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

[Adrian Hunter]

On 2/12/24 04:52, Chao Gao wrote:
>>>> /* 
>>>> * 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?

Bit 17 and 18 should also be in TDX_XFAM_XCR0_MASK
TDX Module does define them, from TDX Module sources:

	#define XCR0_USER_BIT_MASK                  0x000602FF

Thanks for spotting that!

> 
>>>> */
>>>> #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)