This is a note to let you know that I've just added the patch titled
x86/sev: Move early startup code into .head.text section
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-sev-move-early-startup-code-into-.head.text-section.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 428080c9b19bfda37c478cd626dbd3851db1aff9 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
Date: Tue, 27 Feb 2024 16:19:16 +0100
Subject: x86/sev: Move early startup code into .head.text section
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
commit 428080c9b19bfda37c478cd626dbd3851db1aff9 upstream.
In preparation for implementing rigorous build time checks to enforce
that only code that can support it will be called from the early 1:1
mapping of memory, move SEV init code that is called in this manner to
the .head.text section.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Link: https://lore.kernel.org/r/20240227151907.387873-19-ardb+git@xxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/boot/compressed/sev.c | 3 +++
arch/x86/include/asm/sev.h | 10 +++++-----
arch/x86/kernel/sev-shared.c | 23 ++++++++++-------------
arch/x86/kernel/sev.c | 14 ++++++++------
4 files changed, 26 insertions(+), 24 deletions(-)
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -116,6 +116,9 @@ static bool fault_in_kernel_space(unsign
#undef __init
#define __init
+#undef __head
+#define __head
+
#define __BOOT_COMPRESSED
/* Basic instruction decoding support needed */
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -199,15 +199,15 @@ static inline int pvalidate(unsigned lon
struct snp_guest_request_ioctl;
void setup_ghcb(void);
-void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
- unsigned long npages);
-void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
- unsigned long npages);
+void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+ unsigned long npages);
+void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
+ unsigned long npages);
void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
-void __init __noreturn snp_abort(void);
+void __noreturn snp_abort(void);
void snp_dmi_setup(void);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
void snp_accept_memory(phys_addr_t start, phys_addr_t end);
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -89,7 +89,8 @@ static bool __init sev_es_check_cpu_feat
return true;
}
-static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason)
+static void __head __noreturn
+sev_es_terminate(unsigned int set, unsigned int reason)
{
u64 val = GHCB_MSR_TERM_REQ;
@@ -326,13 +327,7 @@ static int sev_cpuid_hv(struct ghcb *ghc
*/
static const struct snp_cpuid_table *snp_cpuid_get_table(void)
{
- void *ptr;
-
- asm ("lea cpuid_table_copy(%%rip), %0"
- : "=r" (ptr)
- : "p" (&cpuid_table_copy));
-
- return ptr;
+ return &RIP_REL_REF(cpuid_table_copy);
}
/*
@@ -391,7 +386,7 @@ static u32 snp_cpuid_calc_xsave_size(u64
return xsave_size;
}
-static bool
+static bool __head
snp_cpuid_get_validated_func(struct cpuid_leaf *leaf)
{
const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -528,7 +523,8 @@ static int snp_cpuid_postprocess(struct
* Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value
* should be treated as fatal by caller.
*/
-static int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
+static int __head
+snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
{
const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -570,7 +566,7 @@ static int snp_cpuid(struct ghcb *ghcb,
* page yet, so it only supports the MSR based communication with the
* hypervisor and only the CPUID exit-code.
*/
-void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
+void __head do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
{
unsigned int subfn = lower_bits(regs->cx, 32);
unsigned int fn = lower_bits(regs->ax, 32);
@@ -1016,7 +1012,8 @@ struct cc_setup_data {
* Search for a Confidential Computing blob passed in as a setup_data entry
* via the Linux Boot Protocol.
*/
-static struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
+static __head
+struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
{
struct cc_setup_data *sd = NULL;
struct setup_data *hdr;
@@ -1043,7 +1040,7 @@ static struct cc_blob_sev_info *find_cc_
* mapping needs to be updated in sync with all the changes to virtual memory
* layout and related mapping facilities throughout the boot process.
*/
-static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
+static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
{
const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table;
int i;
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -26,6 +26,7 @@
#include <linux/dmi.h>
#include <uapi/linux/sev-guest.h>
+#include <asm/init.h>
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
#include <asm/sev.h>
@@ -683,8 +684,9 @@ static u64 __init get_jump_table_addr(vo
return ret;
}
-static void early_set_pages_state(unsigned long vaddr, unsigned long paddr,
- unsigned long npages, enum psc_op op)
+static void __head
+early_set_pages_state(unsigned long vaddr, unsigned long paddr,
+ unsigned long npages, enum psc_op op)
{
unsigned long paddr_end;
u64 val;
@@ -740,7 +742,7 @@ e_term:
sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
}
-void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+void __head early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
unsigned long npages)
{
/*
@@ -2045,7 +2047,7 @@ fail:
*
* Scan for the blob in that order.
*/
-static __init struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+static __head struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
{
struct cc_blob_sev_info *cc_info;
@@ -2071,7 +2073,7 @@ found_cc_info:
return cc_info;
}
-bool __init snp_init(struct boot_params *bp)
+bool __head snp_init(struct boot_params *bp)
{
struct cc_blob_sev_info *cc_info;
@@ -2093,7 +2095,7 @@ bool __init snp_init(struct boot_params
return true;
}
-void __init __noreturn snp_abort(void)
+void __head __noreturn snp_abort(void)
{
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
}
Patches currently in stable-queue which might be from ardb@xxxxxxxxxx are
queue-6.6/x86-head-64-move-the-__head-definition-to-asm-init.h.patch
queue-6.6/x86-efistub-remap-kernel-text-read-only-before-dropping-nx-attribute.patch
queue-6.6/x86-sme-move-early-sme-kernel-encryption-handling-into-.head.text.patch
queue-6.6/x86-sev-move-early-startup-code-into-.head.text-section.patch
queue-6.6/efi-libstub-add-generic-support-for-parsing-mem_encrypt.patch
