From: Yulei Zhang <[email protected]> Refine the fast page fault code so that it can be used in either normal ept mode or direct build EPT mode.
Signed-off-by: Yulei Zhang <[email protected]> --- arch/x86/kvm/mmu/mmu.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index f2124f52b286..fda6c4196854 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3443,12 +3443,13 @@ static bool page_fault_can_be_fast(u32 error_code) * someone else modified the SPTE from its original value. */ static bool -fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, +fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, gpa_t gpa, u64 *sptep, u64 old_spte, u64 new_spte) { gfn_t gfn; - WARN_ON(!sp->role.direct); + WARN_ON(!vcpu->arch.direct_build_tdp && + (!sptep_to_sp(sptep)->role.direct)); /* * Theoretically we could also set dirty bit (and flush TLB) here in @@ -3470,7 +3471,8 @@ fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, * The gfn of direct spte is stable since it is * calculated by sp->gfn. */ - gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt); + + gfn = gpa >> PAGE_SHIFT; kvm_vcpu_mark_page_dirty(vcpu, gfn); } @@ -3498,10 +3500,10 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u32 error_code) { struct kvm_shadow_walk_iterator iterator; - struct kvm_mmu_page *sp; bool fault_handled = false; u64 spte = 0ull; uint retry_count = 0; + int pte_level = 0; if (!page_fault_can_be_fast(error_code)) return false; @@ -3515,8 +3517,15 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, if (!is_shadow_present_pte(spte)) break; - sp = sptep_to_sp(iterator.sptep); - if (!is_last_spte(spte, sp->role.level)) + if (iterator.level < PG_LEVEL_4K) + pte_level = PG_LEVEL_4K; + else + pte_level = iterator.level; + + WARN_ON(!vcpu->arch.direct_build_tdp && + (pte_level != sptep_to_sp(iterator.sptep)->role.level)); + + if (!is_last_spte(spte, pte_level)) break; /* @@ -3559,7 +3568,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, * * See the comments in kvm_arch_commit_memory_region(). */ - if (sp->role.level > PG_LEVEL_4K) + if (pte_level > PG_LEVEL_4K) break; } @@ -3573,7 +3582,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, * since the gfn is not stable for indirect shadow page. See * Documentation/virt/kvm/locking.rst to get more detail. */ - fault_handled = fast_pf_fix_direct_spte(vcpu, sp, + fault_handled = fast_pf_fix_direct_spte(vcpu, cr2_or_gpa, iterator.sptep, spte, new_spte); if (fault_handled) @@ -4106,6 +4115,9 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (fast_page_fault(vcpu, gpa, error_code)) return RET_PF_RETRY; + if (vcpu->arch.direct_build_tdp) + return RET_PF_EMULATE; + r = mmu_topup_memory_caches(vcpu, false); if (r) return r; -- 2.17.1
