Commit 15fb7de1 authored by Brijesh Singh's avatar Brijesh Singh Committed by Paolo Bonzini
Browse files

KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command 



The command is used for copying the incoming buffer into the
SEV guest memory space.

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: 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
Reviewed-by: default avatarSteve Rutherford <srutherford@google.com>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarAshish Kalra <ashish.kalra@amd.com>
Message-Id: <c5d0e3e719db7bb37ea85d79ed4db52e9da06257.1618498113.git.ashish.kalra@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent af43cbbf

Documentation/virt/kvm/amd-memory-encryption.rst

+24 −0
Original line number Diff line number Diff line
@@ -394,6 +394,30 @@ On success, the 'handle' field contains a new handle and on error, a negative va 


For more details, see SEV spec Section 6.12.



16. KVM_SEV_RECEIVE_UPDATE_DATA

----------------------------



The KVM_SEV_RECEIVE_UPDATE_DATA command can be used by the hypervisor to copy

the incoming buffers into the guest memory region with encryption context

created during the KVM_SEV_RECEIVE_START.



Parameters (in): struct kvm_sev_receive_update_data



Returns: 0 on success, -negative on error



::



        struct kvm_sev_launch_receive_update_data {

                __u64 hdr_uaddr;        /* userspace address containing the packet header */

                __u32 hdr_len;



                __u64 guest_uaddr;      /* the destination guest memory region */

                __u32 guest_len;



                __u64 trans_uaddr;      /* the incoming buffer memory region  */

                __u32 trans_len;

        };



References

==========

arch/x86/kvm/svm/sev.c

+79 −0
Original line number Diff line number Diff line
@@ -1475,6 +1475,82 @@ static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp) 
	return ret;

}



static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)

{

	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;

	struct kvm_sev_receive_update_data params;

	struct sev_data_receive_update_data *data;

	void *hdr = NULL, *trans = NULL;

	struct page **guest_page;

	unsigned long n;

	int ret, offset;



	if (!sev_guest(kvm))

		return -EINVAL;



	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,

			sizeof(struct kvm_sev_receive_update_data)))

		return -EFAULT;



	if (!params.hdr_uaddr || !params.hdr_len ||

	    !params.guest_uaddr || !params.guest_len ||

	    !params.trans_uaddr || !params.trans_len)

		return -EINVAL;



	/* Check if we are crossing the page boundary */

	offset = params.guest_uaddr & (PAGE_SIZE - 1);

	if ((params.guest_len + offset > PAGE_SIZE))

		return -EINVAL;



	hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);

	if (IS_ERR(hdr))

		return PTR_ERR(hdr);



	trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);

	if (IS_ERR(trans)) {

		ret = PTR_ERR(trans);

		goto e_free_hdr;

	}



	ret = -ENOMEM;

	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		goto e_free_trans;



	data->hdr_address = __psp_pa(hdr);

	data->hdr_len = params.hdr_len;

	data->trans_address = __psp_pa(trans);

	data->trans_len = params.trans_len;



	/* Pin guest memory */

	ret = -EFAULT;

	guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,

				    PAGE_SIZE, &n, 0);

	if (!guest_page)

		goto e_free;



	/* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */

	data->guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) +

				offset;

	data->guest_address |= sev_me_mask;

	data->guest_len = params.guest_len;

	data->handle = sev->handle;



	ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, data,

				&argp->error);



	sev_unpin_memory(kvm, guest_page, n);



e_free:

	kfree(data);

e_free_trans:

	kfree(trans);

e_free_hdr:

	kfree(hdr);



	return ret;

}



int svm_mem_enc_op(struct kvm *kvm, void __user *argp)

{

	struct kvm_sev_cmd sev_cmd;
@@ -1552,6 +1628,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) 
	case KVM_SEV_RECEIVE_START:

		r = sev_receive_start(kvm, &sev_cmd);

		break;

	case KVM_SEV_RECEIVE_UPDATE_DATA:

		r = sev_receive_update_data(kvm, &sev_cmd);

		break;

	default:

		r = -EINVAL;

		goto out;

include/uapi/linux/kvm.h

+9 −0
Original line number Diff line number Diff line
@@ -1764,6 +1764,15 @@ struct kvm_sev_receive_start { 
	__u32 session_len;

};



struct kvm_sev_receive_update_data {

	__u64 hdr_uaddr;

	__u32 hdr_len;

	__u64 guest_uaddr;

	__u32 guest_len;

	__u64 trans_uaddr;

	__u32 trans_len;

};



#define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)

#define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)

#define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)