Re: [PATCH v3 05/17] s390x: protvirt: Support unpack facility

[Janosch Frank <frankja@linux.ibm.com>]

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On 2/20/20 11:39 AM, Cornelia Huck wrote:
> On Fri, 14 Feb 2020 10:16:24 -0500
> Janosch Frank <frankja@linux.ibm.com> wrote:
> 
>> When a guest has saved a ipib of type 5 and call diagnose308 with
> 
> s/call/calls/
> 
>> subcode 10, we have to setup the protected processing environment via
>> Ultravisor calls. The calls are done by KVM and are exposed via an API.
>>
>> The following steps are necessary:
>> 1. Create a VM (register it with the Ultravisor)
>> 2. Create secure CPUs for all of our current cpus
>> 3. Forward the secure header to the Ultravisor (has all information on
>> how to decrypt the image and VM information)
>> 4. Protect image pages from the host and decrypt them
>> 5. Verify the image integrity
>>
>> Only after step 5 a protected VM is allowed to run.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [Changes
>> to machine]
>> ---
>>  hw/s390x/Makefile.objs              |   1 +
>>  hw/s390x/ipl.c                      |  32 ++++++
>>  hw/s390x/ipl.h                      |   2 +
>>  hw/s390x/pv.c                       | 154 ++++++++++++++++++++++++++++
>>  hw/s390x/pv.h                       |  38 +++++++
>>  hw/s390x/s390-virtio-ccw.c          |  79 ++++++++++++++
>>  include/hw/s390x/s390-virtio-ccw.h  |   1 +
>>  target/s390x/cpu.c                  |   4 +
>>  target/s390x/cpu.h                  |   1 +
>>  target/s390x/cpu_features_def.inc.h |   1 +
>>  10 files changed, 313 insertions(+)
>>  create mode 100644 hw/s390x/pv.c
>>  create mode 100644 hw/s390x/pv.h
> 
> (...)
> 
>> diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c
>> new file mode 100644
>> index 0000000000..5b6a26cba9
>> --- /dev/null
>> +++ b/hw/s390x/pv.c
>> @@ -0,0 +1,154 @@
>> +/*
>> + * Secure execution functions
>> + *
>> + * Copyright IBM Corp. 2019
> 
> Update the year?

ack.

> 
>> + * Author(s):
>> + *  Janosch Frank <frankja@linux.ibm.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
>> + * your option) any later version. See the COPYING file in the top-level
>> + * directory.
>> + */
> 
> (...)
> 
>> +void s390_pv_vm_destroy(void)
>> +{
>> +     s390_pv_cmd_exit(KVM_PV_VM_DESTROY, NULL);
> 
> Why does this exit()? Should Never Happen?

Yes, and we can't recover from this.

> 
>> +}
>> +
>> +int s390_pv_vcpu_create(CPUState *cs)
>> +{
>> +    int rc;
>> +
>> +    rc = s390_pv_cmd_vcpu(cs, KVM_PV_VCPU_CREATE, NULL);
>> +    if (!rc) {
>> +        S390_CPU(cs)->env.pv = true;
>> +    }
>> +
>> +    return rc;
>> +}
>> +
>> +void s390_pv_vcpu_destroy(CPUState *cs)
>> +{
>> +    s390_pv_cmd_vcpu_exit(cs, KVM_PV_VCPU_DESTROY, NULL);
> 
> dito
> 
>> +    S390_CPU(cs)->env.pv = false;
>> +}
> 
> (...)
> 
>> +void s390_pv_perf_clear_reset(void)
>> +{
>> +    s390_pv_cmd_exit(KVM_PV_VM_PREP_RESET, NULL);
> 
> And here. Or is that because the machine should not be left around in
> an undefined state?

If it failed, we could only try again, there's no fixing the problem.
So I chose to rather exit instead of looping around something which most
likely will never recover after the first error.

> 
>> +}
>> +
>> +int s390_pv_verify(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_VERIFY, NULL);
>> +}
>> +
>> +void s390_pv_unshare(void)
>> +{
>> +    s390_pv_cmd_exit(KVM_PV_VM_UNSHARE_ALL, NULL);
>> +}
>> diff --git a/hw/s390x/pv.h b/hw/s390x/pv.h
>> new file mode 100644
>> index 0000000000..7d20bdd12e
>> --- /dev/null
>> +++ b/hw/s390x/pv.h
>> @@ -0,0 +1,38 @@
>> +/*
>> + * Protected Virtualization header
>> + *
>> + * Copyright IBM Corp. 2019
> 
> Year++
> 
>> + * Author(s):
>> + *  Janosch Frank <frankja@linux.ibm.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
>> + * your option) any later version. See the COPYING file in the top-level
>> + * directory.
>> + */
>> +
>> +#ifndef HW_S390_PV_H
>> +#define HW_S390_PV_H
>> +
>> +#ifdef CONFIG_KVM
>> +int s390_pv_vm_create(void);
>> +void s390_pv_vm_destroy(void);
>> +void s390_pv_vcpu_destroy(CPUState *cs);
>> +int s390_pv_vcpu_create(CPUState *cs);
>> +int s390_pv_set_sec_parms(uint64_t origin, uint64_t length);
>> +int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak);
>> +void s390_pv_perf_clear_reset(void);
>> +int s390_pv_verify(void);
>> +void s390_pv_unshare(void);
>> +#else
>> +int s390_pv_vm_create(void) { return 0; }
> 
> I'm wondering why you return 0 here (and below). These function should
> not be called for !KVM, but just to help catch logic error, use -EINVAL
> or so?
> 
>> +void s390_pv_vm_destroy(void) {}
>> +void s390_pv_vcpu_destroy(CPUState *cs) {}
>> +int s390_pv_vcpu_create(CPUState *cs) { return 0; }
>> +int s390_pv_set_sec_parms(uint64_t origin, uint64_t length) { return 0; }
>> +int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak) { return 0: }
>> +void s390_pv_perf_clear_reset(void) {}
>> +int s390_pv_verify(void) { return 0; }
>> +void s390_pv_unshare(void) {}
>> +#endif
>> +
>> +#endif /* HW_S390_PV_H */
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index e759eb5f83..5fa4372083 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -41,6 +41,7 @@
>>  #include "hw/qdev-properties.h"
>>  #include "hw/s390x/tod.h"
>>  #include "sysemu/sysemu.h"
>> +#include "hw/s390x/pv.h"
>>  
>>  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>  {
>> @@ -240,9 +241,11 @@ static void s390_create_sclpconsole(const char *type, Chardev *chardev)
>>  static void ccw_init(MachineState *machine)
>>  {
>>      int ret;
>> +    S390CcwMachineState *ms = S390_CCW_MACHINE(machine);
>>      VirtualCssBus *css_bus;
>>      DeviceState *dev;
>>  
>> +    ms->pv = false;
> 
> I'm wondering why you need to init this to false - isn't it already
> zeroed out?
> 
>>      s390_sclp_init();
>>      /* init memory + setup max page size. Required for the CPU model */
>>      s390_memory_init(machine->ram_size);
>> @@ -318,10 +321,58 @@ static inline void s390_do_cpu_ipl(CPUState *cs, run_on_cpu_data arg)
>>      s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
>>  }
>>  
>> +static int s390_machine_pv_secure(S390CcwMachineState *ms)
>> +{
>> +    CPUState *t;
>> +    int rc;
>> +
>> +    /* Create SE VM */
>> +    rc = s390_pv_vm_create();
>> +    if (rc) {
>> +        return rc;
>> +    }
>> +
>> +    CPU_FOREACH(t) {
>> +        rc = s390_pv_vcpu_create(t);
>> +        if (rc) {
>> +            return rc;
> 
> No need to undo something on error?

There have been changes in this area anyway, since Christian switched to
one create/destroy instead of separate for vm and vcpu.

I'll update the error handling in the new state and send out the patches
ssonish.


> 
>> +        }
>> +    }
>> +
>> +    ms->pv = true;
>> +
>> +    /* Set SE header and unpack */
>> +    rc = s390_ipl_prepare_pv_header();
>> +    if (rc) {
>> +        return rc;
> 
> Also here.
> 
>> +    }
>> +
>> +    /* Decrypt image */
>> +    rc = s390_ipl_pv_unpack();
>> +    if (rc) {
>> +        return rc;
> 
> And here.
> 
>> +    }
>> +
>> +    /* Verify integrity */
>> +    rc = s390_pv_verify();
>> +    return rc;
> 
> And here.
> 
>> +}
> 
> (...)
> 
>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>> index 8da1905485..1dbd84b9d7 100644
>> --- a/target/s390x/cpu.c
>> +++ b/target/s390x/cpu.c
>> @@ -37,6 +37,8 @@
>>  #include "sysemu/hw_accel.h"
>>  #include "hw/qdev-properties.h"
>>  #ifndef CONFIG_USER_ONLY
>> +#include "hw/s390x/s390-virtio-ccw.h"
>> +#include "hw/s390x/pv.h"
>>  #include "hw/boards.h"
>>  #include "sysemu/arch_init.h"
>>  #include "sysemu/sysemu.h"
>> @@ -191,6 +193,7 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
>>  
>>  #if !defined(CONFIG_USER_ONLY)
>>      MachineState *ms = MACHINE(qdev_get_machine());
>> +    S390CcwMachineState *ccw = S390_CCW_MACHINE(ms);
> 
> I find the variable name a bit confusing... maybe ccw_ms?
> 
>>      unsigned int max_cpus = ms->smp.max_cpus;
>>      if (cpu->env.core_id >= max_cpus) {
>>          error_setg(&err, "Unable to add CPU with core-id: %" PRIu32
>> @@ -205,6 +208,7 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
>>          goto out;
>>      }
>>  
>> +    cpu->env.pv = ccw->pv;
> 
> So, if you add a cpu, it will inherit the pv state of the machine...
> doesn't it need any setup?
> 
>>      /* sync cs->cpu_index and env->core_id. The latter is needed for TCG. */
>>      cs->cpu_index = cpu->env.core_id;
>>  #endif
> 
> (...)
> 



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