Re: [PATCH v2 3/8] KVM: x86: Refactor kvm_hv_flush_tlb() to reduce indentation
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: 2021-11-01 10:01:10
Also in:
kvm, linux-arch, lkml
Sean Christopherson [off-list ref] writes:
quoted hunk ↗ jump to hunk
Refactor the "extended" path of kvm_hv_flush_tlb() to reduce the nesting depth for the non-fast sparse path, and to make the code more similar to the extended path in kvm_hv_send_ipi(). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/hyperv.c | 40 +++++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 19 deletions(-)diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index cf18aa1712bf..e68931ed27f6 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c@@ -1814,31 +1814,33 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool if (hc->var_cnt != bitmap_weight((unsigned long *)&valid_bank_mask, 64)) return HV_STATUS_INVALID_HYPERCALL_INPUT; - if (!hc->var_cnt && !all_cpus) + if (all_cpus) + goto do_flush;
You could've probably done:
if (all_cpus) {
kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
goto ret_success;
}
to get rid on the second 'all_cpus' check (and maybe even 'do_flush'
label with some extra work) below.
+
+ if (!hc->var_cnt)
goto ret_success;
- if (!all_cpus) {
- if (hc->fast) {
- if (hc->var_cnt > HV_HYPERCALL_MAX_XMM_REGISTERS - 1)
- return HV_STATUS_INVALID_HYPERCALL_INPUT;
- for (i = 0; i < hc->var_cnt; i += 2) {
- sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]);
- sparse_banks[i + 1] = sse128_hi(hc->xmm[i / 2 + 1]);
- }
- } else {
- if (hc->var_cnt > 64)
- return HV_STATUS_INVALID_HYPERCALL_INPUT;
-
- gpa = hc->ingpa + offsetof(struct hv_tlb_flush_ex,
- hv_vp_set.bank_contents);
- if (unlikely(kvm_read_guest(kvm, gpa, sparse_banks,
- hc->var_cnt *
- sizeof(sparse_banks[0]))))
- return HV_STATUS_INVALID_HYPERCALL_INPUT;
+ if (hc->fast) {
+ if (hc->var_cnt > HV_HYPERCALL_MAX_XMM_REGISTERS - 1)
+ return HV_STATUS_INVALID_HYPERCALL_INPUT;
+ for (i = 0; i < hc->var_cnt; i += 2) {
+ sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]);
+ sparse_banks[i + 1] = sse128_hi(hc->xmm[i / 2 + 1]);
}
+ goto do_flush;
}
+
+ if (hc->var_cnt > 64)
+ return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+ gpa = hc->ingpa + offsetof(struct hv_tlb_flush_ex,
+ hv_vp_set.bank_contents);
+ if (unlikely(kvm_read_guest(kvm, gpa, sparse_banks,
+ hc->var_cnt * sizeof(sparse_banks[0]))))
+ return HV_STATUS_INVALID_HYPERCALL_INPUT;
}
+do_flush:
/*
* vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
* analyze it here, flush TLB regardless of the specified address space.Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> -- Vitaly