[RFC PATCH v6 19/36] KVM: VMX: Get rid of eVMCS specific VMX controls sanitization

Sean Christopherson
2022-08-24T03:04:21Z

With the updated eVMCSv1 definition, there's no known 'problematic'
controls which are exposed in VMX control MSRs but are not present in
eVMCSv1: all known Hyper-V versions either don't expose the new fields
by not setting bits in the VMX feature controls or support the new
eVMCS revision.

Get rid of VMX control MSRs filtering for KVM on Hyper-V.

Note: VMX control MSRs filtering for Hyper-V on KVM
(nested_evmcs_filter_control_msr()) stays as even the updated eVMCSv1
definition doesn't have all the features implemented by KVM and some
fields are still missing. Moreover, nested_evmcs_filter_control_msr()
has to support the original eVMCSv1 version when VMM wishes so.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/evmcs.c | 13 -------------
arch/x86/kvm/vmx/evmcs.h | 1 -
arch/x86/kvm/vmx/vmx.c | 5 -----
3 files changed, 19 deletions(-)

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 38ec41939cab..2365e81cfc6e 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -322,19 +322,6 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
};
const unsigned int nr_evmcs_1_fields = ARRAY_SIZE(vmcs_field_to_evmcs_1);

-#if IS_ENABLED(CONFIG_HYPERV)
-__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
-{
- vmcs_conf->cpu_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_EXEC_CTRL;
- vmcs_conf->pin_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_PINCTRL;
- vmcs_conf->cpu_based_2nd_exec_ctrl &= ~EVMCS1_UNSUPPORTED_2NDEXEC;
- vmcs_conf->cpu_based_3rd_exec_ctrl = 0;
-
- vmcs_conf->vmexit_ctrl &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
- vmcs_conf->vmentry_ctrl &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
-}
-#endif
-
bool nested_enlightened_vmentry(struct kvm_vcpu *vcpu, u64 *evmcs_gpa)
{
struct hv_vp_assist_page assist_page;
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index a2e21bdd17bb..33cd4623bb0b 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -215,7 +215,6 @@ static inline void evmcs_load(u64 phys_addr)
vp_ap->enlighten_vmentry = 1;
}

-__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf);
#else /* !IS_ENABLED(CONFIG_HYPERV) */
static __always_inline void evmcs_write64(unsigned long field, u64 value) {}
static inline void evmcs_write32(unsigned long field, u32 value) {}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 73f9074efc61..6b702c0085ff 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2762,11 +2762,6 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
vmcs_conf->vmexit_ctrl = _vmexit_control;
vmcs_conf->vmentry_ctrl = _vmentry_control;

-#if IS_ENABLED(CONFIG_HYPERV)
- if (enlightened_vmcs)
- evmcs_sanitize_exec_ctrls(vmcs_conf);
-#endif
-
return 0;
}

--
2.37.1.595.g718a3a8f04-goog