a fatal shutdown during TDX private<=>shared conversion
- Annotate sites where VM "exit reasons" are reused as hypercall
numbers.
-----BEGIN PGP SIGNATURE-----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=Hr3D
-----END PGP SIGNATURE-----
Merge tag 'x86_tdx_for_6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 tdx updates from Dave Hansen:
- Fix a race window where load_unaligned_zeropad() could cause a fatal
shutdown during TDX private<=>shared conversion
The race has never been observed in practice but might allow
load_unaligned_zeropad() to catch a TDX page in the middle of its
conversion process which would lead to a fatal and unrecoverable
guest shutdown.
- Annotate sites where VM "exit reasons" are reused as hypercall
numbers.
* tag 'x86_tdx_for_6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix enc_status_change_finish_noop()
x86/tdx: Fix race between set_memory_encrypted() and load_unaligned_zeropad()
x86/mm: Allow guest.enc_status_change_prepare() to fail
x86/tdx: Wrap exit reason with hcall_func()
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
Memory acceptance requires a hypercall and one or multiple module calls.
Make helpers for the calls available in boot stub. It has to accept
memory where kernel image and initrd are placed.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20230606142637.5171-8-kirill.shutemov@linux.intel.com
TDX reuses VMEXIT "reasons" in its guest->host hypercall ABI. This is
confusing because there might not be a VMEXIT involved at *all*.
These instances are supposed to document situation and reduce confusion
by wrapping VMEXIT reasons with hcall_func().
The decompression code does not follow this convention.
Unify the TDX decompression code with the other TDX use of VMEXIT reasons.
No functional changes.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/all/20230505120332.1429957-1-nik.borisov%40suse.com
After TDX_HCALL_ISSUE_STI got dropped, the only flag left is
TDX_HCALL_HAS_OUTPUT. The flag indicates if the caller wants to see
tdx_hypercall_args updated based on the hypercall output.
Drop the flags and provide __tdx_hypercall_ret() that matches
TDX_HCALL_HAS_OUTPUT semantics.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230321003511.9469-1-kirill.shutemov%40linux.intel.com
- Prevent unexpected #VE's from:
- Hosts removing perfectly good guest mappings (SEPT_VE_DISABLE
- Excessive #VE notifications (NOTIFY_ENABLES) which are
delivered via a #VE.
-----BEGIN PGP SIGNATURE-----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=UpyL
-----END PGP SIGNATURE-----
Merge tag 'x86_tdx_for_6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull Intel Trust Domain Extensions (TDX) updates from Dave Hansen:
"Other than a minor fixup, the content here is to ensure that TDX
guests never see virtualization exceptions (#VE's) that might be
induced by the untrusted VMM.
This is a highly desirable property. Without it, #VE exception
handling would fall somewhere between NMIs, machine checks and total
insanity. With it, #VE handling remains pretty mundane.
Summary:
- Fixup comment typo
- Prevent unexpected #VE's from:
- Hosts removing perfectly good guest mappings (SEPT_VE_DISABLE)
- Excessive #VE notifications (NOTIFY_ENABLES) which are delivered
via a #VE"
* tag 'x86_tdx_for_6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall()
x86/tdx: Disable NOTIFY_ENABLES
x86/tdx: Relax SEPT_VE_DISABLE check for debug TD
x86/tdx: Use ReportFatalError to report missing SEPT_VE_DISABLE
x86/tdx: Expand __tdx_hypercall() to handle more arguments
x86/tdx: Refactor __tdx_hypercall() to allow pass down more arguments
x86/tdx: Add more registers to struct tdx_hypercall_args
x86/tdx: Fix typo in comment in __tdx_hypercall()
struct tdx_hypercall_args is used to pass down hypercall arguments to
__tdx_hypercall() assembly routine.
Currently __tdx_hypercall() handles up to 6 arguments. In preparation to
changes in __tdx_hypercall(), expand the structure to 6 more registers
and generate asm offsets for them.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20230126221159.8635-3-kirill.shutemov%40linux.intel.com
Now that arch_cpu_idle() is expected to return with IRQs disabled,
avoid the useless STI/CLI dance.
Per the specs this is supposed to work, but nobody has yet relied up
this behaviour so broken implementations are possible.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.682137572@infradead.org
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
The early decompression code does port I/O for its console output. But,
handling the decompression-time port I/O demands a different approach
from normal runtime because the IDT required to support #VE based port
I/O emulation is not yet set up. Paravirtualizing I/O calls during
the decompression step is acceptable because the decompression code
doesn't have a lot of call sites to IO instruction.
To support port I/O in decompression code, TDX must be detected before
the decompression code might do port I/O. Detect whether the kernel runs
in a TDX guest.
Add an early_is_tdx_guest() interface to query the cached TDX guest
status in the decompression code.
TDX is detected with CPUID. Make cpuid_count() accessible outside
boot/cpuflags.c.
TDX detection in the main kernel is very similar. Move common bits
into <asm/shared/tdx.h>.
The actual port I/O paravirtualization will come later in the series.
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: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220405232939.73860-13-kirill.shutemov@linux.intel.com
