From 38220bc61bdb1614f34a53481f7604720c9e9e5a Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Tue, 20 Feb 2024 10:41:06 +0100 Subject: [PATCH 18/20] smbios: in case of entry point is 'auto' try to build v2 tables 1st RH-Author: Igor Mammedov RH-MergeRequest: 230: Workaround Windows failing to find 64bit SMBIOS entry point with SeaBIOS RH-Jira: RHEL-21705 RH-Acked-by: MST RH-Acked-by: Ani Sinha RH-Commit: [16/18] becbcb3d8dad4842e5939bb75e21f4e737a4a325 JIRA: https://issues.redhat.com/browse/RHEL-21705 QEMU for some time now uses SMBIOS 3.0 for PC/Q35 machines by default, however Windows has a bug in locating SMBIOS 3.0 entrypoint and fails to find tables when booted on SeaBIOS (on UEFI SMBIOS 3.0 tables work fine since firmware hands over tables in another way) Missing SMBIOS tables may lead to some issues for guest though (worst are: possible reactiveation, inability to get virtio drivers from 'Windows Update') It's unclear at this point if MS will fix the issue on their side. So instead of it (or rather in addition) this patch will try to workaround the issue. aka, use smbios-entry-point-type=auto to make QEMU try generating conservative SMBIOS 2.0 tables and if that fails (due to limits/requested configuration) fallback to SMBIOS 3.0 tables. With this in place majority of users will use SMBIOS 2.0 tables which work fine with (Windows + legacy BIOS). The configurations that is not to possible to describe with SMBIOS 2.0 will switch automatically to SMBIOS 3.0 (which will trigger Windows bug but there is nothing QEMU can do here, so go and aks Microsoft to real fix). Signed-off-by: Igor Mammedov Reviewed-by: Ani Sinha Tested-by: Fiona Ebner --- hw/smbios/smbios.c | 52 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 3 deletions(-) diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c index 4521ea386c..3d9dcb0d31 100644 --- a/hw/smbios/smbios.c +++ b/hw/smbios/smbios.c @@ -1097,7 +1097,7 @@ static void smbios_entry_point_setup(SmbiosEntryPointType ep_type) } } -void smbios_get_tables(MachineState *ms, +static bool smbios_get_tables_ep(MachineState *ms, SmbiosEntryPointType ep_type, const struct smbios_phys_mem_area *mem_array, const unsigned int mem_array_size, @@ -1106,6 +1106,7 @@ void smbios_get_tables(MachineState *ms, Error **errp) { unsigned i, dimm_cnt, offset; + ERRP_GUARD(); assert(ep_type == SMBIOS_ENTRY_POINT_TYPE_32 || ep_type == SMBIOS_ENTRY_POINT_TYPE_64); @@ -1192,11 +1193,56 @@ void smbios_get_tables(MachineState *ms, abort(); } - return; + return true; err_exit: g_free(smbios_tables); smbios_tables = NULL; - return; + return false; +} + +void smbios_get_tables(MachineState *ms, + SmbiosEntryPointType ep_type, + const struct smbios_phys_mem_area *mem_array, + const unsigned int mem_array_size, + uint8_t **tables, size_t *tables_len, + uint8_t **anchor, size_t *anchor_len, + Error **errp) +{ + Error *local_err = NULL; + bool is_valid; + ERRP_GUARD(); + + switch (ep_type) { + case SMBIOS_ENTRY_POINT_TYPE_AUTO: + case SMBIOS_ENTRY_POINT_TYPE_32: + is_valid = smbios_get_tables_ep(ms, SMBIOS_ENTRY_POINT_TYPE_32, + mem_array, mem_array_size, + tables, tables_len, + anchor, anchor_len, + &local_err); + if (is_valid || ep_type != SMBIOS_ENTRY_POINT_TYPE_AUTO) { + break; + } + /* + * fall through in case AUTO endpoint is selected and + * SMBIOS 2.x tables can't be generated, to try if SMBIOS 3.x + * tables would work + */ + case SMBIOS_ENTRY_POINT_TYPE_64: + error_free(local_err); + local_err = NULL; + is_valid = smbios_get_tables_ep(ms, SMBIOS_ENTRY_POINT_TYPE_64, + mem_array, mem_array_size, + tables, tables_len, + anchor, anchor_len, + &local_err); + break; + default: + abort(); + } + if (!is_valid) { + error_propagate(errp, local_err); + } } static void save_opt(const char **dest, QemuOpts *opts, const char *name) -- 2.39.3