KVM: x86: Use KVM cpu caps to track UMIP emulation

Set UMIP in kvm_cpu_caps when it is emulated by VMX, even though the
bit will effectively be dropped by do_host_cpuid().  This allows
checking for UMIP emulation via kvm_cpu_caps instead of a dedicated
kvm_x86_ops callback.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d051380..c463730 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1177,7 +1177,6 @@ struct kvm_x86_ops {
        void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu,
                enum exit_fastpath_completion *exit_fastpath);
 
-       bool (*umip_emulated)(void);
        bool (*pt_supported)(void);
 
        int (*check_nested_events)(struct kvm_vcpu *vcpu);

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 997a471..26d2e17 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6088,11 +6088,6 @@ static bool svm_rdtscp_supported(void)
        return boot_cpu_has(X86_FEATURE_RDTSCP);
 }
 
-static bool svm_umip_emulated(void)
-{
-       return false;
-}
-
 static bool svm_pt_supported(void)
 {
        return false;
@@ -7460,7 +7455,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
        .cpuid_update = svm_cpuid_update,
 
        .rdtscp_supported = svm_rdtscp_supported,
-       .umip_emulated = svm_umip_emulated,
        .pt_supported = svm_pt_supported,
 
        .set_supported_cpuid = svm_set_supported_cpuid,

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 16a32d3..bea247f 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7132,6 +7132,10 @@ static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
 {
        switch (entry->function) {
        case 0x7:
+               /*
+                * UMIP needs to be manually set even though vmx_set_cpu_caps()
+                * also sets UMIP since do_host_cpuid() will drop it.
+                */
                if (vmx_umip_emulated())
                        cpuid_entry_set(entry, X86_FEATURE_UMIP);
                break;
@@ -7160,6 +7164,9 @@ static __init void vmx_set_cpu_caps(void)
        if (enable_ept && boot_cpu_has(X86_FEATURE_OSPKE))
                kvm_cpu_cap_check_and_set(X86_FEATURE_PKU);
 
+       if (vmx_umip_emulated())
+               kvm_cpu_cap_set(X86_FEATURE_UMIP);
+
        /* CPUID 0xD.1 */
        if (!vmx_xsaves_supported())
                kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
@@ -7963,7 +7970,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 
        .check_intercept = vmx_check_intercept,
        .handle_exit_irqoff = vmx_handle_exit_irqoff,
-       .umip_emulated = vmx_umip_emulated,
        .pt_supported = vmx_pt_supported,
 
        .request_immediate_exit = vmx_request_immediate_exit,

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 389bc80..51a49a6 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -928,7 +928,7 @@ static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c)
        if (kvm_cpu_cap_has(X86_FEATURE_LA57))
                reserved_bits &= ~X86_CR4_LA57;
 
-       if (kvm_x86_ops->umip_emulated())
+       if (kvm_cpu_cap_has(X86_FEATURE_UMIP))
                reserved_bits &= ~X86_CR4_UMIP;
 
        return reserved_bits;