diff mbox series

[kvm-unit-tests,2/2] arm/run: Fix using qemu-system-aarch64 to run aarch32 tests on aarch64

Message ID 20220309162117.56681-3-alexandru.elisei@arm.com (mailing list archive)
State New, archived
Headers show
Series arm: 32 bit tests improvements | expand

Commit Message

Alexandru Elisei March 9, 2022, 4:21 p.m. UTC 
From: Andrew Jones <drjones@redhat.com>

KVM on arm64 can create 32 bit and 64 bit VMs. kvm-unit-tests tries to
take advantage of this by setting the aarch64=off -cpu option. However,
get_qemu_accelerator() isn't aware that KVM on arm64 can run both types
of VMs and it selects qemu-system-arm instead of qemu-system-aarch64.
This leads to an error in premature_failure() and the test is marked as
skipped:

$ ./run_tests.sh selftest-setup
SKIP selftest-setup (qemu-system-arm: -accel kvm: invalid accelerator kvm)

Fix this by setting QEMU to the correct qemu binary before calling
get_qemu_accelerator().

Signed-off-by: Andrew Jones <drjones@redhat.com>
[ Alex E: Added commit message, changed the logic to make it clearer ]
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 arm/run | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Andrew Jones March 9, 2022, 4:58 p.m. UTC | #1 
On Wed, Mar 09, 2022 at 04:21:17PM +0000, Alexandru Elisei wrote:
> From: Andrew Jones <drjones@redhat.com>
> 
> KVM on arm64 can create 32 bit and 64 bit VMs. kvm-unit-tests tries to
> take advantage of this by setting the aarch64=off -cpu option. However,
> get_qemu_accelerator() isn't aware that KVM on arm64 can run both types
> of VMs and it selects qemu-system-arm instead of qemu-system-aarch64.
> This leads to an error in premature_failure() and the test is marked as
> skipped:
> 
> $ ./run_tests.sh selftest-setup
> SKIP selftest-setup (qemu-system-arm: -accel kvm: invalid accelerator kvm)
> 
> Fix this by setting QEMU to the correct qemu binary before calling
> get_qemu_accelerator().
> 
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> [ Alex E: Added commit message, changed the logic to make it clearer ]
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
>  arm/run | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arm/run b/arm/run
> index 2153bd320751..5fe0a45c4820 100755
> --- a/arm/run
> +++ b/arm/run
> @@ -13,6 +13,11 @@ processor="$PROCESSOR"
>  ACCEL=$(get_qemu_accelerator) ||
>  	exit $?
>  
> +# KVM for arm64 can create a VM in either aarch32 or aarch64 modes.
> +if [ "$ACCEL" = kvm ] && [ -z "$QEMU" ] && [ "$HOST" = "aarch64" ]; then
> +	QEMU=qemu-system-aarch64
> +fi
> +
>  qemu=$(search_qemu_binary) ||
>  	exit $?
>  
> -- 
> 2.35.1
>

So there's a bug with this patch which was also present in the patch I
proposed. By setting $QEMU before we call search_qemu_binary() we may
force a "A QEMU binary was not found." failure even though a perfectly
good 'qemu-kvm' binary is present.

I'll try to come up with something better.

Thanks,
drew
Alexandru Elisei March 9, 2022, 5:12 p.m. UTC | #2 
Hi,

On Wed, Mar 09, 2022 at 05:58:12PM +0100, Andrew Jones wrote:
> On Wed, Mar 09, 2022 at 04:21:17PM +0000, Alexandru Elisei wrote:
> > From: Andrew Jones <drjones@redhat.com>
> > 
> > KVM on arm64 can create 32 bit and 64 bit VMs. kvm-unit-tests tries to
> > take advantage of this by setting the aarch64=off -cpu option. However,
> > get_qemu_accelerator() isn't aware that KVM on arm64 can run both types
> > of VMs and it selects qemu-system-arm instead of qemu-system-aarch64.
> > This leads to an error in premature_failure() and the test is marked as
> > skipped:
> > 
> > $ ./run_tests.sh selftest-setup
> > SKIP selftest-setup (qemu-system-arm: -accel kvm: invalid accelerator kvm)
> > 
> > Fix this by setting QEMU to the correct qemu binary before calling
> > get_qemu_accelerator().
> > 
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > [ Alex E: Added commit message, changed the logic to make it clearer ]
> > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > ---
> >  arm/run | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/arm/run b/arm/run
> > index 2153bd320751..5fe0a45c4820 100755
> > --- a/arm/run
> > +++ b/arm/run
> > @@ -13,6 +13,11 @@ processor="$PROCESSOR"
> >  ACCEL=$(get_qemu_accelerator) ||
> >  	exit $?
> >  
> > +# KVM for arm64 can create a VM in either aarch32 or aarch64 modes.
> > +if [ "$ACCEL" = kvm ] && [ -z "$QEMU" ] && [ "$HOST" = "aarch64" ]; then
> > +	QEMU=qemu-system-aarch64
> > +fi
> > +
> >  qemu=$(search_qemu_binary) ||
> >  	exit $?
> >  
> > -- 
> > 2.35.1
> >
> 
> So there's a bug with this patch which was also present in the patch I
> proposed. By setting $QEMU before we call search_qemu_binary() we may
> force a "A QEMU binary was not found." failure even though a perfectly
> good 'qemu-kvm' binary is present.

I noticed that search_qemu_binary() tries to search for both
qemu-system-ARCH_NAME and qemu-kvm, and I first thought that qemu-kvm is a
legacy name for qemu-system-ARCH_NAME.

I just did some googling, and I think it's actually how certain distros (like
SLES) package qemu-system-ARCH_NAME, is that correct?

If that is so, one idea I toyed with (for something else) is to move the error
messages from search_qemu_binary() to the call sites, that way arm/run can first
try to find qemu-system-aarch64, then fallback to qemu-kvm, and only after both
aren't found exit with an error. Just a suggestion, in case you find it useful.

Thanks,
Alex

> 
> I'll try to come up with something better.
> 
> Thanks,
> drew
>
Andrew Jones March 10, 2022, 6:59 a.m. UTC | #3 
On Wed, Mar 09, 2022 at 05:12:05PM +0000, Alexandru Elisei wrote:
> Hi,
> 
> On Wed, Mar 09, 2022 at 05:58:12PM +0100, Andrew Jones wrote:
> > On Wed, Mar 09, 2022 at 04:21:17PM +0000, Alexandru Elisei wrote:
> > > From: Andrew Jones <drjones@redhat.com>
> > > 
> > > KVM on arm64 can create 32 bit and 64 bit VMs. kvm-unit-tests tries to
> > > take advantage of this by setting the aarch64=off -cpu option. However,
> > > get_qemu_accelerator() isn't aware that KVM on arm64 can run both types
> > > of VMs and it selects qemu-system-arm instead of qemu-system-aarch64.
> > > This leads to an error in premature_failure() and the test is marked as
> > > skipped:
> > > 
> > > $ ./run_tests.sh selftest-setup
> > > SKIP selftest-setup (qemu-system-arm: -accel kvm: invalid accelerator kvm)
> > > 
> > > Fix this by setting QEMU to the correct qemu binary before calling
> > > get_qemu_accelerator().
> > > 
> > > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > > [ Alex E: Added commit message, changed the logic to make it clearer ]
> > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > > ---
> > >  arm/run | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > > 
> > > diff --git a/arm/run b/arm/run
> > > index 2153bd320751..5fe0a45c4820 100755
> > > --- a/arm/run
> > > +++ b/arm/run
> > > @@ -13,6 +13,11 @@ processor="$PROCESSOR"
> > >  ACCEL=$(get_qemu_accelerator) ||
> > >  	exit $?
> > >  
> > > +# KVM for arm64 can create a VM in either aarch32 or aarch64 modes.
> > > +if [ "$ACCEL" = kvm ] && [ -z "$QEMU" ] && [ "$HOST" = "aarch64" ]; then
> > > +	QEMU=qemu-system-aarch64
> > > +fi
> > > +
> > >  qemu=$(search_qemu_binary) ||
> > >  	exit $?
> > >  
> > > -- 
> > > 2.35.1
> > >
> > 
> > So there's a bug with this patch which was also present in the patch I
> > proposed. By setting $QEMU before we call search_qemu_binary() we may
> > force a "A QEMU binary was not found." failure even though a perfectly
> > good 'qemu-kvm' binary is present.
> 
> I noticed that search_qemu_binary() tries to search for both
> qemu-system-ARCH_NAME and qemu-kvm, and I first thought that qemu-kvm is a
> legacy name for qemu-system-ARCH_NAME.
> 
> I just did some googling, and I think it's actually how certain distros (like
> SLES) package qemu-system-ARCH_NAME, is that correct?

Right

> 
> If that is so, one idea I toyed with (for something else) is to move the error
> messages from search_qemu_binary() to the call sites, that way arm/run can first
> try to find qemu-system-aarch64, then fallback to qemu-kvm, and only after both
> aren't found exit with an error. Just a suggestion, in case you find it useful.

We don't have to move the error messages, even if we want to use
search_qemu_binary() as a silent check. We can just call it with
a &>/dev/null and then check its return code. I still need to
allocate some time to think more about this though.

Thanks,
drew
Alexandru Elisei March 10, 2022, 9:28 a.m. UTC | #4 
Hi,

On Thu, Mar 10, 2022 at 07:59:41AM +0100, Andrew Jones wrote:
> On Wed, Mar 09, 2022 at 05:12:05PM +0000, Alexandru Elisei wrote:
> > Hi,
> > 
> > On Wed, Mar 09, 2022 at 05:58:12PM +0100, Andrew Jones wrote:
> > > On Wed, Mar 09, 2022 at 04:21:17PM +0000, Alexandru Elisei wrote:
> > > > From: Andrew Jones <drjones@redhat.com>
> > > > 
> > > > KVM on arm64 can create 32 bit and 64 bit VMs. kvm-unit-tests tries to
> > > > take advantage of this by setting the aarch64=off -cpu option. However,
> > > > get_qemu_accelerator() isn't aware that KVM on arm64 can run both types
> > > > of VMs and it selects qemu-system-arm instead of qemu-system-aarch64.
> > > > This leads to an error in premature_failure() and the test is marked as
> > > > skipped:
> > > > 
> > > > $ ./run_tests.sh selftest-setup
> > > > SKIP selftest-setup (qemu-system-arm: -accel kvm: invalid accelerator kvm)
> > > > 
> > > > Fix this by setting QEMU to the correct qemu binary before calling
> > > > get_qemu_accelerator().
> > > > 
> > > > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > > > [ Alex E: Added commit message, changed the logic to make it clearer ]
> > > > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > > > ---
> > > >  arm/run | 5 +++++
> > > >  1 file changed, 5 insertions(+)
> > > > 
> > > > diff --git a/arm/run b/arm/run
> > > > index 2153bd320751..5fe0a45c4820 100755
> > > > --- a/arm/run
> > > > +++ b/arm/run
> > > > @@ -13,6 +13,11 @@ processor="$PROCESSOR"
> > > >  ACCEL=$(get_qemu_accelerator) ||
> > > >  	exit $?
> > > >  
> > > > +# KVM for arm64 can create a VM in either aarch32 or aarch64 modes.
> > > > +if [ "$ACCEL" = kvm ] && [ -z "$QEMU" ] && [ "$HOST" = "aarch64" ]; then
> > > > +	QEMU=qemu-system-aarch64
> > > > +fi
> > > > +
> > > >  qemu=$(search_qemu_binary) ||
> > > >  	exit $?
> > > >  
> > > > -- 
> > > > 2.35.1
> > > >
> > > 
> > > So there's a bug with this patch which was also present in the patch I
> > > proposed. By setting $QEMU before we call search_qemu_binary() we may
> > > force a "A QEMU binary was not found." failure even though a perfectly
> > > good 'qemu-kvm' binary is present.
> > 
> > I noticed that search_qemu_binary() tries to search for both
> > qemu-system-ARCH_NAME and qemu-kvm, and I first thought that qemu-kvm is a
> > legacy name for qemu-system-ARCH_NAME.
> > 
> > I just did some googling, and I think it's actually how certain distros (like
> > SLES) package qemu-system-ARCH_NAME, is that correct?
> 
> Right

Thanks for confirming it!

> 
> > 
> > If that is so, one idea I toyed with (for something else) is to move the error
> > messages from search_qemu_binary() to the call sites, that way arm/run can first
> > try to find qemu-system-aarch64, then fallback to qemu-kvm, and only after both
> > aren't found exit with an error. Just a suggestion, in case you find it useful.
> 
> We don't have to move the error messages, even if we want to use
> search_qemu_binary() as a silent check. We can just call it with
> a &>/dev/null and then check its return code. I still need to
> allocate some time to think more about this though.

Sure, I'll review and test whatever you come up with.

Thanks,
Alex

> 
> Thanks,
> drew
>
diff mbox series

Patch

diff --git a/arm/run b/arm/run
index 2153bd320751..5fe0a45c4820 100755
--- a/arm/run
+++ b/arm/run
@@ -13,6 +13,11 @@  processor="$PROCESSOR"
 ACCEL=$(get_qemu_accelerator) ||
 	exit $?
 
+# KVM for arm64 can create a VM in either aarch32 or aarch64 modes.
+if [ "$ACCEL" = kvm ] && [ -z "$QEMU" ] && [ "$HOST" = "aarch64" ]; then
+	QEMU=qemu-system-aarch64
+fi
+
 qemu=$(search_qemu_binary) ||
 	exit $?