+static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
+{
+ struct kvm *kvm = vcpu->kvm;
+ int lm = is_long_mode(vcpu);
+ u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
+ : (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
+ u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
+ : kvm->arch.xen_hvm_config.blob_size_32;
+ u32 page_num = data & ~PAGE_MASK;
+ u64 page_addr = data & PAGE_MASK;
+ u8 *page;
+ int r;
+
+ r = -E2BIG;
+ if (page_num >= blob_size)
+ goto out;
+ r = -ENOMEM;
+ page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!page)
+ goto out;
+ r = -EFAULT;
+ if (copy_from_user(page, blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE))
+ goto out_free;
+ if (kvm_write_guest(kvm, page_addr, page, PAGE_SIZE))
+ goto out_free;
+ r = 0;
+out_free:
+ kfree(page);
+out:
+ return r;
+}
+
+static bool kvm_hv_hypercall_enabled(struct kvm *kvm)
+{
+ return kvm->arch.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE;
+}
+
+static bool kvm_hv_msr_partition_wide(u32 msr)
+{
+ bool r = false;
+ switch (msr) {
+ case HV_X64_MSR_GUEST_OS_ID:
+ case HV_X64_MSR_HYPERCALL:
+ r = true;
+ break;
+ }
+
+ return r;
+}
+
+static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+ struct kvm *kvm = vcpu->kvm;
+
+ switch (msr) {
+ case HV_X64_MSR_GUEST_OS_ID:
+ kvm->arch.hv_guest_os_id = data;
+ /* setting guest os id to zero disables hypercall page */
+ if (!kvm->arch.hv_guest_os_id)
+ kvm->arch.hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
+ break;
+ case HV_X64_MSR_HYPERCALL: {
+ u64 gfn;
+ unsigned long addr;
+ u8 instructions[4];
+
+ /* if guest os id is not set hypercall should remain disabled */
+ if (!kvm->arch.hv_guest_os_id)
+ break;
+ if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
+ kvm->arch.hv_hypercall = data;
+ break;
+ }
+ gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
+ addr = gfn_to_hva(kvm, gfn);
+ if (kvm_is_error_hva(addr))
+ return 1;
+ kvm_x86_ops->patch_hypercall(vcpu, instructions);
+ ((unsigned char *)instructions)[3] = 0xc3; /* ret */
+ if (copy_to_user((void __user *)addr, instructions, 4))
+ return 1;
+ kvm->arch.hv_hypercall = data;
+ break;
+ }
+ default:
+ pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
+ "data 0x%llx\n", msr, data);
+ return 1;
+ }
+ return 0;
+}
+
+static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+ switch (msr) {
+ case HV_X64_MSR_APIC_ASSIST_PAGE: {
+ unsigned long addr;
+
+ if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {
+ vcpu->arch.hv_vapic = data;
+ break;
+ }
+ addr = gfn_to_hva(vcpu->kvm, data >>
+ HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT);
+ if (kvm_is_error_hva(addr))
+ return 1;
+ if (clear_user((void __user *)addr, PAGE_SIZE))
+ return 1;
+ vcpu->arch.hv_vapic = data;
+ break;
+ }
+ case HV_X64_MSR_EOI:
+ return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
+ case HV_X64_MSR_ICR:
+ return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
+ case HV_X64_MSR_TPR:
+ return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
+ default:
+ pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
+ "data 0x%llx\n", msr, data);
+ return 1;
+ }
+
+ return 0;
+}
+