From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33519) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fSoXJ-0004FB-8p for qemu-devel@nongnu.org; Tue, 12 Jun 2018 15:00:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fSoXG-0007u6-5x for qemu-devel@nongnu.org; Tue, 12 Jun 2018 15:00:57 -0400 Received: from mail-qt0-x243.google.com ([2607:f8b0:400d:c0d::243]:43450) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fSoXG-0007tw-0G for qemu-devel@nongnu.org; Tue, 12 Jun 2018 15:00:54 -0400 Received: by mail-qt0-x243.google.com with SMTP id y89-v6so23482qtd.10 for ; Tue, 12 Jun 2018 12:00:53 -0700 (PDT) Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= References: <267f42a5-b7ce-379e-ffd1-f2611393d2ff@web.de> <6730e270-9906-a43c-68b0-7a09a0743fa5@siemens.com> <7bb24572-0fc1-00de-3552-aca1111059ed@amsat.org> <63ee188e-0c66-ce7e-03b2-fd58e4da9116@siemens.com> <3a128f8d-46a3-591f-ee09-8c9a3f2401ea@amsat.org> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: Date: Tue, 12 Jun 2018 16:00:48 -0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH] e1000e: Do not auto-clear ICR bits which aren't set in EIAC List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka , Dmitry Fleytman , Jason Wang Cc: Peter Maydell , qemu-devel , Alexander Graf Cc'ing Jason who is also listed as co-maintainer: ./scripts/get_maintainer.pl -f hw/net/e1000e_core.c Dmitry Fleytman (maintainer:e1000e) Jason Wang (odd fixer:Network devices) On 06/12/2018 03:43 PM, Jan Kiszka wrote: > On 2018-06-12 20:38, Philippe Mathieu-Daudé wrote: >> On 06/12/2018 03:30 PM, Jan Kiszka wrote: >>> On 2018-06-12 20:11, Philippe Mathieu-Daudé wrote: >>>> Hi Jan, >>>> >>>> On 06/12/2018 02:22 PM, Jan Kiszka wrote: >>>>> 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 wrote: >>>>>>>> On 2018-04-01 23:17, Jan Kiszka wrote: >>>>>>>>> From: Jan Kiszka >>>>>>>>> >>>>>>>>> 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 >>>>>>>>> --- >>>>>>>>> >>>>>>>>> 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. >>>> >>>> What about the IMS register? It is set just after. >>>> >>>> Looking at b38636b8372, can you test this patch? >>>> >>>> -- >8 -- >>>> diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c >>>> index c93c4661ed..a484b68a5a 100644 >>>> --- a/hw/net/e1000e_core.c >>>> +++ b/hw/net/e1000e_core.c >>>> @@ -2022,13 +2022,13 @@ 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)) { >>>> + if (effective_eiac == E1000_ICR_OTHER) { >>>> + effective_eiac |= E1000_ICR_OTHER_CAUSES; >>>> + } >>>> + >>>> core->mac[IMS] &= ~effective_eiac; >>>> } >>>> } >>>> >>> >>> Before testing this: What would be the reasoning for this change? >> >> Not breaking the purpose of b38636b8372 :) > > I disagree on this expansion of bit 31 ("other causes"). I see no > indication in the spec that setting this bit for autoclear has more > impact than on the very same bit itself. Therefore I'm asking for a > reasoning - based on the spec. Interrupt Cause Registers Other bits in this register are the legacy indication of interrupts as the MDIC complete, management and link status change. There is a specific Other Cause bit that is set if one of these bits are set, this bit can be mapped to a specific MSI-X interrupt message. I spent half an hour reading the relevant parts of the spec and can't figure out, so I'll let the authors of b38636b8372 to review your patch. Regards, Phil.