From: Marian Rotariu <marian.c.rota...@gmail.com>
The introspection tool uses this function to check the hardware support
for EPT switching, which can be used either to singlestep vCPUs
on a unprotected EPT view or to use #VE in order to avoid filter out
VM-exits caused by EPT violations.
Signed-off-by: Marian Rotariu <marian.c.rota...@gmail.com>
Co-developed-by: Ștefan Șicleru <ssicl...@bitdefender.com>
Signed-off-by: Ștefan Șicleru <ssicl...@bitdefender.com>
Signed-off-by: Adalbert Lazăr <ala...@bitdefender.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/vmx/capabilities.h | 8 ++++++++
arch/x86/kvm/vmx/vmx.c | 8 ++++++++
arch/x86/kvm/x86.c | 3 +++
4 files changed, 21 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ab6989745f9c..5eb26135e81b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1301,6 +1301,7 @@ struct kvm_x86_ops {
bool (*gpt_translation_fault)(struct kvm_vcpu *vcpu);
void (*control_singlestep)(struct kvm_vcpu *vcpu, bool enable);
bool (*get_vmfunc_status)(void);
+ bool (*get_eptp_switching_status)(void);
};
struct kvm_x86_nested_ops {
@@ -1422,6 +1423,7 @@ extern u64 kvm_max_tsc_scaling_ratio;
extern u64 kvm_default_tsc_scaling_ratio;
extern u64 kvm_mce_cap_supported;
+extern bool kvm_eptp_switching_supported;
/*
* EMULTYPE_NO_DECODE - Set when re-emulating an instruction (after completing
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index e7d7fcb7e17f..92781e2c523e 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -219,6 +219,14 @@ static inline bool cpu_has_vmx_vmfunc(void)
SECONDARY_EXEC_ENABLE_VMFUNC;
}
+static inline bool cpu_has_vmx_eptp_switching(void)
+{
+ u64 vmx_msr;
+
+ rdmsrl(MSR_IA32_VMX_VMFUNC, vmx_msr);
+ return vmx_msr & VMX_VMFUNC_EPTP_SWITCHING;
+}
+
static inline bool cpu_has_vmx_shadow_vmcs(void)
{
u64 vmx_msr;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ec4396d5f36f..ccbf561b0fc4 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7997,6 +7997,11 @@ static bool vmx_get_vmfunc_status(void)
return cpu_has_vmx_vmfunc();
}
+static bool vmx_get_eptp_switching_status(void)
+{
+ return kvm_eptp_switching_supported;
+}
+
static struct kvm_x86_ops vmx_x86_ops __initdata = {
.hardware_unsetup = hardware_unsetup,
@@ -8139,6 +8144,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.gpt_translation_fault = vmx_gpt_translation_fault,
.control_singlestep = vmx_control_singlestep,
.get_vmfunc_status = vmx_get_vmfunc_status,
+ .get_eptp_switching_status = vmx_get_eptp_switching_status,
};
static __init int hardware_setup(void)
@@ -8178,6 +8184,8 @@ static __init int hardware_setup(void)
!cpu_has_vmx_invept_global())
enable_ept = 0;
+ kvm_eptp_switching_supported = cpu_has_vmx_eptp_switching();
+
if (!cpu_has_vmx_ept_ad_bits() || !enable_ept)
enable_ept_ad_bits = 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index feb20b29bb92..b16b018c74cc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -161,6 +161,9 @@ module_param(force_emulation_prefix, bool, S_IRUGO);
int __read_mostly pi_inject_timer = -1;
module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR);
+bool __read_mostly kvm_eptp_switching_supported;
+EXPORT_SYMBOL_GPL(kvm_eptp_switching_supported);
+
#define KVM_NR_SHARED_MSRS 16
struct kvm_shared_msrs_global {
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