Re: [PATCH v8 05/16] x86/sev: Cache the secrets page address

From: "Nikunj A. Dadhania" <nikunj@amd.com>
To: Borislav Petkov <bp@alien8.de>
Cc: linux-kernel@vger.kernel.org, thomas.lendacky@amd.com,
	x86@kernel.org, kvm@vger.kernel.org, mingo@redhat.com,
	tglx@linutronix.de, dave.hansen@linux.intel.com,
	pgonda@google.com, seanjc@google.com, pbonzini@redhat.com
Subject: Re: [PATCH v8 05/16] x86/sev: Cache the secrets page address
Date: Wed, 17 Apr 2024 13:29:53 +0530	[thread overview]
Message-ID: <d97c6518-b434-42da-bd12-88cf432d1163@amd.com> (raw)
In-Reply-To: <c08e7493-2fde-4624-9395-d1b8b5ab47c7@amd.com>

On 4/17/2024 10:57 AM, Nikunj A. Dadhania wrote:
> On 4/16/2024 8:15 PM, Borislav Petkov wrote:
>> On Thu, Feb 15, 2024 at 05:01:17PM +0530, Nikunj A Dadhania wrote:
>>> +/* Secrets page physical address from the CC blob */
>>> +static u64 secrets_pa __ro_after_init;
>>
>> Since you're going to use this during runtime (are you?), 
> 
> Yes, this is used during runtime, during initial boot will be used by Secure TSC and later by sev-guest driver.
> 
>> why don't you put in here the result of:
>>
>> 	ioremap_encrypted(secrets_pa, PAGE_SIZE);
>>
>> so that you can have it ready and not even have to ioremap each time?
> 

> @@ -2118,6 +2083,14 @@ bool __init snp_init(struct boot_params *bp)
>  	if (!cc_info)
>  		return false;
>  
> +	if (cc_info->secrets_phys && cc_info->secrets_len == PAGE_SIZE) {
> +		secrets_page = ioremap_encrypted(cc_info->secrets_phys, PAGE_SIZE);

ioremap_encrypted() does not work this early, snp guest boot fails, will debug further.

Regards,
Nikunj