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From: Fabiano Rosas <farosas@linux.ibm.com>
To: Alexey Kardashevskiy <aik@ozlabs.ru>, kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, npiggin@gmail.com
Subject: Re: [PATCH v2 6/7] KVM: PPC: mmio: Return to guest after emulation failure
Date: Fri, 07 Jan 2022 13:07:47 +0000	[thread overview]
Message-ID: <87a6g73d98.fsf@linux.ibm.com> (raw)
In-Reply-To: <63f9a19c-0b5c-8746-7ef4-ab72cbda397c@ozlabs.ru>

Alexey Kardashevskiy <aik@ozlabs.ru> writes:

> On 07/01/2022 07:03, Fabiano Rosas wrote:
>> If MMIO emulation fails we don't want to crash the whole guest by
>> returning to userspace.
>> 
>> The original commit bbf45ba57eae ("KVM: ppc: PowerPC 440 KVM
>> implementation") added a todo:
>> 
>>    /* XXX Deliver Program interrupt to guest. */
>> 
>> and later the commit d69614a295ae ("KVM: PPC: Separate loadstore
>> emulation from priv emulation") added the Program interrupt injection
>> but in another file, so I'm assuming it was missed that this block
>> needed to be altered.
>> 
>> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
>
>
> Looks right.
> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>
> but this means if I want to keep debugging those kvm selftests in 
> comfort, I'll have to have some exception handlers in the vm as 
> otherwise the failing $pc is lost after this change :)

Yes! But that will be a problem for any test. These kinds of issues is
why I wanted a trial period before sending the test infrastructure
upstream. Maybe we don't need exception handlers, but just a way to
force the test to crash if it tries to fetch from 0x700.

WARNING: multiple messages have this Message-ID (diff)
From: Fabiano Rosas <farosas@linux.ibm.com>
To: Alexey Kardashevskiy <aik@ozlabs.ru>, kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, npiggin@gmail.com
Subject: Re: [PATCH v2 6/7] KVM: PPC: mmio: Return to guest after emulation failure
Date: Fri, 07 Jan 2022 10:07:47 -0300	[thread overview]
Message-ID: <87a6g73d98.fsf@linux.ibm.com> (raw)
In-Reply-To: <63f9a19c-0b5c-8746-7ef4-ab72cbda397c@ozlabs.ru>

Alexey Kardashevskiy <aik@ozlabs.ru> writes:

> On 07/01/2022 07:03, Fabiano Rosas wrote:
>> If MMIO emulation fails we don't want to crash the whole guest by
>> returning to userspace.
>> 
>> The original commit bbf45ba57eae ("KVM: ppc: PowerPC 440 KVM
>> implementation") added a todo:
>> 
>>    /* XXX Deliver Program interrupt to guest. */
>> 
>> and later the commit d69614a295ae ("KVM: PPC: Separate loadstore
>> emulation from priv emulation") added the Program interrupt injection
>> but in another file, so I'm assuming it was missed that this block
>> needed to be altered.
>> 
>> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
>
>
> Looks right.
> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>
> but this means if I want to keep debugging those kvm selftests in 
> comfort, I'll have to have some exception handlers in the vm as 
> otherwise the failing $pc is lost after this change :)

Yes! But that will be a problem for any test. These kinds of issues is
why I wanted a trial period before sending the test infrastructure
upstream. Maybe we don't need exception handlers, but just a way to
force the test to crash if it tries to fetch from 0x700.

  reply	other threads:[~2022-01-07 13:07 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-06 20:02 [PATCH v2 0/7] KVM: PPC: MMIO fixes Fabiano Rosas
2022-01-06 20:02 ` Fabiano Rosas
2022-01-06 20:02 ` [PATCH v2 1/7] KVM: PPC: Book3S HV: Stop returning internal values to userspace Fabiano Rosas
2022-01-06 20:02   ` Fabiano Rosas
2022-01-06 20:02 ` [PATCH v2 2/7] KVM: PPC: Fix vmx/vsx mixup in mmio emulation Fabiano Rosas
2022-01-06 20:02   ` Fabiano Rosas
2022-01-06 20:03 ` [PATCH v2 3/7] KVM: PPC: Fix mmio length message Fabiano Rosas
2022-01-06 20:03   ` Fabiano Rosas
2022-01-07  0:19   ` Alexey Kardashevskiy
2022-01-07  0:19     ` Alexey Kardashevskiy
2022-01-06 20:03 ` [PATCH v2 4/7] KVM: PPC: Don't use pr_emerg when mmio emulation fails Fabiano Rosas
2022-01-06 20:03   ` Fabiano Rosas
2022-01-06 20:03 ` [PATCH v2 5/7] KVM: PPC: mmio: Queue interrupt at kvmppc_emulate_mmio Fabiano Rosas
2022-01-06 20:03   ` Fabiano Rosas
2022-01-07  0:24   ` Alexey Kardashevskiy
2022-01-07  0:24     ` Alexey Kardashevskiy
2022-01-06 20:03 ` [PATCH v2 6/7] KVM: PPC: mmio: Return to guest after emulation failure Fabiano Rosas
2022-01-06 20:03   ` Fabiano Rosas
2022-01-07  1:08   ` Alexey Kardashevskiy
2022-01-07  1:08     ` Alexey Kardashevskiy
2022-01-07 13:07     ` Fabiano Rosas [this message]
2022-01-07 13:07       ` Fabiano Rosas
2022-01-06 20:03 ` [PATCH v2 7/7] KVM: PPC: mmio: Reject instructions that access more than mmio.data size Fabiano Rosas
2022-01-06 20:03   ` Fabiano Rosas
2022-01-07  0:30   ` Alexey Kardashevskiy
2022-01-07  0:30     ` Alexey Kardashevskiy

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