Re: [PATCHv6 28/30] x86/tdx: ioapic: Add shared bit for IOAPIC base address

Thomas Gleixner
2022-03-17T15:00:14Z

On Wed, Mar 16 2022 at 05:08, Kirill A. Shutemov wrote:
> Introduce a special fixmap helper just for the IOAPIC code. Ensure
> that it marks IOAPIC pages as "shared". This replaces
> set_fixmap_nocache() with __set_fixmap() since __set_fixmap()
> allows custom 'prot' values.
>
> AMD SEV gets IOAPIC pages shared because FIXMAP_PAGE_NOCACHE has _ENC
> bit clear. TDX has to set bit to share the page with the host.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>