The ioctl can be used to retrieve page encryption bitmap for a given gfn range.
Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: "Radim Krčmář" <[email protected]> Cc: Joerg Roedel <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Brijesh Singh <[email protected]> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm.c | 44 ++++++++++++++++++++++++++++++++- arch/x86/kvm/x86.c | 12 +++++++++ include/uapi/linux/kvm.h | 12 +++++++++ 4 files changed, 68 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a54fef979a8e..4dda5891200d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1204,6 +1204,7 @@ struct kvm_x86_ops { bool (*need_emulation_on_page_fault)(struct kvm_vcpu *vcpu); int (*page_enc_status_hc)(struct kvm *kvm, unsigned long gpa, unsigned long sz, unsigned long mode); + int (*get_page_enc_bitmap)(struct kvm *kvm, struct kvm_page_enc_bitmap *bmap); }; struct kvm_arch_async_pf { diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index b47a05a5e137..af9b33e4bb53 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7421,6 +7421,47 @@ static int svm_page_enc_status_hc(struct kvm *kvm, unsigned long gpa, return ret; } +static int svm_get_page_enc_bitmap(struct kvm *kvm, + struct kvm_page_enc_bitmap *bmap) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + unsigned long gfn_start, gfn_end; + unsigned long *bitmap; + unsigned long sz, i; + int ret; + + if (!sev_guest(kvm)) + return -ENOTTY; + + gfn_start = bmap->start; + gfn_end = gfn_start + bmap->num_pages; + + sz = ALIGN(bmap->num_pages, BITS_PER_LONG) / 8; + bitmap = kmalloc(sz, GFP_KERNEL); + if (!bitmap) + return -ENOMEM; + + memset(bitmap, 0xff, sz); /* by default all pages are marked encrypted */ + + mutex_lock(&kvm->lock); + if (sev->page_enc_bmap) { + i = gfn_start; + for_each_clear_bit_from(i, sev->page_enc_bmap, + min(sev->page_enc_bmap_size, gfn_end)) + clear_bit(i - gfn_start, bitmap); + } + mutex_unlock(&kvm->lock); + + ret = -EFAULT; + if (copy_to_user(bmap->enc_bitmap, bitmap, sz)) + goto out; + + ret = 0; +out: + kfree(bitmap); + return ret; +} + static int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -7763,7 +7804,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .need_emulation_on_page_fault = svm_need_emulation_on_page_fault, - .page_enc_status_hc = svm_page_enc_status_hc + .page_enc_status_hc = svm_page_enc_status_hc, + .get_page_enc_bitmap = svm_get_page_enc_bitmap }; static int __init svm_init(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 88a672da68d5..cec986ebc793 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4929,6 +4929,18 @@ long kvm_arch_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_hv_eventfd(kvm, &hvevfd); break; } + case KVM_GET_PAGE_ENC_BITMAP: { + struct kvm_page_enc_bitmap bitmap; + + r = -EFAULT; + if (copy_from_user(&bitmap, argp, sizeof(bitmap))) + goto out; + + r = -ENOTTY; + if (kvm_x86_ops->get_page_enc_bitmap) + r = kvm_x86_ops->get_page_enc_bitmap(kvm, &bitmap); + break; + } default: r = -ENOTTY; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index e31cdb41519f..ce4ae8929d00 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -492,6 +492,16 @@ struct kvm_dirty_log { }; }; +/* for KVM_GET_PAGE_ENC_BITMAP */ +struct kvm_page_enc_bitmap { + __u64 start; + __u64 num_pages; + union { + void __user *enc_bitmap; /* one bit per page */ + __u64 padding2; + }; +}; + /* for KVM_CLEAR_DIRTY_LOG */ struct kvm_clear_dirty_log { __u32 slot; @@ -1451,6 +1461,8 @@ struct kvm_enc_region { /* Available with KVM_CAP_ARM_SVE */ #define KVM_ARM_VCPU_FINALIZE _IOW(KVMIO, 0xc2, int) +#define KVM_GET_PAGE_ENC_BITMAP _IOW(KVMIO, 0xc2, struct kvm_page_enc_bitmap) + /* Secure Encrypted Virtualization command */ enum sev_cmd_id { /* Guest initialization commands */ -- 2.17.1
