On Tue, 22 Nov 2022 at 21:48, Tom Lendacky <thomas.lendacky@xxxxxxx> wrote: > > On 11/22/22 10:10, Ard Biesheuvel wrote: > > After doing some cleanup work on the EFI code in head_64.S, the mixed > > mode code in particular, I noticed that the memory encryption pieces > > could use some attention as well, so I cleaned that up too. > > > > Changes since v2: > > - add some clarifying comments to the EFI mixed mode changes > > - include patch to make the EFI handover protocol optional that was sent > > out separately before > > - rebase onto tip/master > > > > Changes since v1: > > - at Boris's request, split the patches into smaller ones that are > > easier to review > > > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > > Cc: Borislav Petkov <bp@xxxxxxxxx> > > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > > Cc: Michael Roth <michael.roth@xxxxxxx> > > This causes an SEV guest to blow up on boot in the early boot code. It > looks like the stack pointer is not valid and it triple faults on a pushq > instruction (pushq $__KERNEL_CS in arch/x86/boot/compressed/head_64.S of > startup_64). > Thanks for the report. So the mystery here (at least to me) is that all the changes are to the 32-bit code, and startup_64 reloads the stack pointer from the symbol Does your config have CONFIG_EFI_MIXED enabled? Can I reproduce this fully emulated with QEMU? Or do I need a SEV host? > Here is the Qemu register dump: > RAX=00000000029cc260 RBX=ffffffffdd98c000 RCX=0000000000000010 RDX=0000000000000002 > RSI=000000003dec1000 RDI=0000000000000000 RBP=ffffffffdb000000 RSP=ffffffffde36e000 > R8 =000000003dec1410 R9 =000000003dec13fc R10=000000000000006c R11=0000000000000000 > R12=0000000000000000 R13=0000000000000001 R14=0000000000000004 R15=000000003eacdf44 > RIP=0000000002000263 RFL=00200002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 > ES =0000 0000000000000000 00000000 00000000 > CS =0038 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA] > SS =0000 0000000000000000 00000000 00000000 > DS =0000 0000000000000000 00000000 00000000 > FS =0000 0000000000000000 00000000 00000000 > GS =0000 0000000000000000 00000000 00000000 > LDT=0000 0000000000000000 0000ffff 00008200 DPL=0 LDT > TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy > GDT= 00000000029cc270 0000002f > IDT= 000000003f55e018 00000fff > CR0=80010033 CR2=ffffffffde36dff8 CR3=000000003fc01000 CR4=00000668 > DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 > DR6=00000000ffff0ff0 DR7=0000000000000400 > EFER=0000000000000d00 > > Thanks, > Tom > > > > > Ard Biesheuvel (17): > > x86/compressed: efi-mixed: rename efi_thunk_64.S to efi-mixed.S > > x86/compressed: efi-mixed: move 32-bit entrypoint code into .text > > section > > x86/compressed: efi-mixed: move bootargs parsing out of 32-bit startup > > code > > x86/compressed: efi-mixed: move efi32_pe_entry into .text section > > x86/compressed: efi-mixed: move efi32_entry out of head_64.S > > x86/compressed: efi-mixed: move efi32_pe_entry() out of head_64.S > > x86/compressed: efi: merge multiple definitions of image_offset into > > one > > x86/compressed: efi-mixed: simplify IDT/GDT preserve/restore > > x86/compressed: avoid touching ECX in startup32_set_idt_entry() > > x86/compressed: pull global variable ref up into startup32_load_idt() > > x86/compressed: move startup32_load_idt() into .text section > > x86/compressed: move startup32_load_idt() out of head_64.S > > x86/compressed: move startup32_check_sev_cbit() into .text > > x86/compressed: move startup32_check_sev_cbit() out of head_64.S > > x86/compressed: adhere to calling convention in > > get_sev_encryption_bit() > > x86/compressed: only build mem_encrypt.S if AMD_MEM_ENCRYPT=y > > efi: x86: Make the deprecated EFI handover protocol optional > > > > arch/x86/Kconfig | 17 + > > arch/x86/boot/compressed/Makefile | 8 +- > > arch/x86/boot/compressed/efi_mixed.S | 351 ++++++++++++++++++++ > > arch/x86/boot/compressed/efi_thunk_64.S | 195 ----------- > > arch/x86/boot/compressed/head_32.S | 4 - > > arch/x86/boot/compressed/head_64.S | 303 +---------------- > > arch/x86/boot/compressed/mem_encrypt.S | 152 ++++++++- > > arch/x86/boot/header.S | 2 +- > > arch/x86/boot/tools/build.c | 2 + > > drivers/firmware/efi/libstub/x86-stub.c | 2 +- > > 10 files changed, 533 insertions(+), 503 deletions(-) > > create mode 100644 arch/x86/boot/compressed/efi_mixed.S > > delete mode 100644 arch/x86/boot/compressed/efi_thunk_64.S > >
