From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: kvm@vger.kernel.org, jan.kiszka@web.de, agordeev@redhat.com,
drjones@redhat.com, pbonzini@redhat.com
Subject: Re: [kvm-unit-tests RFC PATCH 00/14] VT-d unit test
Date: Thu, 20 Oct 2016 13:08:59 +0200 [thread overview]
Message-ID: <20161020110858.GE8573@potion> (raw)
In-Reply-To: <20161020060551.GG15168@pxdev.xzpeter.org>
2016-10-20 14:05+0800, Peter Xu:
> On Wed, Oct 19, 2016 at 10:21:11PM +0200, Radim Krčmář wrote:
>> 2016-10-14 20:40+0800, Peter Xu:
>> > The problem is, there are many IOMMU error conditions which are
>> > very hard to be triggered in a real guest (IOMMU has merely no
>> > interface for guest user, and it's totally running in the background).
>>
>> I gracefully skipped most of VT-d error handling ... how many of those
>> errors are not a result of a misconfiguration?
>
> Do you mean the error handling codes in hw/i386/intel_iommu.c?
Yes, I meant the error codes that IOMMU will pass to the OS.
> IMHO
> most of those errors will be triggered only if there is bug in guest
> OS IOMMU driver.
We can't know what the OS wanted, so there are no OS bugs for us. :)
If an OS (mis)configures the device, then it should get an expected
error code -- these paths are rarely exercised, so unit tests for them
would be useful too. (Very low priority, though, so I don't expect that
anyone will every write them.)
> Here when I talked about error conditions, I mostly meant potential
> QEMU IOMMU bugs, not guest OS bugs (of course, AFAICT kvm-unit-tests
> are not for guest OS bugs). For example, there are still bugs in IOMMU
> IR, and some of the bugs can hardly be triggered by guest OS. In that
> case, we need this unit test to reproduce the bug, and re-run it to
> verify when I have a fix. Otherwise even if I fixed the bug one day, I
> can never reproduce it, nor can I know whether the fix works.
I see, thanks, this is a great goal for unit tests.
Btw. isn't this series already testing one fixed QEMU bug?
When I run this test with old QEMU (qemu-2.7.0-3.fc26), then I get this
output:
[...]
INTR: setup IRTE index 0
lib/pci.c:52: assert failed: dev && dev->inited && dev->msi_offset
STACK: 40344c 402fd1 400567 40028f
new QEMU works fine, so I assume that we should test it and not assert.
next prev parent reply other threads:[~2016-10-20 11:09 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-14 12:40 [kvm-unit-tests RFC PATCH 00/14] VT-d unit test Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 01/14] x86: vm: allow multiple init for vm setup Peter Xu
2016-10-20 8:17 ` Andrew Jones
2016-10-20 8:24 ` Peter Xu
2016-10-20 8:41 ` Andrew Jones
2016-10-20 8:55 ` Peter Xu
2016-10-20 9:39 ` Andrew Jones
2016-10-20 11:01 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 02/14] x86: smp: allow multiple init for smp setup Peter Xu
2016-10-19 20:23 ` Radim Krčmář
2016-10-20 1:27 ` Peter Xu
2016-10-20 8:20 ` Andrew Jones
2016-10-20 8:27 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 03/14] x86: intel-iommu: add vt-d init test Peter Xu
2016-10-20 9:30 ` Andrew Jones
2016-10-21 9:52 ` Peter Xu
2016-10-21 12:18 ` Andrew Jones
2016-10-24 6:36 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 04/14] pci: refactor init process to pci_dev_init() Peter Xu
2016-10-20 10:02 ` Andrew Jones
2016-10-24 7:00 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 05/14] page: add page alignment checker Peter Xu
2016-10-20 12:23 ` Andrew Jones
2016-10-20 12:30 ` Andrew Jones
2016-10-24 9:58 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 06/14] util: move MAX/MIN macro into util.h Peter Xu
2016-10-20 12:28 ` Andrew Jones
2016-10-24 10:02 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 07/14] vm/page: provide PGDIR_OFFSET() macro Peter Xu
2016-10-20 12:40 ` Andrew Jones
2016-10-14 12:40 ` [kvm-unit-tests PATCH 08/14] x86: pci: add pci_config_{read|write}[bw]() helpers Peter Xu
2016-10-20 12:43 ` Andrew Jones
2016-10-24 10:08 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 09/14] pci: provide pci_set_master() Peter Xu
2016-10-20 12:49 ` Andrew Jones
2016-10-24 10:11 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 10/14] pci: add bdf helpers Peter Xu
2016-10-20 12:55 ` Andrew Jones
2016-10-24 14:44 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 11/14] pci: edu: introduce pci-edu helpers Peter Xu
2016-10-20 13:19 ` Andrew Jones
2016-10-25 3:34 ` Peter Xu
2016-10-25 10:43 ` Andrew Jones
2016-10-25 11:33 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 12/14] x86: intel-iommu: add dmar test Peter Xu
2016-10-19 20:33 ` Radim Krčmář
2016-10-20 5:41 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 13/14] pci: add msi support for 32/64bit address Peter Xu
2016-10-20 13:30 ` Andrew Jones
2016-10-25 6:21 ` Peter Xu
2016-10-14 12:40 ` [kvm-unit-tests PATCH 14/14] x86: intel-iommu: add IR test Peter Xu
2016-10-20 13:45 ` Andrew Jones
2016-10-25 6:52 ` Peter Xu
2016-10-19 20:21 ` [kvm-unit-tests RFC PATCH 00/14] VT-d unit test Radim Krčmář
2016-10-20 6:05 ` Peter Xu
2016-10-20 11:08 ` Radim Krčmář [this message]
2016-10-20 11:23 ` Peter Xu
2016-10-20 11:28 ` Peter Xu
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