In order to avoid creating executable hugepages in the TDP MMU PF handler, remove the dependency between disallowed_hugepage_adjust and the shadow_walk_iterator. This will open the function up to being used by the TDP MMU PF handler in a future patch. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 17 +++++++++-------- arch/x86/kvm/mmu/paging_tmpl.h | 3 ++- 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 6344e7863a0f5..f6e6fc9959c04 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3295,13 +3295,12 @@ static int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn, return level; } -static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it, - gfn_t gfn, kvm_pfn_t *pfnp, int *levelp) +static void disallowed_hugepage_adjust(u64 spte, gfn_t gfn, int cur_level, + kvm_pfn_t *pfnp, int *goal_levelp) { - int level = *levelp; - u64 spte = *it.sptep; + int goal_level = *goal_levelp; - if (it.level == level && level > PG_LEVEL_4K && + if (cur_level == goal_level && goal_level > PG_LEVEL_4K && is_nx_huge_page_enabled() && is_shadow_present_pte(spte) && !is_large_pte(spte)) { @@ -3312,9 +3311,10 @@ static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it, * patching back for them into pfn the next 9 bits of * the address. */ - u64 page_mask = KVM_PAGES_PER_HPAGE(level) - KVM_PAGES_PER_HPAGE(level - 1); + u64 page_mask = KVM_PAGES_PER_HPAGE(goal_level) - + KVM_PAGES_PER_HPAGE(goal_level - 1); *pfnp |= gfn & page_mask; - (*levelp)--; + (*goal_levelp)--; } } @@ -3339,7 +3339,8 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write, * We cannot overwrite existing page tables with an NX * large page, as the leaf could be executable. */ - disallowed_hugepage_adjust(it, gfn, &pfn, &level); + disallowed_hugepage_adjust(*it.sptep, gfn, it.level, + &pfn, &level); base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); if (it.level == level) diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 4dd6b1e5b8cf7..6a8666cb0d24b 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -690,7 +690,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr, * We cannot overwrite existing page tables with an NX * large page, as the leaf could be executable. */ - disallowed_hugepage_adjust(it, gw->gfn, &pfn, &hlevel); + disallowed_hugepage_adjust(*it.sptep, gw->gfn, it.level, + &pfn, &hlevel); base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1); if (it.level == hlevel) -- 2.28.0.709.gb0816b6eb0-goog
