Check the vmcs12 guest_ia32_debugctl value before loading it, to avoid L2
being able to load arbitrary values to hardware IA32_DEBUGCTL.
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 4 ++++
arch/x86/kvm/vmx/vmx.c | 2 +-
arch/x86/kvm/vmx/vmx.h | 2 ++
3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index e073e3008b16..0bda6400e30a 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3193,6 +3193,10 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
CC((vmcs12->guest_bndcfgs & MSR_IA32_BNDCFGS_RSVD))))
return -EINVAL;
+ if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) &&
+ CC(vmcs12->guest_ia32_debugctl & ~vmx_get_supported_debugctl(vcpu, false)))
+ return -EINVAL;
+
if (nested_check_guest_non_reg_state(vmcs12))
return -EINVAL;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9953de0cb32a..9046ee2e9a04 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2179,7 +2179,7 @@ static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu,
return (unsigned long)data;
}
-static u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated)
+u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated)
{
u64 debugctl = 0;
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 6d1e40ecc024..1b80479505d3 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -413,7 +413,9 @@ static inline void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr,
vmx_disable_intercept_for_msr(vcpu, msr, type);
}
+
void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu);
+u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated);
/*
* Note, early Intel manuals have the write-low and read-high bitmap offsets
--
2.46.0
