KVM: arm64: Move SVE state mapping at HYP to finalize-time

We currently map the SVE state to HYP on detection of a PID change.
Although this matches what we do for FPSIMD, this is pretty pointless
for SVE, as the buffer is per-vcpu and has nothing to do with the
thread that is being run.

Move the mapping of the SVE state to finalize-time, which is where
we allocate the state memory, and thus the most logical place to
do this.

Reviewed-by: Andrew Jones <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>

Author: Marc Zyngier

arch/arm64/kvm/fpsimd.c

@@ -43,17 +43,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
 	if (ret)
 		goto error;
 
-	if (vcpu->arch.sve_state) {
-		void *sve_end;
-
-		sve_end = vcpu->arch.sve_state + vcpu_sve_state_size(vcpu);
-
-		ret = create_hyp_mappings(vcpu->arch.sve_state, sve_end,
-					  PAGE_HYP);
-		if (ret)
-			goto error;
-	}
-
 	vcpu->arch.host_thread_info = kern_hyp_va(ti);
 	vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd);
 error:

arch/arm64/kvm/reset.c

@@ -94,6 +94,8 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
 {
 	void *buf;
 	unsigned int vl;
+	size_t reg_sz;
+	int ret;
 
 	vl = vcpu->arch.sve_max_vl;
 
@@ -106,10 +108,17 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
 		    vl > SVE_VL_ARCH_MAX))
 		return -EIO;
 
-	buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL_ACCOUNT);
+	reg_sz = vcpu_sve_state_size(vcpu);
+	buf = kzalloc(reg_sz, GFP_KERNEL_ACCOUNT);
 	if (!buf)
 		return -ENOMEM;
 
+	ret = create_hyp_mappings(buf, buf + reg_sz, PAGE_HYP);
+	if (ret) {
+		kfree(buf);
+		return ret;
+	}
+	
 	vcpu->arch.sve_state = buf;
 	vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED;
 	return 0;