On 20.11.2017 17:55, Igor Mammedov wrote: > On Thu, 16 Nov 2017 13:17:02 +0100 > Thomas Huth <th...@redhat.com> wrote: > >> The bios-tables-test was writing out files that we pass to iasl in >> with the wrong endianness in the header when running on a big endian >> host. So instead of storing mixed endian information in our structures, >> let's keep everything in little endian and byte-swap it only when we >> need a value in the code. >> >> Reported-by: Daniel P. Berrange <berra...@redhat.com> >> Buglink: https://bugs.launchpad.net/qemu/+bug/1724570 >> Suggested-by: Michael S. Tsirkin <m...@redhat.com> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> v2: Fixed vmgenid-test which was accidentially broken in v1 >> >> tests/acpi-utils.h | 27 +++++---------------------- >> tests/bios-tables-test.c | 42 ++++++++++++++++++++++-------------------- >> tests/vmgenid-test.c | 22 ++++++++++++---------- >> 3 files changed, 39 insertions(+), 52 deletions(-) >> >> diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h >> index f8d8723..d5ca5b6 100644 >> --- a/tests/acpi-utils.h >> +++ b/tests/acpi-utils.h >> @@ -28,24 +28,9 @@ typedef struct { >> bool tmp_files_retain; /* do not delete the temp asl/aml */ >> } AcpiSdtTable; >> >> -#define ACPI_READ_FIELD(field, addr) \ >> - do { \ >> - switch (sizeof(field)) { \ >> - case 1: \ >> - field = readb(addr); \ >> - break; \ >> - case 2: \ >> - field = readw(addr); \ >> - break; \ >> - case 4: \ >> - field = readl(addr); \ >> - break; \ >> - case 8: \ >> - field = readq(addr); \ >> - break; \ >> - default: \ >> - g_assert(false); \ >> - } \ > probably it's been discussed but, why not do > leXX_to_cpu() > here, instead of making each place that access read field > to do leXX_to_cpu() manually.? > > Beside of keeping access to structure in natural host order, > it should also be less error-prone as field users don't > have to worry about endianness.
Actually, the readw/l/q functions already do byte-swapping, so the data was stored in host endian order. But Michael said that he'd prefer to store all data from the ACPI tables in little endian mode instead - that's why I've done the patch that way. Thomas
