[tip: x86/tdx] x86/virt/tdx: Reset software states during TDX module shutdown

["tip-bot2 for Chao Gao" <tip-bot2@linutronix.de>]

The following commit has been merged into the x86/tdx branch of tip:

Commit-ID:     522bacc2fbac65fdf2a91fdb5835f832b7aba31e
Gitweb:        https://git.kernel.org/tip/522bacc2fbac65fdf2a91fdb5835f832b7aba31e
Author:        Chao Gao <chao.gao@intel.com>
AuthorDate:    Wed, 20 May 2026 15:29:06 -07:00
Committer:     Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Wed, 20 May 2026 15:37:10 -07:00

x86/virt/tdx: Reset software states during TDX module shutdown

The TDX module requires a one-time global initialization (TDH.SYS.INIT) and
per-CPU initialization (TDH.SYS.LP.INIT) before use. These initializations
are guarded by software flags to prevent repetition.

Reset all software flags guarding the initialization flows to allow the
global and per-CPU initializations to be triggered again after updates.

[ dhansen: trim down changelog ]

Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Lindgren <tony.lindgren@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://patch.msgid.link/20260520133909.409394-18-chao.gao@intel.com
Link: https://patch.msgid.link/20260520222906.A1E5DB91@davehans-spike.ostc.intel.com
---
 arch/x86/virt/vmx/tdx/tdx.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 3fe01b5..37e52cd 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1279,6 +1279,7 @@ int tdx_module_shutdown(void)
 	struct tdx_sys_info_handoff handoff = {};
 	struct tdx_module_args args = {};
 	int ret;
+	int cpu;
 
 	ret = get_tdx_sys_info_handoff(&handoff);
 	/*
@@ -1294,7 +1295,21 @@ int tdx_module_shutdown(void)
 	 */
 	args.rcx = handoff.module_hv;
 
-	return seamcall_prerr(TDH_SYS_SHUTDOWN, &args);
+	ret = seamcall_prerr(TDH_SYS_SHUTDOWN, &args);
+	if (ret)
+		return ret;
+
+	/*
+	 * Clear global and per-CPU initialization flags so the new module
+	 * can be fully re-initialized after a successful update.
+	 *
+	 * No locks needed as no concurrent accesses can occur here.
+	 */
+	memset(&tdx_module_state, 0, sizeof(tdx_module_state));
+	for_each_possible_cpu(cpu)
+		per_cpu(tdx_lp_initialized, cpu) = false;
+
+	return 0;
 }
 
 static bool is_pamt_page(unsigned long phys)