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

[Thomas Huth <thuth@redhat.com>]

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 <frankja@linux.ibm.com>
> ---
[...]
> +++ b/hw/s390x/pv.c
> @@ -0,0 +1,118 @@
> +/*
> + * Secure execution functions
> + *
> + * Copyright IBM Corp. 2019
> + * 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.
> + */
> +#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 <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
> +
> +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...

> +
> +#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