KVM: x86: MMU: Consolidate quickly_check_mmio_pf() and is_mmio_page_fault()

These two have only slight differences:
 - whether 'addr' is of type u64 or of type gva_t
 - whether they have 'direct' parameter or not

Concerning the former, quickly_check_mmio_pf()'s u64 is better because
'addr' needs to be able to have both a guest physical address and a
guest virtual address.

The latter is just a stylistic issue as we can always calculate the mode
from the 'vcpu' as is_mmio_page_fault() does.  This patch keeps the
parameter to make the following patch cleaner.

In addition, the patch renames the function to mmio_info_in_cache() to
make it clear what it actually checks for.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

CVE-2018-12207

(cherry picked from commit ded58749)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

arch/x86/kvm/mmu.c

@@ -3308,7 +3308,7 @@ static bool is_shadow_zero_bits_set(struct kvm_mmu *mmu, u64 spte, int level)
 	return __is_rsvd_bits_set(&mmu->shadow_zero_check, spte, level);
 }
 
-static bool quickly_check_mmio_pf(struct kvm_vcpu *vcpu, u64 addr, bool direct)
+static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 {
 	if (direct)
 		return vcpu_match_mmio_gpa(vcpu, addr);
@@ -3367,7 +3367,7 @@ int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 	u64 spte;
 	bool reserved;
 
-	if (quickly_check_mmio_pf(vcpu, addr, direct))
+	if (mmio_info_in_cache(vcpu, addr, direct))
 		return RET_MMIO_PF_EMULATE;
 
 	reserved = walk_shadow_page_get_mmio_spte(vcpu, addr, &spte);
@@ -4384,19 +4384,12 @@ static void make_mmu_pages_available(struct kvm_vcpu *vcpu)
 	kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
 }
 
-static bool is_mmio_page_fault(struct kvm_vcpu *vcpu, gva_t addr)
-{
-	if (vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu))
-		return vcpu_match_mmio_gpa(vcpu, addr);
-
-	return vcpu_match_mmio_gva(vcpu, addr);
-}
-
 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
 		       void *insn, int insn_len)
 {
 	int r, emulation_type = EMULTYPE_RETRY;
 	enum emulation_result er;
+	bool direct = vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu);
 
 	r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code, false);
 	if (r < 0)
@@ -4407,7 +4400,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
 		goto out;
 	}
 
-	if (is_mmio_page_fault(vcpu, cr2))
+	if (mmio_info_in_cache(vcpu, cr2, direct))
 		emulation_type = 0;
 
 	er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len);