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From: Peter Zijlstra <peterz@infradead.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "Rafael J. Wysocki" <rafael@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Kuppuswamy Sathyanarayanan
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	Elena Reshetova <elena.reshetova@intel.com>,
	Jun Nakajima <jun.nakajima@intel.com>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	"Kalra, Ashish" <ashish.kalra@amd.com>,
	Sean Christopherson <seanjc@google.com>,
	"Huang, Kai" <kai.huang@intel.com>, Baoquan He <bhe@redhat.com>,
	kexec@lists.infradead.org, linux-coco@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 06/14] x86/kexec: Keep CR4.MCE set during kexec for TDX guest
Date: Wed, 15 Nov 2023 13:23:43 +0100	[thread overview]
Message-ID: <20231115122343.GA8262@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231115120044.8034-7-kirill.shutemov@linux.intel.com>

On Wed, Nov 15, 2023 at 03:00:36PM +0300, Kirill A. Shutemov wrote:
> TDX guests are not allowed to clear CR4.MCE. Attempt to clear it leads
> to #VE.
> 
> Use alternatives to keep the flag during kexec for TDX guests.
> 
> The change doesn't affect non-TDX-guest environments.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Kai Huang <kai.huang@intel.com>
> ---
>  arch/x86/kernel/relocate_kernel_64.S | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
> index 56cab1bb25f5..bea89814b48e 100644
> --- a/arch/x86/kernel/relocate_kernel_64.S
> +++ b/arch/x86/kernel/relocate_kernel_64.S
> @@ -145,11 +145,16 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
>  	 * Set cr4 to a known state:
>  	 *  - physical address extension enabled
>  	 *  - 5-level paging, if it was enabled before
> +	 *  - Machine check exception on TDX guest. Clearing MCE is not allowed
> +	 *    in TDX guests.
>  	 */
>  	movl	$X86_CR4_PAE, %eax
>  	testq	$X86_CR4_LA57, %r13
>  	jz	1f
>  	orl	$X86_CR4_LA57, %eax
> +1:
> +	ALTERNATIVE "jmp 1f", "", X86_FEATURE_TDX_GUEST
> +	orl	$X86_CR4_MCE, %eax
>  1:

	ALTERNATIVE "", "orl $X86_CR4_MCE, %eax", X86_FEATURE_TDX_GUEST

?

>  	movq	%rax, %cr4
>  
> -- 
> 2.41.0
> 

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "Rafael J. Wysocki" <rafael@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Kuppuswamy Sathyanarayanan
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	Elena Reshetova <elena.reshetova@intel.com>,
	Jun Nakajima <jun.nakajima@intel.com>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	"Kalra, Ashish" <ashish.kalra@amd.com>,
	Sean Christopherson <seanjc@google.com>,
	"Huang, Kai" <kai.huang@intel.com>, Baoquan He <bhe@redhat.com>,
	kexec@lists.infradead.org, linux-coco@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 06/14] x86/kexec: Keep CR4.MCE set during kexec for TDX guest
Date: Wed, 15 Nov 2023 13:23:43 +0100	[thread overview]
Message-ID: <20231115122343.GA8262@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231115120044.8034-7-kirill.shutemov@linux.intel.com>

On Wed, Nov 15, 2023 at 03:00:36PM +0300, Kirill A. Shutemov wrote:
> TDX guests are not allowed to clear CR4.MCE. Attempt to clear it leads
> to #VE.
> 
> Use alternatives to keep the flag during kexec for TDX guests.
> 
> The change doesn't affect non-TDX-guest environments.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Kai Huang <kai.huang@intel.com>
> ---
>  arch/x86/kernel/relocate_kernel_64.S | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
> index 56cab1bb25f5..bea89814b48e 100644
> --- a/arch/x86/kernel/relocate_kernel_64.S
> +++ b/arch/x86/kernel/relocate_kernel_64.S
> @@ -145,11 +145,16 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
>  	 * Set cr4 to a known state:
>  	 *  - physical address extension enabled
>  	 *  - 5-level paging, if it was enabled before
> +	 *  - Machine check exception on TDX guest. Clearing MCE is not allowed
> +	 *    in TDX guests.
>  	 */
>  	movl	$X86_CR4_PAE, %eax
>  	testq	$X86_CR4_LA57, %r13
>  	jz	1f
>  	orl	$X86_CR4_LA57, %eax
> +1:
> +	ALTERNATIVE "jmp 1f", "", X86_FEATURE_TDX_GUEST
> +	orl	$X86_CR4_MCE, %eax
>  1:

	ALTERNATIVE "", "orl $X86_CR4_MCE, %eax", X86_FEATURE_TDX_GUEST

?

>  	movq	%rax, %cr4
>  
> -- 
> 2.41.0
> 

  reply	other threads:[~2023-11-15 12:23 UTC|newest]

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-15 12:00 [PATCHv3 00/14] x86/tdx: Add kexec support Kirill A. Shutemov
2023-11-15 12:00 ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 01/14] x86/acpi: Extract ACPI MADT wakeup code into a separate file Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-21  2:08   ` Huang, Kai
2023-11-21  2:08     ` Huang, Kai
2023-11-15 12:00 ` [PATCHv3 02/14] x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-21  2:08   ` Huang, Kai
2023-11-21  2:08     ` Huang, Kai
2023-11-15 12:00 ` [PATCHv3 03/14] cpu/hotplug: Add support for declaring CPU offlining not supported Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-21  2:15   ` Huang, Kai
2023-11-21  2:15     ` Huang, Kai
2023-11-21  9:31     ` kirill.shutemov
2023-11-21  9:31       ` kirill.shutemov
2023-11-15 12:00 ` [PATCHv3 04/14] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 05/14] x86/kvm: Do not try to disable kvmclock if it was not enabled Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 06/14] x86/kexec: Keep CR4.MCE set during kexec for TDX guest Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:23   ` Peter Zijlstra [this message]
2023-11-15 12:23     ` Peter Zijlstra
2023-11-15 13:03     ` Kirill A. Shutemov
2023-11-15 13:03       ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 07/14] x86/mm: Make x86_platform.guest.enc_status_change_*() return errno Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 08/14] x86/mm: Return correct level from lookup_address() if pte is none Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 09/14] x86/tdx: Account shared memory Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-21  2:47   ` Huang, Kai
2023-11-21  2:47     ` Huang, Kai
2023-11-21  9:42     ` kirill.shutemov
2023-11-21  9:42       ` kirill.shutemov
2023-11-21  9:49       ` kirill.shutemov
2023-11-21  9:49         ` kirill.shutemov
2023-11-15 12:00 ` [PATCHv3 10/14] x86/tdx: Convert shared memory back to private on kexec Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-21  3:46   ` Huang, Kai
2023-11-21  3:46     ` Huang, Kai
2023-11-21  9:58     ` kirill.shutemov
2023-11-21  9:58       ` kirill.shutemov
2023-11-22 10:07       ` Huang, Kai
2023-11-22 10:07         ` Huang, Kai
2023-11-23 13:47         ` kirill.shutemov
2023-11-23 13:47           ` kirill.shutemov
2023-11-15 12:00 ` [PATCHv3 11/14] x86/mm: Make e820_end_ram_pfn() cover E820_TYPE_ACPI ranges Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 12/14] x86/acpi: Rename fields in acpi_madt_multiproc_wakeup structure Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 12:00 ` [PATCHv3 13/14] x86/acpi: Do not attempt to bring up secondary CPUs in kexec case Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 20:12   ` Kuppuswamy Sathyanarayanan
2023-11-15 20:12     ` Kuppuswamy Sathyanarayanan
2023-11-15 12:00 ` [PATCHv3 14/14] x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method Kirill A. Shutemov
2023-11-15 12:00   ` Kirill A. Shutemov
2023-11-15 20:30   ` kernel test robot
2023-11-23  9:38   ` Huang, Kai
2023-11-23  9:38     ` Huang, Kai
2023-12-01 15:57     ` kirill.shutemov
2023-12-01 15:57       ` kirill.shutemov
2023-12-04 22:43       ` Huang, Kai
2023-12-04 22:43         ` Huang, Kai
2023-11-16 12:10 ` [PATCHv3 00/14] x86/tdx: Add kexec support Baoquan He
2023-11-16 12:10   ` Baoquan He
2023-11-16 12:56   ` Kirill A. Shutemov
2023-11-16 12:56     ` Kirill A. Shutemov
2023-11-16 14:17     ` Baoquan He
2023-11-16 14:17       ` Baoquan He
2023-11-16 14:45       ` Baoquan He
2023-11-16 14:45         ` Baoquan He
2023-11-17 12:47         ` Kirill A. Shutemov
2023-11-17 12:47           ` Kirill A. Shutemov
2023-11-17 15:03           ` Baoquan He
2023-11-17 15:03             ` Baoquan He
2023-11-17 15:46             ` Kirill A. Shutemov
2023-11-17 15:46               ` Kirill A. Shutemov
2023-11-21  6:41               ` Baoquan He
2023-11-21  6:41                 ` Baoquan He
2023-11-21  8:43                 ` Kirill A. Shutemov
2023-11-21  8:43                   ` Kirill A. Shutemov
2023-11-21  9:10                   ` Tao Liu
2023-11-21  9:10                     ` Tao Liu
2023-11-21  9:24                     ` Kirill A. Shutemov
2023-11-21  9:24                       ` Kirill A. Shutemov
2023-11-21 10:15                   ` Baoquan He
2023-11-21 10:15                     ` Baoquan He
2023-11-21 10:40                     ` Kirill A. Shutemov
2023-11-21 10:40                       ` Kirill A. Shutemov
2023-11-21 12:50                       ` Baoquan He
2023-11-21 12:50                         ` Baoquan He
2023-11-28 15:45                 ` Isaku Yamahata
2023-11-28 15:45                   ` Isaku Yamahata

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