[PATCH v2 09/20] kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg

From: Ben Gardon
Date: Wed Oct 14 2020 - 14:28:35 EST


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 | 13 +++++++------
arch/x86/kvm/mmu/paging_tmpl.h | 3 ++-
2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 05024b8ae5a4d..288b97e96202e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3243,13 +3243,12 @@ 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 *levelp)
{
int level = *levelp;
- u64 spte = *it.sptep;

- if (it.level == level && level > PG_LEVEL_4K &&
+ if (cur_level == level && level > PG_LEVEL_4K &&
is_shadow_present_pte(spte) &&
!is_large_pte(spte)) {
/*
@@ -3259,7 +3258,8 @@ 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(level) -
+ KVM_PAGES_PER_HPAGE(level - 1);
*pfnp |= gfn & page_mask;
(*levelp)--;
}
@@ -3292,7 +3292,8 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
* large page, as the leaf could be executable.
*/
if (nx_huge_page_workaround_enabled)
- 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 9a1a15f19beb6..50e268eb8e1a9 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -695,7 +695,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
* large page, as the leaf could be executable.
*/
if (nx_huge_page_workaround_enabled)
- disallowed_hugepage_adjust(it, gw->gfn, &pfn, &level);
+ disallowed_hugepage_adjust(*it.sptep, gw->gfn, it.level,
+ &pfn, &level);

base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
if (it.level == level)
--
2.28.0.1011.ga647a8990f-goog