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From: Juergen Gross <jgross@suse.com>
To: "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"x86@kernel.org" <x86@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v3.1 10/12] x86/mtrr: use new cache_map in mtrr_type_lookup()
Date: Mon, 27 Feb 2023 08:11:06 +0100	[thread overview]
Message-ID: <37c1ad33-e567-d120-08ba-4a30831c2509@suse.com> (raw)
In-Reply-To: <BYAPR21MB168858E9992B909FB7A8D7B8D7AE9@BYAPR21MB1688.namprd21.prod.outlook.com>


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On 26.02.23 18:00, Michael Kelley (LINUX) wrote:
> From: Juergen Gross <jgross@suse.com> Sent: Thursday, February 23, 2023 10:37 PM
>>
>> Instead of crawling through the MTRR register state, use the new
>> cache_map for looking up the cache type(s) of a memory region.
>>
>> This allows now to set the uniform parameter according to the
>> uniformity of the cache mode of the region, instead of setting it
>> only if the complete region is mapped by a single MTRR. This now
>> includes even the region covered by the fixed MTRR registers.
>>
>> Make sure uniform is always set.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>> V3:
>> - new patch
>> V3.1:
>> - fix type_merge() (Michael Kelley)
> 
> Thanks.  This version fixes the problem I previously reported with a normal
> VM.
> 
> However, I'm seeing a different problem in a Confidential VM where
> mtrr_overwrite_state() is used.  In this case, we have no MTRRs, and when
> mtrr_copy_map() is called, the copy is not done, and cache_map is set
> to NULL.  Subsequently when mtrr_type_lookup() is called, the check
> for a NULL cache_map causes MTRR_TYPE_UNCACHABLE to be returned.
> Then we're back to the original problem where pat_x_mtrr_type()
> returns UC- instead of WB.

Sigh. Just removing the test for cache_map being NULL in mtrr_type_lookup()
should do the job.

Will send V4 soon.


Juergen

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  reply	other threads:[~2023-02-27  7:11 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-23  9:32 [PATCH v3 00/12] x86/mtrr: fix handling with PAT but without MTRR Juergen Gross
2023-02-23  9:32 ` [PATCH v3 01/12] x86/mtrr: split off physical address size calculation Juergen Gross
2023-02-23  9:32 ` [PATCH v3 02/12] x86/mtrr: optimize mtrr_calc_physbits() Juergen Gross
2023-02-23  9:32 ` [PATCH v3 03/12] x86/mtrr: support setting MTRR state for software defined MTRRs Juergen Gross
2023-02-26 17:12   ` Michael Kelley (LINUX)
2023-02-27  7:13     ` Juergen Gross
2023-02-23  9:32 ` [PATCH v3 04/12] x86/hyperv: set MTRR state when running as SEV-SNP Hyper-V guest Juergen Gross
2023-02-23  9:32 ` [PATCH v3 05/12] x86/xen: set MTRR state when running as Xen PV initial domain Juergen Gross
     [not found]   ` <a7897030-d420-a741-074a-6e21e7c1629b@oracle.com>
2023-02-27  7:12     ` Juergen Gross
2023-02-27 13:52       ` Boris Ostrovsky
2023-02-27 13:56         ` Juergen Gross
2023-02-23  9:32 ` [PATCH v3 06/12] x86/mtrr: replace vendor tests in MTRR code Juergen Gross
2023-02-23  9:32 ` [PATCH v3 07/12] x86/mtrr: allocate mtrr_value array dynamically Juergen Gross
2023-02-23  9:32 ` [PATCH v3 08/12] x86/mtrr: add get_effective_type() service function Juergen Gross
2023-02-23  9:32 ` [PATCH v3 09/12] x86/mtrr: construct a memory map with cache modes Juergen Gross
2023-02-23  9:32 ` [PATCH v3 10/12] x86/mtrr: use new cache_map in mtrr_type_lookup() Juergen Gross
2023-02-23 19:24   ` Michael Kelley (LINUX)
2023-02-24  5:48     ` Juergen Gross
2023-02-24  6:37   ` [PATCH v3.1 " Juergen Gross
2023-02-26 17:00     ` Michael Kelley (LINUX)
2023-02-27  7:11       ` Juergen Gross [this message]
2023-02-23  9:32 ` [PATCH v3 11/12] x86/mtrr: don't let mtrr_type_lookup() return MTRR_TYPE_INVALID Juergen Gross
2023-02-23  9:32 ` [PATCH v3 12/12] x86/mm: only check uniform after calling mtrr_type_lookup() Juergen Gross

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