From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Sean Christopherson <seanjc@google.com>,
Wanpeng Li <wanpengli@tencent.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT
AND 64-BIT)),
x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
Jim Mattson <jmattson@google.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH 08/10] KVM: x86: APICv: drop immediate APICv disablement on current vCPU
Date: Wed, 23 Jun 2021 14:30:00 +0300 [thread overview]
Message-ID: <20210623113002.111448-9-mlevitsk@redhat.com> (raw)
In-Reply-To: <20210623113002.111448-1-mlevitsk@redhat.com>
Special case of disabling the APICv on the current vCPU right away in
kvm_request_apicv_update doesn't bring much benefit vs raising
KVM_REQ_APICV_UPDATE on it instead, since this request will be processed
on the next entry to the guest.
(the comment about having another #VMEXIT is wrong).
It also hides various assumptions, that APICv enable state matches
the APICv inhibit state, as this special case only makes those states
match on the current vCPU.
Previous patches fixed few such assumptions so now it should be safe
to drop this special case.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/x86.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6f0d9c231249..dcf06acdbf52 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9209,7 +9209,6 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv);
*/
void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit)
{
- struct kvm_vcpu *except;
unsigned long old, new, expected;
if (!kvm_x86_ops.check_apicv_inhibit_reasons ||
@@ -9237,18 +9236,9 @@ void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit)
if (kvm_x86_ops.pre_update_apicv_exec_ctrl)
static_call(kvm_x86_pre_update_apicv_exec_ctrl)(kvm, activate);
- /*
- * Sending request to update APICV for all other vcpus,
- * while update the calling vcpu immediately instead of
- * waiting for another #VMEXIT to handle the request.
- */
- except = kvm_get_running_vcpu();
- kvm_make_all_cpus_request_except(kvm, KVM_REQ_APICV_UPDATE,
- except);
+ kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_UPDATE);
kvm_allow_guest_entries(kvm);
- if (except)
- kvm_vcpu_update_apicv(except);
}
EXPORT_SYMBOL_GPL(kvm_request_apicv_update);
--
2.26.3
next prev parent reply other threads:[~2021-06-23 11:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 11:29 [PATCH 00/10] My AVIC patch queue Maxim Levitsky
2021-06-23 11:29 ` [PATCH 01/10] KVM: x86: extract block/allow guest enteries Maxim Levitsky
2021-06-23 11:29 ` [PATCH 02/10] KVM: x86: APICv: fix race in kvm_request_apicv_update on SVM Maxim Levitsky
2021-06-23 21:50 ` Paolo Bonzini
2021-06-24 8:07 ` Maxim Levitsky
2021-07-07 12:57 ` Maxim Levitsky
2021-07-07 13:58 ` Paolo Bonzini
2021-06-23 11:29 ` [PATCH 03/10] KVM: x86: rename apic_access_page_done to apic_access_memslot_enabled Maxim Levitsky
2021-06-23 21:50 ` Paolo Bonzini
2021-06-23 11:29 ` [PATCH 04/10] KVM: SVM: add warning for mistmatch between AVIC state and AVIC access page state Maxim Levitsky
2021-06-23 21:53 ` Paolo Bonzini
2021-06-24 8:13 ` Maxim Levitsky
2021-06-23 11:29 ` [PATCH 05/10] KVM: SVM: svm_set_vintr don't warn if AVIC is active but is about to be deactivated Maxim Levitsky
2021-06-23 11:29 ` [PATCH 06/10] KVM: SVM: tweak warning about enabled AVIC on nested entry Maxim Levitsky
2021-06-23 21:52 ` Paolo Bonzini
2021-06-23 11:29 ` [PATCH 07/10] KVM: SVM: use vmcb01 in svm_refresh_apicv_exec_ctrl Maxim Levitsky
2021-06-23 21:54 ` Paolo Bonzini
2021-06-24 8:16 ` Maxim Levitsky
2021-06-23 11:30 ` Maxim Levitsky [this message]
2021-06-23 11:30 ` [PATCH 09/10] KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC Maxim Levitsky
2021-06-23 11:30 ` [PATCH 10/10] KVM: x86: hyper-v: Deactivate APICv only when AutoEOI feature is in use Maxim Levitsky
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