Re: [PATCH 4/7] KVM: TDX: restore host xsave state when exit from the guest TD

[Chao Gao]

>>> /* 
>>> * Before returning from TDH.VP.ENTER, the TDX Module assigns:
>>> *   XCR0 to the TD’s user-mode feature bits of XFAM (bits 7:0, 9)
>>> *   IA32_XSS to the TD's supervisor-mode feature bits of XFAM (bits 8, 16:10)

TILECFG state (bit 17) and TILEDATA state (bit 18) are also user state. Are they
cleared unconditionally?

>>> */
>>> #define TDX_XFAM_XCR0_MASK	(GENMASK(7, 0) | BIT(9))
>>> #define TDX_XFAM_XSS_MASK	(GENMASK(16, 10) | BIT(8))
>>> #define TDX_XFAM_MASK		(TDX_XFAM_XCR0_MASK | TDX_XFAM_XSS_MASK)