From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shih-Wei Li <shihwei@cs.columbia.edu>
Subject: Re: [PATCH kvm-unit-tests 2/2] arm64: add micro-bench
Date: Tue, 4 Sep 2018 11:02:43 -0400
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Cc: Christoffer Dall <cdall@cs.columbia.edu>, kvm@vger.kernel.org,
 Marc Zyngier <marc.zyngier@arm.com>, Yury Norov <ynorov@caviumnetworks.com>,
 kvmarm@lists.cs.columbia.edu
To: Andrew Jones <drjones@redhat.com>
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I've tested patch v2 along with the fix in the switch case. The
performance numbers look sane on my seattle server.

Tested-by: Shih-Wei Li <shihwei@cs.columbia.edu>

Thanks,
Shih-Wei

On Mon, Sep 3, 2018 at 11:38 PM, Shih-Wei Li <shihwei@cs.columbia.edu> wrote:
> On Mon, Sep 3, 2018 at 12:31 PM, Andrew Jones <drjones@redhat.com> wrote:
>> On Mon, Sep 03, 2018 at 11:06:51AM -0400, Shih-Wei Li wrote:
>>> On Thu, Aug 30, 2018 at 10:17 AM, Andrew Jones <drjones@redhat.com> wrote:
>>> > +static bool test_init(void)
>>> > +{
>>> > +       int v = gic_init();
>>> > +
>>> > +       if (!v) {
>>> > +               printf("No supported gic present, skipping tests...\n");
>>> > +               return false;
>>> > +       }
>>> > +
>>> > +       if (nr_cpus < 2) {
>>> > +               printf("At least two cpus required, skipping tests...\n");
>>> > +               return false;
>>> > +       }
>>> > +
>>> > +       switch (v) {
>>> > +       case 2:
>>> > +               vgic_dist_base = gicv2_dist_base();
>>> > +               write_eoir = gicv2_write_eoir;
>>> > +       case 3:
>>> > +               vgic_dist_base = gicv3_dist_base();
>>> > +               write_eoir = gicv3_write_eoir;
>>> > +       }
>>>
>>> I think we'll need a "break" in the switch case body for gicv2 here
>>> otherwise it'll fall into the case body below and refer to the wrong
>>> symbols for gicv3.
>>>
>>> As I've tested on my seattle server hardware (with gicv2), this results
>>> to incorrect execution in mmio_read_vgic_exec and a crash in
>>> eoi_exec().
>>>
>>
>> Argh... Obviously my testing of this was pretty poor. You are certainly
>> right that I'm missing breaks in this switch. If you don't mind, please
>> add them, along with the fix in v2, to your local repo and test again.
>> I'll hold off on sending v3 until you've had a chance to test and review
>> more.
>>
>> Thanks,
>> drew
>
> I've added the break to the switch and it resolved the problems I
> mentioned earlier. I'll do more testing and reviewing, and will get
> back to you as soon as I can.
>
> Thanks for formalizing the new patch set for micro-test!
>
> Shih-Wei