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Peter Anvin" Subject: [PATCH v10 01/25] x86/virt/tdx: Clarify try_init_module_global() result caching Date: Wed, 20 May 2026 06:38:04 -0700 Message-ID: <20260520133909.409394-2-chao.gao@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260520133909.409394-1-chao.gao@intel.com> References: <20260520133909.409394-1-chao.gao@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit TDX module global initialization is executed only once. The first call caches both the result and the "done" state, and later callers reuse the saved result. A lock protects that cached state. The current code is hard to read because sysinit_done is accessed under the lock, while sysinit_ret is not. To improve readability, move sysinit_ret accesses within the lock. Group sysinit_ret/sysinit_done updates right after initialization so Caching the result is separate from the initialization itself. Signed-off-by: Chao Gao --- arch/x86/virt/vmx/tdx/tdx.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index c0c6281b08a5..ad56f142dd0b 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -115,28 +115,34 @@ static int try_init_module_global(void) static DEFINE_RAW_SPINLOCK(sysinit_lock); static bool sysinit_done; static int sysinit_ret; + int ret; raw_spin_lock(&sysinit_lock); - if (sysinit_done) + /* Return the "cached" return code. */ + if (sysinit_done) { + ret = sysinit_ret; goto out; + } /* RCX is module attributes and all bits are reserved */ args.rcx = 0; - sysinit_ret = seamcall_prerr(TDH_SYS_INIT, &args); + ret = seamcall_prerr(TDH_SYS_INIT, &args); /* * The first SEAMCALL also detects the TDX module, thus * it can fail due to the TDX module is not loaded. * Dump message to let the user know. */ - if (sysinit_ret == -ENODEV) + if (ret == -ENODEV) pr_err("module not loaded\n"); + /* Save the return code for later callers. */ sysinit_done = true; + sysinit_ret = ret; out: raw_spin_unlock(&sysinit_lock); - return sysinit_ret; + return ret; } /** -- 2.52.0