Userspace application, e.g., QEMU or VMI, must initialize SPP
before {gets|sets} SPP subpages.
Co-developed-by: He Chen <he.chen@xxxxxxxxxxxxxxx>
Signed-off-by: He Chen <he.chen@xxxxxxxxxxxxxxx>
Co-developed-by: Zhang Yi <yi.z.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Zhang Yi <yi.z.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
---
arch/x86/kvm/mmu/spp.c | 79 ++++++++++++++++++++++++++++++++++++
arch/x86/kvm/mmu/spp.h | 11 ++++-
arch/x86/kvm/x86.c | 88 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 2 +
4 files changed, 179 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu/spp.c b/arch/x86/kvm/mmu/spp.c
index 55899eee4398..c9f5180c403b 100644
--- a/arch/x86/kvm/mmu/spp.c
+++ b/arch/x86/kvm/mmu/spp.c
@@ -201,6 +201,46 @@ int kvm_spp_setup_structure(struct kvm_vcpu *vcpu,
return ret;
}
+int spp_flush_sppt(struct kvm *kvm, u64 gfn_base, u32 npages)
+{
+ struct kvm_shadow_walk_iterator iter;
+ struct kvm_vcpu *vcpu;
+ gfn_t gfn = gfn_base;
+ gfn_t gfn_end = gfn_base + npages - 1;
+ u64 spde;
+ int count;
+ bool flush = false;
+
+ vcpu = kvm_get_vcpu(kvm, 0);
+ if (!VALID_PAGE(vcpu->kvm->arch.sppt_root))
+ return -EFAULT;
+
+ for (; gfn <= gfn_end; gfn++) {
+ for_each_shadow_spp_entry(vcpu, (u64)gfn << PAGE_SHIFT, iter) {
+ if (!is_shadow_present_pte(*iter.sptep))
+ break;
+
+ if (iter.level != PT_DIRECTORY_LEVEL)
+ continue;
+
+ spde = *iter.sptep;
+ spde &= ~PT_PRESENT_MASK;
+ spp_spte_set(iter.sptep, spde);
+ count = kvm_spp_level_pages(gfn, gfn_end,
+ PT_DIRECTORY_LEVEL);
+ flush = true;
+ if (count >= npages)
+ goto out;
+ gfn += count;
+ break;
+ }
+ }
+out:
+ if (flush)
+ kvm_flush_remote_tlbs(kvm);
+ return 0;
+}
+
int kvm_spp_get_permission(struct kvm *kvm, u64 gfn, u32 npages,
u32 *access_map)
{
@@ -366,3 +406,42 @@ int kvm_spp_mark_protection(struct kvm *kvm, u64 gfn, u32 access)
}
return ret;
}
+
+int kvm_vm_ioctl_get_subpages(struct kvm *kvm,
+ u64 gfn,
+ u32 npages,
+ u32 *access_map)
+{
+ int ret;
+
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_spp_get_permission(kvm, gfn, npages, access_map);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
+
+int kvm_vm_ioctl_set_subpages(struct kvm *kvm,
+ u64 gfn,
+ u32 npages,
+ u32 *access_map)
+{
+ int ret;
+
+ spin_lock(&kvm->mmu_lock);
+ ret = spp_flush_sppt(kvm, gfn, npages);
+ spin_unlock(&kvm->mmu_lock);
+
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&kvm->slots_lock);
+ spin_lock(&kvm->mmu_lock);
+
+ ret = kvm_spp_set_permission(kvm, gfn, npages, access_map);
+
+ spin_unlock(&kvm->mmu_lock);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
diff --git a/arch/x86/kvm/mmu/spp.h b/arch/x86/kvm/mmu/spp.h
index 9171e682be1f..75d4bfd64dbd 100644
--- a/arch/x86/kvm/mmu/spp.h
+++ b/arch/x86/kvm/mmu/spp.h
@@ -3,15 +3,24 @@
#define __KVM_X86_VMX_SPP_H
#define FULL_SPP_ACCESS (u32)(BIT_ULL(32) - 1)
+#define KVM_SUBPAGE_MAX_PAGES 512
int kvm_spp_get_permission(struct kvm *kvm, u64 gfn, u32 npages,
u32 *access_map);
int kvm_spp_set_permission(struct kvm *kvm, u64 gfn, u32 npages,
u32 *access_map);
int kvm_spp_mark_protection(struct kvm *kvm, u64 gfn, u32 access);
-
+int kvm_vm_ioctl_get_subpages(struct kvm *kvm,
+ u64 gfn,
+ u32 npages,
+ u32 *access_map);
+int kvm_vm_ioctl_set_subpages(struct kvm *kvm,
+ u64 gfn,
+ u32 npages,
+ u32 *access_map);
int kvm_spp_setup_structure(struct kvm_vcpu *vcpu,
u32 access_map, gfn_t gfn);
u32 *gfn_to_subpage_wp_info(struct kvm_memory_slot *slot, gfn_t gfn);
+int spp_flush_sppt(struct kvm *kvm, u64 gfn_base, u32 npages);
#endif /* __KVM_X86_VMX_SPP_H */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cf917139de6b..48871882a00c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -26,6 +26,7 @@
#include "cpuid.h"
#include "pmu.h"
#include "hyperv.h"
+#include "mmu/spp.h"
#include <linux/clocksource.h>
#include <linux/interrupt.h>
@@ -5134,6 +5135,93 @@ long kvm_arch_vm_ioctl(struct file *filp,
case KVM_SET_PMU_EVENT_FILTER:
r = kvm_vm_ioctl_set_pmu_event_filter(kvm, argp);
break;
+ case KVM_SUBPAGES_GET_ACCESS: {
+ struct kvm_subpage spp_info, *pinfo;
+ u32 total;
+
+ r = -ENODEV;
+ if (!kvm->arch.spp_active)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.flags != 0 ||
+ spp_info.npages > KVM_SUBPAGE_MAX_PAGES)
+ goto out;
+ r = 0;
+ if (!spp_info.npages)
+ goto out;
+
+ total = sizeof(spp_info) +
+ sizeof(spp_info.access_map[0]) * spp_info.npages;
+ pinfo = kvzalloc(total, GFP_KERNEL_ACCOUNT);
+
+ r = -ENOMEM;
+ if (!pinfo)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_from_user(pinfo, argp, total))
+ goto out;
+
+ r = kvm_vm_ioctl_get_subpages(kvm,
+ pinfo->gfn_base,
+ pinfo->npages,
+ pinfo->access_map);
+ if (r != pinfo->npages)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_to_user(argp, pinfo, total))
+ goto out;
+
+ r = pinfo->npages;
+ kfree(pinfo);
+ break;
+ }
+ case KVM_SUBPAGES_SET_ACCESS: {
+ struct kvm_subpage spp_info, *pinfo;
+ u32 total;
+
+ r = -ENODEV;
+ if (!kvm->arch.spp_active)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_from_user(&spp_info, argp, sizeof(spp_info)))
+ goto out;
+
+ r = -EINVAL;
+ if (spp_info.flags != 0 ||
+ spp_info.npages > KVM_SUBPAGE_MAX_PAGES)
+ goto out;
+
+ r = 0;
+ if (!spp_info.npages)
+ goto out;
+
+ total = sizeof(spp_info) +
+ sizeof(spp_info.access_map[0]) * spp_info.npages;
+ pinfo = kvzalloc(total, GFP_KERNEL_ACCOUNT);
+
+ r = -ENOMEM;
+ if (!pinfo)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_from_user(pinfo, argp, total))
+ goto out;
+
+ r = kvm_vm_ioctl_set_subpages(kvm,
+ pinfo->gfn_base,
+ pinfo->npages,
+ pinfo->access_map);
+ kfree(pinfo);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index eabd55ec5af7..04af48ee6452 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1272,6 +1272,8 @@ 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)
/* enable ucontrol for s390 */
struct kvm_s390_ucas_mapping {
--
2.17.2
