[PATCH 24/60] kvm: Move kvm_vcpu spinloop members to struct kvm_vcpu_common
Jörg Rödel
joro at 8bytes.org
Mon Jun 8 07:42:16 PDT 2026
From: Joerg Roedel <joerg.roedel at amd.com>
Onlyh one struct kvm_vcpu across all planes can be in a spin-loop.
Move the state to struct kvm_vcpu_common to make detection independent
of the active struct kvm_vcpu.
Signed-off-by: Joerg Roedel <joerg.roedel at amd.com>
---
include/linux/kvm_host.h | 32 +++++++++++++++----------------
virt/kvm/kvm_main.c | 41 ++++++++++++++++++++++------------------
2 files changed, 39 insertions(+), 34 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9220c452aa3a..f6e8a0b653b3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -350,6 +350,20 @@ struct kvm_vcpu_common {
rwlock_t pid_lock;
int sigset_active;
sigset_t sigset;
+ unsigned int halt_poll_ns;
+
+#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
+ /*
+ * Cpu relax intercept or pause loop exit optimization
+ * in_spin_loop: set when a vcpu does a pause loop exit
+ * or cpu relax intercepted.
+ * dy_eligible: indicates whether vcpu is eligible for directed yield.
+ */
+ struct {
+ bool in_spin_loop;
+ bool dy_eligible;
+ } spin_loop;
+#endif
/* Scheduling state */
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -373,8 +387,6 @@ struct kvm_vcpu {
struct kvm_run *run;
- unsigned int halt_poll_ns;
-
u64 plane_requests;
/* S390 only */
@@ -398,18 +410,6 @@ struct kvm_vcpu {
} async_pf;
#endif
-#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
- /*
- * Cpu relax intercept or pause loop exit optimization
- * in_spin_loop: set when a vcpu does a pause loop exit
- * or cpu relax intercepted.
- * dy_eligible: indicates whether vcpu is eligible for directed yield.
- */
- struct {
- bool in_spin_loop;
- bool dy_eligible;
- } spin_loop;
-#endif
struct kvm_vcpu_arch arch;
struct kvm_vcpu_stat stat;
char stats_id[KVM_STATS_NAME_SIZE];
@@ -2500,11 +2500,11 @@ extern struct kvm_device_ops kvm_arm_vgic_v5_ops;
static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
{
- vcpu->spin_loop.in_spin_loop = val;
+ vcpu->common->spin_loop.in_spin_loop = val;
}
static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
{
- vcpu->spin_loop.dy_eligible = val;
+ vcpu->common->spin_loop.dy_eligible = val;
}
#else /* !CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1858880ee3d3..24ff8748a317 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -485,6 +485,9 @@ static int kvm_vcpu_init_common(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned
vcpu->common = no_free_ptr(common);
+ kvm_vcpu_set_in_spin_loop(vcpu, false);
+ kvm_vcpu_set_dy_eligible(vcpu, false);
+
return 0;
out_drop_counter:
@@ -515,8 +518,6 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
vcpu->vcpu_id = id;
kvm_async_pf_vcpu_init(vcpu);
- kvm_vcpu_set_in_spin_loop(vcpu, false);
- kvm_vcpu_set_dy_eligible(vcpu, false);
vcpu->last_used_slot = NULL;
vcpu->plane_level = 0;
@@ -3721,9 +3722,10 @@ void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
{
+ struct kvm_vcpu_common *common = vcpu->common;
unsigned int old, val, grow, grow_start;
- old = val = vcpu->halt_poll_ns;
+ old = val = common->halt_poll_ns;
grow_start = READ_ONCE(halt_poll_ns_grow_start);
grow = READ_ONCE(halt_poll_ns_grow);
if (!grow)
@@ -3733,16 +3735,17 @@ static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
if (val < grow_start)
val = grow_start;
- vcpu->halt_poll_ns = val;
+ common->halt_poll_ns = val;
out:
trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
}
static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
{
+ struct kvm_vcpu_common *common = vcpu->common;
unsigned int old, val, shrink, grow_start;
- old = val = vcpu->halt_poll_ns;
+ old = val = common->halt_poll_ns;
shrink = READ_ONCE(halt_poll_ns_shrink);
grow_start = READ_ONCE(halt_poll_ns_grow_start);
if (shrink == 0)
@@ -3753,7 +3756,7 @@ static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
if (val < grow_start)
val = 0;
- vcpu->halt_poll_ns = val;
+ common->halt_poll_ns = val;
trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
}
@@ -3864,19 +3867,20 @@ void kvm_vcpu_halt(struct kvm_vcpu *vcpu)
{
unsigned int max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu);
bool halt_poll_allowed = !kvm_arch_no_poll(vcpu);
+ struct kvm_vcpu_common *common = vcpu->common;
ktime_t start, cur, poll_end;
bool waited = false;
bool do_halt_poll;
u64 halt_ns;
- if (vcpu->halt_poll_ns > max_halt_poll_ns)
- vcpu->halt_poll_ns = max_halt_poll_ns;
+ if (common->halt_poll_ns > max_halt_poll_ns)
+ common->halt_poll_ns = max_halt_poll_ns;
- do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns;
+ do_halt_poll = halt_poll_allowed && common->halt_poll_ns;
start = cur = poll_end = ktime_get();
if (do_halt_poll) {
- ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns);
+ ktime_t stop = ktime_add_ns(start, common->halt_poll_ns);
do {
if (kvm_vcpu_check_block(vcpu) < 0)
@@ -3914,18 +3918,18 @@ void kvm_vcpu_halt(struct kvm_vcpu *vcpu)
if (!vcpu_valid_wakeup(vcpu)) {
shrink_halt_poll_ns(vcpu);
} else if (max_halt_poll_ns) {
- if (halt_ns <= vcpu->halt_poll_ns)
+ if (halt_ns <= common->halt_poll_ns)
;
/* we had a long block, shrink polling */
- else if (vcpu->halt_poll_ns &&
+ else if (common->halt_poll_ns &&
halt_ns > max_halt_poll_ns)
shrink_halt_poll_ns(vcpu);
/* we had a short halt and our poll time is too small */
- else if (vcpu->halt_poll_ns < max_halt_poll_ns &&
+ else if (common->halt_poll_ns < max_halt_poll_ns &&
halt_ns < max_halt_poll_ns)
grow_halt_poll_ns(vcpu);
} else {
- vcpu->halt_poll_ns = 0;
+ common->halt_poll_ns = 0;
}
}
@@ -4046,13 +4050,14 @@ EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_vcpu_yield_to);
static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
+ struct kvm_vcpu_common *common = vcpu->common;
bool eligible;
- eligible = !vcpu->spin_loop.in_spin_loop ||
- vcpu->spin_loop.dy_eligible;
+ eligible = !common->spin_loop.in_spin_loop ||
+ common->spin_loop.dy_eligible;
- if (vcpu->spin_loop.in_spin_loop)
- kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
+ if (common->spin_loop.in_spin_loop)
+ kvm_vcpu_set_dy_eligible(vcpu, !common->spin_loop.dy_eligible);
return eligible;
#else
--
2.53.0
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