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Subject[PATCH 09/22] kvm: mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
From
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@google.com>
---
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
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