From: Paolo Bonzini <pbonzini@redhat.com>
To: Nadav Amit <nadav.amit@gmail.com>,
"Christopherson, Sean J" <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Po-Hsu Lin <po-hsu.lin@canonical.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [kvm-unit-tests PATCHv2] unittests.cfg: Increase timeout for apic test
Date: Tue, 20 Oct 2020 10:48:24 +0200 [thread overview]
Message-ID: <d1277875-6b7a-f7fe-8a58-78ba5ae0ba1d@redhat.com> (raw)
In-Reply-To: <C67F3473-32FE-4099-BBB1-8BB31B1ED95D@gmail.com>
On 19/10/20 18:52, Nadav Amit wrote:
> IIRC, this test failed on VMware, and according to our previous discussions,
> does not follow the SDM as NMIs might be collapsed [1].
>
> [1] https://marc.info/?l=kvm&m=145876994031502&w=2
So should KVM be changed to always collapse NMIs, like this?
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 105261402921..4032336ecba3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -668,7 +668,7 @@ EXPORT_SYMBOL_GPL(kvm_inject_emulated_page_fault);
void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
- atomic_inc(&vcpu->arch.nmi_queued);
+ atomic_set(&vcpu->arch.nmi_queued, 1);
kvm_make_request(KVM_REQ_NMI, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_inject_nmi);
@@ -8304,18 +8304,7 @@ static void inject_pending_event(struct kvm_vcpu
*vcpu, bool *req_immediate_exit
static void process_nmi(struct kvm_vcpu *vcpu)
{
- unsigned limit = 2;
-
- /*
- * x86 is limited to one NMI running, and one NMI pending after it.
- * If an NMI is already in progress, limit further NMIs to just one.
- * Otherwise, allow two (and we'll inject the first one immediately).
- */
- if (kvm_x86_ops.get_nmi_mask(vcpu) || vcpu->arch.nmi_injected)
- limit = 1;
-
- vcpu->arch.nmi_pending += atomic_xchg(&vcpu->arch.nmi_queued, 0);
- vcpu->arch.nmi_pending = min(vcpu->arch.nmi_pending, limit);
+ vcpu->arch.nmi_pending |= atomic_xchg(&vcpu->arch.nmi_queued, 0);
kvm_make_request(KVM_REQ_EVENT, vcpu);
}
Paolo
next prev parent reply other threads:[~2020-10-20 8:48 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-13 9:12 [kvm-unit-tests PATCHv2] unittests.cfg: Increase timeout for apic test Po-Hsu Lin
2020-10-15 15:59 ` Vitaly Kuznetsov
2020-10-15 16:35 ` Sean Christopherson
2020-10-16 17:02 ` Paolo Bonzini
2020-10-16 17:40 ` Andrew Jones
2020-10-20 5:53 ` Thomas Huth
2020-10-20 8:49 ` Andrew Jones
2020-10-19 11:32 ` Vitaly Kuznetsov
2020-10-19 16:37 ` Christopherson, Sean J
2020-10-19 16:52 ` Nadav Amit
2020-10-20 8:48 ` Paolo Bonzini [this message]
2020-10-20 15:05 ` Christopherson, Sean J
2020-10-30 8:15 ` Po-Hsu Lin
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