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| author | Sean Christopherson <seanjc@google.com> | 2021-12-08 01:52:23 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-19 12:14:43 -0500 |
| commit | af52f5aa5c1b46809834b728a13a1af5aab451e9 (patch) | |
| tree | 547765cbf3af99c39393ac41e54fe16d5edb2b58 | |
| parent | e422b88969489e67fd1a87a6ef4ef5c30bb53edb (diff) | |
| download | linux-af52f5aa5c1b46809834b728a13a1af5aab451e9.tar.gz linux-af52f5aa5c1b46809834b728a13a1af5aab451e9.tar.bz2 linux-af52f5aa5c1b46809834b728a13a1af5aab451e9.zip | |
KVM: SVM: Use kvm_vcpu_is_blocking() in AVIC load to handle preemption
Use kvm_vcpu_is_blocking() to determine whether or not the vCPU should be
marked running during avic_vcpu_load(). Drop avic_is_running, which
really should have been named "vcpu_is_not_blocking", as it tracked if
the vCPU was blocking, not if it was actually running, e.g. it was set
during svm_create_vcpu() when the vCPU was obviously not running.
This is technically a teeny tiny functional change, as the vCPU will be
marked IsRunning=1 on being reloaded if the vCPU is preempted between
svm_vcpu_blocking() and prepare_to_rcuwait(). But that's a benign change
as the vCPU will be marked IsRunning=0 when KVM voluntarily schedules out
the vCPU.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211208015236.1616697-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm/avic.c | 14 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 |
3 files changed, 9 insertions, 12 deletions
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 7efe034c44c1..368813320121 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -975,6 +975,7 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { u64 entry; /* ID = 0xff (broadcast), ID > 0xff (reserved) */ + bool is_blocking = kvm_vcpu_is_blocking(vcpu); int h_physical_id = kvm_cpu_get_apicid(cpu); struct vcpu_svm *svm = to_svm(vcpu); @@ -992,12 +993,17 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK); entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; - if (svm->avic_is_running) + + /* + * Don't mark the vCPU as running if its blocking, i.e. if the vCPU is + * preempted after svm_vcpu_blocking() but before KVM voluntarily + * schedules out the vCPU. + */ + if (!is_blocking) entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); - avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, - svm->avic_is_running); + avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, !is_blocking); } void avic_vcpu_put(struct kvm_vcpu *vcpu) @@ -1018,11 +1024,9 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu) */ static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) { - struct vcpu_svm *svm = to_svm(vcpu); int cpu = get_cpu(); WARN_ON(cpu != vcpu->cpu); - svm->avic_is_running = is_run; if (kvm_vcpu_apicv_active(vcpu)) { if (is_run) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index bf0c3a67d836..d21ef0381d29 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1440,12 +1440,6 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) if (err) goto error_free_vmsa_page; - /* We initialize this flag to true to make sure that the is_running - * bit would be set the first time the vcpu is loaded. - */ - if (irqchip_in_kernel(vcpu->kvm) && kvm_apicv_activated(vcpu->kvm)) - svm->avic_is_running = true; - svm->msrpm = svm_vcpu_alloc_msrpm(); if (!svm->msrpm) { err = -ENOMEM; diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index fd0685b2ce55..5178f6b245e1 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -225,7 +225,6 @@ struct vcpu_svm { u32 dfr_reg; struct page *avic_backing_page; u64 *avic_physical_id_cache; - bool avic_is_running; /* * Per-vcpu list of struct amd_svm_iommu_ir: |