Re: [PATCH v2 4/5] x86/virt/tdx: Add extra memory to TDX module for the extensions

[Edgecombe, Rick P]

Hey Kiryl,

On Tue, 2026-09-15 at 18:26 +0800, Xu Yilun wrote:
> An alternative solution is to use a loop that gives memory on a memory
> error code - TDX_EXT_MEMORY_POOL_REQUIRED, add one page per iteration
> until TDH.EXT.INIT succeeds. Something like:
> 
> 	do {
> 		ret = tdh_sys_init();
> 		if (ret == TDX_EXT_MEMORY_POOL_REQUIRED)
> 			tdh_ext_mem_add(); //single page
> 	} while (ret == TDX_EXT_MEMORY_POOL_REQUIRED);
> 
> This approach is slightly simpler as we don't have to query the module
> for the total memory, no memory pre-allocation or segmentation math.
> But allocating a single 4K page per iteration may cause permanent memory
> fragmentation.

So this is definitely a bad thing to do? Even if this is running at boot before
much fragmentation could have happened? Don't early boot allocations tend to be
more physically contiguous?