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Message-ID: <24713e0d-779f-4084-ba5c-7375d4b05955@linux.intel.com>
Date: Fri, 19 Apr 2024 11:03:28 -0700
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Subject: Re: [PATCH 15/14] x86/gds: Lock GDS mitigation when keylocker feature
 is present
To: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
 linux-kernel@vger.kernel.org
Cc: x86@kernel.org, dan.j.williams@intel.com, bernie.keany@intel.com,
 charishma1.gairuboyina@intel.com, chang.seok.bae@intel.com,
 Josh Poimboeuf <jpoimboe@kernel.org>, antonio.gomez.iglesias@linux.intel.com
References: <20240407230432.912290-1-chang.seok.bae@intel.com>
 <20240419-gds-lock-v1-1-adcbef6ce24b@linux.intel.com>
Content-Language: en-US
From: Daniel Sneddon <daniel.sneddon@linux.intel.com>
In-Reply-To: <20240419-gds-lock-v1-1-adcbef6ce24b@linux.intel.com>
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On 4/19/24 10:47, Pawan Gupta wrote:
> +	u64 gds_lock = 0;
>  
>  	switch (gds_mitigation) {
>  	case GDS_MITIGATION_OFF:
> @@ -769,6 +769,8 @@ void update_gds_msr(void)
>  		 * the same state. Make sure the mitigation is enabled on all
>  		 * CPUs.
>  		 */
> +		gds_lock = GDS_MITG_LOCKED;
Can't we just drop the new gds_lock var and set mcu_ctrl |= GDS_MITG_LOCKED here?
> +		fallthrough;
>  	case GDS_MITIGATION_FULL:
>  		rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl);
>  		mcu_ctrl &= ~GDS_MITG_DIS;
> @@ -779,6 +781,7 @@ void update_gds_msr(void)
>  		return;
>  	}
>  
> +	mcu_ctrl |= gds_lock;
>  	wrmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl);