From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: mlevitsk@redhat.com, seanjc@google.com
Subject: [PATCH v3 6/7] KVM: mips, x86: do not rely on KVM_REQ_UNHALT
Date: Mon, 22 Aug 2022 13:06:58 -0400 [thread overview]
Message-ID: <20220822170659.2527086-7-pbonzini@redhat.com> (raw)
In-Reply-To: <20220822170659.2527086-1-pbonzini@redhat.com>
KVM_REQ_UNHALT is a weird request that simply reports the value of
kvm_arch_vcpu_runnable() on exit from kvm_vcpu_halt(). Only
MIPS and x86 are looking at it, the others just clear it. Check
the state of the vCPU directly so that the request is handled
as a nop on all architectures.
No functional change intended, except for corner cases where an
event arrive immediately after a signal become pending or after
another similar host-side event.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/mips/kvm/emulate.c | 7 +++----
arch/x86/kvm/x86.c | 9 ++++++++-
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index b494d8d39290..1d7c56defe93 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -955,13 +955,12 @@ enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
kvm_vcpu_halt(vcpu);
/*
- * We we are runnable, then definitely go off to user space to
+ * We are runnable, then definitely go off to user space to
* check if any I/O interrupts are pending.
*/
- if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
- kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+ kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+ if (kvm_arch_vcpu_runnable(vcpu))
vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
- }
}
return EMULATE_DONE;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f901cd872b6d..66ae2f2cb618 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10633,7 +10633,14 @@ static inline int vcpu_block(struct kvm_vcpu *vcpu)
if (hv_timer)
kvm_lapic_switch_to_hv_timer(vcpu);
- if (!kvm_check_request(KVM_REQ_UNHALT, vcpu))
+ kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+
+ /*
+ * If the vCPU is not runnable, a signal or another host event
+ * of some kind is pending; service it without changing the
+ * the vCPU's activity state.
+ */
+ if (!kvm_arch_vcpu_runnable(vcpu))
return 1;
}
--
2.31.1
next prev parent reply other threads:[~2022-08-22 17:07 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-22 17:06 [PATCH v3 0/7] KVM: x86: never write to memory from kvm_vcpu_check_block Paolo Bonzini
2022-08-22 17:06 ` [PATCH v3 1/7] KVM: x86: check validity of argument to KVM_SET_MP_STATE Paolo Bonzini
2022-08-22 17:06 ` [PATCH v3 2/7] KVM: x86: make vendor code check for all nested events Paolo Bonzini
2022-08-22 17:06 ` [PATCH v3 3/7] KVM: nVMX: Make an event request when pending an MTF nested VM-Exit Paolo Bonzini
2022-08-22 17:52 ` Jim Mattson
2022-08-22 19:40 ` Paolo Bonzini
2022-08-22 17:06 ` [PATCH v3 4/7] KVM: x86: lapic does not have to process INIT if it is blocked Paolo Bonzini
2022-08-22 17:06 ` [PATCH v3 5/7] KVM: x86: never write to memory from kvm_vcpu_check_block Paolo Bonzini
2022-08-22 17:06 ` Paolo Bonzini [this message]
2022-08-22 17:06 ` [PATCH v3 7/7] KVM: remove KVM_REQ_UNHALT Paolo Bonzini
2022-09-08 15:36 ` [PATCH v3 0/7] KVM: x86: never write to memory from kvm_vcpu_check_block Sean Christopherson
2022-09-17 1:02 ` Sean Christopherson
2022-09-20 1:15 ` Sean Christopherson
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