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

Vitaly Kuznetsov
2018-12-05T15:36:26Z

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;
}
--
2.19.2