[RFC PATCH 01/10] KVM: x86/mmu: make kvm_mmu_do_page_fault() receive single argument

[Isaku Yamahata]

Introduce struct kvm_page_fault handler and its initialization function.
Make the caller of kvm page fault handler allocate/initialize
struct kvm_page_fault, and pass it to kvm_mmu_do_page_fault() instead
of many arguments.

No functional change is intended.

Signed-off-by: Isaku Yamahata <isaku.yamah...@intel.com>
---
 arch/x86/kvm/mmu.h     | 29 ++++++++++++++++++++++++-----
 arch/x86/kvm/mmu/mmu.c |  6 ++++--
 arch/x86/kvm/x86.c     |  4 +++-
 3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index c68bfc3e2402..245c5d7fd3dd 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -106,17 +106,36 @@ static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu)
                                 vcpu->arch.mmu->shadow_root_level);
 }
 
+struct kvm_page_fault {
+       /* arguments to kvm page fault handler */
+       struct kvm_vcpu *vcpu;
+       gpa_t cr2_or_gpa;
+       u32 error_code;
+       bool prefault;
+};
+
+static inline void kvm_page_fault_init(
+       struct kvm_page_fault *kpf, struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
+       u32 error_code, bool prefault)
+{
+       kpf->vcpu = vcpu;
+       kpf->cr2_or_gpa = cr2_or_gpa;
+       kpf->error_code = error_code;
+       kpf->prefault = prefault;
+}
+
 int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
                       bool prefault);
 
-static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t 
cr2_or_gpa,
-                                       u32 err, bool prefault)
+static inline int kvm_mmu_do_page_fault(struct kvm_page_fault *kpf)
 {
 #ifdef CONFIG_RETPOLINE
-       if (likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault))
-               return kvm_tdp_page_fault(vcpu, cr2_or_gpa, err, prefault);
+       if (likely(kpf->vcpu->arch.mmu->page_fault == kvm_tdp_page_fault))
+               return kvm_tdp_page_fault(kpf->vcpu, kpf->cr2_or_gpa,
+                                         kpf->error_code, kpf->prefault);
 #endif
-       return vcpu->arch.mmu->page_fault(vcpu, cr2_or_gpa, err, prefault);
+       return kpf->vcpu->arch.mmu->page_fault(kpf->vcpu, kpf->cr2_or_gpa,
+                                              kpf->error_code, kpf->prefault);
 }
 
 /*
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 951dae4e7175..8ea2afcb528c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5006,6 +5006,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t 
cr2_or_gpa, u64 error_code,
 {
        int r, emulation_type = EMULTYPE_PF;
        bool direct = vcpu->arch.mmu->direct_map;
+       struct kvm_page_fault kpf;
 
        if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa)))
                return RET_PF_RETRY;
@@ -5018,8 +5019,9 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t 
cr2_or_gpa, u64 error_code,
        }
 
        if (r == RET_PF_INVALID) {
-               r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
-                                         lower_32_bits(error_code), false);
+               kvm_page_fault_init(&kpf, vcpu, cr2_or_gpa,
+                                   lower_32_bits(error_code), false);
+               r = kvm_mmu_do_page_fault(&kpf);
                if (WARN_ON_ONCE(r == RET_PF_INVALID))
                        return -EIO;
        }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eca63625aee4..999ed561de64 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11083,6 +11083,7 @@ EXPORT_SYMBOL_GPL(kvm_set_rflags);
 void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf 
*work)
 {
        int r;
+       struct kvm_page_fault kpf;
 
        if ((vcpu->arch.mmu->direct_map != work->arch.direct_map) ||
              work->wakeup_all)
@@ -11096,7 +11097,8 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, 
struct kvm_async_pf *work)
              work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu))
                return;
 
-       kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true);
+       kvm_page_fault_init(&kpf, vcpu, work->cr2_or_gpa, 0, true);
+       kvm_mmu_do_page_fault(&kpf);
 }
 
 static inline u32 kvm_async_pf_hash_fn(gfn_t gfn)
-- 
2.25.1