linux_dsm_epyc7002/arch/x86/kvm
Andrea Arcangeli 3dcb2a3fa5 KVM: retpolines: x86: eliminate retpoline from svm.c exit handlers
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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15 11:43:57 +01:00
..
vmx KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers 2019-11-15 11:43:56 +01:00
cpuid.c kvm: x86: Expose RDPID in KVM_GET_SUPPORTED_CPUID 2019-10-22 13:31:12 +02:00
cpuid.h x86/cpufeatures: Combine word 11 and 12 into a new scattered features word 2019-06-20 12:38:44 +02:00
debugfs.c KVM: no need to check return value of debugfs_create functions 2019-08-05 12:55:49 +02:00
emulate.c KVM: x86: set ctxt->have_exception in x86_decode_insn() 2019-09-11 18:01:34 +02:00
hyperv.c KVM: x86: hyper-v: set NoNonArchitecturalCoreSharing CPUID bit when SMT is impossible 2019-09-24 13:37:30 +02:00
hyperv.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
i8254.c kvm: x86: Add memcg accounting to KVM allocations 2019-02-20 22:48:30 +01:00
i8254.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
i8259.c kvm: x86: Add memcg accounting to KVM allocations 2019-02-20 22:48:30 +01:00
ioapic.c kvm: x86: ioapic and apic debug macros cleanup 2019-07-15 20:39:01 +02:00
ioapic.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq_comm.c KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
irq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320 2019-06-05 17:37:05 +02:00
irq.h KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
Kconfig kvm: x86: add host poll control msrs 2019-06-18 11:43:46 +02:00
kvm_cache_regs.h KVM: x86: Fold decache_cr3() into cache_reg() 2019-10-22 13:34:16 +02:00
lapic.c KVM: LAPIC: Loosen filter for adaptive tuning of lapic_timer_advance_ns 2019-09-26 12:31:29 +02:00
lapic.h KVM: LAPIC: Tune lapic_timer_advance_ns smoothly 2019-09-24 14:35:06 +02:00
Makefile KVM: x86: fix TRACE_INCLUDE_PATH and remove -I. header search paths 2019-01-25 19:12:37 +01:00
mmu_audit.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
mmu.c KVM: x86: fix nested guest live migration with PML 2019-09-27 13:13:39 +02:00
mmu.h KVM: x86/mmu: Add explicit access mask for MMIO SPTEs 2019-08-22 10:09:24 +02:00
mmutrace.h KVM: x86/mmu: Explicitly track only a single invalid mmu generation 2019-09-24 14:36:00 +02:00
mtrr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
page_track.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
paging_tmpl.h KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
pmu_amd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
pmu.c KVM: x86/vPMU: Declare kvm_pmu->reprogram_pmi field using DECLARE_BITMAP 2019-10-22 13:39:32 +02:00
pmu.h KVM: x86: PMU Event Filter 2019-07-11 15:08:28 +02:00
svm.c KVM: retpolines: x86: eliminate retpoline from svm.c exit handlers 2019-11-15 11:43:57 +01:00
trace.h KVM: nVMX: trace nested VM-Enter failures detected by H/W 2019-09-11 17:34:17 +02:00
tss.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
x86.c KVM: x86: get rid of odd out jump label in pdptrs_changed 2019-11-11 15:11:28 +01:00
x86.h KVM: x86: Move IA32_XSS-swapping on VM-entry/VM-exit to common x86 code 2019-10-22 15:46:53 +02:00