Re: [PATCH v2 03/13] s390x: protvirt: Support unpack facility

[Janosch Frank]

On 12/4/19 11:48 AM, Thomas Huth wrote:
> On 29/11/2019 10.47, Janosch Frank wrote:
>> When a guest has saved a ipib of type 5 and call diagnose308 with
>> 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 <address@hidden>
>> ---
> [...]
>> +++ b/hw/s390x/pv.c
>> @@ -0,0 +1,118 @@
>> +/*
>> + * Secure execution functions
>> + *
>> + * Copyright IBM Corp. 2019
>> + * Author(s):
>> + *  Janosch Frank <address@hidden>
>> + *
>> + * 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.
>> + */
>> +#include "qemu/osdep.h"
>> +#include <sys/ioctl.h>
>> +
>> +#include <linux/kvm.h>
>> +
>> +#include "qemu/error-report.h"
>> +#include "sysemu/kvm.h"
>> +#include "pv.h"
>> +
>> +static int s390_pv_cmd(uint32_t cmd, void *data)
>> +{
>> +    int rc;
>> +    struct kvm_pv_cmd pv_cmd = {
>> +        .cmd = cmd,
>> +        .data = (uint64_t)data,
>> +    };
>> +
>> +    rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
>> +    if (rc) {
>> +        error_report("KVM PV command failed cmd: %d rc: %d", cmd, rc);
>> +        exit(1);
>> +    }
>> +    return rc;
>> +}
>> +
>> +static int s390_pv_cmd_vcpu(CPUState *cs, uint32_t cmd, void *data)
>> +{
>> +    int rc;
>> +    struct kvm_pv_cmd pv_cmd = {
>> +        .cmd = cmd,
>> +        .data = (uint64_t)data,
>> +    };
>> +
>> +    rc = kvm_vcpu_ioctl(cs, KVM_S390_PV_COMMAND_VCPU, &pv_cmd);
>> +    if (rc) {
>> +        error_report("KVM PV VCPU command failed cmd: %d rc: %d", cmd, rc);
>> +        exit(1);
>> +    }
>> +    return rc;
>> +}
>> +
>> +int s390_pv_vm_create(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_CREATE, NULL);
>> +}
>> +
>> +int s390_pv_vm_destroy(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_DESTROY, NULL);
>> +}
>> +
>> +int s390_pv_vcpu_create(CPUState *cs)
>> +{
>> +    return s390_pv_cmd_vcpu(cs, KVM_PV_VCPU_CREATE, NULL);
>> +}
>> +
>> +int s390_pv_vcpu_destroy(CPUState *cs)
>> +{
>> +    S390CPU *cpu = S390_CPU(cs);
>> +    CPUS390XState *env = &cpu->env;
>> +    int rc;
>> +
>> +    rc = s390_pv_cmd_vcpu(cs, KVM_PV_VCPU_DESTROY, NULL);
>> +    if (!rc) {
>> +        env->pv = false;
>> +    }
>> +    return rc;
>> +}
>> +
>> +int s390_pv_set_sec_parms(uint64_t origin, uint64_t length)
>> +{
>> +    struct kvm_s390_pv_sec_parm args = {
>> +        .origin = origin,
>> +        .length = length,
>> +    };
>> +
>> +    return s390_pv_cmd(KVM_PV_VM_SET_SEC_PARMS, &args);
>> +}
>> +
>> +/*
>> + * Called for each component in the SE type IPL parameter block 0.
>> + */
>> +int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak)
>> +{
>> +    struct kvm_s390_pv_unp args = {
>> +        .addr = addr,
>> +        .size = size,
>> +        .tweak = tweak,
>> +    };
>> +
>> +    return s390_pv_cmd(KVM_PV_VM_UNPACK, &args);
>> +}
>> +
>> +int s390_pv_perf_clear_reset(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_PERF_CLEAR_RESET, NULL);
>> +}
>> +
>> +int s390_pv_verify(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_VERIFY, NULL);
>> +}
>> +
>> +int s390_pv_unshare(void)
>> +{
>> +    return s390_pv_cmd(KVM_PV_VM_UNSHARE, NULL);
>> +}
>> diff --git a/hw/s390x/pv.h b/hw/s390x/pv.h
>> new file mode 100644
>> index 0000000000..eb074e4bc9
>> --- /dev/null
>> +++ b/hw/s390x/pv.h
>> @@ -0,0 +1,26 @@
>> +/*
>> + * Protected Virtualization header
>> + *
>> + * Copyright IBM Corp. 2019
>> + * Author(s):
>> + *  Janosch Frank <address@hidden>
>> + *
>> + * 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
>> +
>> +int s390_pv_vm_create(void);
>> +int s390_pv_vm_destroy(void);
>> +int 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);
>> +int s390_pv_perf_clear_reset(void);
>> +int s390_pv_verify(void);
>> +int s390_pv_unshare(void);
> 
> I still think you should make all those functions returning "void"
> instead of "int" - since errors results in an exit() in s390_pv_cmd()
> and s390_pv_cmd_vcpu() anyway...

Hey Thomas,

I have requested an error code for diag 308 subcode 10 that tells the
VM, that we didn't succeed starting a secure guest. Once that is in
place, I'll need to check the return codes.

Although I'm a bit unsure how I should hook that up because of the
diag308/reset handler split.



> 
>> +
>> +#endif /* HW_S390_PV_H */
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index c1d1440272..f9481ccace 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)
>>  {
>> @@ -322,6 +323,7 @@ static void s390_machine_reset(MachineState *machine)
>>  {
>>      enum s390_reset reset_type;
>>      CPUState *cs, *t;
>> +    S390CPU *cpu;
>>  
>>      /* get the reset parameters, reset them once done */
>>      s390_ipl_get_reset_request(&cs, &reset_type);
>> @@ -329,6 +331,8 @@ static void s390_machine_reset(MachineState *machine)
>>      /* all CPUs are paused and synchronized at this point */
>>      s390_cmma_reset();
>>  
>> +    cpu = S390_CPU(cs);
>> +
>>      switch (reset_type) {
>>      case S390_RESET_EXTERNAL:
>>      case S390_RESET_REIPL:
>> @@ -357,6 +361,28 @@ static void s390_machine_reset(MachineState *machine)
>>          run_on_cpu(cs, s390_do_cpu_initial_reset, RUN_ON_CPU_NULL);
>>          run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
>>          break;
>> +    case S390_RESET_PV: /* Subcode 10 */
>> +        subsystem_reset();
>> +        s390_crypto_reset();
>> +
>> +        CPU_FOREACH(t) {
>> +            run_on_cpu(t, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
>> +        }
>> +
>> +        /* Create SE VM */
>> +        s390_pv_vm_create();
>> +        CPU_FOREACH(t) {
>> +            s390_pv_vcpu_create(t);
>> +        }
>> +
>> +        /* Set SE header and unpack */
>> +        s390_ipl_prepare_pv_header();
>> +        /* Decrypt image */
>> +        s390_ipl_pv_unpack();
>> +        /* Verify integrity */
>> +        s390_pv_verify();
>> +        s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
>> +        break;
> 
> ... and here you completely ignore the return codes of all the new
> functions.
> 
>  Thomas
>

signature.asc
Description: OpenPGP digital signature