Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-31 Thread Andrew Jones 
On Wed, Jul 31, 2019 at 02:57:38PM +0200, Paolo Bonzini wrote:
> On 31/07/19 13:16, Thomas Huth wrote:
> > Or maybe even better: Let's move this file into lib/x86_64/ and
> > lib/aarch64/ instead, since there is more different code between the
> > architectures here than common code.
> 
> All good solutions, just choose one. :))
>

Agreed, and I like this last solution (move to arch-code) the best.

Thanks,
drew

Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-31 Thread Paolo Bonzini 
On 31/07/19 13:16, Thomas Huth wrote:
> Or maybe even better: Let's move this file into lib/x86_64/ and
> lib/aarch64/ instead, since there is more different code between the
> architectures here than common code.

All good solutions, just choose one. :))

Paolo

Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-31 Thread Thomas Huth 
On 31/07/2019 12.28, Andrew Jones wrote:
> On Wed, Jul 31, 2019 at 11:43:16AM +0200, Thomas Huth wrote:
>> On 30/07/2019 12.48, Andrew Jones wrote:
>>> On Tue, Jul 30, 2019 at 12:01:11PM +0200, Thomas Huth wrote:
 On s390x, we can neither exit via PIO nor MMIO, but have to use
 an instruction like DIAGNOSE. While we're at it, rename UCALL_PIO
 to UCALL_DEFAULT, since PIO only works on x86 anyway, and this
 way we can re-use the "default" type for the DIAGNOSE exit on s390x.

 Now that ucall() is implemented, we can use it in the sync_reg_test
 on s390x, too.

 Signed-off-by: Thomas Huth 
 ---
  .../testing/selftests/kvm/include/kvm_util.h  |  2 +-
  tools/testing/selftests/kvm/lib/ucall.c   | 34 +++
  .../selftests/kvm/s390x/sync_regs_test.c  |  6 ++--
  3 files changed, 32 insertions(+), 10 deletions(-)

 diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
 b/tools/testing/selftests/kvm/include/kvm_util.h
 index e0e66b115ef2..c37aea2e33e5 100644
 --- a/tools/testing/selftests/kvm/include/kvm_util.h
 +++ b/tools/testing/selftests/kvm/include/kvm_util.h
 @@ -167,7 +167,7 @@ int vm_create_device(struct kvm_vm *vm, struct 
 kvm_create_device *cd);
  
  /* ucall implementation types */
  typedef enum {
 -  UCALL_PIO,
 +  UCALL_DEFAULT,
>>>
>>> I'd rather we keep explicit types defined; keep PIO and add DIAG. Then
>>> we can have
>>>
>>> /*  Set default ucall types */
>>> #if defined(__x86_64__)
>>>   ucall_type = UCALL_PIO;
>>> #elif defined(__aarch64__)
>>>   ucall_type = UCALL_MMIO;
>>>   ucall_requires_init = true;
>>> #elif defined(__s390x__)
>>>   ucall_type = UCALL_DIAG;
>>> #endif
>>>
>>> And add an assert in get_ucall()
>>>
>>>  assert(!ucall_requires_init || ucall_initialized);
>>
>> I'm not sure whether I really like that. It's yet another additional
>> #ifdef block, and yet another variable ...
>>
>> What do you think about removing the enum completely and simply code it
>> directly, without the ucall_type indirection, i.e.:
>>
>> void ucall(uint64_t cmd, int nargs, ...)
>> {
>>  struct ucall uc = {
>>  .cmd = cmd,
>>  };
>>  va_list va;
>>  int i;
>>
>>  nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS;
>>
>>  va_start(va, nargs);
>>  for (i = 0; i < nargs; ++i)
>>  uc.args[i] = va_arg(va, uint64_t);
>>  va_end(va);
>>
>> #if defined(__x86_64__)
>>
>>  /* Exit via PIO */
>>  asm volatile("in %[port], %%al"
>>  : : [port] "d" (UCALL_PIO_PORT), "D" () : "rax");
>>
>> #elif defined(__aarch64__)
>>
>>  *ucall_exit_mmio_addr = (vm_vaddr_t)
>>
>> #elif defined(__s390x__)
>>
>>  /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
>>  asm volatile ("diag 0,%0,0x501" : : "a"() : "memory");
>>
>> #endif
>> }
>>
>> I think that's way less confusing than having to understand the meaning
>> of ucall_type etc. before...?
>>
> 
> Sounds good to me.

Or maybe even better: Let's move this file into lib/x86_64/ and
lib/aarch64/ instead, since there is more different code between the
architectures here than common code.

 Thomas

Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-31 Thread Andrew Jones 
On Wed, Jul 31, 2019 at 11:43:16AM +0200, Thomas Huth wrote:
> On 30/07/2019 12.48, Andrew Jones wrote:
> > On Tue, Jul 30, 2019 at 12:01:11PM +0200, Thomas Huth wrote:
> >> On s390x, we can neither exit via PIO nor MMIO, but have to use
> >> an instruction like DIAGNOSE. While we're at it, rename UCALL_PIO
> >> to UCALL_DEFAULT, since PIO only works on x86 anyway, and this
> >> way we can re-use the "default" type for the DIAGNOSE exit on s390x.
> >>
> >> Now that ucall() is implemented, we can use it in the sync_reg_test
> >> on s390x, too.
> >>
> >> Signed-off-by: Thomas Huth 
> >> ---
> >>  .../testing/selftests/kvm/include/kvm_util.h  |  2 +-
> >>  tools/testing/selftests/kvm/lib/ucall.c   | 34 +++
> >>  .../selftests/kvm/s390x/sync_regs_test.c  |  6 ++--
> >>  3 files changed, 32 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
> >> b/tools/testing/selftests/kvm/include/kvm_util.h
> >> index e0e66b115ef2..c37aea2e33e5 100644
> >> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> >> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> >> @@ -167,7 +167,7 @@ int vm_create_device(struct kvm_vm *vm, struct 
> >> kvm_create_device *cd);
> >>  
> >>  /* ucall implementation types */
> >>  typedef enum {
> >> -  UCALL_PIO,
> >> +  UCALL_DEFAULT,
> > 
> > I'd rather we keep explicit types defined; keep PIO and add DIAG. Then
> > we can have
> > 
> > /*  Set default ucall types */
> > #if defined(__x86_64__)
> >   ucall_type = UCALL_PIO;
> > #elif defined(__aarch64__)
> >   ucall_type = UCALL_MMIO;
> >   ucall_requires_init = true;
> > #elif defined(__s390x__)
> >   ucall_type = UCALL_DIAG;
> > #endif
> > 
> > And add an assert in get_ucall()
> > 
> >  assert(!ucall_requires_init || ucall_initialized);
> 
> I'm not sure whether I really like that. It's yet another additional
> #ifdef block, and yet another variable ...
> 
> What do you think about removing the enum completely and simply code it
> directly, without the ucall_type indirection, i.e.:
> 
> void ucall(uint64_t cmd, int nargs, ...)
> {
>   struct ucall uc = {
>   .cmd = cmd,
>   };
>   va_list va;
>   int i;
> 
>   nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS;
> 
>   va_start(va, nargs);
>   for (i = 0; i < nargs; ++i)
>   uc.args[i] = va_arg(va, uint64_t);
>   va_end(va);
> 
> #if defined(__x86_64__)
> 
>   /* Exit via PIO */
>   asm volatile("in %[port], %%al"
>   : : [port] "d" (UCALL_PIO_PORT), "D" () : "rax");
> 
> #elif defined(__aarch64__)
> 
>   *ucall_exit_mmio_addr = (vm_vaddr_t)
> 
> #elif defined(__s390x__)
> 
>   /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
>   asm volatile ("diag 0,%0,0x501" : : "a"() : "memory");
> 
> #endif
> }
> 
> I think that's way less confusing than having to understand the meaning
> of ucall_type etc. before...?
>

Sounds good to me.

Thanks,
drew

Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-31 Thread Thomas Huth 
On 30/07/2019 12.48, Andrew Jones wrote:
> On Tue, Jul 30, 2019 at 12:01:11PM +0200, Thomas Huth wrote:
>> On s390x, we can neither exit via PIO nor MMIO, but have to use
>> an instruction like DIAGNOSE. While we're at it, rename UCALL_PIO
>> to UCALL_DEFAULT, since PIO only works on x86 anyway, and this
>> way we can re-use the "default" type for the DIAGNOSE exit on s390x.
>>
>> Now that ucall() is implemented, we can use it in the sync_reg_test
>> on s390x, too.
>>
>> Signed-off-by: Thomas Huth 
>> ---
>>  .../testing/selftests/kvm/include/kvm_util.h  |  2 +-
>>  tools/testing/selftests/kvm/lib/ucall.c   | 34 +++
>>  .../selftests/kvm/s390x/sync_regs_test.c  |  6 ++--
>>  3 files changed, 32 insertions(+), 10 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
>> b/tools/testing/selftests/kvm/include/kvm_util.h
>> index e0e66b115ef2..c37aea2e33e5 100644
>> --- a/tools/testing/selftests/kvm/include/kvm_util.h
>> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
>> @@ -167,7 +167,7 @@ int vm_create_device(struct kvm_vm *vm, struct 
>> kvm_create_device *cd);
>>  
>>  /* ucall implementation types */
>>  typedef enum {
>> -UCALL_PIO,
>> +UCALL_DEFAULT,
> 
> I'd rather we keep explicit types defined; keep PIO and add DIAG. Then
> we can have
> 
> /*  Set default ucall types */
> #if defined(__x86_64__)
>   ucall_type = UCALL_PIO;
> #elif defined(__aarch64__)
>   ucall_type = UCALL_MMIO;
>   ucall_requires_init = true;
> #elif defined(__s390x__)
>   ucall_type = UCALL_DIAG;
> #endif
> 
> And add an assert in get_ucall()
> 
>  assert(!ucall_requires_init || ucall_initialized);

I'm not sure whether I really like that. It's yet another additional
#ifdef block, and yet another variable ...

What do you think about removing the enum completely and simply code it
directly, without the ucall_type indirection, i.e.:

void ucall(uint64_t cmd, int nargs, ...)
{
struct ucall uc = {
.cmd = cmd,
};
va_list va;
int i;

nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS;

va_start(va, nargs);
for (i = 0; i < nargs; ++i)
uc.args[i] = va_arg(va, uint64_t);
va_end(va);

#if defined(__x86_64__)

/* Exit via PIO */
asm volatile("in %[port], %%al"
: : [port] "d" (UCALL_PIO_PORT), "D" () : "rax");

#elif defined(__aarch64__)

*ucall_exit_mmio_addr = (vm_vaddr_t)

#elif defined(__s390x__)

/* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
asm volatile ("diag 0,%0,0x501" : : "a"() : "memory");

#endif
}

I think that's way less confusing than having to understand the meaning
of ucall_type etc. before...?

 Thomas

Re: [PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-30 Thread Andrew Jones 
On Tue, Jul 30, 2019 at 12:01:11PM +0200, Thomas Huth wrote:
> On s390x, we can neither exit via PIO nor MMIO, but have to use
> an instruction like DIAGNOSE. While we're at it, rename UCALL_PIO
> to UCALL_DEFAULT, since PIO only works on x86 anyway, and this
> way we can re-use the "default" type for the DIAGNOSE exit on s390x.
> 
> Now that ucall() is implemented, we can use it in the sync_reg_test
> on s390x, too.
> 
> Signed-off-by: Thomas Huth 
> ---
>  .../testing/selftests/kvm/include/kvm_util.h  |  2 +-
>  tools/testing/selftests/kvm/lib/ucall.c   | 34 +++
>  .../selftests/kvm/s390x/sync_regs_test.c  |  6 ++--
>  3 files changed, 32 insertions(+), 10 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
> b/tools/testing/selftests/kvm/include/kvm_util.h
> index e0e66b115ef2..c37aea2e33e5 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -167,7 +167,7 @@ int vm_create_device(struct kvm_vm *vm, struct 
> kvm_create_device *cd);
>  
>  /* ucall implementation types */
>  typedef enum {
> - UCALL_PIO,
> + UCALL_DEFAULT,

I'd rather we keep explicit types defined; keep PIO and add DIAG. Then
we can have

/*  Set default ucall types */
#if defined(__x86_64__)
  ucall_type = UCALL_PIO;
#elif defined(__aarch64__)
  ucall_type = UCALL_MMIO;
  ucall_requires_init = true;
#elif defined(__s390x__)
  ucall_type = UCALL_DIAG;
#endif

And add an assert in get_ucall()

 assert(!ucall_requires_init || ucall_initialized);


>   UCALL_MMIO,
>  } ucall_type_t;
>  
> diff --git a/tools/testing/selftests/kvm/lib/ucall.c 
> b/tools/testing/selftests/kvm/lib/ucall.c
> index dd9a66700f96..55534dd014dc 100644
> --- a/tools/testing/selftests/kvm/lib/ucall.c
> +++ b/tools/testing/selftests/kvm/lib/ucall.c
> @@ -30,7 +30,7 @@ void ucall_init(struct kvm_vm *vm, ucall_type_t type, void 
> *arg)
>   ucall_type = type;
>   sync_global_to_guest(vm, ucall_type);
>  
> - if (type == UCALL_PIO)
> + if (type == UCALL_DEFAULT)
>   return;
>  
>   if (type == UCALL_MMIO) {
> @@ -84,11 +84,18 @@ void ucall_uninit(struct kvm_vm *vm)
>   sync_global_to_guest(vm, ucall_exit_mmio_addr);
>  }
>  
> -static void ucall_pio_exit(struct ucall *uc)
> +static void ucall_default_exit(struct ucall *uc)
>  {
> -#ifdef __x86_64__
> +#if defined(__x86_64__)
> + /* Exit via PIO */
>   asm volatile("in %[port], %%al"
>   : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax");
> +#elif defined(__s390x__)
> + /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
> + asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory");
> +#else
> + fprintf(stderr, "No default ucall available on this architecture.\n");
> + exit(1);
>  #endif
>  }
>  
> @@ -113,8 +120,8 @@ void ucall(uint64_t cmd, int nargs, ...)
>   va_end(va);
>  
>   switch (ucall_type) {
> - case UCALL_PIO:
> - ucall_pio_exit();
> + case UCALL_DEFAULT:
> + ucall_default_exit();
>   break;
>   case UCALL_MMIO:
>   ucall_mmio_exit();
> @@ -128,15 +135,28 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, 
> struct ucall *uc)
>   struct ucall ucall = {};
>   bool got_ucall = false;
>  
> -#ifdef __x86_64__
> - if (ucall_type == UCALL_PIO && run->exit_reason == KVM_EXIT_IO &&
> +#if defined(__x86_64__)
> + if (ucall_type == UCALL_DEFAULT && run->exit_reason == KVM_EXIT_IO &&
>   run->io.port == UCALL_PIO_PORT) {
>   struct kvm_regs regs;
>   vcpu_regs_get(vm, vcpu_id, );
>   memcpy(, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), 
> sizeof(ucall));
>   got_ucall = true;
>   }
> +#elif defined(__s390x__)
> + if (ucall_type == UCALL_DEFAULT &&
> + run->exit_reason == KVM_EXIT_S390_SIEIC &&
> + run->s390_sieic.icptcode == 4 &&
> + (run->s390_sieic.ipa >> 8) == 0x83 &&/* 0x83 means DIAGNOSE */
> + (run->s390_sieic.ipb >> 16) == 0x501) {
> + int reg = run->s390_sieic.ipa & 0xf;
> +
> + memcpy(, addr_gva2hva(vm, run->s.regs.gprs[reg]),
> +sizeof(ucall));
> + got_ucall = true;
> + }
>  #endif
> +
>   if (ucall_type == UCALL_MMIO && run->exit_reason == KVM_EXIT_MMIO &&
>   run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) {
>   vm_vaddr_t gva;
> diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c 
> b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> index e85ff0d69548..bbc93094519b 100644
> --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> @@ -25,9 +25,11 @@
>  
>  static void guest_code(void)
>  {
> + register u64 stage asm("11") = 0;
> +
>   for (;;) {
> - asm volatile ("diag 0,0,0x501");
> - asm volatile ("ahi 11,1");
> +

[PATCH 1/2] KVM: selftests: Implement ucall() for s390x

2019-07-30 Thread Thomas Huth 
On s390x, we can neither exit via PIO nor MMIO, but have to use
an instruction like DIAGNOSE. While we're at it, rename UCALL_PIO
to UCALL_DEFAULT, since PIO only works on x86 anyway, and this
way we can re-use the "default" type for the DIAGNOSE exit on s390x.

Now that ucall() is implemented, we can use it in the sync_reg_test
on s390x, too.

Signed-off-by: Thomas Huth 
---
 .../testing/selftests/kvm/include/kvm_util.h  |  2 +-
 tools/testing/selftests/kvm/lib/ucall.c   | 34 +++
 .../selftests/kvm/s390x/sync_regs_test.c  |  6 ++--
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
b/tools/testing/selftests/kvm/include/kvm_util.h
index e0e66b115ef2..c37aea2e33e5 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -167,7 +167,7 @@ int vm_create_device(struct kvm_vm *vm, struct 
kvm_create_device *cd);
 
 /* ucall implementation types */
 typedef enum {
-   UCALL_PIO,
+   UCALL_DEFAULT,
UCALL_MMIO,
 } ucall_type_t;
 
diff --git a/tools/testing/selftests/kvm/lib/ucall.c 
b/tools/testing/selftests/kvm/lib/ucall.c
index dd9a66700f96..55534dd014dc 100644
--- a/tools/testing/selftests/kvm/lib/ucall.c
+++ b/tools/testing/selftests/kvm/lib/ucall.c
@@ -30,7 +30,7 @@ void ucall_init(struct kvm_vm *vm, ucall_type_t type, void 
*arg)
ucall_type = type;
sync_global_to_guest(vm, ucall_type);
 
-   if (type == UCALL_PIO)
+   if (type == UCALL_DEFAULT)
return;
 
if (type == UCALL_MMIO) {
@@ -84,11 +84,18 @@ void ucall_uninit(struct kvm_vm *vm)
sync_global_to_guest(vm, ucall_exit_mmio_addr);
 }
 
-static void ucall_pio_exit(struct ucall *uc)
+static void ucall_default_exit(struct ucall *uc)
 {
-#ifdef __x86_64__
+#if defined(__x86_64__)
+   /* Exit via PIO */
asm volatile("in %[port], %%al"
: : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax");
+#elif defined(__s390x__)
+   /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
+   asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory");
+#else
+   fprintf(stderr, "No default ucall available on this architecture.\n");
+   exit(1);
 #endif
 }
 
@@ -113,8 +120,8 @@ void ucall(uint64_t cmd, int nargs, ...)
va_end(va);
 
switch (ucall_type) {
-   case UCALL_PIO:
-   ucall_pio_exit();
+   case UCALL_DEFAULT:
+   ucall_default_exit();
break;
case UCALL_MMIO:
ucall_mmio_exit();
@@ -128,15 +135,28 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, 
struct ucall *uc)
struct ucall ucall = {};
bool got_ucall = false;
 
-#ifdef __x86_64__
-   if (ucall_type == UCALL_PIO && run->exit_reason == KVM_EXIT_IO &&
+#if defined(__x86_64__)
+   if (ucall_type == UCALL_DEFAULT && run->exit_reason == KVM_EXIT_IO &&
run->io.port == UCALL_PIO_PORT) {
struct kvm_regs regs;
vcpu_regs_get(vm, vcpu_id, );
memcpy(, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), 
sizeof(ucall));
got_ucall = true;
}
+#elif defined(__s390x__)
+   if (ucall_type == UCALL_DEFAULT &&
+   run->exit_reason == KVM_EXIT_S390_SIEIC &&
+   run->s390_sieic.icptcode == 4 &&
+   (run->s390_sieic.ipa >> 8) == 0x83 &&/* 0x83 means DIAGNOSE */
+   (run->s390_sieic.ipb >> 16) == 0x501) {
+   int reg = run->s390_sieic.ipa & 0xf;
+
+   memcpy(, addr_gva2hva(vm, run->s.regs.gprs[reg]),
+  sizeof(ucall));
+   got_ucall = true;
+   }
 #endif
+
if (ucall_type == UCALL_MMIO && run->exit_reason == KVM_EXIT_MMIO &&
run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) {
vm_vaddr_t gva;
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c 
b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index e85ff0d69548..bbc93094519b 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -25,9 +25,11 @@
 
 static void guest_code(void)
 {
+   register u64 stage asm("11") = 0;
+
for (;;) {
-   asm volatile ("diag 0,0,0x501");
-   asm volatile ("ahi 11,1");
+   GUEST_SYNC(0);
+   asm volatile ("ahi %0,1" : : "r"(stage));
}
 }
 
-- 
2.21.0