Re: [PATCH v8 02/15] s390x: protvirt: Support unpack facility

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

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On 3/10/20 4:26 PM, David Hildenbrand wrote:
> On 10.03.20 14:39, Janosch Frank wrote:
>> The unpack facility provides the means to setup a protected guest. A
>> protected guest can not be introspected by the hypervisor or any
> 
> "cannot"
> 
>> user/administrator of the machine it is running on.
>>
>> Protected guests are encrypted at rest and need a special boot
>> mechanism via diag308 subcode 8 and 10.
>>
>> Code 8 sets the PV specific IPLB which is retained seperately from
> 
> "separately"

Time to find out why my flyspel hooks are failing...

> 
>> those set via code 5.
>>
>> Code 10 is used to unpack the VM into protected memory, verify its
>> integrity and start it.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Co-developed-by: Christian Borntraeger <borntraeger@de.ibm.com> [Changes
>> to machine]
> 
> [...]
> 
>> +static inline bool ipl_valid_pv_components(IplParameterBlock *iplb)
>> +{
>> +    IPLBlockPV *ipib_pv = &iplb->pv;
>> +    int i;
>> +
>> +    if (ipib_pv->num_comp == 0) {
>> +        return false;
>> +    }
>> +
>> +    for (i = 0; i < ipib_pv->num_comp; i++) {
>> +        /* Addr must be 4k aligned */
>> +        if (ipib_pv->components[i].addr & ~TARGET_PAGE_MASK) {
> 
> I usually find
> 
> QEMU_IS_ALIGNED(ipib_pv->components[i].addr, TARGET_PAGE_MASK)
> 
> nicer
> 
> [...]

huh, didn't know it existed.
I'll have a try with it.

> 
>> diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c
>> new file mode 100644
>> index 0000000000..1ba8bc7242
>> --- /dev/null
>> +++ b/hw/s390x/pv.c
>> @@ -0,0 +1,104 @@
>> +/*
>> + * Protected Virtualization functions
>> + *
>> + * Copyright IBM Corp. 2020
>> + * 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 <linux/kvm.h>
>> +
>> +#include "qemu/error-report.h"
>> +#include "sysemu/kvm.h"
>> +#include "pv.h"
>> +
>> +const char *cmd_names[] = {
>> +    "VM_ENABLE",
>> +    "VM_DISABLE",
>> +    "VM_SET_SEC_PARAMS",
>> +    "VM_UNPACK",
>> +    "VM_VERIFY",
>> +    "VM_PREP_RESET",
>> +    "VM_UNSHARE_ALL",
>> +};
>> +
>> +static int s390_pv_cmd(uint32_t cmd, void *data)
>> +{
>> +    int rc;
> 
> reverse x... :)

ack
Just FYI, I like christmas trees the right side up

> 
>> +    struct kvm_pv_cmd pv_cmd = {
>> +        .cmd = cmd,
>> +        .data = (uint64_t)data,
>> +    };
>> +
> 
> and then maybe
> 
> int rc =  ...

Ack

> 
>> +    rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
>> +    if (rc) {
>> +        error_report("KVM PV command %d (%s) failed: header rc %x rrc %x "
>> +                     "IOCTL rc: %d", cmd, cmd_names[cmd], pv_cmd.rc, pv_cmd.rrc,
>> +                     rc);
>> +    }
>> +    return rc;
>> +}
>> +
>> +static void s390_pv_cmd_exit(uint32_t cmd, void *data)
>> +{
>> +    int rc;
>> +
>> +    rc = s390_pv_cmd(cmd, data);
> 
> int rc = ...

Ack

> 
>> +    if (rc) {
>> +        exit(1);
>> +    }
>> +}
>> +
> 
> [...]
> 
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 895498cca6..455ad31718 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -41,6 +41,8 @@
>>  #include "hw/qdev-properties.h"
>>  #include "hw/s390x/tod.h"
>>  #include "sysemu/sysemu.h"
>> +#include "hw/s390x/pv.h"
>> +#include <linux/kvm.h>
>>  
>>  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>>  {
>> @@ -316,10 +318,80 @@ static inline void s390_do_cpu_ipl(CPUState *cs, run_on_cpu_data arg)
>>      s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
>>  }
>>  
>> +static void s390_machine_unprotect(S390CcwMachineState *ms)
>> +{
>> +
> 
> superfluous empty line
> 
>> +    s390_pv_vm_disable();
>> +    ms->pv = false;
>> +}
>> +
> 
> [...]

Ack

> 
>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>> index 3dd396e870..bcb9e47767 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"
> 
> Do you need that include here? I don't think so.
> 
>>  #include "hw/boards.h"
>>  #include "sysemu/arch_init.h"
>>  #include "sysemu/sysemu.h"
>> @@ -174,6 +176,27 @@ static void s390_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
>>      info->print_insn = print_insn_s390;
>>  }
>>  
>> +#if !defined(CONFIG_USER_ONLY)
>> +bool s390_is_pv(void)
>> +{
>> +    static S390CcwMachineState *ccw;
>> +    Object *obj;
>> +
>> +    if (ccw) {
>> +        return ccw->pv;
>> +    }
>> +
>> +    /* we have to bail out for the "none" machine */
>> +    obj = object_dynamic_cast(qdev_get_machine(),
>> +                              TYPE_S390_CCW_MACHINE);
>> +    if (!obj) {
>> +        return false;
>> +    }
>> +    ccw = S390_CCW_MACHINE(obj);
>> +    return ccw->pv;
>> +}
>> +#endif
>> +
> 
> Nit: I *think* this would be better placed in hw/s390x/pv.h

I'll think about it

> 
>>  static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
>>  {
>>      CPUState *cs = CPU(dev);
>> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
>> index 1d17709d6e..8fa25d9ed5 100644
>> --- a/target/s390x/cpu.h
>> +++ b/target/s390x/cpu.h
>> @@ -762,6 +762,7 @@ static inline void s390_do_cpu_load_normal(CPUState *cs, run_on_cpu_data arg)
>>  
>>  
>>  /* cpu.c */
>> +bool s390_is_pv(void);
> 
> Wonder if this will compile with CONFIG_USER_ONLY (maybe we need a
> "return false" dummy). I assume you test-compiled that with all variants
> (CONFIG_TCG, CONFIG_USER_ONLY, ...)

Oh, right...

> 
> 
> .. we're almost there ... :)
> 



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