[PATCH v3 0/5] TDX host: kexec() support

From: Kai Huang <kai.huang@intel.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, dave.hansen@intel.com, bp@alien8.de,
	kirill.shutemov@linux.intel.com, tglx@linutronix.de,
	mingo@redhat.com, hpa@zytor.com, luto@kernel.org,
	peterz@infradead.org, rick.p.edgecombe@intel.com,
	thomas.lendacky@amd.com, ashish.kalra@amd.com,
	chao.gao@intel.com, bhe@redhat.com, nik.borisov@suse.com,
	pbonzini@redhat.com, seanjc@google.com
Subject: [PATCH v3 0/5] TDX host: kexec() support
Date: Mon,  8 Apr 2024 00:44:53 +1200	[thread overview]
Message-ID: <cover.1712493366.git.kai.huang@intel.com> (raw)

Currently kexec() support and TDX host are muturally exclusive in the
Kconfig.  This series adds the TDX host kexec support so that they can
work together and can be enabled at the same time in the Kconfig.

v2 -> v3:
 - Change to only do WBINVD for bare-metal, as Kirill/Tom pointed out
   WBINVD in TDX guests and SEV-ES/SEV-SNP guests triggers #VE.

 v2: https://lore.kernel.org/linux-kernel/cover.1710811610.git.kai.huang@intel.com/

v1 -> v2:
 - Do unconditional WBINVD during kexec() -- Boris
 - Change to cover crash kexec() -- Rick
 - Add a new patch (last one) to add a mechanism to reset all TDX private
   pages due to having to cover crash kexec().
 - Other code improvements  -- Dave
 - Rebase to latest tip/master.

 v1: https://lore.kernel.org/linux-kernel/cover.1706698706.git.kai.huang@intel.com/

Hi Dave, Sean, Paolo,

The last patch provides a new mechanism to handle all other TDX private
pages when they become possible to exist, e.g., when KVM is ready to run
TDX guests.  It's not mandatory at this stage because currently we only
have PAMT as private pages, but if we agree it's the right way to do then
it can be applied together with rest patches too.

Hi Tom, Ashish,

This series touches AMD SME code too, and I don't have AMD machine to
test.  I appreciate if you can help to review and/or test.

Kai Huang (5):
  x86/kexec: do unconditional WBINVD for bare-metal in stop_this_cpu()
  x86/kexec: do unconditional WBINVD for bare-metal in relocate_kernel()
  x86/kexec: Reset TDX private memory on platforms with TDX erratum
  x86/virt/tdx: Remove the !KEXEC_CORE dependency
  x86/virt/tdx: Add TDX memory reset notifier to reset other private
    pages

 arch/x86/Kconfig                     |   1 -
 arch/x86/include/asm/kexec.h         |   2 +-
 arch/x86/include/asm/tdx.h           |  16 +++++
 arch/x86/kernel/machine_kexec_64.c   |  29 ++++++--
 arch/x86/kernel/process.c            |  18 +++--
 arch/x86/kernel/relocate_kernel_64.S |  14 ++--
 arch/x86/virt/vmx/tdx/tdx.c          | 100 +++++++++++++++++++++++++++
 7 files changed, 158 insertions(+), 22 deletions(-)

base-commit: 6569784d306a8d356bb2517c1528c1d611a51922
-- 
2.43.2