[RFC PATCH v1 02/34] KVM: x86: export .get_eptp_switching_status()
From: Adalbert Lazăr <hidden>
Date: 2020-07-22 16:02:28
Also in:
kvm
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Marian Rotariu <redacted> 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 <redacted> Co-developed-by: Ștefan Șicleru <redacted> Signed-off-by: Ștefan Șicleru <redacted> Signed-off-by: Adalbert Lazăr <redacted> --- 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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