mb/emulation/qemu-q35: Fix running qemu-i386 with SMM
Depending on whether qemu emulates an amd64 or i386 machine the SMM
save state will differ. The smbase offsets are incompatible between
those save states.
TESTED: Both qemu-system-i386 and qemu-system-x86_64 (v7.0.50) have a
working smihandler, ASEG and TSEG.
Change-Id: Ic6994c8d6e10fd06655129dbd801f1f9d5fd639f
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55138
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/mainboard/emulation/qemu-q35/cpu.c b/src/mainboard/emulation/qemu-q35/cpu.c
index fe3a571..2a2707a 100644
--- a/src/mainboard/emulation/qemu-q35/cpu.c
+++ b/src/mainboard/emulation/qemu-q35/cpu.c
@@ -2,9 +2,11 @@
#include <console/console.h>
#include <cpu/x86/mp.h>
+#include <stddef.h>
#include <stdint.h>
#include <cpu/intel/smm_reloc.h>
#include <cpu/amd/amd64_save_state.h>
+#include <cpu/x86/legacy_save_state.h>
#include <mainboard/emulation/qemu-i440fx/fw_cfg.h>
static void get_smm_info(uintptr_t *perm_smbase, size_t *perm_smsize,
@@ -31,19 +33,47 @@
* resides in the ramstage module. This occurs by trampolining from the default
* SMRAM entry point to here.
*/
+
+__packed union save_state {
+ amd64_smm_state_save_area_t amd64;
+ struct {
+ char _reserved[sizeof(amd64_smm_state_save_area_t)
+ - sizeof(legacy_smm_state_save_area_t)];
+ legacy_smm_state_save_area_t legacy;
+ };
+};
+
+_Static_assert(sizeof(union save_state) == sizeof(amd64_smm_state_save_area_t),
+ "Incorrect save state union size");
+
+_Static_assert(offsetof(union save_state, amd64.smm_revision)
+ == offsetof(union save_state, legacy.smm_revision),
+ "Incompatible SMM save state revision offset");
+
static void relocation_handler(int cpu, uintptr_t curr_smbase,
uintptr_t staggered_smbase)
{
- /* The em64t101 save state is sufficiently compatible with older
- save states with regards of smbase, smm_revision. */
- amd64_smm_state_save_area_t *save_state;
+ union save_state *save_state =
+ (void *)(curr_smbase + SMM_DEFAULT_SIZE - sizeof(*save_state));
+
u32 smbase = staggered_smbase;
- save_state = (void *)(curr_smbase + SMM_DEFAULT_SIZE - sizeof(*save_state));
- save_state->smbase = smbase;
+ /* The SMM save state revision is always at a compatible offset */
+ const u32 revision = save_state->legacy.smm_revision;
+ switch (revision) {
+ case 0x00020000:
+ save_state->legacy.smbase = smbase;
+ break;
+ case 0x00020064:
+ save_state->amd64.smbase = smbase;
+ break;
+ default:
+ printk(BIOS_ERR, "Unknown SMM revision 0x%x, not relocating SMM\n", revision);
+ return;
+ };
printk(BIOS_DEBUG, "In relocation handler: cpu %d\n", cpu);
- printk(BIOS_DEBUG, "SMM revision: 0x%08x\n", save_state->smm_revision);
+ printk(BIOS_DEBUG, "SMM revision: 0x%08x\n", revision);
printk(BIOS_DEBUG, "New SMBASE=0x%08x\n", smbase);
}