diff options
| author | Andi Kleen | 2022-04-06 02:29:27 +0300 |
|---|---|---|
| committer | Dave Hansen | 2022-04-07 08:27:52 -0700 |
| commit | 32e72854fa5fef6bc72e27c54f31897db9092acb (patch) | |
| tree | d7f92cfbbb06a823c39219ef479f9d7664e26c2a /arch/x86/kernel/head64.c | |
| parent | 03149948832a078f759022ed5b92e722d8d23c26 (diff) | |
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/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 6dff50c3edd6..ecbf50e5b8e0 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -417,6 +417,9 @@ void __init do_early_exception(struct pt_regs *regs, int trapnr) trapnr == X86_TRAP_VC && handle_vc_boot_ghcb(regs)) return; + if (trapnr == X86_TRAP_VE && tdx_early_handle_ve(regs)) + return; + early_fixup_exception(regs, trapnr); } |