From: Nikolay Borisov <nik.borisov@suse.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
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
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Peter Zijlstra <peterz@infradead.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: [PATCHv6 09/16] x86/mm: Adding callbacks to prepare encrypted memory for kexec
Date: Mon, 29 Jan 2024 09:22:13 +0200 [thread overview]
Message-ID: <fed13d3d-c87c-4e5c-9451-779200c35a1c@suse.com> (raw)
In-Reply-To: <20240124125557.493675-10-kirill.shutemov@linux.intel.com>
On 24.01.24 г. 14:55 ч., Kirill A. Shutemov wrote:
> AMD SEV and Intel TDX guests allocate shared buffers for performing I/O.
> This is done by allocating pages normally from the buddy allocator and
> then converting them to shared using set_memory_decrypted().
>
> On kexec, the second kernel is unaware of which memory has been
> converted in this manner. It only sees E820_TYPE_RAM. Accessing shared
> memory as private is fatal.
>
> Therefore, the memory state must be reset to its original state before
> starting the new kernel with kexec.
>
> The process of converting shared memory back to private occurs in two
> steps:
>
> - enc_kexec_stop_conversion() stops new conversions.
>
> - enc_kexec_unshare_mem() unshares all existing shared memory, reverting
> it back to private.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
next prev parent reply other threads:[~2024-01-29 7:22 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-24 12:55 [PATCHv6 00/16] x86/tdx: Add kexec support Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 01/16] x86/acpi: Extract ACPI MADT wakeup code into a separate file Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 02/16] x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 03/16] cpu/hotplug: Add support for declaring CPU offlining not supported Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 04/16] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 05/16] x86/kexec: Keep CR4.MCE set during kexec for TDX guest Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 06/16] x86/mm: Make x86_platform.guest.enc_status_change_*() return errno Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 07/16] x86/mm: Return correct level from lookup_address() if pte is none Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 08/16] x86/tdx: Account shared memory Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 09/16] x86/mm: Adding callbacks to prepare encrypted memory for kexec Kirill A. Shutemov
2024-01-29 7:22 ` Nikolay Borisov [this message]
2024-01-24 12:55 ` [PATCHv6 10/16] x86/tdx: Convert shared memory back to private on kexec Kirill A. Shutemov
2024-01-29 10:24 ` Kalra, Ashish
2024-01-29 10:36 ` Kirill A. Shutemov
2024-01-29 13:09 ` Kalra, Ashish
2024-01-29 13:34 ` Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 11/16] x86/mm: Make e820_end_ram_pfn() cover E820_TYPE_ACPI ranges Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 12/16] x86/acpi: Rename fields in acpi_madt_multiproc_wakeup structure Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 13/16] x86/acpi: Do not attempt to bring up secondary CPUs in kexec case Kirill A. Shutemov
2024-01-24 12:55 ` [PATCHv6 14/16] x86/smp: Add smp_ops.stop_this_cpu() callback Kirill A. Shutemov
2024-01-26 14:08 ` Huang, Kai
2024-01-24 12:55 ` [PATCHv6 15/16] x86/mm: Introduce kernel_ident_mapping_free() Kirill A. Shutemov
2024-01-26 14:10 ` Huang, Kai
2024-01-24 12:55 ` [PATCHv6 16/16] x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method Kirill A. Shutemov
2024-01-26 14:21 ` Huang, Kai
2024-01-27 18:15 ` kirill.shutemov
2024-01-26 20:03 ` Kuppuswamy Sathyanarayanan
2024-01-27 19:35 ` Kirill A. Shutemov
2024-01-30 13:43 ` [PATCHv6 00/16] x86/tdx: Add kexec support Paolo Bonzini
2024-01-30 13:55 ` Kirill A. Shutemov
2024-01-30 14:59 ` Paolo Bonzini
2024-01-30 15:15 ` Kirill A. Shutemov
2024-01-30 14:04 ` Huang, Kai
2024-01-31 7:31 ` Nikolay Borisov
2024-01-31 12:47 ` Baoquan He
2024-01-31 12:58 ` Nikolay Borisov
2024-01-31 13:07 ` Huang, Kai
2024-01-31 15:23 ` Baoquan He
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