| Message ID | 1502165135-4784-2-git-send-email-longpeng2@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/08/2017 06:05, Longpeng(Mike) wrote: > return 1; > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c > index ce865bd..4ea8c38 100644 > --- a/arch/s390/kvm/diag.c > +++ b/arch/s390/kvm/diag.c > @@ -150,7 +150,7 @@ static int __diag_time_slice_end(struct kvm_vcpu *vcpu) > { > VCPU_EVENT(vcpu, 5, "%s", "diag time slice end"); > vcpu->stat.diagnose_44++; > - kvm_vcpu_on_spin(vcpu); > + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); > return 0; > } > IIUC, diag is a privileged instruction so this an also be "true". Paolo
On Tue, 8 Aug 2017 09:34:14 +0200 Paolo Bonzini <pbonzini@redhat.com> wrote: > On 08/08/2017 06:05, Longpeng(Mike) wrote: > > return 1; > > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c > > index ce865bd..4ea8c38 100644 > > --- a/arch/s390/kvm/diag.c > > +++ b/arch/s390/kvm/diag.c > > @@ -150,7 +150,7 @@ static int __diag_time_slice_end(struct kvm_vcpu *vcpu) > > { > > VCPU_EVENT(vcpu, 5, "%s", "diag time slice end"); > > vcpu->stat.diagnose_44++; > > - kvm_vcpu_on_spin(vcpu); > > + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); > > return 0; > > } > > > > IIUC, diag is a privileged instruction so this an also be "true". > > Paolo Yes, indeed.
> +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) > +{ > + return false; > +} why don't we need an EXPORT_SYMBOL here? > + > /* Just ensure a guest exit from a particular CPU */ > static void exit_vm_noop(void *info) > { > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 15252d7..e7720d2 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2317,7 +2317,7 @@ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) > #endif > } > > -void kvm_vcpu_on_spin(struct kvm_vcpu *me) > +void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool me_in_kern) > { > struct kvm *kvm = me->kvm; > struct kvm_vcpu *vcpu; > @@ -2348,6 +2348,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) > continue; > if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu)) > continue; > + if (me_in_kern && !kvm_arch_vcpu_in_kernel(vcpu)) > + continue; hm, does this patch compile? (me_in_kern) I would even move this to an other patch. Maybe even split into a) introducing kvm_arch_vcpu_in_kernel() for all archs b) modifying kvm_vcpu_on_spin(), passing the result from kvm_arch_vcpu_in_kernel() c) filling kvm_arch_vcpu_in_kernel() with life for different archs (multiple patches) d) pimping kvm_vcpu_on_spin() > if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) > continue; > >
On 08.08.2017 10:42, David Hildenbrand wrote: > >> +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) >> +{ >> + return false; >> +} > > why don't we need an EXPORT_SYMBOL here? > >> + >> /* Just ensure a guest exit from a particular CPU */ >> static void exit_vm_noop(void *info) >> { >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index 15252d7..e7720d2 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -2317,7 +2317,7 @@ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) >> #endif >> } >> >> -void kvm_vcpu_on_spin(struct kvm_vcpu *me) >> +void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool me_in_kern) >> { >> struct kvm *kvm = me->kvm; >> struct kvm_vcpu *vcpu; >> @@ -2348,6 +2348,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) >> continue; >> if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu)) >> continue; >> + if (me_in_kern && !kvm_arch_vcpu_in_kernel(vcpu)) >> + continue; > > > hm, does this patch compile? (me_in_kern) pardon me, missed the parameter, so ignore this comment. comment regarding splitting up below still holds :) > > I would even move this to an other patch. > > Maybe even split into > > a) introducing kvm_arch_vcpu_in_kernel() for all archs > b) modifying kvm_vcpu_on_spin(), passing the result from > kvm_arch_vcpu_in_kernel() > c) filling kvm_arch_vcpu_in_kernel() with life for different archs > (multiple patches) > d) pimping kvm_vcpu_on_spin() > >> if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) >> continue; >> >> > >
diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 54442e3..a7ea5db 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -67,7 +67,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) { trace_kvm_wfx(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); } else { trace_kvm_wfx(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 17d8a16..d6c8cb6 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -84,7 +84,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index d4b2ad1..70208be 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -98,6 +98,12 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) return !!(vcpu->arch.pending_exceptions); } +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return false; +} +EXPORT_SYMBOL_GPL(kvm_arch_vcpu_in_kernel); + int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return 1; diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 1a75c0b..6184c45 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -58,6 +58,12 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) return !!(v->arch.pending_exceptions) || kvm_request_pending(v); } +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return false; +} +EXPORT_SYMBOL_GPL(kvm_arch_vcpu_in_kernel); + int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return 1; diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index ce865bd..4ea8c38 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -150,7 +150,7 @@ static int __diag_time_slice_end(struct kvm_vcpu *vcpu) { VCPU_EVENT(vcpu, 5, "%s", "diag time slice end"); vcpu->stat.diagnose_44++; - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); return 0; } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index af09d34..0b0c689 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2447,6 +2447,12 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) return kvm_s390_vcpu_has_irq(vcpu, 0); } +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return false; +} +EXPORT_SYMBOL_GPL(kvm_arch_vcpu_in_kernel); + void kvm_s390_vcpu_block(struct kvm_vcpu *vcpu) { atomic_or(PROG_BLOCK_SIE, &vcpu->arch.sie_block->prog20); diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 337b6d2..cd0e6e6 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1268,7 +1268,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) switch (code) { case HVCALL_NOTIFY_LONG_SPIN_WAIT: - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); break; case HVCALL_POST_MESSAGE: case HVCALL_SIGNAL_EVENT: diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1107626..e6ed24e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3749,7 +3749,9 @@ static int interrupt_window_interception(struct vcpu_svm *svm) static int pause_interception(struct vcpu_svm *svm) { - kvm_vcpu_on_spin(&(svm->vcpu)); + struct kvm_vcpu *vcpu = &(svm->vcpu); + + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); return 1; } diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9b21b12..9d6223a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6761,7 +6761,7 @@ static int handle_pause(struct kvm_vcpu *vcpu) if (ple_gap) grow_ple_window(vcpu); - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, kvm_arch_vcpu_in_kernel(vcpu)); return kvm_skip_emulated_instruction(vcpu); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d734aa8..4430be6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8439,6 +8439,12 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) return kvm_vcpu_running(vcpu) || kvm_vcpu_has_events(vcpu); } +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return false; +} +EXPORT_SYMBOL_GPL(kvm_arch_vcpu_in_kernel); + int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 21a6fd6..91460aa 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -720,7 +720,7 @@ int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data, bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu); void kvm_vcpu_kick(struct kvm_vcpu *vcpu); int kvm_vcpu_yield_to(struct kvm_vcpu *target); -void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu); +void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool me_in_kern); void kvm_load_guest_fpu(struct kvm_vcpu *vcpu); void kvm_put_guest_fpu(struct kvm_vcpu *vcpu); @@ -800,6 +800,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, void kvm_arch_hardware_unsetup(void); void kvm_arch_check_processor_compat(void *rtn); int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu); +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu); int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu); #ifndef __KVM_HAVE_ARCH_VM_ALLOC diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index a39a1e1..862f820 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -416,6 +416,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) && !v->arch.power_off && !v->arch.pause); } +bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu) +{ + return false; +} + /* Just ensure a guest exit from a particular CPU */ static void exit_vm_noop(void *info) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 15252d7..e7720d2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2317,7 +2317,7 @@ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) #endif } -void kvm_vcpu_on_spin(struct kvm_vcpu *me) +void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool me_in_kern) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; @@ -2348,6 +2348,8 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me) continue; if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu)) continue; + if (me_in_kern && !kvm_arch_vcpu_in_kernel(vcpu)) + continue; if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) continue;
If the vcpu(me) exit due to request a usermode spinlock, then the spinlock-holder may be preempted in usermode or kernmode. But if the vcpu(me) is in kernmode, then the holder must be preempted in kernmode, so we should choose a vcpu in kernmode as the most eligible candidate. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted or spinlock exit. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> --- arch/arm/kvm/handle_exit.c | 2 +- arch/arm64/kvm/handle_exit.c | 2 +- arch/mips/kvm/mips.c | 6 ++++++ arch/powerpc/kvm/powerpc.c | 6 ++++++ arch/s390/kvm/diag.c | 2 +- arch/s390/kvm/kvm-s390.c | 6 ++++++ arch/x86/kvm/hyperv.c | 2 +- arch/x86/kvm/svm.c | 4 +++- arch/x86/kvm/vmx.c | 2 +- arch/x86/kvm/x86.c | 6 ++++++ include/linux/kvm_host.h | 3 ++- virt/kvm/arm/arm.c | 5 +++++ virt/kvm/kvm_main.c | 4 +++- 13 files changed, 42 insertions(+), 8 deletions(-)