Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCHv2 12/29] x86/boot/compressed: Support TDX guest port I/O at decompression time | Date | Mon, 24 Jan 2022 18:01:58 +0300 |
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Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls.
But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling.
Hook up TDX-specific port I/O helpers if booting in TDX environment.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- arch/x86/boot/compressed/Makefile | 2 +- arch/x86/boot/compressed/tdcall.S | 3 ++ arch/x86/boot/compressed/tdx.c | 59 +++++++++++++++++++++++++++++++ arch/x86/include/asm/shared/tdx.h | 23 ++++++++++++ arch/x86/include/asm/tdx.h | 21 ----------- 5 files changed, 86 insertions(+), 22 deletions(-) create mode 100644 arch/x86/boot/compressed/tdcall.S
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 732f6b21ecbd..8fd0e6ae2e1f 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -101,7 +101,7 @@ ifdef CONFIG_X86_64 endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o -vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o +vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a diff --git a/arch/x86/boot/compressed/tdcall.S b/arch/x86/boot/compressed/tdcall.S new file mode 100644 index 000000000000..aafadc136c88 --- /dev/null +++ b/arch/x86/boot/compressed/tdcall.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include "../../kernel/tdcall.S" diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 6853376fe69a..f2e1449c74cd 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -5,6 +5,10 @@ #include "../cpuflags.h" #include "../string.h" +#include "../io.h" + +#include <vdso/limits.h> +#include <uapi/asm/vmx.h> #include <asm/shared/tdx.h> @@ -15,6 +19,54 @@ bool early_is_tdx_guest(void) return tdx_guest_detected; } +static inline unsigned int tdx_io_in(int size, int port) +{ + struct tdx_hypercall_output out; + + __tdx_hypercall(TDX_HYPERCALL_STANDARD, EXIT_REASON_IO_INSTRUCTION, + size, 0, port, 0, &out); + + return out.r10 ? UINT_MAX : out.r11; +} + +static inline void tdx_io_out(int size, int port, u64 value) +{ + struct tdx_hypercall_output out; + + __tdx_hypercall(TDX_HYPERCALL_STANDARD, EXIT_REASON_IO_INSTRUCTION, + size, 1, port, value, &out); +} + +static inline unsigned char tdx_inb(int port) +{ + return tdx_io_in(1, port); +} + +static inline unsigned short tdx_inw(int port) +{ + return tdx_io_in(2, port); +} + +static inline unsigned int tdx_inl(int port) +{ + return tdx_io_in(4, port); +} + +static inline void tdx_outb(unsigned char value, int port) +{ + tdx_io_out(1, port, value); +} + +static inline void tdx_outw(unsigned short value, int port) +{ + tdx_io_out(2, port, value); +} + +static inline void tdx_outl(unsigned int value, int port) +{ + tdx_io_out(4, port, value); +} + void early_tdx_detect(void) { u32 eax, sig[3]; @@ -26,4 +78,11 @@ void early_tdx_detect(void) /* Cache TDX guest feature status */ tdx_guest_detected = true; + + pio_ops.inb = tdx_inb; + pio_ops.inw = tdx_inw; + pio_ops.inl = tdx_inl; + pio_ops.outb = tdx_outb; + pio_ops.outw = tdx_outw; + pio_ops.outl = tdx_outl; } diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 12bede46d048..4a0218bedc75 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -1,7 +1,30 @@ #ifndef _ASM_X86_SHARED_TDX_H #define _ASM_X86_SHARED_TDX_H +#include <linux/types.h> + +/* + * Used in __tdx_hypercall() to gather the output registers' values + * of the TDCALL instruction when requesting services from the VMM. + * This is a software only structure and not part of the TDX + * module/VMM ABI. + */ +struct tdx_hypercall_output { + u64 r10; + u64 r11; + u64 r12; + u64 r13; + u64 r14; + u64 r15; +}; + +#define TDX_HYPERCALL_STANDARD 0 + #define TDX_CPUID_LEAF_ID 0x21 #define TDX_IDENT "IntelTDX " +/* Used to request services from the VMM */ +u64 __tdx_hypercall(u64 type, u64 fn, u64 r12, u64 r13, u64 r14, + u64 r15, struct tdx_hypercall_output *out); + #endif diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index 53f7dd0fbe58..27eb4ab2fdd2 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -7,8 +7,6 @@ #include <asm/ptrace.h> #include <asm/shared/tdx.h> -#define TDX_HYPERCALL_STANDARD 0 - /* * Used in __tdx_module_call() to gather the output registers' * values of the TDCALL instruction when requesting services from @@ -24,21 +22,6 @@ struct tdx_module_output { u64 r11; }; -/* - * Used in __tdx_hypercall() to gather the output registers' values - * of the TDCALL instruction when requesting services from the VMM. - * This is a software only structure and not part of the TDX - * module/VMM ABI. - */ -struct tdx_hypercall_output { - u64 r10; - u64 r11; - u64 r12; - u64 r13; - u64 r14; - u64 r15; -}; - /* * Used by the #VE exception handler to gather the #VE exception * info from the TDX module. This is a software only structure @@ -64,10 +47,6 @@ bool is_tdx_guest(void); u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, struct tdx_module_output *out); -/* Used to request services from the VMM */ -u64 __tdx_hypercall(u64 type, u64 fn, u64 r12, u64 r13, u64 r14, - u64 r15, struct tdx_hypercall_output *out); - bool tdx_get_ve_info(struct ve_info *ve); bool tdx_handle_virt_exception(struct pt_regs *regs, struct ve_info *ve); -- 2.34.1
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