* [PATCH v1] KVM: VMX: Remove unnecessary parentheses @ 2026-03-05 23:54 Xin Li (Intel) 2026-03-06 6:17 ` BillXiang 0 siblings, 1 reply; 3+ messages in thread From: Xin Li (Intel) @ 2026-03-05 23:54 UTC (permalink / raw) To: kvm, linux-kernel Cc: seanjc, pbonzini, tglx, mingo, bp, dave.hansen, x86, hpa, xin From: Xin Li <xin@zytor.com> Drop redundant parentheses; & takes precedence over &&. Signed-off-by: Xin Li <xin@zytor.com> --- arch/x86/kvm/vmx/capabilities.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h index 4e371c93ae16..0dad9e7c4ff4 100644 --- a/arch/x86/kvm/vmx/capabilities.h +++ b/arch/x86/kvm/vmx/capabilities.h @@ -107,7 +107,7 @@ static inline bool cpu_has_load_perf_global_ctrl(void) static inline bool cpu_has_load_cet_ctrl(void) { - return (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE); + return vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE; } static inline bool cpu_has_save_perf_global_ctrl(void) @@ -162,7 +162,7 @@ static inline bool cpu_has_vmx_ept(void) static inline bool vmx_umip_emulated(void) { return !boot_cpu_has(X86_FEATURE_UMIP) && - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC); + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC; } static inline bool cpu_has_vmx_rdtscp(void) @@ -376,9 +376,9 @@ static inline bool cpu_has_vmx_invvpid_global(void) static inline bool cpu_has_vmx_intel_pt(void) { - return (vmcs_config.misc & VMX_MISC_INTEL_PT) && - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA) && - (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL); + return vmcs_config.misc & VMX_MISC_INTEL_PT && + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA && + vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL; } /* base-commit: 5128b972fb2801ad9aca54d990a75611ab5283a9 -- 2.53.0 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v1] KVM: VMX: Remove unnecessary parentheses 2026-03-05 23:54 [PATCH v1] KVM: VMX: Remove unnecessary parentheses Xin Li (Intel) @ 2026-03-06 6:17 ` BillXiang 2026-03-06 16:24 ` Sean Christopherson 0 siblings, 1 reply; 3+ messages in thread From: BillXiang @ 2026-03-06 6:17 UTC (permalink / raw) To: Xin Li (Intel), kvm, linux-kernel Cc: seanjc, pbonzini, tglx, mingo, bp, dave.hansen, x86, hpa On 3/6/2026 7:54 AM, Xin Li (Intel) wrote: > From: Xin Li <xin@zytor.com> > > Drop redundant parentheses; & takes precedence over &&. I would not recommend relying on default operator precedence. > > Signed-off-by: Xin Li <xin@zytor.com> > --- > arch/x86/kvm/vmx/capabilities.h | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h > index 4e371c93ae16..0dad9e7c4ff4 100644 > --- a/arch/x86/kvm/vmx/capabilities.h > +++ b/arch/x86/kvm/vmx/capabilities.h > @@ -107,7 +107,7 @@ static inline bool cpu_has_load_perf_global_ctrl(void) > > static inline bool cpu_has_load_cet_ctrl(void) > { > - return (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE); > + return vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE; > } > > static inline bool cpu_has_save_perf_global_ctrl(void) > @@ -162,7 +162,7 @@ static inline bool cpu_has_vmx_ept(void) > static inline bool vmx_umip_emulated(void) > { > return !boot_cpu_has(X86_FEATURE_UMIP) && > - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC); > + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC; > } > > static inline bool cpu_has_vmx_rdtscp(void) > @@ -376,9 +376,9 @@ static inline bool cpu_has_vmx_invvpid_global(void) > > static inline bool cpu_has_vmx_intel_pt(void) > { > - return (vmcs_config.misc & VMX_MISC_INTEL_PT) && > - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA) && > - (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL); > + return vmcs_config.misc & VMX_MISC_INTEL_PT && > + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA && > + vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL; > } Removing the parentheses could significantly reduce code readability here. > > /* > > base-commit: 5128b972fb2801ad9aca54d990a75611ab5283a9 ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v1] KVM: VMX: Remove unnecessary parentheses 2026-03-06 6:17 ` BillXiang @ 2026-03-06 16:24 ` Sean Christopherson 0 siblings, 0 replies; 3+ messages in thread From: Sean Christopherson @ 2026-03-06 16:24 UTC (permalink / raw) To: BillXiang Cc: Xin Li (Intel), kvm, linux-kernel, pbonzini, tglx, mingo, bp, dave.hansen, x86, hpa On Fri, Mar 06, 2026, BillXiang wrote: > On 3/6/2026 7:54 AM, Xin Li (Intel) wrote: > > From: Xin Li <xin@zytor.com> > > > > Drop redundant parentheses; & takes precedence over &&. > > I would not recommend relying on default operator precedence. Eh, in practice, the kernel heavily relies on operator precedence all over the place, so I'm not worried about correctness. But as you note below, judicious use of parentheses can help readability. > > Signed-off-by: Xin Li <xin@zytor.com> > > --- > > arch/x86/kvm/vmx/capabilities.h | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h > > index 4e371c93ae16..0dad9e7c4ff4 100644 > > --- a/arch/x86/kvm/vmx/capabilities.h > > +++ b/arch/x86/kvm/vmx/capabilities.h > > @@ -107,7 +107,7 @@ static inline bool cpu_has_load_perf_global_ctrl(void) > > > > static inline bool cpu_has_load_cet_ctrl(void) > > { > > - return (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE); > > + return vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE; > > } > > > > static inline bool cpu_has_save_perf_global_ctrl(void) > > @@ -162,7 +162,7 @@ static inline bool cpu_has_vmx_ept(void) > > static inline bool vmx_umip_emulated(void) > > { > > return !boot_cpu_has(X86_FEATURE_UMIP) && > > - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC); > > + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_DESC; > > } > > > > static inline bool cpu_has_vmx_rdtscp(void) > > @@ -376,9 +376,9 @@ static inline bool cpu_has_vmx_invvpid_global(void) > > > > static inline bool cpu_has_vmx_intel_pt(void) > > { > > - return (vmcs_config.misc & VMX_MISC_INTEL_PT) && > > - (vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA) && > > - (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL); > > + return vmcs_config.misc & VMX_MISC_INTEL_PT && > > + vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA && > > + vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL; > > } > > Removing the parentheses could significantly reduce code readability here. +1. For cases like cpu_has_load_cet_ctrl() where it's a single statement, I'm 100% in favor of dropping the parentheses because they're pure noise. E.g. putting them in the return statement is kinda like doing this: if ((vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_CET_STATE)) But for code where there are multiple checks, IMO it's totally fine to use parentheses, and probably even encourage. Can you send a v2 to just clean up cpu_has_load_cet_ctrl()? Ah, and the changelog will need to be different, because there's no &&, which is another argument for treating "return x & y;" differently. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-03-06 16:24 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-05 23:54 [PATCH v1] KVM: VMX: Remove unnecessary parentheses Xin Li (Intel) 2026-03-06 6:17 ` BillXiang 2026-03-06 16:24 ` Sean Christopherson
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