KVM: x86/MMU: Simplify flow of vmx_get_mt_mask

Remove the gotos from vmx_get_mt_mask.  It's easier to build the whole
memory type at once, than it is to combine separate cacheability and
ipat fields.

No functional change intended.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20211115234603.2908381-12-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9453743..01eab6d 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6947,7 +6947,6 @@ static int __init vmx_check_processor_compat(void)
 static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 {
        u8 cache;
-       u64 ipat = 0;
 
        /* We wanted to honor guest CD/MTRR/PAT, but doing so could result in
         * memory aliases with conflicting memory types and sometimes MCEs.
@@ -6967,30 +6966,22 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
         * EPT memory type is used to emulate guest CD/MTRR.
         */
 
-       if (is_mmio) {
-               cache = MTRR_TYPE_UNCACHABLE;
-               goto exit;
-       }
+       if (is_mmio)
+               return MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT;
 
-       if (!kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
-               ipat = VMX_EPT_IPAT_BIT;
-               cache = MTRR_TYPE_WRBACK;
-               goto exit;
-       }
+       if (!kvm_arch_has_noncoherent_dma(vcpu->kvm))
+               return (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IPAT_BIT;
 
        if (kvm_read_cr0(vcpu) & X86_CR0_CD) {
-               ipat = VMX_EPT_IPAT_BIT;
                if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
                        cache = MTRR_TYPE_WRBACK;
                else
                        cache = MTRR_TYPE_UNCACHABLE;
-               goto exit;
-       }
 
-       cache = kvm_mtrr_get_guest_memory_type(vcpu, gfn);
+               return (cache << VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IPAT_BIT;
+       }
 
-exit:
-       return (cache << VMX_EPT_MT_EPTE_SHIFT) | ipat;
+       return kvm_mtrr_get_guest_memory_type(vcpu, gfn) << VMX_EPT_MT_EPTE_SHIFT;
 }
 
 static void vmcs_set_secondary_exec_control(struct vcpu_vmx *vmx, u32 new_ctl)