Re: [Qemu-devel] [PATCH] e1000e: Do not auto-clear ICR bits which aren't set in EIAC

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2018-05-22 09:00, Jan Kiszka wrote:
> On 2018-04-16 17:29, Peter Maydell wrote:
>> On 16 April 2018 at 16:25, Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>> On 2018-04-01 23:17, Jan Kiszka wrote:
>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>
>>>> The spec does not justify clearing of any E1000_ICR_OTHER_CAUSES when
>>>> E1000_ICR_OTHER is set in EIAC. In fact, removing this code fixes the
>>>> issue the Linux driver runs into since 4aea7a5c5e94 ("e1000e: Avoid
>>>> receiver overrun interrupt bursts") and was worked around by
>>>> 745d0bd3af99 ("e1000e: Remove Other from EIAC").
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>> ---
>>>>
>>>> This resolves the issue I reported on February 18 ("e1000e: MSI-X
>>>> problem with recent Linux drivers").
>>>>
>>>>  hw/net/e1000e_core.c | 4 ----
>>>>  1 file changed, 4 deletions(-)
>>>>
>>>> diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
>>>> index ecf9b15555..d38f025c0f 100644
>>>> --- a/hw/net/e1000e_core.c
>>>> +++ b/hw/net/e1000e_core.c
>>>> @@ -2022,10 +2022,6 @@ e1000e_msix_notify_one(E1000ECore *core, uint32_t cause, uint32_t int_cfg)
>>>>
>>>>      effective_eiac = core->mac[EIAC] & cause;
>>>>
>>>> -    if (effective_eiac == E1000_ICR_OTHER) {
>>>> -        effective_eiac |= E1000_ICR_OTHER_CAUSES;
>>>> -    }
>>>> -
>>>>      core->mac[ICR] &= ~effective_eiac;
>>>>
>>>>      if (!(core->mac[CTRL_EXT] & E1000_CTRL_EXT_IAME)) {
>>>>
>>>
>>> Ping for this - as well as https://patchwork.ozlabs.org/patch/895476.
>>>
>>> Given that q35 uses e1000e by default and many Linux kernel versions no
>>> longer work, this should likely go into upcoming and stable versions
>>
>> I'd rather not put it into 2.12 at this point in the release
>> cycle unless it's a regression from 2.11, I think.
> 
> Second ping - nothing hit the repo so far, nor did I receive feedback.
> 

And another ping. For both.

These days I had to help someone with a broken QEMU setup that failed
installing from network. It turned out that "modprobe e1000e IntMode=0"
was needed to workaround the issues my patches address.

Jan

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