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| author | Ladi Prosek <lprosek@redhat.com> | 2017-10-17 16:02:39 +0200 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2017-10-18 21:21:22 +0200 |
| commit | cc3d967f7e32ceeb9b78dc962126ebcf1a2b24b2 (patch) | |
| tree | b5a6a7dc1f6c9c181be3bab24d05b5066b423ce0 /arch/x86/kvm/svm.c | |
| parent | 9b8ebbdb74b5ad76b9dfd8b101af17839174b126 (diff) | |
| download | lwn-cc3d967f7e32ceeb9b78dc962126ebcf1a2b24b2.tar.gz lwn-cc3d967f7e32ceeb9b78dc962126ebcf1a2b24b2.zip | |
KVM: SVM: detect opening of SMI window using STGI intercept
Commit 05cade71cf3b ("KVM: nSVM: fix SMI injection in guest mode") made
KVM mask SMI if GIF=0 but it didn't do anything to unmask it when GIF is
enabled.
The issue manifests for me as a significantly longer boot time of Windows
guests when running with SMM-enabled OVMF.
This commit fixes it by intercepting STGI instead of requesting immediate
exit if the reason why SMM was masked is GIF.
Fixes: 05cade71cf3b ("KVM: nSVM: fix SMI injection in guest mode")
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index ff94552f85d0..b71daed3cca2 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3187,7 +3187,7 @@ static int stgi_interception(struct vcpu_svm *svm) /* * If VGIF is enabled, the STGI intercept is only added to - * detect the opening of the NMI window; remove it now. + * detect the opening of the SMI/NMI window; remove it now. */ if (vgif_enabled(svm)) clr_intercept(svm, INTERCEPT_STGI); @@ -5476,6 +5476,19 @@ static int svm_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase) return ret; } +static int enable_smi_window(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + if (!gif_set(svm)) { + if (vgif_enabled(svm)) + set_intercept(svm, INTERCEPT_STGI); + /* STGI will cause a vm exit */ + return 1; + } + return 0; +} + static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -5590,6 +5603,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .smi_allowed = svm_smi_allowed, .pre_enter_smm = svm_pre_enter_smm, .pre_leave_smm = svm_pre_leave_smm, + .enable_smi_window = enable_smi_window, }; static int __init svm_init(void) |