From: Adalbert Lazar <alazar@xxxxxxxxxxxxxxx>
This function is used by the introspection subsytem to enable/disable
MSR register interception.
The patch adds back the __vmx_enable_intercept_for_msr() function
removed with the commit 40d8338d095e
("KVM: VMX: remove functions that enable msr intercepts").
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/svm.c | 11 +++++++++
arch/x86/kvm/vmx.c | 53 +++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 7 ++++++
4 files changed, 75 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 516798431328..8842d8e1e4ee 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1079,6 +1079,8 @@ struct kvm_x86_ops {
int (*pre_enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
int (*pre_leave_smm)(struct kvm_vcpu *vcpu, u64 smbase);
int (*enable_smi_window)(struct kvm_vcpu *vcpu);
+
+ void (*msr_intercept)(struct kvm_vcpu *vcpu, unsigned int msr, bool enable);
};
struct kvm_arch_async_pf {
@@ -1451,4 +1453,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
unsigned long start, unsigned long end);
+void kvm_arch_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+ bool enable);
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index eb714f1cdf7e..5f7482851223 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5505,6 +5505,15 @@ static int enable_smi_window(struct kvm_vcpu *vcpu)
return 0;
}
+static void svm_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+ bool enable)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ u32 *msrpm = svm->msrpm;
+
+ set_msr_interception(msrpm, msr, enable, enable);
+}
+
static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
@@ -5620,6 +5629,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.pre_enter_smm = svm_pre_enter_smm,
.pre_leave_smm = svm_pre_leave_smm,
.enable_smi_window = enable_smi_window,
+
+ .msr_intercept = svm_msr_intercept,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8eba631c4dbd..9c984bbe263e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12069,6 +12069,57 @@ static int enable_smi_window(struct kvm_vcpu *vcpu)
return 0;
}
+static void __vmx_enable_intercept_for_msr(unsigned long *msr_bitmap,
+ u32 msr, int type)
+{
+ int f = sizeof(unsigned long);
+
+ if (!cpu_has_vmx_msr_bitmap())
+ return;
+
+ /*
+ * See Intel PRM Vol. 3, 24.6.9 (MSR-Bitmap Address). Early manuals
+ * have the write-low and read-high bitmap offsets the wrong way round.
+ * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
+ */
+ if (msr <= 0x1fff) {
+ if (type & MSR_TYPE_R)
+ /* read-low */
+ __set_bit(msr, msr_bitmap + 0x000 / f);
+
+ if (type & MSR_TYPE_W)
+ /* write-low */
+ __set_bit(msr, msr_bitmap + 0x800 / f);
+
+ } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
+ msr &= 0x1fff;
+ if (type & MSR_TYPE_R)
+ /* read-high */
+ __set_bit(msr, msr_bitmap + 0x400 / f);
+
+ if (type & MSR_TYPE_W)
+ /* write-high */
+ __set_bit(msr, msr_bitmap + 0xc00 / f);
+
+ }
+}
+
+static void vmx_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+ bool enabled)
+{
+ if (enabled) {
+ __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode, msr,
+ MSR_TYPE_W);
+ __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy, msr,
+ MSR_TYPE_W);
+ } else {
+ __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy, msr,
+ MSR_TYPE_W);
+ __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode, msr,
+ MSR_TYPE_W);
+ }
+}
+
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,
@@ -12199,6 +12250,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.pre_enter_smm = vmx_pre_enter_smm,
.pre_leave_smm = vmx_pre_leave_smm,
.enable_smi_window = enable_smi_window,
+
+ .msr_intercept = vmx_msr_intercept,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1cec2c62a0b0..e1a3c2c6ec08 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8871,6 +8871,13 @@ bool kvm_vector_hashing_enabled(void)
}
EXPORT_SYMBOL_GPL(kvm_vector_hashing_enabled);
+void kvm_arch_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+ bool enable)
+{
+ kvm_x86_ops->msr_intercept(vcpu, msr, enable);
+}
+EXPORT_SYMBOL_GPL(kvm_arch_msr_intercept);
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
