[PATCH RESEND v4 6/9] KVM: VMX: Introduce SPP user-space IOCTLs

Yang Weijiang
2019-08-14T07:03:01Z

User application, e.g., QEMU or VMI, must initialize SPP
before gets/sets SPP subpages, the dynamic initialization is to
reduce the extra storage cost if the SPP feature is not not used.

Co-developed-by: He Chen <he.chen@linux.intel.com>
Signed-off-by: He Chen <he.chen@linux.intel.com>
Co-developed-by: Zhang Yi <yi.z.zhang@linux.intel.com>
Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/kvm/x86.c | 90 ++++++++++++++++++++++++++++++++++++++++
include/linux/kvm_host.h | 4 ++
include/uapi/linux/kvm.h | 3 ++
3 files changed, 97 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c7cb17941344..54a1d2423a17 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4589,6 +4589,23 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
return r;
}

+static int kvm_vm_ioctl_get_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ return kvm_arch_get_subpages(kvm, spp_info);
+}
+
+static int kvm_vm_ioctl_set_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ return kvm_arch_set_subpages(kvm, spp_info);
+}
+
+static int kvm_vm_ioctl_init_spp(struct kvm *kvm)
+{
+ return kvm_arch_init_spp(kvm);
+}
+
int kvm_get_subpages(struct kvm *kvm,
struct kvm_subpage *spp_info)
{
@@ -4922,8 +4939,55 @@ long kvm_arch_vm_ioctl(struct file *filp,
if (copy_from_user(&hvevfd, argp, sizeof(hvevfd)))
goto out;
r = kvm_vm_ioctl_hv_eventfd(kvm, &hvevfd);
+ }
+ case KVM_SUBPAGES_GET_ACCESS: {
+ struct kvm_subpage spp_info;
+
+ if (!kvm->arch.spp_active) {
+ r = -ENODEV;
+ goto out;
+ }
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.npages == 0 ||
+ spp_info.npages > SUBPAGE_MAX_BITMAP)
+ goto out;
+
+ r = kvm_vm_ioctl_get_subpages(kvm, &spp_info);
+ if (copy_to_user(argp, &spp_info, sizeof(spp_info))) {
+ r = -EFAULT;
+ goto out;
+ }
+ break;
+ }
+ case KVM_SUBPAGES_SET_ACCESS: {
+ struct kvm_subpage spp_info;
+
+ if (!kvm->arch.spp_active) {
+ r = -ENODEV;
+ goto out;
+ }
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.npages == 0 ||
+ spp_info.npages > SUBPAGE_MAX_BITMAP)
+ goto out;
+
+ r = kvm_vm_ioctl_set_subpages(kvm, &spp_info);
break;
}
+ case KVM_INIT_SPP: {
+ r = kvm_vm_ioctl_init_spp(kvm);
+ break;
+ }
default:
r = -ENOTTY;
}
@@ -9925,6 +9989,32 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
return kvm_x86_ops->update_pi_irte(kvm, host_irq, guest_irq, set);
}

+int kvm_arch_get_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ if (!kvm_x86_ops->get_subpages)
+ return -EINVAL;
+
+ return kvm_x86_ops->get_subpages(kvm, spp_info);
+}
+
+int kvm_arch_set_subpages(struct kvm *kvm,
+ struct kvm_subpage *spp_info)
+{
+ if (!kvm_x86_ops->set_subpages)
+ return -EINVAL;
+
+ return kvm_x86_ops->set_subpages(kvm, spp_info);
+}
+
+int kvm_arch_init_spp(struct kvm *kvm)
+{
+ if (!kvm_x86_ops->init_spp)
+ return -EINVAL;
+
+ return kvm_x86_ops->init_spp(kvm);
+}
+
bool kvm_vector_hashing_enabled(void)
{
return vector_hashing;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index da30fcbb2727..b5ae112f209f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -852,6 +852,10 @@ struct kvm_mmu_page *kvm_mmu_get_spp_page(struct kvm_vcpu *vcpu,
int kvm_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info);
int kvm_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info);
int kvm_init_spp(struct kvm *kvm);
+int kvm_arch_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info);
+int kvm_arch_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info);
+int kvm_arch_init_spp(struct kvm *kvm);
+
#ifndef __KVM_HAVE_ARCH_VM_ALLOC
/*
* All architectures that want to use vzalloc currently also
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 2c75a87ab3b5..5754f8d21e7d 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1246,6 +1246,9 @@ struct kvm_vfio_spapr_tce {
struct kvm_userspace_memory_region)
#define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47)
#define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64)
+#define KVM_SUBPAGES_GET_ACCESS _IOR(KVMIO, 0x49, __u64)
+#define KVM_SUBPAGES_SET_ACCESS _IOW(KVMIO, 0x4a, __u64)
+#define KVM_INIT_SPP _IOW(KVMIO, 0x4b, __u64)

/* enable ucontrol for s390 */
struct kvm_s390_ucas_mapping {
--
2.17.2