Re: [PATCH 00/17] KVM: selftests: aarch64: Test userspace IRQ injection

From: Andrew Jones <drjones@redhat.com>
To: Ricardo Koller <ricarkol@google.com>
Cc: kvm@vger.kernel.org, maz@kernel.org,
	kvmarm@lists.cs.columbia.edu, eric.auger@redhat.com,
	alexandru.elisei@arm.com, Paolo Bonzini <pbonzini@redhat.com>,
	oupton@google.com, james.morse@arm.com, suzuki.poulose@arm.com,
	shuah@kernel.org, jingzhangos@google.com, pshier@google.com,
	rananta@google.com, reijiw@google.com
Subject: Re: [PATCH 00/17] KVM: selftests: aarch64: Test userspace IRQ injection
Date: Tue, 23 Nov 2021 15:25:24 +0100	[thread overview]
Message-ID: <20211123142524.4bjhdvw5pkx3g5ct@gator.home> (raw)
In-Reply-To: <20211109023906.1091208-1-ricarkol@google.com>

On Mon, Nov 08, 2021 at 06:38:49PM -0800, Ricardo Koller wrote:
> This series adds a new test, aarch64/vgic-irq, that validates the injection of
> different types of IRQs from userspace using various methods and configurations
> (when applicable):
> 
>     Intid        Method     |       |          Configuration
>                             |       |
>                IRQ_LINE     |       |
>     SGI        LEVEL_INFO   |       |
>     PPI    x   IRQFD        |   x   | level-sensitive  x  EOIR + DIR
>     SPI        ISPENDR      |       | edge-triggered      EOIR only
>     bogus      ISACTIVER    |       |
>                             |       |
> 
> vgic-irq is implemented by having a single vcpu started in any of the 4 (2x2)
> configurations above.  The guest then "asks" userspace to inject all intids of
> a given IRQ type using each applicable method via a GUEST_SYNC call.  The
> applicable methods and intids for a given configuration are specified in tables
> like this one:
> 
>     /* edge-triggered */
>     static struct kvm_inject_desc inject_edge_fns[] = {
>             /*                            sgi    ppi    spi */
>             { KVM_IRQ_LINE,               false, false, true },
>             { IRQFD,                      false, false, true },
>             { ISPENDR,                    true,  false, true },
>     };
> 
> Based on the (example) table above, a guest running in an edge-triggered
> configuration will try injecting SGIs and SPIs.  The specific methods are also
> given in the table, e.g.: SGIs are injected from userspace by writing into the
> ISPENDR register.
> 
> This test also adds some extra edge tests like: IRQ preemption, restoring
> active IRQs, trying to inject bogus intid's (e.g., above the configured KVM
> nr_irqs).
> 
> Note that vgic-irq is currently limited to a single vcpu, GICv3, and does not
> test the vITS (no MSIs).
> 
> - Commits 1-3 add some GICv3 library functions on the guest side, e.g.: set the
>   priority of an IRQ.
> - Commits 4-5 add some vGICv3 library functions on the userspace side, e.g.: a
>   wrapper for KVM_IRQ_LINE.
> - Commit 6 adds the basic version of this test: inject an SPI using
>   KVM_IRQ_LINE.
> - Commits 7-17 add other IRQs types, methods and configurations.
>

Hi Ricardo,

I didn't review this in detail, but it looks good and quite thorough. Out
of curiosity did thoroughness come from attempting to get coverage on KVM
code? I.e were you running some sort of code coverage tool on KVM with
these tests?

Unfortunately I probably won't have a chance to look much closer than the
scan I just did, so FWIW

For the series

Acked-by: Andrew Jones <drjones@redhat.com>

Thanks,
drew