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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2021-05-06 22:14:41 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-05-07 12:06:23 +0200 |
| commit | ce7ea0cfdc2e9ff31d12da31c3226deddb9644f5 (patch) | |
| tree | 921b38c2bc256a037a897cdb62889aeab8f3fd4f | |
| parent | KVM: SVM: Invert user pointer casting in SEV {en,de}crypt helpers (diff) | |
| download | linux-ce7ea0cfdc2e9ff31d12da31c3226deddb9644f5.tar.xz linux-ce7ea0cfdc2e9ff31d12da31c3226deddb9644f5.zip | |
KVM: SVM: Move GHCB unmapping to fix RCU warning
When an SEV-ES guest is running, the GHCB is unmapped as part of the
vCPU run support. However, kvm_vcpu_unmap() triggers an RCU dereference
warning with CONFIG_PROVE_LOCKING=y because the SRCU lock is released
before invoking the vCPU run support.
Move the GHCB unmapping into the prepare_guest_switch callback, which is
invoked while still holding the SRCU lock, eliminating the RCU dereference
warning.
Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <b2f9b79d15166f2c3e4375c0d9bc3268b7696455.1620332081.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 5 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 |
3 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index eb241c1a4add..5bc887e9a986 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2197,7 +2197,7 @@ vmgexit_err: return -EINVAL; } -static void pre_sev_es_run(struct vcpu_svm *svm) +void sev_es_unmap_ghcb(struct vcpu_svm *svm) { if (!svm->ghcb) return; @@ -2233,9 +2233,6 @@ void pre_sev_run(struct vcpu_svm *svm, int cpu) struct svm_cpu_data *sd = per_cpu(svm_data, cpu); int asid = sev_get_asid(svm->vcpu.kvm); - /* Perform any SEV-ES pre-run actions */ - pre_sev_es_run(svm); - /* Assign the asid allocated with this SEV guest */ svm->asid = asid; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 8124f51e9488..4dd9b7856e5b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1437,6 +1437,9 @@ static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu) struct vcpu_svm *svm = to_svm(vcpu); struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu); + if (sev_es_guest(vcpu->kvm)) + sev_es_unmap_ghcb(svm); + if (svm->guest_state_loaded) return; diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 84b3133c2251..e44567ceb865 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -581,6 +581,7 @@ void sev_es_init_vmcb(struct vcpu_svm *svm); void sev_es_create_vcpu(struct vcpu_svm *svm); void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector); void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu); +void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ |