Messages in this thread | | | Date | Sun, 22 May 2022 07:53:57 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH 11/22] KVM: x86: hyper-v: replace bitmap_weight() with hweight64() |
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On Tue, May 10, 2022 at 08:47:39AM -0700, Yury Norov wrote: > kvm_hv_flush_tlb() applies bitmap API to a u64 variable valid_bank_mask. > Since valid_bank_mask has a fixed size, we can use hweight64() and avoid > excessive bloating.
In kvm_hv_send_ipi(), valid_bank_mask is unsigned long, not u64.
This results in:
arch/x86/kvm/hyperv.c: In function 'kvm_hv_send_ipi': include/asm-generic/bitops/const_hweight.h:21:76: error: right shift count >= width of type
on all 32-bit builds.
Guenter
> > CC: Borislav Petkov <bp@alien8.de> > CC: Dave Hansen <dave.hansen@linux.intel.com> > CC: H. Peter Anvin <hpa@zytor.com> > CC: Ingo Molnar <mingo@redhat.com> > CC: Jim Mattson <jmattson@google.com> > CC: Joerg Roedel <joro@8bytes.org> > CC: Paolo Bonzini <pbonzini@redhat.com> > CC: Sean Christopherson <seanjc@google.com> > CC: Thomas Gleixner <tglx@linutronix.de> > CC: Vitaly Kuznetsov <vkuznets@redhat.com> > CC: Wanpeng Li <wanpengli@tencent.com> > CC: kvm@vger.kernel.org > CC: linux-kernel@vger.kernel.org > CC: x86@kernel.org > Signed-off-by: Yury Norov <yury.norov@gmail.com> > --- > arch/x86/kvm/hyperv.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index 41585f0edf1e..b652b856df2b 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -1855,7 +1855,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) > all_cpus = flush_ex.hv_vp_set.format != > HV_GENERIC_SET_SPARSE_4K; > > - if (hc->var_cnt != bitmap_weight((unsigned long *)&valid_bank_mask, 64)) > + if (hc->var_cnt != hweight64(valid_bank_mask)) > return HV_STATUS_INVALID_HYPERCALL_INPUT; > > if (all_cpus) > @@ -1956,7 +1956,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) > valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask; > all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL; > > - if (hc->var_cnt != bitmap_weight(&valid_bank_mask, 64)) > + if (hc->var_cnt != hweight64(valid_bank_mask)) > return HV_STATUS_INVALID_HYPERCALL_INPUT; > > if (all_cpus) > -- > 2.32.0 >
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