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authorVitaly Kuznetsov <vkuznets@redhat.com>2022-08-30 15:37:11 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2022-09-26 12:02:41 -0400
commitf4d361b4c29477dbcc6e436b9425ee2716aecc6e (patch)
tree898fdd54724232f867a6c2560c32f6649b1303d5 /arch/x86/kvm
parent85ab071af83952a44473e3d02304c17053ade2f4 (diff)
downloadlinux-f4d361b4c29477dbcc6e436b9425ee2716aecc6e.tar.bz2
KVM: nVMX: Refactor unsupported eVMCS controls logic to use 2-d array
Refactor the handling of unsupported eVMCS to use a 2-d array to store the set of unsupported controls. KVM's handling of eVMCS is completely broken as there is no way for userspace to query which features are unsupported, nor does KVM prevent userspace from attempting to enable unsupported features. A future commit will remedy that by filtering and enforcing unsupported features when eVMCS, but that needs to be opt-in from userspace to avoid breakage, i.e. KVM needs to maintain its legacy behavior by snapshotting the exact set of controls that are currently (un)supported by eVMCS. No functional change intended. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> [sean: split to standalone patch, write changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20220830133737.1539624-8-vkuznets@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/vmx/evmcs.c60
1 files changed, 50 insertions, 10 deletions
diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 9139c70b6008..a82af2482f84 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -345,6 +345,45 @@ uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
return 0;
}
+enum evmcs_revision {
+ EVMCSv1_LEGACY,
+ NR_EVMCS_REVISIONS,
+};
+
+enum evmcs_ctrl_type {
+ EVMCS_EXIT_CTRLS,
+ EVMCS_ENTRY_CTRLS,
+ EVMCS_2NDEXEC,
+ EVMCS_PINCTRL,
+ EVMCS_VMFUNC,
+ NR_EVMCS_CTRLS,
+};
+
+static const u32 evmcs_unsupported_ctrls[NR_EVMCS_CTRLS][NR_EVMCS_REVISIONS] = {
+ [EVMCS_EXIT_CTRLS] = {
+ [EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_VMEXIT_CTRL,
+ },
+ [EVMCS_ENTRY_CTRLS] = {
+ [EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_VMENTRY_CTRL,
+ },
+ [EVMCS_2NDEXEC] = {
+ [EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_2NDEXEC,
+ },
+ [EVMCS_PINCTRL] = {
+ [EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_PINCTRL,
+ },
+ [EVMCS_VMFUNC] = {
+ [EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_VMFUNC,
+ },
+};
+
+static u32 evmcs_get_unsupported_ctls(enum evmcs_ctrl_type ctrl_type)
+{
+ enum evmcs_revision evmcs_rev = EVMCSv1_LEGACY;
+
+ return evmcs_unsupported_ctrls[ctrl_type][evmcs_rev];
+}
+
void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata)
{
u32 ctl_low = (u32)*pdata;
@@ -357,21 +396,21 @@ void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata)
switch (msr_index) {
case MSR_IA32_VMX_EXIT_CTLS:
case MSR_IA32_VMX_TRUE_EXIT_CTLS:
- ctl_high &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
+ ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_EXIT_CTRLS);
break;
case MSR_IA32_VMX_ENTRY_CTLS:
case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
- ctl_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
+ ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_ENTRY_CTRLS);
break;
case MSR_IA32_VMX_PROCBASED_CTLS2:
- ctl_high &= ~EVMCS1_UNSUPPORTED_2NDEXEC;
+ ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_2NDEXEC);
break;
case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
case MSR_IA32_VMX_PINBASED_CTLS:
- ctl_high &= ~EVMCS1_UNSUPPORTED_PINCTRL;
+ ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_PINCTRL);
break;
case MSR_IA32_VMX_VMFUNC:
- ctl_low &= ~EVMCS1_UNSUPPORTED_VMFUNC;
+ ctl_low &= ~evmcs_get_unsupported_ctls(EVMCS_VMFUNC);
break;
}
@@ -384,7 +423,7 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
u32 unsupp_ctl;
unsupp_ctl = vmcs12->pin_based_vm_exec_control &
- EVMCS1_UNSUPPORTED_PINCTRL;
+ evmcs_get_unsupported_ctls(EVMCS_PINCTRL);
if (unsupp_ctl) {
trace_kvm_nested_vmenter_failed(
"eVMCS: unsupported pin-based VM-execution controls",
@@ -393,7 +432,7 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
}
unsupp_ctl = vmcs12->secondary_vm_exec_control &
- EVMCS1_UNSUPPORTED_2NDEXEC;
+ evmcs_get_unsupported_ctls(EVMCS_2NDEXEC);
if (unsupp_ctl) {
trace_kvm_nested_vmenter_failed(
"eVMCS: unsupported secondary VM-execution controls",
@@ -402,7 +441,7 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
}
unsupp_ctl = vmcs12->vm_exit_controls &
- EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
+ evmcs_get_unsupported_ctls(EVMCS_EXIT_CTRLS);
if (unsupp_ctl) {
trace_kvm_nested_vmenter_failed(
"eVMCS: unsupported VM-exit controls",
@@ -411,7 +450,7 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
}
unsupp_ctl = vmcs12->vm_entry_controls &
- EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
+ evmcs_get_unsupported_ctls(EVMCS_ENTRY_CTRLS);
if (unsupp_ctl) {
trace_kvm_nested_vmenter_failed(
"eVMCS: unsupported VM-entry controls",
@@ -419,7 +458,8 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
ret = -EINVAL;
}
- unsupp_ctl = vmcs12->vm_function_control & EVMCS1_UNSUPPORTED_VMFUNC;
+ unsupp_ctl = vmcs12->vm_function_control &
+ evmcs_get_unsupported_ctls(EVMCS_VMFUNC);
if (unsupp_ctl) {
trace_kvm_nested_vmenter_failed(
"eVMCS: unsupported VM-function controls",