[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v5 0/2] vfio/common: remove spurious tpm-crb-cmd misalignment
From: |
Eric Auger |
Subject: |
Re: [PATCH v5 0/2] vfio/common: remove spurious tpm-crb-cmd misalignment warning |
Date: |
Wed, 23 Nov 2022 09:16:05 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 |
Hi Michael,
On 11/23/22 07:34, Michael S. Tsirkin wrote:
> On Fri, May 06, 2022 at 03:25:08PM +0200, Eric Auger wrote:
>> The CRB command buffer currently is a RAM MemoryRegion and given
>> its base address alignment, it causes an error report on
>> vfio_listener_region_add(). This region could have been a RAM device
>> region, easing the detection of such safe situation but this option
>> was not well received.
> Eric could you point me at this discussion please?
> We are now asked to proliferate stuff like this into vdpa
> as well, this just doesn't scale. I'd like to see whether we
> can make it a RAM device region after all - was a patch
> like that posted?
The bulk of the discussion happened in
https://lore.kernel.org/all/20220208133842.112017-1-eric.auger@redhat.com/#r
See exchanges with Peter who was against turning the CRB cmd/response
buffer into a RAM device region at that time, hence the current workaround.
You will see there also discussions about the buffer size in
https://lore.kernel.org/all/eae7e6e6-2f56-c263-f1d2-19104201c8ec@redhat.com/
Thanks
Eric
>
>> So let's add a helper function that uses the
>> memory region owner type to detect the situation is safe wrt
>> the assignment. Other device types can be checked here if such kind
>> of problem occurs again.
>>
>> As TPM devices can be compiled out we need to introduce a stub
>> for TPM_IS_CRB.
>>
>> Best Regards
>>
>> Eric
>>
>> This series can be found at:
>> https://github.com/eauger/qemu/tree/tpm-crb-vfio-v5
>>
>> History:
>>
>> v4 -> v5:
>> - Add sysemu: tpm: Add a stub function for TPM_IS_CRB to fix
>> compilation error if CONFIG_TPM is unset
>>
>> Eric Auger (2):
>> sysemu: tpm: Add a stub function for TPM_IS_CRB
>> vfio/common: remove spurious tpm-crb-cmd misalignment warning
>>
>> hw/vfio/common.c | 27 ++++++++++++++++++++++++++-
>> hw/vfio/trace-events | 1 +
>> include/sysemu/tpm.h | 6 ++++++
>> 3 files changed, 33 insertions(+), 1 deletion(-)
>>
>> --
>> 2.35.1
>>
>>
>>