TDX supports 4K, 2M and 1G page sizes. The corresponding values are
defined by the TDX module spec and used as TDX module ABI. Currently,
they are used in try_accept_one() when the TDX guest tries to accept a
page. However currently try_accept_one() uses hard-coded magic values.
Define TDX supported page sizes as macros and get rid of the hard-coded
values in try_accept_one(). TDX host support will need to use them too.
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/all/20231208170740.53979-2-dave.hansen%40intel.com
Now the TDX_HYPERCALL asm is basically identical to the TDX_MODULE_CALL
with both '\saved' and '\ret' enabled, with two minor things though:
1) The way to restore the structure pointer is different
The TDX_HYPERCALL uses RCX as spare to restore the structure pointer,
but the TDX_MODULE_CALL assumes no spare register can be used. In other
words, TDX_MODULE_CALL already covers what TDX_HYPERCALL does.
2) TDX_MODULE_CALL only clears shared registers for TDH.VP.ENTER
For this just need to make that code available for the non-host case.
Thus, remove the TDX_HYPERCALL and reimplement the __tdx_hypercall()
using the TDX_MODULE_CALL.
Extend the TDX_MODULE_CALL to cover "clear shared registers" for
TDG.VP.VMCALL. Introduce a new __tdcall_saved_ret() to replace the
temporary __tdcall_hypercall().
The __tdcall_saved_ret() can also be used for those new TDCALLs which
require more input/output registers than the basic TDCALLs do.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/e68a2473fb6f5bcd78b078cae7510e9d0753b3df.1692096753.git.kai.huang%40intel.com
Now the 'struct tdx_hypercall_args' and 'struct tdx_module_args' are
almost the same, and the TDX_HYPERCALL and TDX_MODULE_CALL asm macro
share similar code pattern too. The __tdx_hypercall() and __tdcall()
should be unified to use the same assembly code.
As a preparation to unify them, simplify the TDX_HYPERCALL to make it
more like the TDX_MODULE_CALL.
The TDX_HYPERCALL takes the pointer of 'struct tdx_hypercall_args' as
function call argument, and does below extra things comparing to the
TDX_MODULE_CALL:
1) It sets RAX to 0 (TDG.VP.VMCALL leaf) internally;
2) It sets RCX to the (fixed) bitmap of shared registers internally;
3) It calls __tdx_hypercall_failed() internally (and panics) when the
TDCALL instruction itself fails;
4) After TDCALL, it moves R10 to RAX to return the return code of the
VMCALL leaf, regardless the '\ret' asm macro argument;
Firstly, change the TDX_HYPERCALL to take the same function call
arguments as the TDX_MODULE_CALL does: TDCALL leaf ID, and the pointer
to 'struct tdx_module_args'. Then 1) and 2) can be moved to the
caller:
- TDG.VP.VMCALL leaf ID can be passed via the function call argument;
- 'struct tdx_module_args' is 'struct tdx_hypercall_args' + RCX, thus
the bitmap of shared registers can be passed via RCX in the
structure.
Secondly, to move 3) and 4) out of assembly, make the TDX_HYPERCALL
always save output registers to the structure. The caller then can:
- Call __tdx_hypercall_failed() when TDX_HYPERCALL returns error;
- Return R10 in the structure as the return code of the VMCALL leaf;
With above changes, change the asm function from __tdx_hypercall() to
__tdcall_hypercall(), and reimplement __tdx_hypercall() as the C wrapper
of it. This avoids having to add another wrapper of __tdx_hypercall()
(_tdx_hypercall() is already taken).
The __tdcall_hypercall() will be replaced with a __tdcall() variant
using TDX_MODULE_CALL in a later commit as the final goal is to have one
assembly to handle both TDCALL and TDVMCALL.
Currently, the __tdx_hypercall() asm is in '.noinstr.text'. To keep
this unchanged, annotate __tdx_hypercall(), which is a C function now,
as 'noinstr'.
Remove the __tdx_hypercall_ret() as __tdx_hypercall() already does so.
Implement __tdx_hypercall() in tdx-shared.c so it can be shared with the
compressed code.
Opportunistically fix a checkpatch error complaining using space around
parenthesis '(' and ')' while moving the bitmap of shared registers to
<asm/shared/tdx.h>.
[ dhansen: quash new calls of __tdx_hypercall_ret() that showed up ]
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/0cbf25e7aee3256288045023a31f65f0cef90af4.1692096753.git.kai.huang%40intel.com
Currently, the TDX_MODULE_CALL asm macro, which handles both TDCALL and
SEAMCALL, takes one parameter for each input register and an optional
'struct tdx_module_output' (a collection of output registers) as output.
This is different from the TDX_HYPERCALL macro which uses a single
'struct tdx_hypercall_args' to carry all input/output registers.
The newer TDX versions introduce more TDCALLs/SEAMCALLs which use more
input/output registers. Also, the TDH.VP.ENTER (which isn't covered
by the current TDX_MODULE_CALL macro) basically can use all registers
that the TDX_HYPERCALL does. The current TDX_MODULE_CALL macro isn't
extendible to cover those cases.
Similar to the TDX_HYPERCALL macro, simplify the TDX_MODULE_CALL macro
to use a single structure 'struct tdx_module_args' to carry all the
input/output registers. Currently, R10/R11 are only used as output
register but not as input by any TDCALL/SEAMCALL. Change to also use
R10/R11 as input register to make input/output registers symmetric.
Currently, the TDX_MODULE_CALL macro depends on the caller to pass a
non-NULL 'struct tdx_module_output' to get additional output registers.
Similar to the TDX_HYPERCALL macro, change the TDX_MODULE_CALL macro to
take a new 'ret' macro argument to indicate whether to save the output
registers to the 'struct tdx_module_args'. Also introduce a new
__tdcall_ret() for that purpose, similar to the __tdx_hypercall_ret().
Note the tdcall(), which is a wrapper of __tdcall(), is called by three
callers: tdx_parse_tdinfo(), tdx_get_ve_info() and tdx_early_init().
The former two need the additional output but the last one doesn't. For
simplicity, make tdcall() always call __tdcall_ret() to avoid another
"_ret()" wrapper. The last caller tdx_early_init() isn't performance
critical anyway.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/483616c1762d85eb3a3c3035a7de061cfacf2f14.1692096753.git.kai.huang%40intel.com
Hookup TDX-specific code to accept memory.
Accepting the memory is done with ACCEPT_PAGE module call on every page
in the range. MAP_GPA hypercall is not required as the unaccepted memory
is considered private already.
Extract the part of tdx_enc_status_changed() that does memory acceptance
in a new helper. Move the helper tdx-shared.c. It is going to be used by
both main kernel and decompressor.
[ bp: Fix the INTEL_TDX_GUEST=y, KVM_GUEST=n build. ]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230606142637.5171-10-kirill.shutemov@linux.intel.com
