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| author |   Wanpeng Li <wanpeng.li@hotmail.com> | 2016-10-24 18:23:13 +0800 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2016-11-02 21:32:17 +0100 |
| commit | 8003c9ae204e21204e49816c5ea629357e283b06 (patch) | |
| tree | 4972d819077e3a2e7d172ed4c799d76a5275e4f2 /arch/x86/kvm/lapic.h | |
| parent | KVM: LAPIC: rename start/cancel_hv_tscdeadline to start/cancel_hv_timer (diff) | |
| download | linux-dev-8003c9ae204e21204e49816c5ea629357e283b06.tar.xz linux-dev-8003c9ae204e21204e49816c5ea629357e283b06.zip | |
KVM: LAPIC: add APIC Timer periodic/oneshot mode VMX preemption timer support
Most windows guests still utilize APIC Timer periodic/oneshot mode
instead of tsc-deadline mode, and the APIC Timer periodic/oneshot
mode are still emulated by high overhead hrtimer on host. This patch
converts the expected expire time of the periodic/oneshot mode to
guest deadline tsc in order to leverage VMX preemption timer logic
for APIC Timer tsc-deadline mode. After each preemption timer vmexit
preemption timer is restarted to emulate LVTT current-count register
is automatically reloaded from the initial-count register when the
count reaches 0. This patch reduces ~5600 cycles for each APIC Timer
periodic mode operation virtualization.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Squashed with my fixes that were reviewed-by Paolo.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86/kvm/lapic.h')
| -rw-r--r-- | arch/x86/kvm/lapic.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 031db2631a1a..e0c80233b3e1 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -15,6 +15,7 @@ struct kvm_timer { struct hrtimer timer; s64 period; /* unit: ns */ + ktime_t target_expiration; u32 timer_mode; u32 timer_mode_mask; u64 tscdeadline; |