On 09.07.2025 08:10, Chen, Jiqian wrote:
> On 2025/7/8 23:13, Jan Beulich wrote:
>> On 04.07.2025 09:08, Jiqian Chen wrote:
>>> @@ -193,6 +234,42 @@ static void cf_check mask_write(
>>> msi->mask = val;
>>> }
>>>
>>> +static int cf_check cleanup_msi(const struct pci_dev *pdev)
>>> +{
>>> + int rc;
>>> + unsigned int end;
>>> + struct vpci *vpci = pdev->vpci;
>>> + const unsigned int msi_pos = pdev->msi_pos;
>>> + const unsigned int ctrl = msi_control_reg(msi_pos);
>>> +
>>> + if ( !msi_pos || !vpci->msi )
>>> + return 0;
>>> +
>>> + if ( vpci->msi->masking )
>>> + end = msi_pending_bits_reg(msi_pos, vpci->msi->address64);
>>> + else
>>> + end = msi_mask_bits_reg(msi_pos, vpci->msi->address64) - 2;
>>
>> What's this "- 2" for? If there's no masking support, you want to cut off
>> _at_ the mask register, not 2 bytes ahead of it? Just like you cut off at
>> the pending bits register when there is masking support.
> "-2" here is to cut the reserved 2 bytes of Message Data if there is no
> masking support.
Hmm, init_msi() doesn't intercept Extended Message Data when present. I
think that's wrong there, leading to the oddity here. (Imo such use of
hard coded numbers would almost always want to be accompanied by a
comment.)
Jan
