[PATCH 1/2] KVM: x86/mmu: Move flush logic from mmu_page_zap_pte() to FNAME(invlpg)

From: Sean Christopherson
Date: Tue Aug 04 2020 - 12:14:21 EST


Move the logic that controls whether or not FNAME(invlpg) needs to flush
fully into FNAME(invlpg) so that mmu_page_zap_pte() doesn't return a
value. This allows a future patch to redefine the return semantics for
mmu_page_zap_pte() so that it can recursively zap orphaned child shadow
pages for nested TDP MMUs.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 10 +++-------
arch/x86/kvm/mmu/paging_tmpl.h | 7 +++++--
2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 862bf418214e2..bdc10a53cd6ad 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2614,7 +2614,7 @@ static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
}
}

-static bool mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
+static void mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
u64 *spte)
{
u64 pte;
@@ -2630,13 +2630,9 @@ static bool mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
child = to_shadow_page(pte & PT64_BASE_ADDR_MASK);
drop_parent_pte(child, spte);
}
- return true;
- }
-
- if (is_mmio_spte(pte))
+ } else if (is_mmio_spte(pte)) {
mmu_spte_clear_no_track(spte);
-
- return false;
+ }
}

static void kvm_mmu_page_unlink_children(struct kvm *kvm,
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 0172a949f6a75..1fe7edc5732da 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -895,6 +895,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
{
struct kvm_shadow_walk_iterator iterator;
struct kvm_mmu_page *sp;
+ u64 old_spte;
int level;
u64 *sptep;

@@ -917,7 +918,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
sptep = iterator.sptep;

sp = sptep_to_sp(sptep);
- if (is_last_spte(*sptep, level)) {
+ old_spte = *sptep;
+ if (is_last_spte(old_spte, level)) {
pt_element_t gpte;
gpa_t pte_gpa;

@@ -927,7 +929,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
pte_gpa = FNAME(get_level1_sp_gpa)(sp);
pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);

- if (mmu_page_zap_pte(vcpu->kvm, sp, sptep))
+ mmu_page_zap_pte(vcpu->kvm, sp, sptep);
+ if (is_shadow_present_pte(old_spte))
kvm_flush_remote_tlbs_with_address(vcpu->kvm,
sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));

--
2.28.0


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Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment; filename="0002-KVM-x86-MMU-Recursively-zap-nested-TDP-SPs-when-zapp.patch"