Re: [PATCH v2 11/21] x86/virt/seamldr: Allocate and populate a module update request
From: Binbin Wu
Date: Thu Nov 27 2025 - 03:39:23 EST
On 11/27/2025 4:30 PM, Binbin Wu wrote:
On 10/1/2025 10:52 AM, Chao Gao wrote:
[...]
+According to the link [2] you provided above, it seems that the layout of
+/* Allocate and populate a seamldr_params */
+static struct seamldr_params *alloc_seamldr_params(const void *module, int module_size,
+ const void *sig, int sig_size)
+{
+ struct seamldr_params *params;
+ const u8 *ptr;
+ int i;
+
+ BUILD_BUG_ON(sizeof(struct seamldr_params) != SZ_4K);
+ if (module_size > SEAMLDR_MAX_NR_MODULE_4KB_PAGES * SZ_4K)
+ return ERR_PTR(-EINVAL);
+
+ if (!IS_ALIGNED(module_size, SZ_4K) || !IS_ALIGNED(sig_size, SZ_4K) ||
+ !IS_ALIGNED((unsigned long)module, SZ_4K) ||
+ !IS_ALIGNED((unsigned long)sig, SZ_4K))
+ return ERR_PTR(-EINVAL);
+
+ /* seamldr_params accepts one 4KB-page for sigstruct */
+ if (sig_size != SZ_4K)
tdx_blob as following:
tdx_blob
|- u16 version
|- u16 checksum
|- u32 offset_of_module --------------------------------------|
|- u8 signature[8] |
|- u32 len 8KB + (N * 4KB) |
|- u32 resv1 |
|- u64 resv2[509] |
|- u8 data[] |
|- _u64 sigstruct[256] //2KB sigstruct |
|- _u64 reserved2[256] |
|- _u64 reserved3[N*512] //4KB aligned, optional, N >=0 |
|- _u8 module[] //<-----------------------------|
Sorry about the mess.
tdx_blob
|- u16 version
|- u16 checksum
|- u32 offset_of_module --------------------------------------|
|- u8 signature[8] |
|- u32 len 8KB + (N * 4KB) |
|- u32 resv1 |
|- u64 resv2[509] |
|- u8 data[] |
|- _u64 sigstruct[256] //2KB sigstruct |
|- _u64 reserved2[256] |
|- _u64 reserved3[N*512] //4KB aligned, optional, N >=0 |
|- _u8 module[] //<-----------------------------|
If N is not 0 for reserved3, then the sig_size passed will not be 4KB.