diff options
| author | Andi Kleen <ak@linux.intel.com> | 2022-04-06 02:29:27 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-04-07 18:27:52 +0300 |
| commit | 32e72854fa5fef6bc72e27c54f31897db9092acb (patch) | |
| tree | d7f92cfbbb06a823c39219ef479f9d7664e26c2a /arch/x86/include/asm/tdx.h | |
| parent | 03149948832a078f759022ed5b92e722d8d23c26 (diff) | |
| download | linux-32e72854fa5fef6bc72e27c54f31897db9092acb.tar.xz | |
x86/tdx: Port I/O: Add early boot support
TDX guests cannot do port I/O directly. The TDX module triggers a #VE
exception to let the guest kernel emulate port I/O by converting them
into TDCALLs to call the host.
But before IDT handlers are set up, port I/O cannot be emulated using
normal kernel #VE handlers. To support the #VE-based emulation during
this boot window, add a minimal early #VE handler support in early
exception handlers. This is similar to what AMD SEV does. This is
mainly to support earlyprintk's serial driver, as well as potentially
the VGA driver.
The early handler only supports I/O-related #VE exceptions. Unhandled or
failed exceptions will be handled via early_fixup_exceptions() (like
normal exception failures). At runtime I/O-related #VE exceptions (along
with other types) handled by virt_exception_kernel().
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220405232939.73860-19-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/include/asm/tdx.h')
| -rw-r--r-- | arch/x86/include/asm/tdx.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index 7944fd1ae07d..9ffd0d2e6e0f 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -65,11 +65,15 @@ bool tdx_handle_virt_exception(struct pt_regs *regs, struct ve_info *ve); void tdx_safe_halt(void); +bool tdx_early_handle_ve(struct pt_regs *regs); + #else static inline void tdx_early_init(void) { }; static inline void tdx_safe_halt(void) { }; +static inline bool tdx_early_handle_ve(struct pt_regs *regs) { return false; } + #endif /* CONFIG_INTEL_TDX_GUEST */ #endif /* !__ASSEMBLY__ */ |