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Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess proble
From: |
Thomas Huth |
Subject: |
Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl |
Date: |
Mon, 20 Nov 2017 21:00:28 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 |
On 20.11.2017 17:55, Igor Mammedov wrote:
> On Thu, 16 Nov 2017 13:17:02 +0100
> Thomas Huth <address@hidden> 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 <address@hidden>
>> Buglink: https://bugs.launchpad.net/qemu/+bug/1724570
>> Suggested-by: Michael S. Tsirkin <address@hidden>
>> Signed-off-by: Thomas Huth <address@hidden>
>> ---
>> 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
- [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Thomas Huth, 2017/11/16
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Igor Mammedov, 2017/11/20
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl,
Thomas Huth <=
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Michael S. Tsirkin, 2017/11/20
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Igor Mammedov, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Michael S. Tsirkin, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Igor Mammedov, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Michael S. Tsirkin, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Igor Mammedov, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Michael S. Tsirkin, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Igor Mammedov, 2017/11/21
- Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl, Michael S. Tsirkin, 2017/11/21