Expose the feature to L1 hypervisor if host CPU supports it, since
certain hypervisors requires it for own purposes.

According to Intel SDM A.1, if CPU supports the feature,
VMX_INSTRUCTION_INFO field of VMCS will contain detailed information
about INS/OUTS instructions handling. This field is already copied to
VMCS12 for L1 hypervisor (see prepare_vmcs12 routine) independently of
feature presence.

Signed-off-by: Jan Dakinevich <[email protected]>
---
v1:
 * don't copy to basic_cap bits, which are already copied to size field
 * fix commit message

 arch/x86/kvm/vmx.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a4bb2bd..10f9fb5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -939,6 +939,7 @@ static DEFINE_SPINLOCK(vmx_vpid_lock);
 static struct vmcs_config {
        int size;
        int order;
+       u32 basic_cap;
        u32 revision_id;
        u32 pin_based_exec_ctrl;
        u32 cpu_based_exec_ctrl;
@@ -1215,6 +1216,11 @@ static inline bool cpu_has_vmx_ple(void)
                SECONDARY_EXEC_PAUSE_LOOP_EXITING;
 }
 
+static inline bool cpu_has_vmx_basic_inout(void)
+{
+       return  (((u64)vmcs_config.basic_cap << 32) & VMX_BASIC_INOUT);
+}
+
 static inline bool cpu_need_virtualize_apic_accesses(struct kvm_vcpu *vcpu)
 {
        return flexpriority_enabled && lapic_in_kernel(vcpu);
@@ -2877,6 +2883,8 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 
msr_index, u64 *pdata)
                *pdata = VMCS12_REVISION | VMX_BASIC_TRUE_CTLS |
                           ((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
                           (VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
+               if (cpu_has_vmx_basic_inout())
+                       *pdata |= VMX_BASIC_INOUT;
                break;
        case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
        case MSR_IA32_VMX_PINBASED_CTLS:
@@ -3458,6 +3466,7 @@ static __init int setup_vmcs_config(struct vmcs_config 
*vmcs_conf)
 
        vmcs_conf->size = vmx_msr_high & 0x1fff;
        vmcs_conf->order = get_order(vmcs_config.size);
+       vmcs_conf->basic_cap = vmx_msr_high & ~0x1fff;
        vmcs_conf->revision_id = vmx_msr_low;
 
        vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
-- 
1.9.1

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