diff options
| author |   Sean Christopherson <seanjc@google.com> | 2021-10-08 19:12:15 -0700 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2021-12-08 04:24:55 -0500 |
| commit | c95717218add161f3e93bd454743506ed5bdd8e1 (patch) | |
| tree | 06a5fe55ac367d3caabc22c7a3bfddea1ba9a76b /arch/x86/kvm/vmx/posted_intr.c | |
| parent | KVM: VMX: Skip Posted Interrupt updates if APICv is hard disabled (diff) | |
| download | wireguard-linux-c95717218add161f3e93bd454743506ed5bdd8e1.tar.xz wireguard-linux-c95717218add161f3e93bd454743506ed5bdd8e1.zip | |
KVM: VMX: Drop unnecessary PI logic to handle impossible conditions
Drop sanity checks on the validity of the previous pCPU when handling
vCPU block/unlock for posted interrupts. The intention behind the sanity
checks is to avoid memory corruption in case of a race or incorrect locking,
but the code has been stable for a few years now and the checks get in
the way of eliminating kvm_vcpu.pre_cpu.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-23-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 | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index ee4ddc6e268b..f15d4a7450a5 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -123,12 +123,10 @@ static void __pi_post_block(struct kvm_vcpu *vcpu) } while (cmpxchg64(&pi_desc->control, old.control, new.control) != old.control); - if (!WARN_ON_ONCE(vcpu->pre_pcpu == -1)) { - spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); - list_del(&vcpu->blocked_vcpu_list); - spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); - vcpu->pre_pcpu = -1; - } + spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + list_del(&vcpu->blocked_vcpu_list); + spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + vcpu->pre_pcpu = -1; } /* @@ -156,14 +154,12 @@ int pi_pre_block(struct kvm_vcpu *vcpu) WARN_ON(irqs_disabled()); local_irq_disable(); - if (!WARN_ON_ONCE(vcpu->pre_pcpu != -1)) { - vcpu->pre_pcpu = vcpu->cpu; - spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); - list_add_tail(&vcpu->blocked_vcpu_list, - &per_cpu(blocked_vcpu_on_cpu, - vcpu->pre_pcpu)); - spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); - } + + vcpu->pre_pcpu = vcpu->cpu; + spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); + list_add_tail(&vcpu->blocked_vcpu_list, + &per_cpu(blocked_vcpu_on_cpu, vcpu->pre_pcpu)); + spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->pre_pcpu)); do { old.control = new.control = pi_desc->control; |