[v4] tests/migration-test: Allow testing older machine types

[PATCH v4 08/12] tests/qtest/migration: Specify the geometry of the bootsector

Posted by Fabiano Rosas 2 years, 3 months ago

We're about to enable the x86_64 tests to run with the q35 machine,
but that machine does not work with the program we use to dirty the
memory for the tests.

The issue is that QEMU needs to guess the geometry of the "disk" we
give to it and the guessed geometry doesn't pass the sanity checks
done by SeaBIOS. This causes SeaBIOS to interpret the geometry as if
needing a translation from LBA to CHS and SeaBIOS ends up miscomputing
the number of cylinders and aborting due to that.

The reason things work with the "pc" machine is that is uses ATA
instead of AHCI like q35 and SeaBIOS has an exception for ATA that
ends up skipping the sanity checks and ignoring translation
altogether.

Workaround this situation by specifying a geometry in the command
line.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/migration-test.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 43d0b83771..b45a389de8 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -757,7 +757,9 @@ static int test_migrate_start(QTestState **from, QTestState **to,
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
         memory_size = "150M";
         machine_alias = "pc";
-        arch_opts = g_strdup_printf("-drive file=%s,format=raw", bootpath);
+        arch_opts = g_strdup_printf(
+            "-drive if=none,id=d0,file=%s,format=raw "
+            "-device ide-hd,drive=d0,secs=1,cyls=1,heads=1", bootpath);
         start_address = X86_TEST_MEM_START;
         end_address = X86_TEST_MEM_END;
     } else if (g_str_equal(arch, "s390x")) {
-- 
2.35.3

Re: [PATCH v4 08/12] tests/qtest/migration: Specify the geometry of the bootsector

Posted by Juan Quintela 2 years, 3 months ago

Fabiano Rosas <farosas@suse.de> wrote:
> We're about to enable the x86_64 tests to run with the q35 machine,
> but that machine does not work with the program we use to dirty the
> memory for the tests.
>
> The issue is that QEMU needs to guess the geometry of the "disk" we
> give to it and the guessed geometry doesn't pass the sanity checks
> done by SeaBIOS. This causes SeaBIOS to interpret the geometry as if
> needing a translation from LBA to CHS and SeaBIOS ends up miscomputing
> the number of cylinders and aborting due to that.
>
> The reason things work with the "pc" machine is that is uses ATA
> instead of AHCI like q35 and SeaBIOS has an exception for ATA that
> ends up skipping the sanity checks and ignoring translation
> altogether.
>
> Workaround this situation by specifying a geometry in the command
> line.
>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Juan Quintela <quintela@redhat.com>

Re: [PATCH v4 08/12] tests/qtest/migration: Specify the geometry of the bootsector

Posted by Thomas Huth 2 years, 3 months ago

On 18/10/2023 21.27, Fabiano Rosas wrote:
> We're about to enable the x86_64 tests to run with the q35 machine,
> but that machine does not work with the program we use to dirty the
> memory for the tests.
> 
> The issue is that QEMU needs to guess the geometry of the "disk" we
> give to it and the guessed geometry doesn't pass the sanity checks
> done by SeaBIOS. This causes SeaBIOS to interpret the geometry as if
> needing a translation from LBA to CHS and SeaBIOS ends up miscomputing
> the number of cylinders and aborting due to that.
> 
> The reason things work with the "pc" machine is that is uses ATA
> instead of AHCI like q35 and SeaBIOS has an exception for ATA that
> ends up skipping the sanity checks and ignoring translation
> altogether.
> 
> Workaround this situation by specifying a geometry in the command
> line.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>   tests/qtest/migration-test.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 43d0b83771..b45a389de8 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -757,7 +757,9 @@ static int test_migrate_start(QTestState **from, QTestState **to,
>       if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
>           memory_size = "150M";
>           machine_alias = "pc";
> -        arch_opts = g_strdup_printf("-drive file=%s,format=raw", bootpath);
> +        arch_opts = g_strdup_printf(
> +            "-drive if=none,id=d0,file=%s,format=raw "
> +            "-device ide-hd,drive=d0,secs=1,cyls=1,heads=1", bootpath);
>           start_address = X86_TEST_MEM_START;
>           end_address = X86_TEST_MEM_END;
>       } else if (g_str_equal(arch, "s390x")) {

Acked-by: Thomas Huth <thuth@redhat.com>