Messages in this thread Patch in this message | | | Date | Thu, 27 Oct 2022 16:51:34 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH v6 01/21] x86/tdx: Use enum to define page level of TDX supported page sizes |
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On Thu, Oct 27, 2022 at 08:42:16AM +0000, Huang, Kai wrote: > On Thu, 2022-10-27 at 15:08 +0800, Li, Xiaoyao wrote: > > > @@ -663,27 +662,16 @@ static bool try_accept_one(phys_addr_t *start, > > > unsigned long len, > > > if (len < accept_size) > > > return false; > > > > > > + /* TDX only supports 4K/2M/1G page sizes */ > > > > yes, a page can be mapped as 1G size to TD via secure/shared EPT. But > > for this particular TDX_ACCEPT_PAGE case, it only supports 4K and 2M > > currently, which is defined in TDX module spec. > > I checked the TDX module public spec, and it appears you are right. But I am > not sure whether it will be changed in the future?
The spec says:
Level of the Secure EPT entry that maps the private page to be accepted: either 0 (4KB) or 1 (2MB) – see 20.5.1
Yes, it is about 4k and 2M, but it also refers 20.5.1, which lists sizes up to 16PB.
Ultimately, it does not matter: if TDX module doesn't support the size or cannot accept the memory for other reason guest kernel will fallback to smaller size.
-- Kiryl Shutsemau / Kirill A. Shutemov
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