Thread (50 messages) 50 messages, 6 authors, 2022-11-18
STALE1336d

[PATCH 05/14] KVM: s390: Clear valid_wakeup in kvm_s390_handle_wait(), not in arch hook

From: Sean Christopherson <seanjc@google.com>
Date: 2021-09-25 00:55:54
Also in: kvm, kvmarm, linux-arm-kernel, lkml
Subsystem: kernel virtual machine for s390 (kvm/s390), s390 architecture, the rest · Maintainers: Christian Borntraeger, Janosch Frank, Claudio Imbrenda, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds

Move the clearing of valid_wakeup out of kvm_arch_vcpu_block_finish() so
that a future patch can drop said arch hook.  Unlike the other blocking-
related arch hooks (vcpu_blocking/unblocking()), vcpu_block_finish() needs
to be called even if the KVM doesn't actually block the vCPU.  This will
allow future patches to differentiate between truly blocking the vCPU and
emulating a halt condition without introducing a contradiction.

Alternatively, the hook could be renamed to kvm_arch_vcpu_halt_finish(),
but there's literally one call site in s390, and future cleanup can also
be done to handle valid_wakeup fully within kvm_s390_handle_wait() and
allow generic KVM to drop vcpu_valid_wakeup().

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/s390/kvm/interrupt.c | 1 +
 arch/s390/kvm/kvm-s390.c  | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 10722455fd02..520450a7956f 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1336,6 +1336,7 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 no_timer:
 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 	kvm_vcpu_block(vcpu);
+	vcpu->valid_wakeup = false;
 	__unset_cpu_idle(vcpu);
 	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 7cabe6778b1b..08ed68639a21 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -5082,7 +5082,7 @@ static inline unsigned long nonhyp_mask(int i)
 
 void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu)
 {
-	vcpu->valid_wakeup = false;
+
 }
 
 static int __init kvm_s390_init(void)
-- 
2.33.0.685.g46640cef36-goog
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