linux-kernel - Re: [PATCH v3 05/16] x86/virt/tdx: Allocate reference counters for PAMT memory

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Message-ID: <c8b69a9c5709d8bc482ce724f23da01e8d151727.camel@intel.com>
Date: Mon, 29 Sep 2025 17:41:38 +0000
From: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
To: "binbin.wu@...ux.intel.com" <binbin.wu@...ux.intel.com>
CC: "kvm@...r.kernel.org" <kvm@...r.kernel.org>, "linux-coco@...ts.linux.dev"
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Subject: Re: [PATCH v3 05/16] x86/virt/tdx: Allocate reference counters for
 PAMT memory

On Tue, 2025-09-23 at 15:45 +0800, Binbin Wu wrote:
> > +/*
> > + * Allocate PAMT reference counters for all physical memory.
> > + *
> > + * It consumes 2MiB for every 1TiB of physical memory.
> > + */
> > +static int init_pamt_metadata(void)
> > +{
> > +	size_t size = max_pfn / PTRS_PER_PTE * sizeof(*pamt_refcounts);
> 
> Is there guarantee that max_pfn is PTRS_PER_PTE aligned?
> If not, it should be rounded up.

Vmalloc() should handle it?