From bede6eb4db19424477c36dace426ae12255f4a0d Mon Sep 17 00:00:00 2001 From: Binbin Wu Date: Wed, 22 Mar 2023 12:58:22 +0800 Subject: [PATCH] KVM: x86: Use boolean return value for is_{pae,pse,paging}() Convert is_{pae,pse,paging}() to use kvm_is_cr{0,4}_bit_set() and return bools. Returning an "int" requires not one, but two implicit casts, first from "unsigned long" to "int", and then again to a "bool". Both casts are more than a bit dangerous; the ulong=>int casts would drop a bit on 64-bit kernels _if_ the bits in question weren't in the lower 32 bits, and the int=>bool cast can result in false negatives/positives, e.g. see commit 0c928ff26bd6 ("KVM: SVM: Fix benign "bool vs. int" comparison in svm_set_cr0()"). Suggested-by: Sean Christopherson Signed-off-by: Binbin Wu Link: https://lore.kernel.org/r/20230322045824.22970-3-binbin.wu@linux.intel.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/svm.c | 2 +- arch/x86/kvm/x86.h | 12 ++++++------ 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 19794a8ea28c..70183d2271b5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1802,7 +1802,7 @@ void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) if (!npt_enabled) { hcr0 |= X86_CR0_PG | X86_CR0_WP; - if (old_paging != !!is_paging(vcpu)) + if (old_paging != is_paging(vcpu)) svm_set_cr4(vcpu, kvm_read_cr4(vcpu)); } diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 6d68c6772105..577b82358529 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -171,19 +171,19 @@ static inline bool mmu_is_nested(struct kvm_vcpu *vcpu) return vcpu->arch.walk_mmu == &vcpu->arch.nested_mmu; } -static inline int is_pae(struct kvm_vcpu *vcpu) +static inline bool is_pae(struct kvm_vcpu *vcpu) { - return kvm_read_cr4_bits(vcpu, X86_CR4_PAE); + return kvm_is_cr4_bit_set(vcpu, X86_CR4_PAE); } -static inline int is_pse(struct kvm_vcpu *vcpu) +static inline bool is_pse(struct kvm_vcpu *vcpu) { - return kvm_read_cr4_bits(vcpu, X86_CR4_PSE); + return kvm_is_cr4_bit_set(vcpu, X86_CR4_PSE); } -static inline int is_paging(struct kvm_vcpu *vcpu) +static inline bool is_paging(struct kvm_vcpu *vcpu) { - return likely(kvm_read_cr0_bits(vcpu, X86_CR0_PG)); + return likely(kvm_is_cr0_bit_set(vcpu, X86_CR0_PG)); } static inline bool is_pae_paging(struct kvm_vcpu *vcpu) -- 2.11.0