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authorLadi Prosek <lprosek@redhat.com>2017-10-17 17:02:39 +0300
committerRadim Krčmář <rkrcmar@redhat.com>2017-10-18 22:21:22 +0300
commitcc3d967f7e32ceeb9b78dc962126ebcf1a2b24b2 (patch)
treeb5a6a7dc1f6c9c181be3bab24d05b5066b423ce0 /arch/x86/kvm
parent9b8ebbdb74b5ad76b9dfd8b101af17839174b126 (diff)
downloadlinux-cc3d967f7e32ceeb9b78dc962126ebcf1a2b24b2.tar.xz
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')
-rw-r--r--arch/x86/kvm/svm.c16
-rw-r--r--arch/x86/kvm/vmx.c6
-rw-r--r--arch/x86/kvm/x86.c22
3 files changed, 35 insertions, 9 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)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c460b0b439d3..69d45734091f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11973,6 +11973,11 @@ static int vmx_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)
return 0;
}
+static int enable_smi_window(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+
static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -12102,6 +12107,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.smi_allowed = vmx_smi_allowed,
.pre_enter_smm = vmx_pre_enter_smm,
.pre_leave_smm = vmx_pre_leave_smm,
+ .enable_smi_window = enable_smi_window,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5669af09b732..3b51c8659741 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6892,17 +6892,23 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (inject_pending_event(vcpu, req_int_win) != 0)
req_immediate_exit = true;
else {
- /* Enable NMI/IRQ window open exits if needed.
+ /* Enable SMI/NMI/IRQ window open exits if needed.
*
- * SMIs have two cases: 1) they can be nested, and
- * then there is nothing to do here because RSM will
- * cause a vmexit anyway; 2) or the SMI can be pending
- * because inject_pending_event has completed the
- * injection of an IRQ or NMI from the previous vmexit,
- * and then we request an immediate exit to inject the SMI.
+ * SMIs have three cases:
+ * 1) They can be nested, and then there is nothing to
+ * do here because RSM will cause a vmexit anyway.
+ * 2) There is an ISA-specific reason why SMI cannot be
+ * injected, and the moment when this changes can be
+ * intercepted.
+ * 3) Or the SMI can be pending because
+ * inject_pending_event has completed the injection
+ * of an IRQ or NMI from the previous vmexit, and
+ * then we request an immediate exit to inject the
+ * SMI.
*/
if (vcpu->arch.smi_pending && !is_smm(vcpu))
- req_immediate_exit = true;
+ if (!kvm_x86_ops->enable_smi_window(vcpu))
+ req_immediate_exit = true;
if (vcpu->arch.nmi_pending)
kvm_x86_ops->enable_nmi_window(vcpu);
if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)