Re: [PATCH] x86/hyper-v: Stop caring about EOI for direct stimers

Paolo Bonzini
2018-12-14T10:36:59Z

On 05/12/18 16:36, Vitaly Kuznetsov wrote:
> Turns out we over-engineered Direct Mode for stimers a bit: unlike
> traditional stimers where we may want to try to re-inject the message upon
> EOI, Direct Mode stimers just set the irq in APIC and kvm_apic_set_irq()
> fails only when APIC is disabled (see APIC_DM_FIXED case in
> __apic_accept_irq()). Remove the redundant part.
>
> Suggested-by: Roman Kagan <rkagan@virtuozzo.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> arch/x86/kvm/hyperv.c | 36 +++---------------------------------
> 1 file changed, 3 insertions(+), 33 deletions(-)
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index e6a2a085644a..0a16a77e6ac3 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -56,21 +56,8 @@ static inline int synic_get_sint_vector(u64 sint_value)
> static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
> int vector)
> {
> - struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
> - struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
> - struct kvm_vcpu_hv_stimer *stimer;
> int i;
>
> - for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++) {
> - stimer = &hv_vcpu->stimer[i];
> - if (stimer->config.enable && stimer->config.direct_mode &&
> - stimer->config.apic_vector == vector)
> - return true;
> - }
> -
> - if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
> - return false;
> -
> for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
> if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
> return true;
> @@ -96,14 +83,14 @@ static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
> static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
> int vector)
> {
> + if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
> + return;
> +
> if (synic_has_vector_connected(synic, vector))
> __set_bit(vector, synic->vec_bitmap);
> else
> __clear_bit(vector, synic->vec_bitmap);
>
> - if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
> - return;
> -
> if (synic_has_vector_auto_eoi(synic, vector))
> __set_bit(vector, synic->auto_eoi_bitmap);
> else
> @@ -382,9 +369,7 @@ int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
>
> void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
> {
> - struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
> struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
> - struct kvm_vcpu_hv_stimer *stimer;
> int i;
>
> trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
> @@ -392,14 +377,6 @@ void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
> for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
> if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
> kvm_hv_notify_acked_sint(vcpu, i);
> -
> - for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++) {
> - stimer = &hv_vcpu->stimer[i];
> - if (stimer->msg_pending && stimer->config.enable &&
> - stimer->config.direct_mode &&
> - stimer->config.apic_vector == vector)
> - stimer_mark_pending(stimer, false);
> - }
> }
>
> static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
> @@ -566,8 +543,6 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
> static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
> bool host)
> {
> - struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
> - struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
> union hv_stimer_config new_config = {.as_uint64 = config},
> old_config = {.as_uint64 = stimer->config.as_uint64};
>
> @@ -580,11 +555,6 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
> new_config.enable = 0;
> stimer->config.as_uint64 = new_config.as_uint64;
>
> - if (old_config.direct_mode)
> - synic_update_vector(&hv_vcpu->synic, old_config.apic_vector);
> - if (new_config.direct_mode)
> - synic_update_vector(&hv_vcpu->synic, new_config.apic_vector);
> -
> stimer_mark_pending(stimer, false);
> return 0;
> }
>

Queued, thanks.

Paolo