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| author | Sean Christopherson <seanjc@google.com> | 2021-10-09 05:11:57 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-12-08 12:24:46 +0300 |
| commit | 510958e997217e39a16b47afb5a44dfa39013964 (patch) | |
| tree | 16592511358ed082554d278cc95e27e437922dd1 /virt/kvm/kvm_main.c | |
| parent | 6f390916c4fb359507d9ac4bf1b28a4f8abee5c0 (diff) | |
| download | linux-510958e997217e39a16b47afb5a44dfa39013964.tar.xz | |
KVM: Force PPC to define its own rcuwait object
Do not define/reference kvm_vcpu.wait if __KVM_HAVE_ARCH_WQP is true, and
instead force the architecture (PPC) to define its own rcuwait object.
Allowing common KVM to directly access vcpu->wait without a guard makes
it all too easy to introduce potential bugs, e.g. kvm_vcpu_block(),
kvm_vcpu_on_spin(), and async_pf_execute() all operate on vcpu->wait, not
the result of kvm_arch_vcpu_get_wait(), and so may do the wrong thing for
PPC.
Due to PPC's shenanigans with respect to callbacks and waits (it switches
to the virtual core's wait object at KVM_RUN!?!?), it's not clear whether
or not this fixes any bugs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a26b069a6929..11db44f4110e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -422,7 +422,9 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) vcpu->kvm = kvm; vcpu->vcpu_id = id; vcpu->pid = NULL; +#ifndef __KVM_HAVE_ARCH_WQP rcuwait_init(&vcpu->wait); +#endif kvm_async_pf_vcpu_init(vcpu); vcpu->pre_pcpu = -1; @@ -3284,6 +3286,7 @@ update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { + struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); bool halt_poll_allowed = !kvm_arch_no_poll(vcpu); ktime_t start, cur, poll_end; bool waited = false; @@ -3322,7 +3325,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) } - prepare_to_rcuwait(&vcpu->wait); + prepare_to_rcuwait(wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); @@ -3332,7 +3335,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) waited = true; schedule(); } - finish_rcuwait(&vcpu->wait); + finish_rcuwait(wait); cur = ktime_get(); if (waited) { vcpu->stat.generic.halt_wait_ns += @@ -3544,7 +3547,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) continue; if (vcpu == me) continue; - if (rcuwait_active(&vcpu->wait) && + if (rcuwait_active(kvm_arch_vcpu_get_wait(vcpu)) && !vcpu_dy_runnable(vcpu)) continue; if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && |