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-rw-r--r--arch/x86/boot/boot.h37
-rw-r--r--arch/x86/boot/compressed/Makefile1
-rw-r--r--arch/x86/boot/compressed/head_64.S27
-rw-r--r--arch/x86/boot/compressed/misc.c12
-rw-r--r--arch/x86/boot/compressed/misc.h4
-rw-r--r--arch/x86/boot/compressed/pgtable.h2
-rw-r--r--arch/x86/boot/compressed/tdcall.S3
-rw-r--r--arch/x86/boot/compressed/tdx.c77
-rw-r--r--arch/x86/boot/compressed/tdx.h13
-rw-r--r--arch/x86/boot/cpuflags.c3
-rw-r--r--arch/x86/boot/cpuflags.h1
-rw-r--r--arch/x86/boot/io.h41
-rw-r--r--arch/x86/boot/main.c4
13 files changed, 181 insertions, 44 deletions
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 34c9dbb6a47d..b42b91606ca8 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -26,6 +26,7 @@
#include "bitops.h"
#include "ctype.h"
#include "cpuflags.h"
+#include "io.h"
/* Useful macros */
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
@@ -35,44 +36,10 @@ extern struct boot_params boot_params;
#define cpu_relax() asm volatile("rep; nop")
-/* Basic port I/O */
-static inline void outb(u8 v, u16 port)
-{
- asm volatile("outb %0,%1" : : "a" (v), "dN" (port));
-}
-static inline u8 inb(u16 port)
-{
- u8 v;
- asm volatile("inb %1,%0" : "=a" (v) : "dN" (port));
- return v;
-}
-
-static inline void outw(u16 v, u16 port)
-{
- asm volatile("outw %0,%1" : : "a" (v), "dN" (port));
-}
-static inline u16 inw(u16 port)
-{
- u16 v;
- asm volatile("inw %1,%0" : "=a" (v) : "dN" (port));
- return v;
-}
-
-static inline void outl(u32 v, u16 port)
-{
- asm volatile("outl %0,%1" : : "a" (v), "dN" (port));
-}
-static inline u32 inl(u16 port)
-{
- u32 v;
- asm volatile("inl %1,%0" : "=a" (v) : "dN" (port));
- return v;
-}
-
static inline void io_delay(void)
{
const u16 DELAY_PORT = 0x80;
- asm volatile("outb %%al,%0" : : "dN" (DELAY_PORT));
+ outb(0, DELAY_PORT);
}
/* These functions are used to reference data in other segments. */
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index e69c3d2e0628..19e1905dcbf6 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -101,6 +101,7 @@ ifdef CONFIG_X86_64
endif
vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
+vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o
vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 4cd661165d4a..d33f060900d2 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -289,7 +289,7 @@ SYM_FUNC_START(startup_32)
pushl %eax
/* Enter paged protected Mode, activating Long Mode */
- movl $(X86_CR0_PG | X86_CR0_PE), %eax /* Enable Paging and Protected mode */
+ movl $CR0_STATE, %eax
movl %eax, %cr0
/* Jump from 32bit compatibility mode into 64bit mode. */
@@ -649,12 +649,28 @@ SYM_CODE_START(trampoline_32bit_src)
movl $MSR_EFER, %ecx
rdmsr
btsl $_EFER_LME, %eax
+ /* Avoid writing EFER if no change was made (for TDX guest) */
+ jc 1f
wrmsr
- popl %edx
+1: popl %edx
popl %ecx
+#ifdef CONFIG_X86_MCE
+ /*
+ * Preserve CR4.MCE if the kernel will enable #MC support.
+ * Clearing MCE may fault in some environments (that also force #MC
+ * support). Any machine check that occurs before #MC support is fully
+ * configured will crash the system regardless of the CR4.MCE value set
+ * here.
+ */
+ movl %cr4, %eax
+ andl $X86_CR4_MCE, %eax
+#else
+ movl $0, %eax
+#endif
+
/* Enable PAE and LA57 (if required) paging modes */
- movl $X86_CR4_PAE, %eax
+ orl $X86_CR4_PAE, %eax
testl %edx, %edx
jz 1f
orl $X86_CR4_LA57, %eax
@@ -668,8 +684,9 @@ SYM_CODE_START(trampoline_32bit_src)
pushl $__KERNEL_CS
pushl %eax
- /* Enable paging again */
- movl $(X86_CR0_PG | X86_CR0_PE), %eax
+ /* Enable paging again. */
+ movl %cr0, %eax
+ btsl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
lret
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index ca6820f99b40..cf690d8712f4 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -48,6 +48,8 @@ void *memmove(void *dest, const void *src, size_t n);
*/
struct boot_params *boot_params;
+struct port_io_ops pio_ops;
+
memptr free_mem_ptr;
memptr free_mem_end_ptr;
@@ -374,6 +376,16 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
lines = boot_params->screen_info.orig_video_lines;
cols = boot_params->screen_info.orig_video_cols;
+ init_default_io_ops();
+
+ /*
+ * Detect TDX guest environment.
+ *
+ * It has to be done before console_init() in order to use
+ * paravirtualized port I/O operations if needed.
+ */
+ early_tdx_detect();
+
console_init();
/*
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 4ca2857ea041..4910bf230d7b 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -22,17 +22,19 @@
#include <linux/linkage.h>
#include <linux/screen_info.h>
#include <linux/elf.h>
-#include <linux/io.h>
#include <asm/page.h>
#include <asm/boot.h>
#include <asm/bootparam.h>
#include <asm/desc_defs.h>
+#include "tdx.h"
+
#define BOOT_CTYPE_H
#include <linux/acpi.h>
#define BOOT_BOOT_H
#include "../ctype.h"
+#include "../io.h"
#include "efi.h"
diff --git a/arch/x86/boot/compressed/pgtable.h b/arch/x86/boot/compressed/pgtable.h
index 6ff7e81b5628..cc9b2529a086 100644
--- a/arch/x86/boot/compressed/pgtable.h
+++ b/arch/x86/boot/compressed/pgtable.h
@@ -6,7 +6,7 @@
#define TRAMPOLINE_32BIT_PGTABLE_OFFSET 0
#define TRAMPOLINE_32BIT_CODE_OFFSET PAGE_SIZE
-#define TRAMPOLINE_32BIT_CODE_SIZE 0x70
+#define TRAMPOLINE_32BIT_CODE_SIZE 0x80
#define TRAMPOLINE_32BIT_STACK_END TRAMPOLINE_32BIT_SIZE
diff --git a/arch/x86/boot/compressed/tdcall.S b/arch/x86/boot/compressed/tdcall.S
new file mode 100644
index 000000000000..46d0495e0d3a
--- /dev/null
+++ b/arch/x86/boot/compressed/tdcall.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "../../coco/tdx/tdcall.S"
diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c
new file mode 100644
index 000000000000..918a7606f53c
--- /dev/null
+++ b/arch/x86/boot/compressed/tdx.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "../cpuflags.h"
+#include "../string.h"
+#include "../io.h"
+#include "error.h"
+
+#include <vdso/limits.h>
+#include <uapi/asm/vmx.h>
+
+#include <asm/shared/tdx.h>
+
+/* Called from __tdx_hypercall() for unrecoverable failure */
+void __tdx_hypercall_failed(void)
+{
+ error("TDVMCALL failed. TDX module bug?");
+}
+
+static inline unsigned int tdx_io_in(int size, u16 port)
+{
+ struct tdx_hypercall_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = EXIT_REASON_IO_INSTRUCTION,
+ .r12 = size,
+ .r13 = 0,
+ .r14 = port,
+ };
+
+ if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
+ return UINT_MAX;
+
+ return args.r11;
+}
+
+static inline void tdx_io_out(int size, u16 port, u32 value)
+{
+ struct tdx_hypercall_args args = {
+ .r10 = TDX_HYPERCALL_STANDARD,
+ .r11 = EXIT_REASON_IO_INSTRUCTION,
+ .r12 = size,
+ .r13 = 1,
+ .r14 = port,
+ .r15 = value,
+ };
+
+ __tdx_hypercall(&args, 0);
+}
+
+static inline u8 tdx_inb(u16 port)
+{
+ return tdx_io_in(1, port);
+}
+
+static inline void tdx_outb(u8 value, u16 port)
+{
+ tdx_io_out(1, port, value);
+}
+
+static inline void tdx_outw(u16 value, u16 port)
+{
+ tdx_io_out(2, port, value);
+}
+
+void early_tdx_detect(void)
+{
+ u32 eax, sig[3];
+
+ cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2], &sig[1]);
+
+ if (memcmp(TDX_IDENT, sig, sizeof(sig)))
+ return;
+
+ /* Use hypercalls instead of I/O instructions */
+ pio_ops.f_inb = tdx_inb;
+ pio_ops.f_outb = tdx_outb;
+ pio_ops.f_outw = tdx_outw;
+}
diff --git a/arch/x86/boot/compressed/tdx.h b/arch/x86/boot/compressed/tdx.h
new file mode 100644
index 000000000000..9055482cd35c
--- /dev/null
+++ b/arch/x86/boot/compressed/tdx.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_TDX_H
+#define BOOT_COMPRESSED_TDX_H
+
+#include <linux/types.h>
+
+#ifdef CONFIG_INTEL_TDX_GUEST
+void early_tdx_detect(void);
+#else
+static inline void early_tdx_detect(void) { };
+#endif
+
+#endif /* BOOT_COMPRESSED_TDX_H */
diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c
index a0b75f73dc63..a83d67ec627d 100644
--- a/arch/x86/boot/cpuflags.c
+++ b/arch/x86/boot/cpuflags.c
@@ -71,8 +71,7 @@ int has_eflag(unsigned long mask)
# define EBX_REG "=b"
#endif
-static inline void cpuid_count(u32 id, u32 count,
- u32 *a, u32 *b, u32 *c, u32 *d)
+void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d)
{
asm volatile(".ifnc %%ebx,%3 ; movl %%ebx,%3 ; .endif \n\t"
"cpuid \n\t"
diff --git a/arch/x86/boot/cpuflags.h b/arch/x86/boot/cpuflags.h
index 2e20814d3ce3..475b8fde90f7 100644
--- a/arch/x86/boot/cpuflags.h
+++ b/arch/x86/boot/cpuflags.h
@@ -17,5 +17,6 @@ extern u32 cpu_vendor[3];
int has_eflag(unsigned long mask);
void get_cpuflags(void);
+void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d);
#endif
diff --git a/arch/x86/boot/io.h b/arch/x86/boot/io.h
new file mode 100644
index 000000000000..110880907f87
--- /dev/null
+++ b/arch/x86/boot/io.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_IO_H
+#define BOOT_IO_H
+
+#include <asm/shared/io.h>
+
+#undef inb
+#undef inw
+#undef inl
+#undef outb
+#undef outw
+#undef outl
+
+struct port_io_ops {
+ u8 (*f_inb)(u16 port);
+ void (*f_outb)(u8 v, u16 port);
+ void (*f_outw)(u16 v, u16 port);
+};
+
+extern struct port_io_ops pio_ops;
+
+/*
+ * Use the normal I/O instructions by default.
+ * TDX guests override these to use hypercalls.
+ */
+static inline void init_default_io_ops(void)
+{
+ pio_ops.f_inb = __inb;
+ pio_ops.f_outb = __outb;
+ pio_ops.f_outw = __outw;
+}
+
+/*
+ * Redirect port I/O operations via pio_ops callbacks.
+ * TDX guests override these callbacks with TDX-specific helpers.
+ */
+#define inb pio_ops.f_inb
+#define outb pio_ops.f_outb
+#define outw pio_ops.f_outw
+
+#endif
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
index e3add857c2c9..1202d4f8a390 100644
--- a/arch/x86/boot/main.c
+++ b/arch/x86/boot/main.c
@@ -17,6 +17,8 @@
struct boot_params boot_params __attribute__((aligned(16)));
+struct port_io_ops pio_ops;
+
char *HEAP = _end;
char *heap_end = _end; /* Default end of heap = no heap */
@@ -133,6 +135,8 @@ static void init_heap(void)
void main(void)
{
+ init_default_io_ops();
+
/* First, copy the boot header into the "zeropage" */
copy_boot_params();