Re: [PATCH v4.5 09/36] KVM: s390: protvirt: Add initial vm and cpu lifecycle handling

Christian Borntraeger
2020-02-26T11:03:42Z

On 26.02.20 11:38, Cornelia Huck wrote:
> On Tue, 25 Feb 2020 16:48:22 -0500
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>
>> From: Janosch Frank <frankja@linux.ibm.com>
>>
>> This contains 3 main changes:
>> 1. changes in SIE control block handling for secure guests
>> 2. helper functions for create/destroy/unpack secure guests
>> 3. KVM_S390_PV_COMMAND ioctl to allow userspace dealing with secure
>> machines
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> [borntraeger@de.ibm.com: patch merging, splitting, fixing]
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>> arch/s390/include/asm/kvm_host.h | 24 ++-
>> arch/s390/include/asm/uv.h | 69 ++++++++
>> arch/s390/kvm/Makefile | 2 +-
>> arch/s390/kvm/kvm-s390.c | 209 +++++++++++++++++++++++-
>> arch/s390/kvm/kvm-s390.h | 33 ++++
>> arch/s390/kvm/pv.c | 269 +++++++++++++++++++++++++++++++
>> include/uapi/linux/kvm.h | 31 ++++
>> 7 files changed, 633 insertions(+), 4 deletions(-)
>> create mode 100644 arch/s390/kvm/pv.c
>
>> +int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
>> +{
>> + struct uv_cb_cgc uvcb = {
>
> Broken indentation.

Fixes.

>
>> + .header.cmd = UVC_CMD_CREATE_SEC_CONF,
>> + .header.len = sizeof(uvcb)
>> + };
>> + int cc, ret;
>> + u16 dummy;
>> +
>> + ret = kvm_s390_pv_alloc_vm(kvm);
>> + if (ret)
>> + return ret;
>> +
>> + /* Inputs */
>> + uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
>
> What is 'MSO'? (i.e., where is that 'M' coming from?)

Origin. (the one for the sie block).

>
>> + uvcb.guest_stor_len = kvm->arch.pv.guest_len;
>> + uvcb.guest_asce = kvm->arch.gmap->asce;
>> + uvcb.guest_sca = (unsigned long)kvm->arch.sca;
>> + uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
>> + uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
>> +
>> + cc = uv_call(0, (u64)&uvcb);
>> + *rc = uvcb.header.rc;
>> + *rrc = uvcb.header.rrc;
>> + KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
>> + uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
>> +
>> + /* Outputs */
>> + kvm->arch.pv.handle = uvcb.guest_handle;
>
> Is this valid if the call failed?

if not we would clear it below
>
>> +
>> + if (cc) {
>> + if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
>> + kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);

here

>> + else
>> + kvm_s390_pv_dealloc_vm(kvm);

or here

>> + return -EIO;
>> + }
>> + kvm->arch.gmap->guest_handle = uvcb.guest_handle;
>
> ...especially as you assign that handle only down here.

>
>> + atomic_set(&kvm->mm->context.is_protected, 1);
>> + return 0;
>> +}
>> +
>> +int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
>> + u16 *rrc)
>> +{
>> + struct uv_cb_ssc uvcb = {
>> + .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
>> + .header.len = sizeof(uvcb),
>> + .sec_header_origin = (u64)hdr,
>> + .sec_header_len = length,
>> + .guest_handle = kvm_s390_pv_get_handle(kvm),
>> + };
>> + int cc = uv_call(0, (u64)&uvcb);
>> +
>> + *rc = uvcb.header.rc;
>> + *rrc = uvcb.header.rrc;
>> + KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
>> + *rc, *rrc);
>> + if (cc)
>> + return -EINVAL;
>> + return 0;
>
> Maybe
> return cc ? -EINVAL : 0;

Yes.