From: Ard Biesheuvel Date: Sun, 4 May 2025 09:52:35 +0000 (+0200) Subject: x86/sev: Move instruction decoder into separate source file X-Git-Tag: v6.16-rc1~195^2~30^2~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ae862964cbc562582576da91b0b92742a574c437;p=thirdparty%2Fkernel%2Flinux.git x86/sev: Move instruction decoder into separate source file As a first step towards disentangling the SEV #VC handling code -which is shared between the decompressor and the core kernel- from the SEV startup code, move the decompressor's copy of the instruction decoder into a separate source file. Code movement only - no functional change intended. Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: Arnd Bergmann Cc: David Woodhouse Cc: Dionna Amalie Glaze Cc: H. Peter Anvin Cc: Kees Cook Cc: Kevin Loughlin Cc: Len Brown Cc: Linus Torvalds Cc: Rafael J. Wysocki Cc: Tom Lendacky Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20250504095230.2932860-30-ardb+git@google.com --- diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 0fcad7b7e0078..f4f7b22d81137 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -44,10 +44,10 @@ KBUILD_CFLAGS += -D__DISABLE_EXPORTS KBUILD_CFLAGS += $(call cc-option,-Wa$(comma)-mrelax-relocations=no) KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h -# sev.c indirectly includes inat-table.h which is generated during +# sev-decode-insn.c indirectly includes inat-table.c which is generated during # compilation and stored in $(objtree). Add the directory to the includes so # that the compiler finds it even with out-of-tree builds (make O=/some/path). -CFLAGS_sev.o += -I$(objtree)/arch/x86/lib/ +CFLAGS_sev-handle-vc.o += -I$(objtree)/arch/x86/lib/ KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ @@ -96,7 +96,7 @@ ifdef CONFIG_X86_64 vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/mem_encrypt.o vmlinux-objs-y += $(obj)/pgtable_64.o - vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o + vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o $(obj)/sev-handle-vc.o endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index dd8d1a85f6716..04de48c8d4cf6 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -136,6 +136,9 @@ static inline void console_init(void) #endif #ifdef CONFIG_AMD_MEM_ENCRYPT +struct es_em_ctxt; +struct insn; + void sev_enable(struct boot_params *bp); void snp_check_features(void); void sev_es_shutdown_ghcb(void); @@ -143,6 +146,10 @@ extern bool sev_es_check_ghcb_fault(unsigned long address); void snp_set_page_private(unsigned long paddr); void snp_set_page_shared(unsigned long paddr); void sev_prep_identity_maps(unsigned long top_level_pgt); + +enum es_result vc_decode_insn(struct es_em_ctxt *ctxt); +bool insn_has_rep_prefix(struct insn *insn); +void sev_insn_decode_init(void); #else static inline void sev_enable(struct boot_params *bp) { diff --git a/arch/x86/boot/compressed/sev-handle-vc.c b/arch/x86/boot/compressed/sev-handle-vc.c new file mode 100644 index 0000000000000..b1aa073b732c5 --- /dev/null +++ b/arch/x86/boot/compressed/sev-handle-vc.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "misc.h" + +#include +#include +#include +#include +#include +#include + +#define __BOOT_COMPRESSED + +/* Basic instruction decoding support needed */ +#include "../../lib/inat.c" +#include "../../lib/insn.c" + +/* + * Copy a version of this function here - insn-eval.c can't be used in + * pre-decompression code. + */ +bool insn_has_rep_prefix(struct insn *insn) +{ + insn_byte_t p; + int i; + + insn_get_prefixes(insn); + + for_each_insn_prefix(insn, i, p) { + if (p == 0xf2 || p == 0xf3) + return true; + } + + return false; +} + +enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) +{ + char buffer[MAX_INSN_SIZE]; + int ret; + + memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE); + + ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64); + if (ret < 0) + return ES_DECODE_FAILED; + + return ES_OK; +} + +extern void sev_insn_decode_init(void) __alias(inat_init_tables); diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index f4b7f1784bea4..6fe7e85ade6bb 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -29,25 +29,6 @@ static struct ghcb boot_ghcb_page __aligned(PAGE_SIZE); struct ghcb *boot_ghcb; -/* - * Copy a version of this function here - insn-eval.c can't be used in - * pre-decompression code. - */ -static bool insn_has_rep_prefix(struct insn *insn) -{ - insn_byte_t p; - int i; - - insn_get_prefixes(insn); - - for_each_insn_prefix(insn, i, p) { - if (p == 0xf2 || p == 0xf3) - return true; - } - - return false; -} - /* * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and * doesn't use segments. @@ -74,20 +55,6 @@ static inline void sev_es_wr_ghcb_msr(u64 val) boot_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m); } -static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) -{ - char buffer[MAX_INSN_SIZE]; - int ret; - - memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE); - - ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64); - if (ret < 0) - return ES_DECODE_FAILED; - - return ES_OK; -} - static enum es_result vc_write_mem(struct es_em_ctxt *ctxt, void *dst, char *buf, size_t size) { @@ -122,10 +89,6 @@ static bool fault_in_kernel_space(unsigned long address) #define __BOOT_COMPRESSED -/* Basic instruction decoding support needed */ -#include "../../lib/inat.c" -#include "../../lib/insn.c" - extern struct svsm_ca *boot_svsm_caa; extern u64 boot_svsm_caa_pa; @@ -230,7 +193,7 @@ static bool early_setup_ghcb(void) boot_ghcb = &boot_ghcb_page; /* Initialize lookup tables for the instruction decoder */ - inat_init_tables(); + sev_insn_decode_init(); /* SNP guest requires the GHCB GPA must be registered */ if (sev_snp_enabled())