From: Santosh Shukla <santosh.shukla@amd.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Tom Lendacky <thomas.lendacky@amd.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <santosh.shukla@amd.com>,
<mlevitsk@redhat.com>, <mail@maciej.szmigiero.name>
Subject: [PATCHv4 6/8] KVM: nSVM: implement nested VNMI
Date: Mon, 29 Aug 2022 15:38:48 +0530 [thread overview]
Message-ID: <20220829100850.1474-7-santosh.shukla@amd.com> (raw)
In-Reply-To: <20220829100850.1474-1-santosh.shukla@amd.com>
In order to support nested VNMI requires saving and restoring the VNMI
bits during nested entry and exit.
In case of L1 and L2 both using VNMI- Copy VNMI bits from vmcb12 to
vmcb02 during entry and vice-versa during exit.
And in case of L1 uses VNMI and L2 doesn't- Copy VNMI bits from vmcb01 to
vmcb02 during entry and vice-versa during exit.
Tested with the KVM-unit-test and Nested Guest scenario.
Signed-off-by: Santosh Shukla <santosh.shukla@amd.com>
---
v3:
- Added code to save and restore VNMI bit for L1 using vnmi and L2
doesn't for the entry and exit case.
v2:
- Save the V_NMI_PENDING/MASK state in vmcb12 on vmexit.
- Tested nested environment - L1 injecting vnmi to L2.
- Tested vnmi in kvm-unit-test.
arch/x86/kvm/svm/nested.c | 27 +++++++++++++++++++++++++++
arch/x86/kvm/svm/svm.c | 5 +++++
arch/x86/kvm/svm/svm.h | 6 ++++++
3 files changed, 38 insertions(+)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 76dcc8a3e849..3d986ec83147 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -662,6 +662,11 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
else
int_ctl_vmcb01_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
+ if (nested_vnmi_enabled(svm))
+ int_ctl_vmcb12_bits |= (V_NMI_PENDING | V_NMI_ENABLE | V_NMI_MASK);
+ else
+ int_ctl_vmcb01_bits |= (V_NMI_PENDING | V_NMI_ENABLE | V_NMI_MASK);
+
/* Copied from vmcb01. msrpm_base can be overwritten later. */
vmcb02->control.nested_ctl = vmcb01->control.nested_ctl;
vmcb02->control.iopm_base_pa = vmcb01->control.iopm_base_pa;
@@ -1010,6 +1015,28 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
vmcb12->control.event_inj = svm->nested.ctl.event_inj;
vmcb12->control.event_inj_err = svm->nested.ctl.event_inj_err;
+ if (nested_vnmi_enabled(svm)) {
+ if (vmcb02->control.int_ctl & V_NMI_MASK)
+ vmcb12->control.int_ctl |= V_NMI_MASK;
+ else
+ vmcb12->control.int_ctl &= ~V_NMI_MASK;
+
+ if (vmcb02->control.int_ctl & V_NMI_PENDING)
+ vmcb12->control.int_ctl |= V_NMI_PENDING;
+ else
+ vmcb12->control.int_ctl &= ~V_NMI_PENDING;
+ } else {
+ if (vmcb02->control.int_ctl & V_NMI_MASK)
+ vmcb01->control.int_ctl |= V_NMI_MASK;
+ else
+ vmcb01->control.int_ctl &= ~V_NMI_MASK;
+
+ if (vmcb02->control.int_ctl & V_NMI_PENDING)
+ vmcb01->control.int_ctl |= V_NMI_PENDING;
+ else
+ vmcb01->control.int_ctl &= ~V_NMI_PENDING;
+ }
+
if (!kvm_pause_in_guest(vcpu->kvm)) {
vmcb01->control.pause_filter_count = vmcb02->control.pause_filter_count;
vmcb_mark_dirty(vmcb01, VMCB_INTERCEPTS);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4aa7606a9aa2..2e50a7ab32db 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4217,6 +4217,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
svm->vgif_enabled = vgif && guest_cpuid_has(vcpu, X86_FEATURE_VGIF);
+ svm->vnmi_enabled = vnmi && guest_cpuid_has(vcpu, X86_FEATURE_V_NMI);
+
svm_recalc_instruction_intercepts(vcpu, svm);
/* For sev guests, the memory encryption bit is not reserved in CR3. */
@@ -4967,6 +4969,9 @@ static __init void svm_set_cpu_caps(void)
if (vgif)
kvm_cpu_cap_set(X86_FEATURE_VGIF);
+ if (vnmi)
+ kvm_cpu_cap_set(X86_FEATURE_V_NMI);
+
/* Nested VM can receive #VMEXIT instead of triggering #GP */
kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK);
}
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 7857a89d0ec8..4d6245ef5b6c 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -253,6 +253,7 @@ struct vcpu_svm {
bool pause_filter_enabled : 1;
bool pause_threshold_enabled : 1;
bool vgif_enabled : 1;
+ bool vnmi_enabled : 1;
u32 ldr_reg;
u32 dfr_reg;
@@ -533,6 +534,11 @@ static inline bool is_x2apic_msrpm_offset(u32 offset)
(msr < (APIC_BASE_MSR + 0x100));
}
+static inline bool nested_vnmi_enabled(struct vcpu_svm *svm)
+{
+ return svm->vnmi_enabled && (svm->nested.ctl.int_ctl & V_NMI_ENABLE);
+}
+
static inline struct vmcb *get_vnmi_vmcb(struct vcpu_svm *svm)
{
if (!vnmi)
--
2.25.1
next prev parent reply other threads:[~2022-08-29 10:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-29 10:08 [PATCHv4 0/8] Virtual NMI feature Santosh Shukla
2022-08-29 10:08 ` [PATCHv4 1/8] x86/cpu: Add CPUID feature bit for VNMI Santosh Shukla
2022-08-31 23:42 ` Jim Mattson
2022-09-01 12:45 ` Shukla, Santosh
2022-09-01 17:43 ` Jim Mattson
2022-09-05 7:49 ` Shukla, Santosh
2022-08-29 10:08 ` [PATCHv4 2/8] KVM: SVM: Add VNMI bit definition Santosh Shukla
2022-08-29 10:08 ` [PATCHv4 3/8] KVM: SVM: Add VNMI support in get/set_nmi_mask Santosh Shukla
2022-08-29 10:08 ` [PATCHv4 4/8] KVM: SVM: Report NMI not allowed when Guest busy handling VNMI Santosh Shukla
2022-08-29 10:08 ` [PATCHv4 5/8] KVM: SVM: Add VNMI support in inject_nmi Santosh Shukla
2022-08-29 10:08 ` Santosh Shukla [this message]
2022-08-29 10:08 ` [PATCHv4 7/8] KVM: nSVM: emulate VMEXIT_INVALID case for nested VNMI Santosh Shukla
2022-08-29 10:08 ` [PATCHv4 8/8] KVM: SVM: Enable VNMI feature Santosh Shukla
2022-10-06 18:40 ` [PATCHv4 0/8] Virtual NMI feature Sean Christopherson
2022-10-10 5:46 ` Santosh Shukla
2022-10-10 15:51 ` Sean Christopherson
2022-10-16 5:49 ` Santosh Shukla
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