diff mbox series

[RFC,v3,29/59] KVM: x86: Add option to force LAPIC expiration wait

Message ID 9cc794352494e0ef4a2a1d4291b937653b39e780.1637799475.git.isaku.yamahata@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM: X86: TDX support | expand

Commit Message

Isaku Yamahata Nov. 25, 2021, 12:20 a.m. UTC 
From: Sean Christopherson <sean.j.christopherson@intel.com>

Add an option to skip the IRR check in kvm_wait_lapic_expire().  This
will be used by TDX to wait if there is an outstanding notification for
a TD, i.e. a virtual interrupt is being triggered via posted interrupt
processing.  KVM TDX doesn't emulate PI processing, i.e. there will
never be a bit set in IRR/ISR, so the default behavior for APICv of
querying the IRR doesn't work as intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/lapic.c   | 4 ++--
 arch/x86/kvm/lapic.h   | 2 +-
 arch/x86/kvm/svm/svm.c | 2 +-
 arch/x86/kvm/vmx/vmx.c | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

Comments

Thomas Gleixner Nov. 25, 2021, 7:53 p.m. UTC | #1 
On Wed, Nov 24 2021 at 16:20, isaku yamahata wrote:
> Add an option to skip the IRR check in kvm_wait_lapic_expire().

Yay for consistency. $Subject says 'Add option to force wait'. Changelog
says 'Add option to skip ... check'. Can you make your mind up?

Also the change at hand is not adding an option. It's adding a function
argument. You surely can spot the difference between option and function
argument, right?

Changelogs are meant to be readable by mere mortals.

Thanks,

        tglx
diff mbox series

Patch

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 1bfcd325d0d2..beef195b9d15 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1625,12 +1625,12 @@  static void __kvm_wait_lapic_expire(struct kvm_vcpu *vcpu)
 		__wait_lapic_expire(vcpu, tsc_deadline - guest_tsc);
 }
 
-void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu)
+void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu, bool force_wait)
 {
 	if (lapic_in_kernel(vcpu) &&
 	    vcpu->arch.apic->lapic_timer.expired_tscdeadline &&
 	    vcpu->arch.apic->lapic_timer.timer_advance_ns &&
-	    lapic_timer_int_injected(vcpu))
+	    (force_wait || lapic_timer_int_injected(vcpu)))
 		__kvm_wait_lapic_expire(vcpu);
 }
 EXPORT_SYMBOL_GPL(kvm_wait_lapic_expire);
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 2b44e533fc8d..2a0119ef9e96 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -233,7 +233,7 @@  static inline int kvm_lapic_latched_init(struct kvm_vcpu *vcpu)
 
 bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);
 
-void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu);
+void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu, bool force_wait);
 
 void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq,
 			      unsigned long *vcpu_bitmap);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 1bf410add13b..e33cbf9613d9 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3885,7 +3885,7 @@  static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 	clgi();
 	kvm_load_guest_xsave_state(vcpu);
 
-	kvm_wait_lapic_expire(vcpu);
+	kvm_wait_lapic_expire(vcpu, false);
 
 	/*
 	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5e4c6ac9fe69..1e20e85a958f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6647,7 +6647,7 @@  static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	if (enable_preemption_timer)
 		vmx_update_hv_timer(vcpu);
 
-	kvm_wait_lapic_expire(vcpu);
+	kvm_wait_lapic_expire(vcpu, false);
 
 	/*
 	 * If this vCPU has touched SPEC_CTRL, restore the guest's value if