Return a 'bool' instead of an 'int' for various PTE accessors that are
boolean in nature, e.g. is_shadow_present_pte(). Returning an int is
goofy and potentially dangerous, e.g. if a flag being checked is moved
into the upper 32 bits of a SPTE, then the compiler may silently squash
the entire check since casting to an int is guaranteed to yield a
return value of '0'.
Opportunistically refactor is_last_spte() so that it naturally returns
a bool value instead of letting it implicitly cast 0/1 to false/true.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/mmu.h | 2 +-
arch/x86/kvm/mmu/spte.h | 12 ++++--------
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 581925e476d6..f61e18dad2f3 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -145,7 +145,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
*
* TODO: introduce APIs to split these two cases.
*/
-static inline int is_writable_pte(unsigned long pte)
+static inline bool is_writable_pte(unsigned long pte)
{
return pte & PT_WRITABLE_MASK;
}
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 2b3a30bd38b0..398fd1bb13a7 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -185,23 +185,19 @@ static inline bool is_access_track_spte(u64 spte)
return !spte_ad_enabled(spte) && (spte & shadow_acc_track_mask) == 0;
}
-static inline int is_shadow_present_pte(u64 pte)
+static inline bool is_shadow_present_pte(u64 pte)
{
return (pte != 0) && !is_mmio_spte(pte);
}
-static inline int is_large_pte(u64 pte)
+static inline bool is_large_pte(u64 pte)
{
return pte & PT_PAGE_SIZE_MASK;
}
-static inline int is_last_spte(u64 pte, int level)
+static inline bool is_last_spte(u64 pte, int level)
{
- if (level == PG_LEVEL_4K)
- return 1;
- if (is_large_pte(pte))
- return 1;
- return 0;
+ return (level == PG_LEVEL_4K) || is_large_pte(pte);
}
static inline bool is_executable_pte(u64 spte)
--
2.30.0.280.ga3ce27912f-goog
