From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Subject: [PATCH v3 1/4] KVM: LAPIC: Make lapic timer unpinned when timer is injected by pi
Date: Tue, 11 Jun 2019 20:17:06 +0800 [thread overview]
Message-ID: <1560255429-7105-2-git-send-email-wanpengli@tencent.com> (raw)
In-Reply-To: <1560255429-7105-1-git-send-email-wanpengli@tencent.com>
From: Wanpeng Li <wanpengli@tencent.com>
Make lapic timer unpinned when timer is injected by posted-interrupt,
the emulated timer can be offload to the housekeeping cpus.
The host admin should fine tuned, e.g. dedicated instances scenario
w/ nohz_full cover the pCPUs which vCPUs resident, several pCPUs
surplus for housekeeping, disable mwait/hlt/pause vmexits to occupy
the pCPUs, fortunately preemption timer is disabled after mwait is
exposed to guest which makes emulated timer offload can be possible.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
arch/x86/kvm/lapic.c | 20 ++++++++++++++++----
arch/x86/kvm/lapic.h | 1 +
arch/x86/kvm/vmx/vmx.c | 3 ++-
arch/x86/kvm/x86.c | 5 +++++
arch/x86/kvm/x86.h | 2 ++
include/linux/sched/isolation.h | 2 ++
kernel/sched/isolation.c | 6 ++++++
7 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index fcf42a3..e57eeba 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -127,6 +127,12 @@ static inline u32 kvm_x2apic_id(struct kvm_lapic *apic)
return apic->vcpu->vcpu_id;
}
+inline bool posted_interrupt_inject_timer_enabled(struct kvm_vcpu *vcpu)
+{
+ return pi_inject_timer && kvm_vcpu_apicv_active(vcpu);
+}
+EXPORT_SYMBOL_GPL(posted_interrupt_inject_timer_enabled);
+
static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map,
u32 dest_id, struct kvm_lapic ***cluster, u16 *mask) {
switch (map->mode) {
@@ -1581,7 +1587,9 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic)
likely(ns > apic->lapic_timer.timer_advance_ns)) {
expire = ktime_add_ns(now, ns);
expire = ktime_sub_ns(expire, ktimer->timer_advance_ns);
- hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start(&ktimer->timer, expire,
+ posted_interrupt_inject_timer_enabled(vcpu) ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_ABS_PINNED);
} else
apic_timer_expired(apic);
@@ -1683,7 +1691,8 @@ static void start_sw_period(struct kvm_lapic *apic)
hrtimer_start(&apic->lapic_timer.timer,
apic->lapic_timer.target_expiration,
- HRTIMER_MODE_ABS_PINNED);
+ posted_interrupt_inject_timer_enabled(apic->vcpu) ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_ABS_PINNED);
}
bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu)
@@ -2320,7 +2329,8 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns)
apic->vcpu = vcpu;
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS_PINNED);
+ posted_interrupt_inject_timer_enabled(vcpu) ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_ABS_PINNED);
apic->lapic_timer.timer.function = apic_timer_fn;
if (timer_advance_ns == -1) {
apic->lapic_timer.timer_advance_ns = 1000;
@@ -2509,7 +2519,9 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
timer = &vcpu->arch.apic->lapic_timer.timer;
if (hrtimer_cancel(timer))
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
+ hrtimer_start_expires(timer,
+ posted_interrupt_inject_timer_enabled(vcpu) ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_ABS_PINNED);
}
/*
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index f974a3d..7b85a7c 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -231,6 +231,7 @@ void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu);
void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu);
bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu);
void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu);
+inline bool posted_interrupt_inject_timer_enabled(struct kvm_vcpu *vcpu);
static inline enum lapic_mode kvm_apic_mode(u64 apic_base)
{
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index da24f18..6d3c0b1 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7042,7 +7042,8 @@ static int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
u64 tscl, guest_tscl, delta_tsc, lapic_timer_advance_cycles;
struct kvm_timer *ktimer = &vcpu->arch.apic->lapic_timer;
- if (kvm_mwait_in_guest(vcpu->kvm))
+ if (kvm_mwait_in_guest(vcpu->kvm) ||
+ posted_interrupt_inject_timer_enabled(vcpu))
return -EOPNOTSUPP;
vmx = to_vmx(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6200d5a..35c4884 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -54,6 +54,7 @@
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/sched/stat.h>
+#include <linux/sched/isolation.h>
#include <linux/mem_encrypt.h>
#include <trace/events/kvm.h>
@@ -155,6 +156,9 @@ EXPORT_SYMBOL_GPL(enable_vmware_backdoor);
static bool __read_mostly force_emulation_prefix = false;
module_param(force_emulation_prefix, bool, S_IRUGO);
+bool __read_mostly pi_inject_timer = 0;
+module_param(pi_inject_timer, bool, S_IRUGO | S_IWUSR);
+
#define KVM_NR_SHARED_MSRS 16
struct kvm_shared_msrs_global {
@@ -7030,6 +7034,7 @@ int kvm_arch_init(void *opaque)
host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
kvm_lapic_init();
+ pi_inject_timer = housekeeping_enabled(HK_FLAG_TIMER);
#ifdef CONFIG_X86_64
pvclock_gtod_register_notifier(&pvclock_gtod_notifier);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 275b3b6..aa539d6 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -296,6 +296,8 @@ extern unsigned int min_timer_period_us;
extern bool enable_vmware_backdoor;
+extern bool pi_inject_timer;
+
extern struct static_key kvm_no_apic_vcpu;
static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index b0fb144..6fc5407 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -19,6 +19,7 @@ enum hk_flags {
DECLARE_STATIC_KEY_FALSE(housekeeping_overridden);
extern int housekeeping_any_cpu(enum hk_flags flags);
extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags);
+extern bool housekeeping_enabled(enum hk_flags flags);
extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags);
extern bool housekeeping_test_cpu(int cpu, enum hk_flags flags);
extern void __init housekeeping_init(void);
@@ -38,6 +39,7 @@ static inline const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
static inline void housekeeping_affine(struct task_struct *t,
enum hk_flags flags) { }
static inline void housekeeping_init(void) { }
+static inline bool housekeeping_enabled(enum hk_flags flags) { }
#endif /* CONFIG_CPU_ISOLATION */
static inline bool housekeeping_cpu(int cpu, enum hk_flags flags)
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 123ea07..ccb2808 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -14,6 +14,12 @@ EXPORT_SYMBOL_GPL(housekeeping_overridden);
static cpumask_var_t housekeeping_mask;
static unsigned int housekeeping_flags;
+bool housekeeping_enabled(enum hk_flags flags)
+{
+ return !!(housekeeping_flags & flags);
+}
+EXPORT_SYMBOL_GPL(housekeeping_enabled);
+
int housekeeping_any_cpu(enum hk_flags flags)
{
if (static_branch_unlikely(&housekeeping_overridden))
--
2.7.4
next prev parent reply other threads:[~2019-06-11 12:17 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-11 12:17 [PATCH v3 0/4] KVM: LAPIC: Implement Exitless Timer Wanpeng Li
2019-06-11 12:17 ` Wanpeng Li [this message]
2019-06-11 20:39 ` [PATCH v3 1/4] KVM: LAPIC: Make lapic timer unpinned when timer is injected by pi Marcelo Tosatti
2019-06-12 0:45 ` Wanpeng Li
2019-06-12 16:15 ` Marcelo Tosatti
2019-06-11 12:17 ` [PATCH v3 2/4] KVM: LAPIC: lapic timer interrupt is injected by posted interrupt Wanpeng Li
2019-06-11 20:18 ` Marcelo Tosatti
2019-06-12 1:48 ` Wanpeng Li
2019-06-12 15:22 ` Radim Krčmář
2019-06-12 21:51 ` Marcelo Tosatti
2019-06-11 12:17 ` [PATCH v3 3/4] KVM: LAPIC: Ignore timer migration when lapic timer is injected by posted-interrupt Wanpeng Li
2019-06-11 12:17 ` [PATCH v3 4/4] KVM: LAPIC: add advance timer support to pi_inject_timer Wanpeng Li
2019-06-13 7:59 ` [PATCH v3 0/4] KVM: LAPIC: Implement Exitless Timer Maxim Levitsky
2019-06-13 8:25 ` Wanpeng Li
2019-06-13 9:49 ` Maxim Levitsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1560255429-7105-2-git-send-email-wanpengli@tencent.com \
--to=kernellwp@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).