Commit 59414c98 authored by Brijesh Singh's avatar Brijesh Singh

KVM: SVM: Add support for KVM_SEV_LAUNCH_START command

The KVM_SEV_LAUNCH_START command is used to create a memory encryption
context within the SEV firmware. In order to do so, the guest owner
should provide the guest's policy, its public Diffie-Hellman (PDH) key
and session information. The command implements the LAUNCH_START flow
defined in SEV spec Section 6.2.

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
Improvements-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
parent 70cd94e6
......@@ -750,6 +750,8 @@ enum kvm_irqchip_mode {
struct kvm_sev_info {
bool active; /* SEV enabled guest */
unsigned int asid; /* ASID used for this guest */
unsigned int handle; /* SEV firmware handle */
int fd; /* SEV device fd */
};
struct kvm_arch {
......
......@@ -1538,11 +1538,45 @@ static void sev_asid_free(struct kvm *kvm)
__sev_asid_free(sev->asid);
}
static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
{
struct sev_data_decommission *decommission;
struct sev_data_deactivate *data;
if (!handle)
return;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return;
/* deactivate handle */
data->handle = handle;
sev_guest_deactivate(data, NULL);
wbinvd_on_all_cpus();
sev_guest_df_flush(NULL);
kfree(data);
decommission = kzalloc(sizeof(*decommission), GFP_KERNEL);
if (!decommission)
return;
/* decommission handle */
decommission->handle = handle;
sev_guest_decommission(decommission, NULL);
kfree(decommission);
}
static void sev_vm_destroy(struct kvm *kvm)
{
struct kvm_sev_info *sev = &kvm->arch.sev_info;
if (!sev_guest(kvm))
return;
sev_unbind_asid(kvm, sev->handle);
sev_asid_free(kvm);
}
......@@ -5708,6 +5742,122 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
return ret;
}
static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
{
struct sev_data_activate *data;
int asid = sev_get_asid(kvm);
int ret;
wbinvd_on_all_cpus();
ret = sev_guest_df_flush(error);
if (ret)
return ret;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
/* activate ASID on the given handle */
data->handle = handle;
data->asid = asid;
ret = sev_guest_activate(data, error);
kfree(data);
return ret;
}
static int sev_issue_cmd(int fd, int id, void *data, int *error)
{
struct fd f;
int ret;
f = fdget(fd);
if (!f.file)
return -EBADF;
ret = sev_issue_cmd_external_user(f.file, id, data, error);
fdput(f);
return ret;
}
static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
{
struct kvm_sev_info *sev = &kvm->arch.sev_info;
struct sev_data_launch_start *start;
struct kvm_sev_launch_start params;
void *dh_blob, *session_blob;
int *error = &argp->error;
int ret;
if (!sev_guest(kvm))
return -ENOTTY;
if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
return -EFAULT;
start = kzalloc(sizeof(*start), GFP_KERNEL);
if (!start)
return -ENOMEM;
dh_blob = NULL;
if (params.dh_uaddr) {
dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
if (IS_ERR(dh_blob)) {
ret = PTR_ERR(dh_blob);
goto e_free;
}
start->dh_cert_address = __sme_set(__pa(dh_blob));
start->dh_cert_len = params.dh_len;
}
session_blob = NULL;
if (params.session_uaddr) {
session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
if (IS_ERR(session_blob)) {
ret = PTR_ERR(session_blob);
goto e_free_dh;
}
start->session_address = __sme_set(__pa(session_blob));
start->session_len = params.session_len;
}
start->handle = params.handle;
start->policy = params.policy;
/* create memory encryption context */
ret = sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, start, error);
if (ret)
goto e_free_session;
/* Bind ASID to this guest */
ret = sev_bind_asid(kvm, start->handle, error);
if (ret)
goto e_free_session;
/* return handle to userspace */
params.handle = start->handle;
if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params))) {
sev_unbind_asid(kvm, start->handle);
ret = -EFAULT;
goto e_free_session;
}
sev->handle = start->handle;
sev->fd = argp->sev_fd;
e_free_session:
kfree(session_blob);
e_free_dh:
kfree(dh_blob);
e_free:
kfree(start);
return ret;
}
static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
{
struct kvm_sev_cmd sev_cmd;
......@@ -5725,6 +5875,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
case KVM_SEV_INIT:
r = sev_guest_init(kvm, &sev_cmd);
break;
case KVM_SEV_LAUNCH_START:
r = sev_launch_start(kvm, &sev_cmd);
break;
default:
r = -EINVAL;
goto out;
......
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