KVM: x86/mmu: Initialize fault.{gfn,slot} earlier for direct MMUs

Move the initialization of fault.{gfn,slot} earlier in the page fault
handling code for fully direct MMUs. This will enable a future commit to
split out TDP MMU page fault handling without needing to duplicate the
initialization of these 2 fields.

Opportunistically take advantage of the fact that fault.gfn is
initialized in kvm_tdp_page_fault() rather than recomputing it from
fault->addr.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220921173546.2674386-8-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e2e8c4d..cc26834 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4306,9 +4306,6 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
        bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
        int r;
 
-       fault->gfn = fault->addr >> PAGE_SHIFT;
-       fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn);
-
        if (page_fault_handle_page_track(vcpu, fault))
                return RET_PF_EMULATE;
 
@@ -4412,7 +4409,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
        if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
                for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) {
                        int page_num = KVM_PAGES_PER_HPAGE(fault->max_level);
-                       gfn_t base = (fault->addr >> PAGE_SHIFT) & ~(page_num - 1);
+                       gfn_t base = fault->gfn & ~(page_num - 1);
 
                        if (kvm_mtrr_check_gfn_range_consistency(vcpu, base, page_num))
                                break;

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 1556f59..0698907 100644 (file)
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -280,6 +280,11 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
        };
        int r;
 
+       if (vcpu->arch.mmu->root_role.direct) {
+               fault.gfn = fault.addr >> PAGE_SHIFT;
+               fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn);
+       }
+
        /*
         * Async #PF "faults", a.k.a. prefetch faults, are not faults from the
         * guest perspective and have already been counted at the time of the