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author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2022-04-06 02:29:25 +0300 |
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committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-04-07 08:27:52 -0700 |
commit | 4c5b9aac6cade51aef64cc6ed67f2ad5acda9aed (patch) | |
tree | 6bef19d8aa11b9470c4ce4b5b9c05418ac4429e8 /arch/x86/boot/compressed/tdx.c | |
parent | eb4ea1ae8f45e3249e7586f30be8977478202a37 (diff) | |
download | linux-stable-4c5b9aac6cade51aef64cc6ed67f2ad5acda9aed.tar.gz linux-stable-4c5b9aac6cade51aef64cc6ed67f2ad5acda9aed.tar.bz2 linux-stable-4c5b9aac6cade51aef64cc6ed67f2ad5acda9aed.zip |
x86/boot: Port I/O: Add decompression-time support for TDX
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>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220405232939.73860-17-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/boot/compressed/tdx.c')
-rw-r--r-- | arch/x86/boot/compressed/tdx.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 5f6d01a2f1f4..918a7606f53c 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -2,9 +2,65 @@ #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]; @@ -13,4 +69,9 @@ void early_tdx_detect(void) 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; } |