Userspace application, e.g., QEMU or VMI, must initialize SPP
before {gets|sets} SPP subpages.Co-developed-by: He Chen <[email protected]> Signed-off-by: He Chen <[email protected]> Co-developed-by: Zhang Yi <[email protected]> Signed-off-by: Zhang Yi <[email protected]> Signed-off-by: Yang Weijiang <[email protected]> --- 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 df5d79b17ef3..25207f1ac9f8 100644 --- a/arch/x86/kvm/mmu/spp.c +++ b/arch/x86/kvm/mmu/spp.c @@ -205,6 +205,46 @@ 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) { @@ -371,3 +411,42 @@ 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 35e4b57dbabf..c0b09d8be31b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -28,6 +28,7 @@ #include "pmu.h" #include "hyperv.h" #include "lapic.h" +#include "mmu/spp.h" #include <linux/clocksource.h> #include <linux/interrupt.h> @@ -5196,6 +5197,93 @@ 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 63a477720a17..2b70cf0d402a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1280,6 +1280,8 @@ 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
