prevent generic KVM from attepting to wake a vCPU
with the wrong rcuwait object.

Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211213174556.3871157-1-seanjc@google.com

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7986911b873c040efb2df20ef77e35c58f350906..f64e45d6c0f4c13903a3e899118c95915ec18f92 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4442,6 +4442,7 @@ static int kvmppc_run_vcpu(struct kvm_vcpu *vcpu)
 int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
                          unsigned long lpcr)
 {
+       struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
        struct kvm_run *run = vcpu->run;
        int trap, r, pcpu;
        int srcu_idx;
@@ -4588,7 +4589,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
        if (is_kvmppc_resume_guest(r) && !kvmppc_vcpu_check_block(vcpu)) {
                kvmppc_set_timer(vcpu);
 
-               prepare_to_rcuwait(&vcpu->wait);
+               prepare_to_rcuwait(wait);
                for (;;) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        if (signal_pending(current)) {
@@ -4605,7 +4606,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
                        schedule();
                        trace_kvmppc_vcore_blocked(vc, 1);
                }
-               finish_rcuwait(&vcpu->wait);
+               finish_rcuwait(wait);
        }
        vcpu->arch.ceded = 0;