On Thu, Jul 13, 2017 at 05:33:30PM +0200, Laszlo Ersek wrote: > On 07/13/17 14:00, gengdongjiu wrote: > > Laszlo, > > Thank you for your review and comments. > > > > > > On 2017/7/13 18:33, Laszlo Ersek wrote: > >> On 07/12/17 04:08, Dongjiu Geng wrote: > > [snip] > > >>> --- a/include/qemu/uuid.h > >>> +++ b/include/qemu/uuid.h > >>> @@ -44,6 +44,17 @@ typedef struct { > >>> > >>> #define UUID_NONE "00000000-0000-0000-0000-000000000000" > >>> > >>> +#define UUID_BE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \ > >>> +{{{ ((a) >> 24) & 0xff, ((a) >> 16) & 0xff, ((a) >> 8) & 0xff, (a) & > >>> 0xff, \ > >>> + ((b) >> 8) & 0xff, (b) & 0xff, \ > >>> + ((c) >> 8) & 0xff, (c) & 0xff, \ > >>> + (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } } } > >>> + > >>> +/* Platform Memory, this is from UEFI 2.6 N.2.2 Section Descriptor */ > >>> +#define UEFI_CPER_SEC_PLATFORM_MEM \ > >>> + UUID_BE(0xA5BC1114, 0x6F64, 0x4EDE, 0xB8, 0x63, 0x3E, 0x83, \ > >>> + 0xED, 0x7C, 0x83, 0xB1) > >>> + > >>> void qemu_uuid_generate(QemuUUID *out); > >>> > >>> int qemu_uuid_is_null(const QemuUUID *uu); > >>> > >> > >> (e) I think the addition of UUID_BE should be split out to a separate > >> patch; it adds a general facility. It should likely be the very first > >> patch in the series. > > Ok. > > > >> > >> (f) While I think it is justified to have UUID_BE() in "qemu/uuid.h", I > >> think UEFI_CPER_SEC_PLATFORM_MEM is too specific to have here. > >> > >> If UEFI_CPER_SEC_PLATFORM_MEM were *not* a standardized UUID, I would > >> suggest moving it to the implementation ("include/hw/acpi/hest_ghes.h" > >> -- which in turn should be moved to patch #2, see my remark (d)), *plus* > >> I would suggest eliminating the new #include from "acpi-defs.h", see my > >> remark (b). > > understand your idea. > > > >> > >> However, given that this UUID *is* standard, I suggest keeping the (b) > >> #include as you currently propose, and to move the definition of > >> UEFI_CPER_SEC_PLATFORM_MEM to "acpi-defs.h". > > I agree with you. > > > >> > >> I vaguely recall that Michael commented on this previously, but I don't > >> remember what he said. Michael, are you OK with my suggestion? > > Laszlo, I pasted Michael's comments here, as shown below. Michael said > > the definition > > should use build_append_int_noprefix to add data. but I think it may not > > good, becuase > > the section "UEFI_CPER_SEC_PLATFORM_MEM" is runtime recorded as CPER, not a > > ACPI/HEST > > table member, so it is not generated when system boot up. > > I agree: the UUID in question is not placed into the ACPI payload / > fw_cfg blobs, it is written into guest memory at runtime, into the > firmware-allocated area, if and when there is a hardware error to report. > > Thanks > Laszlo
The main point is that wrapping it up in a macro with an unreadable name is not really helpful when it's only used in a single place. > > On the other hand,UEFI_CPER_SEC_PLATFORM_MEM > > definition is from UEFI spec 2.6, N.2.2 Section Descriptor: {0xA5BC1114, > > 0x6F64, 0x4EDE, {0xB8, 0x63, 0x3E, 0x83, 0xED, 0x7C, 0x83, 0xB1}}. > > if use build_append_int_noprefix to add, may confuse others. > > > > ----------------------------------------------------------------- > > ----------------------------------------------------------------- > > There's no reason to define these messy one-time use macros. > > They just make it hard to look things up in the spec. > > > > > > You can use build_append_int_noprefix to add data of > > any length in LE format. > > ----------------------------------------------------------------- > > ----------------------------------------------------------------- > > > > Hi Michael, > > what is your suggestion about it? do you agree with Laszlo? My main point is that the macros do not seem helpful.