x86/hyperv: Introduce HV_MAX_SPARSE_VCPU_BANKS/HV_VCPUS_PER_SPARSE_BA…

…NK constants It may not come clear from where the magical '64' value used in __cpumask_to_vpset() come from. Moreover, '64' means both the maximum sparse bank number as well as the number of vCPUs per bank. Add defines to make things clear. These defines are also going to be used by KVM. No functional change. Reviewed-by: Maxim Levitsky <[email protected]> Reviewed-by: Sean Christopherson <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
josf · Nov 18, 2022 · bd19c94 · bd19c94
1 parent aee7382
commit bd19c94
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Showing 2 changed files with 11 additions and 5 deletions.
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
@@ -399,6 +399,11 @@ struct hv_vpset {
 	u64 bank_contents[];
 } __packed;
 
+/* The maximum number of sparse vCPU banks which can be encoded by 'struct hv_vpset' */
+#define HV_MAX_SPARSE_VCPU_BANKS (64)
+/* The number of vCPUs in one sparse bank */
+#define HV_VCPUS_PER_SPARSE_BANK (64)
+
 /* HvCallSendSyntheticClusterIpi hypercall */
 struct hv_send_ipi {
 	u32 vector;

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
@@ -211,17 +211,18 @@ static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
 {
 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
 	int this_cpu = smp_processor_id();
+	int max_vcpu_bank = hv_max_vp_index / HV_VCPUS_PER_SPARSE_BANK;
 
-	/* valid_bank_mask can represent up to 64 banks */
-	if (hv_max_vp_index / 64 >= 64)
+	/* vpset.valid_bank_mask can represent up to HV_MAX_SPARSE_VCPU_BANKS banks */
+	if (max_vcpu_bank >= HV_MAX_SPARSE_VCPU_BANKS)
 		return 0;
 
 	/*
 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
 	 * structs are not cleared between calls, we risk flushing unneeded
 	 * vCPUs otherwise.
 	 */
-	for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
+	for (vcpu_bank = 0; vcpu_bank <= max_vcpu_bank; vcpu_bank++)
 		vpset->bank_contents[vcpu_bank] = 0;
 
 	/*
@@ -233,8 +234,8 @@ static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
 		vcpu = hv_cpu_number_to_vp_number(cpu);
 		if (vcpu == VP_INVAL)
 			return -1;
-		vcpu_bank = vcpu / 64;
-		vcpu_offset = vcpu % 64;
+		vcpu_bank = vcpu / HV_VCPUS_PER_SPARSE_BANK;
+		vcpu_offset = vcpu % HV_VCPUS_PER_SPARSE_BANK;
 		__set_bit(vcpu_offset, (unsigned long *)
 			  &vpset->bank_contents[vcpu_bank]);
 		if (vcpu_bank >= nr_bank)