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KVM: x86/mmu: Remove lpage_is_disallowed() check from set_spte()

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Remove the late "lpage is disallowed" check from set_spte() now that the
initial check is performed after acquiring mmu_lock.  Fold the guts of
the remaining helper, __mmu_gfn_lpage_is_disallowed(), into
kvm_mmu_hugepage_adjust() to eliminate the unnecessary slot !NULL check.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-01-08 12:24:47 -08:00 committed by Paolo Bonzini
parent 293e306e7f
commit 2c0629f4b9
1 changed files with 3 additions and 36 deletions
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39
arch/x86/kvm/mmu/mmu.c
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@ -1264,28 +1264,6 @@ static void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp)
list_del(&sp->lpage_disallowed_link);
}
static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
struct kvm_memory_slot *slot)
{
struct kvm_lpage_info *linfo;
if (slot) {
linfo = lpage_info_slot(gfn, slot, level);
return !!linfo->disallow_lpage;
}
return true;
}
static bool mmu_gfn_lpage_is_disallowed(struct kvm_vcpu *vcpu, gfn_t gfn,
int level)
{
struct kvm_memory_slot *slot;
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return __mmu_gfn_lpage_is_disallowed(gfn, level, slot);
}
static inline bool memslot_valid_for_gpte(struct kvm_memory_slot *slot,
bool no_dirty_log)
{
@ -3078,18 +3056,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
spte |= (u64)pfn << PAGE_SHIFT;
if (pte_access & ACC_WRITE_MASK) {
/*
* Legacy code to handle an obsolete scenario where a different
* vcpu creates new sp in the window between this vcpu's query
* of lpage_is_disallowed() and acquiring mmu_lock. No longer
* necessary now that lpage_is_disallowed() is called after
* acquiring mmu_lock.
*/
if (level > PT_PAGE_TABLE_LEVEL &&
mmu_gfn_lpage_is_disallowed(vcpu, gfn, level))
goto done;
spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
/*
@ -3121,7 +3087,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
set_pte:
if (mmu_spte_update(sptep, spte))
ret |= SET_SPTE_NEED_REMOTE_TLB_FLUSH;
done:
return ret;
}
@ -3309,6 +3274,7 @@ static int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,
int max_level, kvm_pfn_t *pfnp)
{
struct kvm_memory_slot *slot;
struct kvm_lpage_info *linfo;
kvm_pfn_t pfn = *pfnp;
kvm_pfn_t mask;
int level;
@ -3326,7 +3292,8 @@ static int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,
max_level = min(max_level, kvm_x86_ops->get_lpage_level());
for ( ; max_level > PT_PAGE_TABLE_LEVEL; max_level--) {
if (!__mmu_gfn_lpage_is_disallowed(gfn, max_level, slot))
linfo = lpage_info_slot(gfn, slot, max_level);
if (!linfo->disallow_lpage)
break;
}