* Re: [PATCH] PPC: KVM: fix VCPU run for HV KVM
@ 2014-02-04 8:03 ` Alexey Kardashevskiy
0 siblings, 0 replies; 12+ messages in thread
From: Alexey Kardashevskiy @ 2014-02-04 8:03 UTC (permalink / raw)
To: Alexander Graf
Cc: linuxppc-dev, Paul Mackerras, kvm-ppc,
kvm@vger.kernel.org mailing list,
linux-kernel@vger.kernel.org list
On 01/13/2014 02:44 AM, Alexander Graf wrote:
>
> On 10.01.2014, at 08:21, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>
>> When write to MMIO happens and there is an ioeventfd for that and
>> is handled successfully, ioeventfd_write() returns 0 (success) and
>> kvmppc_handle_store() returns EMULATE_DONE. Then kvmppc_emulate_mmio()
>> converts EMULATE_DONE to RESUME_GUEST_NV and this broke from the loop.
>>
>> This adds handling of RESUME_GUEST_NV in kvmppc_vcpu_run_hv().
>>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Suggested-by: Paul Mackerras <paulus@samba.org>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>
>> This definitely needs a better commit message. Please, help.
>> ps. it seems like ioeventfd never worked on ppc64. hm.
>>
>> ---
>> arch/powerpc/kvm/book3s_hv.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 072287f..24f363f 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -1569,7 +1569,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
>> vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
>> srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
>> }
>> - } while (r == RESUME_GUEST);
>> + } while ((r == RESUME_GUEST_NV) || (r == RESUME_GUEST));
>
> How about
>
> while(!(r & RESUME_FLAG_HOST));
Rather "while(!(r & RESUME_FLAG_HOST) && (r > 0));" and still not obvious
that this is really better.
Paul agrees with the original patch (and made a better commit message for
our internal tree) but I just cannot make him reply in this thread, keep
constantly asking him but to no avail :)
> That should cover all RESUME_GUEST_XXX cases just fine. Apart from that
> I agree that we should check for ! FLAG_HOST bit rather than the actual
> RESUME_GUEST value in all case where we check for it (read: please
> update all places).
There are 3 places remotely similar to this and none of them requires a fix
like above.
--
Alexey
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PPC: KVM: fix VCPU run for HV KVM
@ 2014-02-04 8:03 ` Alexey Kardashevskiy
0 siblings, 0 replies; 12+ messages in thread
From: Alexey Kardashevskiy @ 2014-02-04 8:03 UTC (permalink / raw)
To: Alexander Graf
Cc: Paul Mackerras, linuxppc-dev, kvm@vger.kernel.org mailing list,
kvm-ppc, linux-kernel@vger.kernel.org list
On 01/13/2014 02:44 AM, Alexander Graf wrote:
>
> On 10.01.2014, at 08:21, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>
>> When write to MMIO happens and there is an ioeventfd for that and
>> is handled successfully, ioeventfd_write() returns 0 (success) and
>> kvmppc_handle_store() returns EMULATE_DONE. Then kvmppc_emulate_mmio()
>> converts EMULATE_DONE to RESUME_GUEST_NV and this broke from the loop.
>>
>> This adds handling of RESUME_GUEST_NV in kvmppc_vcpu_run_hv().
>>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Suggested-by: Paul Mackerras <paulus@samba.org>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>
>> This definitely needs a better commit message. Please, help.
>> ps. it seems like ioeventfd never worked on ppc64. hm.
>>
>> ---
>> arch/powerpc/kvm/book3s_hv.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>> index 072287f..24f363f 100644
>> --- a/arch/powerpc/kvm/book3s_hv.c
>> +++ b/arch/powerpc/kvm/book3s_hv.c
>> @@ -1569,7 +1569,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
>> vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
>> srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
>> }
>> - } while (r == RESUME_GUEST);
>> + } while ((r == RESUME_GUEST_NV) || (r == RESUME_GUEST));
>
> How about
>
> while(!(r & RESUME_FLAG_HOST));
Rather "while(!(r & RESUME_FLAG_HOST) && (r > 0));" and still not obvious
that this is really better.
Paul agrees with the original patch (and made a better commit message for
our internal tree) but I just cannot make him reply in this thread, keep
constantly asking him but to no avail :)
> That should cover all RESUME_GUEST_XXX cases just fine. Apart from that
> I agree that we should check for ! FLAG_HOST bit rather than the actual
> RESUME_GUEST value in all case where we check for it (read: please
> update all places).
There are 3 places remotely similar to this and none of them requires a fix
like above.
--
Alexey
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] PPC: KVM: fix VCPU run for HV KVM
2014-02-04 8:03 ` Alexey Kardashevskiy
(?)
@ 2014-02-04 8:09 ` Alexander Graf
-1 siblings, 0 replies; 12+ messages in thread
From: Alexander Graf @ 2014-02-04 8:09 UTC (permalink / raw)
To: Alexey Kardashevskiy
Cc: linuxppc-dev, Paul Mackerras, kvm-ppc,
kvm@vger.kernel.org mailing list,
linux-kernel@vger.kernel.org list
On 04.02.2014, at 09:03, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> On 01/13/2014 02:44 AM, Alexander Graf wrote:
>>
>> On 10.01.2014, at 08:21, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>
>>> When write to MMIO happens and there is an ioeventfd for that and
>>> is handled successfully, ioeventfd_write() returns 0 (success) and
>>> kvmppc_handle_store() returns EMULATE_DONE. Then kvmppc_emulate_mmio()
>>> converts EMULATE_DONE to RESUME_GUEST_NV and this broke from the loop.
>>>
>>> This adds handling of RESUME_GUEST_NV in kvmppc_vcpu_run_hv().
>>>
>>> Cc: Michael S. Tsirkin <mst@redhat.com>
>>> Suggested-by: Paul Mackerras <paulus@samba.org>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>> ---
>>>
>>> This definitely needs a better commit message. Please, help.
>>> ps. it seems like ioeventfd never worked on ppc64. hm.
>>>
>>> ---
>>> arch/powerpc/kvm/book3s_hv.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>>> index 072287f..24f363f 100644
>>> --- a/arch/powerpc/kvm/book3s_hv.c
>>> +++ b/arch/powerpc/kvm/book3s_hv.c
>>> @@ -1569,7 +1569,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
>>> vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
>>> srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
>>> }
>>> - } while (r = RESUME_GUEST);
>>> + } while ((r = RESUME_GUEST_NV) || (r = RESUME_GUEST));
>>
>> How about
>>
>> while(!(r & RESUME_FLAG_HOST));
>
>
> Rather "while(!(r & RESUME_FLAG_HOST) && (r > 0));" and still not obvious
> that this is really better.
>
> Paul agrees with the original patch (and made a better commit message for
> our internal tree) but I just cannot make him reply in this thread, keep
> constantly asking him but to no avail :)
>
>
>> That should cover all RESUME_GUEST_XXX cases just fine. Apart from that
>> I agree that we should check for ! FLAG_HOST bit rather than the actual
>> RESUME_GUEST value in all case where we check for it (read: please
>> update all places).
>
> There are 3 places remotely similar to this and none of them requires a fix
> like above.
Not today. Then someone goes in and realizes that CEDE advanced version 8 should clear r15 at which point you have to set RESUME_GUEST_NV and are in the same mess again. Let's just always treat RESUME_GUEST_NV and RESUME_GUEST as identical when checking for it.
If you like, add a small helper like
static inline bool is_resume_guest(int r) {
return (r = RESUME_GUEST || r = RESUME_GUEST_NV);
}
in a header and use that one instead. That way we're guaranteed to be consistent.
Alex
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH] PPC: KVM: fix VCPU run for HV KVM
@ 2014-02-04 8:09 ` Alexander Graf
0 siblings, 0 replies; 12+ messages in thread
From: Alexander Graf @ 2014-02-04 8:09 UTC (permalink / raw)
To: Alexey Kardashevskiy
Cc: linuxppc-dev, Paul Mackerras, kvm-ppc,
kvm@vger.kernel.org mailing list,
linux-kernel@vger.kernel.org list
On 04.02.2014, at 09:03, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> On 01/13/2014 02:44 AM, Alexander Graf wrote:
>>
>> On 10.01.2014, at 08:21, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>
>>> When write to MMIO happens and there is an ioeventfd for that and
>>> is handled successfully, ioeventfd_write() returns 0 (success) and
>>> kvmppc_handle_store() returns EMULATE_DONE. Then kvmppc_emulate_mmio()
>>> converts EMULATE_DONE to RESUME_GUEST_NV and this broke from the loop.
>>>
>>> This adds handling of RESUME_GUEST_NV in kvmppc_vcpu_run_hv().
>>>
>>> Cc: Michael S. Tsirkin <mst@redhat.com>
>>> Suggested-by: Paul Mackerras <paulus@samba.org>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>> ---
>>>
>>> This definitely needs a better commit message. Please, help.
>>> ps. it seems like ioeventfd never worked on ppc64. hm.
>>>
>>> ---
>>> arch/powerpc/kvm/book3s_hv.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
>>> index 072287f..24f363f 100644
>>> --- a/arch/powerpc/kvm/book3s_hv.c
>>> +++ b/arch/powerpc/kvm/book3s_hv.c
>>> @@ -1569,7 +1569,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
>>> vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
>>> srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
>>> }
>>> - } while (r == RESUME_GUEST);
>>> + } while ((r == RESUME_GUEST_NV) || (r == RESUME_GUEST));
>>
>> How about
>>
>> while(!(r & RESUME_FLAG_HOST));
>
>
> Rather "while(!(r & RESUME_FLAG_HOST) && (r > 0));" and still not obvious
> that this is really better.
>
> Paul agrees with the original patch (and made a better commit message for
> our internal tree) but I just cannot make him reply in this thread, keep
> constantly asking him but to no avail :)
>
>
>> That should cover all RESUME_GUEST_XXX cases just fine. Apart from that
>> I agree that we should check for ! FLAG_HOST bit rather than the actual
>> RESUME_GUEST value in all case where we check for it (read: please
>> update all places).
>
> There are 3 places remotely similar to this and none of them requires a fix
> like above.
Not today. Then someone goes in and realizes that CEDE advanced version 8 should clear r15 at which point you have to set RESUME_GUEST_NV and are in the same mess again. Let's just always treat RESUME_GUEST_NV and RESUME_GUEST as identical when checking for it.
If you like, add a small helper like
static inline bool is_resume_guest(int r) {
return (r == RESUME_GUEST || r == RESUME_GUEST_NV);
}
in a header and use that one instead. That way we're guaranteed to be consistent.
Alex
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH] PPC: KVM: fix VCPU run for HV KVM
@ 2014-02-04 8:09 ` Alexander Graf
0 siblings, 0 replies; 12+ messages in thread
From: Alexander Graf @ 2014-02-04 8:09 UTC (permalink / raw)
To: Alexey Kardashevskiy
Cc: Paul Mackerras, linuxppc-dev, kvm@vger.kernel.org mailing list,
kvm-ppc, linux-kernel@vger.kernel.org list
On 04.02.2014, at 09:03, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> On 01/13/2014 02:44 AM, Alexander Graf wrote:
>>=20
>> On 10.01.2014, at 08:21, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>=20
>>> When write to MMIO happens and there is an ioeventfd for that and
>>> is handled successfully, ioeventfd_write() returns 0 (success) and
>>> kvmppc_handle_store() returns EMULATE_DONE. Then =
kvmppc_emulate_mmio()
>>> converts EMULATE_DONE to RESUME_GUEST_NV and this broke from the =
loop.
>>>=20
>>> This adds handling of RESUME_GUEST_NV in kvmppc_vcpu_run_hv().
>>>=20
>>> Cc: Michael S. Tsirkin <mst@redhat.com>
>>> Suggested-by: Paul Mackerras <paulus@samba.org>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>> ---
>>>=20
>>> This definitely needs a better commit message. Please, help.
>>> ps. it seems like ioeventfd never worked on ppc64. hm.
>>>=20
>>> ---
>>> arch/powerpc/kvm/book3s_hv.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>=20
>>> diff --git a/arch/powerpc/kvm/book3s_hv.c =
b/arch/powerpc/kvm/book3s_hv.c
>>> index 072287f..24f363f 100644
>>> --- a/arch/powerpc/kvm/book3s_hv.c
>>> +++ b/arch/powerpc/kvm/book3s_hv.c
>>> @@ -1569,7 +1569,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_run =
*run, struct kvm_vcpu *vcpu)
>>> vcpu->arch.fault_dar, =
vcpu->arch.fault_dsisr);
>>> srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
>>> }
>>> - } while (r =3D=3D RESUME_GUEST);
>>> + } while ((r =3D=3D RESUME_GUEST_NV) || (r =3D=3D RESUME_GUEST));
>>=20
>> How about
>>=20
>> while(!(r & RESUME_FLAG_HOST));
>=20
>=20
> Rather "while(!(r & RESUME_FLAG_HOST) && (r > 0));" and still not =
obvious
> that this is really better.
>=20
> Paul agrees with the original patch (and made a better commit message =
for
> our internal tree) but I just cannot make him reply in this thread, =
keep
> constantly asking him but to no avail :)
>=20
>=20
>> That should cover all RESUME_GUEST_XXX cases just fine. Apart from =
that
>> I agree that we should check for ! FLAG_HOST bit rather than the =
actual
>> RESUME_GUEST value in all case where we check for it (read: please
>> update all places).
>=20
> There are 3 places remotely similar to this and none of them requires =
a fix
> like above.
Not today. Then someone goes in and realizes that CEDE advanced version =
8 should clear r15 at which point you have to set RESUME_GUEST_NV and =
are in the same mess again. Let's just always treat RESUME_GUEST_NV and =
RESUME_GUEST as identical when checking for it.
If you like, add a small helper like
static inline bool is_resume_guest(int r) {
return (r =3D=3D RESUME_GUEST || r =3D=3D RESUME_GUEST_NV);
}
in a header and use that one instead. That way we're guaranteed to be =
consistent.
Alex
^ permalink raw reply [flat|nested] 12+ messages in thread