[PATCH v13 06/85] KVM: x86/mmu: Invert @can_unsync and renamed to @synchronizing

Sean Christopherson
2024-10-10T18:25:04Z

Invert the polarity of "can_unsync" and rename the parameter to
"synchronizing" to allow a future change to set the Accessed bit if KVM
is synchronizing an existing SPTE. Querying "can_unsync" in that case is
nonsensical, as the fact that KVM can't unsync SPTEs doesn't provide any
justification for setting the Accessed bit.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/mmu/mmu.c | 12 ++++++------
arch/x86/kvm/mmu/mmu_internal.h | 2 +-
arch/x86/kvm/mmu/paging_tmpl.h | 2 +-
arch/x86/kvm/mmu/spte.c | 4 ++--
arch/x86/kvm/mmu/spte.h | 2 +-
arch/x86/kvm/mmu/tdp_mmu.c | 4 ++--
6 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index a8c64069aa89..0f21d6f76cab 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2795,7 +2795,7 @@ static void kvm_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
* be write-protected.
*/
int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,
- gfn_t gfn, bool can_unsync, bool prefetch)
+ gfn_t gfn, bool synchronizing, bool prefetch)
{
struct kvm_mmu_page *sp;
bool locked = false;
@@ -2810,12 +2810,12 @@ int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,

/*
* The page is not write-tracked, mark existing shadow pages unsync
- * unless KVM is synchronizing an unsync SP (can_unsync = false). In
- * that case, KVM must complete emulation of the guest TLB flush before
- * allowing shadow pages to become unsync (writable by the guest).
+ * unless KVM is synchronizing an unsync SP. In that case, KVM must
+ * complete emulation of the guest TLB flush before allowing shadow
+ * pages to become unsync (writable by the guest).
*/
for_each_gfn_valid_sp_with_gptes(kvm, sp, gfn) {
- if (!can_unsync)
+ if (synchronizing)
return -EPERM;

if (sp->unsync)
@@ -2941,7 +2941,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
}

wrprot = make_spte(vcpu, sp, slot, pte_access, gfn, pfn, *sptep, prefetch,
- true, host_writable, &spte);
+ false, host_writable, &spte);

if (*sptep == spte) {
ret = RET_PF_SPURIOUS;
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index c98827840e07..4da83544c4e1 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -164,7 +164,7 @@ static inline gfn_t gfn_round_for_level(gfn_t gfn, int level)
}

int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,
- gfn_t gfn, bool can_unsync, bool prefetch);
+ gfn_t gfn, bool synchronizing, bool prefetch);

void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index ae7d39ff2d07..6e7bd8921c6f 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -963,7 +963,7 @@ static int FNAME(sync_spte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int
host_writable = spte & shadow_host_writable_mask;
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
make_spte(vcpu, sp, slot, pte_access, gfn,
- spte_to_pfn(spte), spte, true, false,
+ spte_to_pfn(spte), spte, true, true,
host_writable, &spte);

return mmu_spte_update(sptep, spte);
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index 5521608077ec..0e47fea1a2d9 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -157,7 +157,7 @@ bool spte_has_volatile_bits(u64 spte)
bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
const struct kvm_memory_slot *slot,
unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn,
- u64 old_spte, bool prefetch, bool can_unsync,
+ u64 old_spte, bool prefetch, bool synchronizing,
bool host_writable, u64 *new_spte)
{
int level = sp->role.level;
@@ -248,7 +248,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
* e.g. it's write-tracked (upper-level SPs) or has one or more
* shadow pages and unsync'ing pages is not allowed.
*/
- if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, can_unsync, prefetch)) {
+ if (mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, synchronizing, prefetch)) {
wrprot = true;
pte_access &= ~ACC_WRITE_MASK;
spte &= ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask);
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 2cb816ea2430..c81cac9358e0 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -499,7 +499,7 @@ bool spte_has_volatile_bits(u64 spte);
bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
const struct kvm_memory_slot *slot,
unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn,
- u64 old_spte, bool prefetch, bool can_unsync,
+ u64 old_spte, bool prefetch, bool synchronizing,
bool host_writable, u64 *new_spte);
u64 make_huge_page_split_spte(struct kvm *kvm, u64 huge_spte,
union kvm_mmu_page_role role, int index);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 3c6583468742..76bca7a726c1 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1033,8 +1033,8 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL);
else
wrprot = make_spte(vcpu, sp, fault->slot, ACC_ALL, iter->gfn,
- fault->pfn, iter->old_spte, fault->prefetch, true,
- fault->map_writable, &new_spte);
+ fault->pfn, iter->old_spte, fault->prefetch,
+ false, fault->map_writable, &new_spte);

if (new_spte == iter->old_spte)
ret = RET_PF_SPURIOUS;
--
2.47.0.rc1.288.g06298d1525-goog