From: Brijesh Singh <brijesh.singh@amd.com>
Date: Mon, 4 Dec 2017 10:57:26 -0600
Subject: KVM: Introduce KVM_MEMORY_ENCRYPT_OP ioctl
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Git-commit: 5acc5c063196b4a531a761a954023c1848ec832b
Patch-mainline: v4.16-rc1
References: bsc#1063068

If the hardware supports memory encryption then the
KVM_MEMORY_ENCRYPT_OP ioctl can be used by qemu to issue a platform
specific memory encryption commands.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
---
 Documentation/virtual/kvm/api.txt |   16 ++++++++++++++++
 arch/x86/include/asm/kvm_host.h   |    2 ++
 arch/x86/kvm/x86.c                |    6 ++++++
 include/uapi/linux/kvm.h          |    2 ++
 4 files changed, 26 insertions(+)

--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1080,6 +1080,8 @@ struct kvm_x86_ops {
 	int (*pre_enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
 	int (*pre_leave_smm)(struct kvm_vcpu *vcpu, u64 smbase);
 	int (*enable_smi_window)(struct kvm_vcpu *vcpu);
+
+	int (*mem_enc_op)(struct kvm *kvm, void __user *argp);
 };
 
 struct kvm_arch_async_pf {
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4295,6 +4295,12 @@ set_identity_unlock:
 		r = kvm_vm_ioctl_enable_cap(kvm, &cap);
 		break;
 	}
+	case KVM_MEMORY_ENCRYPT_OP: {
+		r = -ENOTTY;
+		if (kvm_x86_ops->mem_enc_op)
+			r = kvm_x86_ops->mem_enc_op(kvm, argp);
+		break;
+	}
 	default:
 		r = -ENOTTY;
 	}
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3446,6 +3446,22 @@ array bounds check and the array access.
 These fields use the same bit definitions as the new
 H_GET_CPU_CHARACTERISTICS hypercall.
 
+4.109 KVM_MEMORY_ENCRYPT_OP
+
+Capability: basic
+Architectures: x86
+Type: system
+Parameters: an opaque platform specific structure (in/out)
+Returns: 0 on success; -1 on error
+
+If the platform supports creating encrypted VMs then this ioctl can be used
+for issuing platform-specific memory encryption commands to manage those
+encrypted VMs.
+
+Currently, this ioctl is used for issuing Secure Encrypted Virtualization
+(SEV) commands on AMD Processors. The SEV commands are defined in
+Documentation/virtual/kvm/amd-memory-encryption.txt.
+
 5. The kvm_run structure
 ------------------------
 
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1361,6 +1361,8 @@ struct kvm_s390_ucas_mapping {
 /* Available with KVM_CAP_S390_CMMA_MIGRATION */
 #define KVM_S390_GET_CMMA_BITS      _IOWR(KVMIO, 0xb8, struct kvm_s390_cmma_log)
 #define KVM_S390_SET_CMMA_BITS      _IOW(KVMIO, 0xb9, struct kvm_s390_cmma_log)
+/* Memory Encryption Commands */
+#define KVM_MEMORY_ENCRYPT_OP      _IOWR(KVMIO, 0xba, unsigned long)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)