From: Andrea Arcangeli <aarcange@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Peter Xu <peterx@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 16/17] KVM: retpolines: x86: eliminate retpoline from svm.c exit handlers
Date: Fri, 20 Sep 2019 17:25:08 -0400 [thread overview]
Message-ID: <20190920212509.2578-17-aarcange@redhat.com> (raw)
In-Reply-To: <20190920212509.2578-1-aarcange@redhat.com>
It's enough to check the exit value and issue a direct call to avoid
the retpoline for all the common vmexit reasons.
After this commit is applied, here the most common retpolines executed
under a high resolution timer workload in the guest on a SVM host:
[..]
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
ktime_get_update_offsets_now+70
hrtimer_interrupt+131
smp_apic_timer_interrupt+106
apic_timer_interrupt+15
start_sw_timer+359
restart_apic_timer+85
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 1940
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_r12+33
force_qs_rnp+217
rcu_gp_kthread+1270
kthread+268
ret_from_fork+34
]: 4644
@[]: 25095
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
lapic_next_event+28
clockevents_program_event+148
hrtimer_start_range_ns+528
start_sw_timer+356
restart_apic_timer+85
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 41474
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
clockevents_program_event+148
hrtimer_start_range_ns+528
start_sw_timer+356
restart_apic_timer+85
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 41474
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
ktime_get+58
clockevents_program_event+84
hrtimer_start_range_ns+528
start_sw_timer+356
restart_apic_timer+85
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 41887
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
lapic_next_event+28
clockevents_program_event+148
hrtimer_try_to_cancel+168
hrtimer_cancel+21
kvm_set_lapic_tscdeadline_msr+43
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 42723
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
clockevents_program_event+148
hrtimer_try_to_cancel+168
hrtimer_cancel+21
kvm_set_lapic_tscdeadline_msr+43
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 42766
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
ktime_get+58
clockevents_program_event+84
hrtimer_try_to_cancel+168
hrtimer_cancel+21
kvm_set_lapic_tscdeadline_msr+43
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 42848
@[
trace_retpoline+1
__trace_retpoline+30
__x86_indirect_thunk_rax+33
ktime_get+58
start_sw_timer+279
restart_apic_timer+85
kvm_set_msr_common+1497
msr_interception+142
vcpu_enter_guest+684
kvm_arch_vcpu_ioctl_run+261
kvm_vcpu_ioctl+559
do_vfs_ioctl+164
ksys_ioctl+96
__x64_sys_ioctl+22
do_syscall_64+89
entry_SYSCALL_64_after_hwframe+68
]: 499845
@total: 1780243
SVM has no TSC based programmable preemption timer so it is invoking
ktime_get() frequently.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---
arch/x86/kvm/svm.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ca9fd1762519..7324243b0a82 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4991,6 +4991,20 @@ static int handle_exit(struct kvm_vcpu *vcpu)
return 0;
}
+#ifdef CONFIG_RETPOLINE
+ if (exit_code == SVM_EXIT_MSR)
+ return msr_interception(svm);
+ else if (exit_code == SVM_EXIT_VINTR)
+ return interrupt_window_interception(svm);
+ else if (exit_code == SVM_EXIT_INTR)
+ return intr_interception(svm);
+ else if (exit_code == SVM_EXIT_HLT)
+ return halt_interception(svm);
+ else if (exit_code == SVM_EXIT_NPF)
+ return npf_interception(svm);
+ else if (exit_code == SVM_EXIT_CPUID)
+ return cpuid_interception(svm);
+#endif
return svm_exit_handlers[exit_code](svm);
}
next prev parent reply other threads:[~2019-09-20 21:25 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-20 21:24 [PATCH 00/17] KVM monolithic v1 Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 01/17] x86: spec_ctrl: fix SPEC_CTRL initialization after kexec Andrea Arcangeli
2019-09-23 10:22 ` Paolo Bonzini
2019-09-23 15:30 ` Sean Christopherson
2019-09-23 17:34 ` Andrea Arcangeli
2019-09-23 22:27 ` Sean Christopherson
2019-09-20 21:24 ` [PATCH 02/17] KVM: monolithic: x86: convert the kvm_x86_ops methods to external functions Andrea Arcangeli
2019-09-23 10:19 ` Paolo Bonzini
2019-09-23 16:13 ` Sean Christopherson
2019-09-23 16:51 ` Paolo Bonzini
2019-09-23 19:21 ` Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 03/17] KVM: monolithic: x86: handle the request_immediate_exit variation Andrea Arcangeli
2019-09-23 22:35 ` Sean Christopherson
2019-09-23 23:06 ` Andrea Arcangeli
2019-09-23 23:45 ` Sean Christopherson
2019-09-24 0:24 ` Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 04/17] KVM: monolithic: x86: convert the kvm_pmu_ops methods to external functions Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 05/17] KVM: monolithic: x86: enable the kvm_x86_ops " Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 06/17] KVM: monolithic: x86: enable the kvm_pmu_ops " Andrea Arcangeli
2019-09-20 21:24 ` [PATCH 07/17] KVM: monolithic: x86: adjust the section prefixes Andrea Arcangeli
2019-09-23 10:15 ` Paolo Bonzini
2019-09-25 12:13 ` Andrea Arcangeli
2019-09-25 12:32 ` Paolo Bonzini
2019-09-20 21:25 ` [PATCH 08/17] KVM: monolithic: adjust the section prefixes in the KVM common code Andrea Arcangeli
2019-09-20 21:25 ` [PATCH 09/17] KVM: monolithic: x86: remove kvm.ko Andrea Arcangeli
2019-09-20 21:25 ` [PATCH 10/17] KVM: monolithic: x86: use the external functions instead of kvm_x86_ops Andrea Arcangeli
2019-09-23 10:02 ` Paolo Bonzini
2019-09-20 21:25 ` [PATCH 11/17] KVM: monolithic: x86: remove exports Andrea Arcangeli
2019-09-20 21:25 ` [PATCH 12/17] KVM: monolithic: remove exports from KVM common code Andrea Arcangeli
2019-09-20 21:25 ` [PATCH 13/17] KVM: monolithic: x86: drop the kvm_pmu_ops structure Andrea Arcangeli
2019-09-23 10:21 ` Paolo Bonzini
2019-09-24 0:51 ` Andrea Arcangeli
2019-09-24 1:24 ` Paolo Bonzini
2019-09-20 21:25 ` [PATCH 14/17] KVM: monolithic: x86: inline more exit handlers in vmx.c Andrea Arcangeli
2019-09-23 10:19 ` Paolo Bonzini
2019-09-24 1:00 ` Andrea Arcangeli
2019-09-24 1:25 ` Paolo Bonzini
2019-09-24 1:55 ` Andrea Arcangeli
2019-09-24 2:56 ` Andrea Arcangeli
2019-09-25 7:52 ` Paolo Bonzini
2019-09-20 21:25 ` [PATCH 15/17] KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers Andrea Arcangeli
2019-09-23 9:31 ` Vitaly Kuznetsov
2019-09-23 9:57 ` Paolo Bonzini
2019-09-23 19:05 ` Andrea Arcangeli
2019-09-23 20:23 ` Sean Christopherson
2019-09-23 21:08 ` Andrea Arcangeli
2019-09-23 21:24 ` Sean Christopherson
2019-09-23 23:43 ` Andrea Arcangeli
2019-09-23 23:52 ` Sean Christopherson
2019-09-24 0:16 ` Paolo Bonzini
2019-09-24 0:35 ` Sean Christopherson
2019-09-24 0:37 ` Paolo Bonzini
2019-09-24 0:15 ` Paolo Bonzini
2019-09-24 0:38 ` Andrea Arcangeli
2019-09-24 0:46 ` Sean Christopherson
2019-09-24 21:46 ` Andrea Arcangeli
2019-09-25 7:50 ` Paolo Bonzini
2019-09-23 16:37 ` Sean Christopherson
2019-09-23 16:53 ` Paolo Bonzini
2019-09-23 17:42 ` Andrea Arcangeli
2019-09-23 18:15 ` Sean Christopherson
2019-09-23 19:12 ` Andrea Arcangeli
[not found] ` <E8FE7592-69C3-455E-8D80-A2D73BB2E14C@dinechin.org>
2019-09-25 20:51 ` Andrea Arcangeli
2019-09-23 16:28 ` Sean Christopherson
2019-09-20 21:25 ` Andrea Arcangeli [this message]
2019-09-23 10:01 ` [PATCH 16/17] KVM: retpolines: x86: eliminate retpoline from svm.c " Paolo Bonzini
2019-09-20 21:25 ` [PATCH 17/17] x86: retpolines: eliminate retpoline from msr event handlers Andrea Arcangeli
2019-09-23 15:39 ` [PATCH 00/17] KVM monolithic v1 Sean Christopherson
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