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-rw-r--r--arch/x86/kernel/Makefile6
-rw-r--r--arch/x86/kernel/cc_platform.c69
-rw-r--r--arch/x86/kernel/crash_dump_64.c4
-rw-r--r--arch/x86/kernel/head64.c9
-rw-r--r--arch/x86/kernel/kvm.c3
-rw-r--r--arch/x86/kernel/kvmclock.c4
-rw-r--r--arch/x86/kernel/machine_kexec_64.c19
-rw-r--r--arch/x86/kernel/pci-swiotlb.c9
-rw-r--r--arch/x86/kernel/relocate_kernel_64.S2
-rw-r--r--arch/x86/kernel/sev.c6
10 files changed, 107 insertions, 24 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8f4e8fa6ed75..2ff3e600f426 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -21,6 +21,7 @@ CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
CFLAGS_REMOVE_head64.o = -pg
CFLAGS_REMOVE_sev.o = -pg
+CFLAGS_REMOVE_cc_platform.o = -pg
endif
KASAN_SANITIZE_head$(BITS).o := n
@@ -29,6 +30,7 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n
KASAN_SANITIZE_stacktrace.o := n
KASAN_SANITIZE_paravirt.o := n
KASAN_SANITIZE_sev.o := n
+KASAN_SANITIZE_cc_platform.o := n
# With some compiler versions the generated code results in boot hangs, caused
# by several compilation units. To be safe, disable all instrumentation.
@@ -47,6 +49,7 @@ endif
KCOV_INSTRUMENT := n
CFLAGS_head$(BITS).o += -fno-stack-protector
+CFLAGS_cc_platform.o += -fno-stack-protector
CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
@@ -147,6 +150,9 @@ obj-$(CONFIG_UNWINDER_FRAME_POINTER) += unwind_frame.o
obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o
obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev.o
+
+obj-$(CONFIG_ARCH_HAS_CC_PLATFORM) += cc_platform.o
+
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
new file mode 100644
index 000000000000..03bb2f343ddb
--- /dev/null
+++ b/arch/x86/kernel/cc_platform.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Confidential Computing Platform Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#include <linux/export.h>
+#include <linux/cc_platform.h>
+#include <linux/mem_encrypt.h>
+
+#include <asm/processor.h>
+
+static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)
+{
+#ifdef CONFIG_INTEL_TDX_GUEST
+ return false;
+#else
+ return false;
+#endif
+}
+
+/*
+ * SME and SEV are very similar but they are not the same, so there are
+ * times that the kernel will need to distinguish between SME and SEV. The
+ * cc_platform_has() function is used for this. When a distinction isn't
+ * needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
+ *
+ * The trampoline code is a good example for this requirement. Before
+ * paging is activated, SME will access all memory as decrypted, but SEV
+ * will access all memory as encrypted. So, when APs are being brought
+ * up under SME the trampoline area cannot be encrypted, whereas under SEV
+ * the trampoline area must be encrypted.
+ */
+static bool amd_cc_platform_has(enum cc_attr attr)
+{
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ switch (attr) {
+ case CC_ATTR_MEM_ENCRYPT:
+ return sme_me_mask;
+
+ case CC_ATTR_HOST_MEM_ENCRYPT:
+ return sme_me_mask && !(sev_status & MSR_AMD64_SEV_ENABLED);
+
+ case CC_ATTR_GUEST_MEM_ENCRYPT:
+ return sev_status & MSR_AMD64_SEV_ENABLED;
+
+ case CC_ATTR_GUEST_STATE_ENCRYPT:
+ return sev_status & MSR_AMD64_SEV_ES_ENABLED;
+
+ default:
+ return false;
+ }
+#else
+ return false;
+#endif
+}
+
+
+bool cc_platform_has(enum cc_attr attr)
+{
+ if (sme_me_mask)
+ return amd_cc_platform_has(attr);
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(cc_platform_has);
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 045e82e8945b..a7f617a3981d 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -10,6 +10,7 @@
#include <linux/crash_dump.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include <linux/cc_platform.h>
static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
unsigned long offset, int userbuf,
@@ -73,5 +74,6 @@ ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
- return read_from_oldmem(buf, count, ppos, 0, sev_active());
+ return read_from_oldmem(buf, count, ppos, 0,
+ cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));
}
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index de01903c3735..fc5371a7e9d1 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -19,7 +19,7 @@
#include <linux/start_kernel.h>
#include <linux/io.h>
#include <linux/memblock.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
#include <linux/pgtable.h>
#include <asm/processor.h>
@@ -284,8 +284,13 @@ unsigned long __head __startup_64(unsigned long physaddr,
* The bss section will be memset to zero later in the initialization so
* there is no need to zero it after changing the memory encryption
* attribute.
+ *
+ * This is early code, use an open coded check for SME instead of
+ * using cc_platform_has(). This eliminates worries about removing
+ * instrumentation or checking boot_cpu_data in the cc_platform_has()
+ * function.
*/
- if (mem_encrypt_active()) {
+ if (sme_get_me_mask()) {
vaddr = (unsigned long)__start_bss_decrypted;
vaddr_end = (unsigned long)__end_bss_decrypted;
for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b656456c3a94..8863d1941f1b 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -27,6 +27,7 @@
#include <linux/nmi.h>
#include <linux/swait.h>
#include <linux/syscore_ops.h>
+#include <linux/cc_platform.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
@@ -418,7 +419,7 @@ static void __init sev_map_percpu_data(void)
{
int cpu;
- if (!sev_active())
+ if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
return;
for_each_possible_cpu(cpu) {
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 73c74b961d0f..462dd8e9b03d 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -16,9 +16,9 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/set_memory.h>
+#include <linux/cc_platform.h>
#include <asm/hypervisor.h>
-#include <asm/mem_encrypt.h>
#include <asm/x86_init.h>
#include <asm/kvmclock.h>
@@ -223,7 +223,7 @@ static void __init kvmclock_init_mem(void)
* hvclock is shared between the guest and the hypervisor, must
* be mapped decrypted.
*/
- if (sev_active()) {
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
r = set_memory_decrypted((unsigned long) hvclock_mem,
1UL << order);
if (r) {
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 131f30fdcfbd..f5da4a18070a 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -17,6 +17,7 @@
#include <linux/suspend.h>
#include <linux/vmalloc.h>
#include <linux/efi.h>
+#include <linux/cc_platform.h>
#include <asm/init.h>
#include <asm/tlbflush.h>
@@ -166,7 +167,7 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
}
pte = pte_offset_kernel(pmd, vaddr);
- if (sev_active())
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
prot = PAGE_KERNEL_EXEC;
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
@@ -206,7 +207,7 @@ static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
level4p = (pgd_t *)__va(start_pgtable);
clear_page(level4p);
- if (sev_active()) {
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
info.page_flag |= _PAGE_ENC;
info.kernpg_flag |= _PAGE_ENC;
}
@@ -358,7 +359,7 @@ void machine_kexec(struct kimage *image)
(unsigned long)page_list,
image->start,
image->preserve_context,
- sme_active());
+ cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT));
#ifdef CONFIG_KEXEC_JUMP
if (image->preserve_context)
@@ -569,12 +570,12 @@ void arch_kexec_unprotect_crashkres(void)
*/
int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
{
- if (sev_active())
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
return 0;
/*
- * If SME is active we need to be sure that kexec pages are
- * not encrypted because when we boot to the new kernel the
+ * If host memory encryption is active we need to be sure that kexec
+ * pages are not encrypted because when we boot to the new kernel the
* pages won't be accessed encrypted (initially).
*/
return set_memory_decrypted((unsigned long)vaddr, pages);
@@ -582,12 +583,12 @@ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages)
{
- if (sev_active())
+ if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
return;
/*
- * If SME is active we need to reset the pages back to being
- * an encrypted mapping before freeing them.
+ * If host memory encryption is active we need to reset the pages back
+ * to being an encrypted mapping before freeing them.
*/
set_memory_encrypted((unsigned long)vaddr, pages);
}
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index c2cfa5e7c152..814ab46a0dad 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -6,7 +6,7 @@
#include <linux/swiotlb.h>
#include <linux/memblock.h>
#include <linux/dma-direct.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
#include <asm/iommu.h>
#include <asm/swiotlb.h>
@@ -45,11 +45,10 @@ int __init pci_swiotlb_detect_4gb(void)
swiotlb = 1;
/*
- * If SME is active then swiotlb will be set to 1 so that bounce
- * buffers are allocated and used for devices that do not support
- * the addressing range required for the encryption mask.
+ * Set swiotlb to 1 so that bounce buffers are allocated and used for
+ * devices that can't support DMA to encrypted memory.
*/
- if (sme_active())
+ if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
swiotlb = 1;
return swiotlb;
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index c53271aebb64..c8fe74a28143 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -47,7 +47,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
* %rsi page_list
* %rdx start address
* %rcx preserve_context
- * %r8 sme_active
+ * %r8 host_mem_enc_active
*/
/* Save the CPU context, used for jumping back */
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 50c773c3384c..88c46136bbda 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -11,7 +11,7 @@
#include <linux/sched/debug.h> /* For show_regs() */
#include <linux/percpu-defs.h>
-#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
#include <linux/printk.h>
#include <linux/mm_types.h>
#include <linux/set_memory.h>
@@ -615,7 +615,7 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
int cpu;
u64 pfn;
- if (!sev_es_active())
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
return 0;
pflags = _PAGE_NX | _PAGE_RW;
@@ -774,7 +774,7 @@ void __init sev_es_init_vc_handling(void)
BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
- if (!sev_es_active())
+ if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
return;
if (!sev_es_check_cpu_features())
generated by cgit (git 2.34.1) at 2025-06-04 10:24:12 +0000