From 8f32d5e563cbf0507756aa929134b1a110b47a62 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 10 Aug 2021 23:52:41 +0300 Subject: [PATCH 1/1] KVM: x86/mmu: allow kvm_faultin_pfn to return page fault handling code This will allow it to return RET_PF_EMULATE for APIC mmio emulation. This code is based on a patch from Sean Christopherson: https://lkml.org/lkml/2021/7/19/2970 Suggested-by: Sean Christopherson Signed-off-by: Maxim Levitsky Reviewed-by: Paolo Bonzini Message-Id: <20210810205251.424103-7-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 17 ++++++++++------- arch/x86/kvm/mmu/paging_tmpl.h | 4 ++-- 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index e85ec37a8468..38e36cff82af 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3886,7 +3886,7 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, gpa_t cr2_or_gpa, kvm_pfn_t *pfn, hva_t *hva, - bool write, bool *writable) + bool write, bool *writable, int *r) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); bool async; @@ -3897,7 +3897,7 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, * be zapped before KVM inserts a new MMIO SPTE for the gfn. */ if (slot && (slot->flags & KVM_MEMSLOT_INVALID)) - return true; + goto out_retry; /* Don't expose private memslots to L2. */ if (is_guest_mode(vcpu) && !kvm_is_visible_memslot(slot)) { @@ -3917,14 +3917,17 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, if (kvm_find_async_pf_gfn(vcpu, gfn)) { trace_kvm_async_pf_doublefault(cr2_or_gpa, gfn); kvm_make_request(KVM_REQ_APF_HALT, vcpu); - return true; + goto out_retry; } else if (kvm_arch_setup_async_pf(vcpu, cr2_or_gpa, gfn)) - return true; + goto out_retry; } *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable, hva); - return false; + +out_retry: + *r = RET_PF_RETRY; + return true; } static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, @@ -3955,8 +3958,8 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, smp_rmb(); if (kvm_faultin_pfn(vcpu, prefault, gfn, gpa, &pfn, &hva, - write, &map_writable)) - return RET_PF_RETRY; + write, &map_writable, &r)) + return r; if (handle_abnormal_pfn(vcpu, is_tdp ? 0 : gpa, gfn, pfn, ACC_ALL, &r)) return r; diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index f349eae69bf3..7d03e9b7ccfa 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -882,8 +882,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, smp_rmb(); if (kvm_faultin_pfn(vcpu, prefault, walker.gfn, addr, &pfn, &hva, - write_fault, &map_writable)) - return RET_PF_RETRY; + write_fault, &map_writable, &r)) + return r; if (handle_abnormal_pfn(vcpu, addr, walker.gfn, pfn, walker.pte_access, &r)) return r; -- 2.39.2