linux-kernel - [PATCH v3 18/24] x86/virt/tdx: Add loud warning when tdx_pamt

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Message-ID: <20260106102318.25227-1-yan.y.zhao@intel.com>
Date: Tue,  6 Jan 2026 18:23:18 +0800
From: Yan Zhao <yan.y.zhao@...el.com>
To: pbonzini@...hat.com,
	seanjc@...gle.com
Cc: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org,
	x86@...nel.org,
	rick.p.edgecombe@...el.com,
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	binbin.wu@...ux.intel.com,
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	yan.y.zhao@...el.com
Subject: [PATCH v3 18/24] x86/virt/tdx: Add loud warning when tdx_pamt_put() fails.

tdx_pamt_put() does not return any error to its caller when SEAMCALL
TDH_PHYMEM_PAMT_REMOVE fails. Though pamt_refcount for the failed 2MB
physical range is increased (so the DPAMT pages stay added), it will cause
that the 2MB physical range can only be mapped at 4KB level, i.e., later
SEAMCALL TDH_MEM_PAGE_AUG on the 2MB range at 2MB level will therefore fail
forever.

Since tdx_pamt_put() only fails when there are bugs in the host kernel or
in the TDX module, simply add a loud warning to aid debugging after such an
error occurs.

Link: https://lore.kernel.org/all/67d55b24ef1a80af615c3672e8436e0ac32e8efa.camel@intel.com
Suggested-by: Rick Edgecombe <rick.p.edgecombe@...el.com>
Signed-off-by: Yan Zhao <yan.y.zhao@...el.com>
---
v3:
- new patch
---
 arch/x86/virt/vmx/tdx/tdx.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index c12665389b67..76963c563906 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -2348,8 +2348,7 @@ void tdx_pamt_put(struct page *page)
 			 */
 			atomic_inc(pamt_refcount);
 
-			pr_err("TDH_PHYMEM_PAMT_REMOVE failed: %#llx\n", tdx_status);
-
+			WARN_ONCE(1, "TDH_PHYMEM_PAMT_REMOVE failed: %#llx\n", tdx_status);
 			/*
 			 * Don't free pamt_pa_array as it could hold garbage
 			 * when tdh_phymem_pamt_remove() fails.
-- 
2.43.2