From: Dan Williams <dan.j.williams@intel.com>
To: Kai Huang <kai.huang@intel.com>, <linux-kernel@vger.kernel.org>,
<kvm@vger.kernel.org>
Cc: <linux-mm@kvack.org>, <seanjc@google.com>, <pbonzini@redhat.com>,
<dave.hansen@intel.com>, <dan.j.williams@intel.com>,
<rafael.j.wysocki@intel.com>, <kirill.shutemov@linux.intel.com>,
<ying.huang@intel.com>, <reinette.chatre@intel.com>,
<len.brown@intel.com>, <tony.luck@intel.com>,
<peterz@infradead.org>, <ak@linux.intel.com>,
<isaku.yamahata@intel.com>, <chao.gao@intel.com>,
<sathyanarayanan.kuppuswamy@linux.intel.com>,
<bagasdotme@gmail.com>, <sagis@google.com>, <imammedo@redhat.com>,
<kai.huang@intel.com>
Subject: RE: [PATCH v7 10/20] x86/virt/tdx: Use all system memory when initializing TDX module as TDX memory
Date: Wed, 23 Nov 2022 17:50:37 -0800 [thread overview]
Message-ID: <637ecded7b0f9_160eb329418@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <9b545148275b14a8c7edef1157f8ec44dc8116ee.1668988357.git.kai.huang@intel.com>
Kai Huang wrote:
> TDX reports a list of "Convertible Memory Region" (CMR) to indicate all
> memory regions that can possibly be used by the TDX module, but they are
> not automatically usable to the TDX module. As a step of initializing
> the TDX module, the kernel needs to choose a list of memory regions (out
> from convertible memory regions) that the TDX module can use and pass
> those regions to the TDX module. Once this is done, those "TDX-usable"
> memory regions are fixed during module's lifetime. No more TDX-usable
> memory can be added to the TDX module after that.
>
> The initial support of TDX guests will only allocate TDX guest memory
> from the global page allocator. To keep things simple, this initial
> implementation simply guarantees all pages in the page allocator are TDX
> memory. To achieve this, use all system memory in the core-mm at the
> time of initializing the TDX module as TDX memory, and at the meantime,
> refuse to add any non-TDX-memory in the memory hotplug.
>
> Specifically, walk through all memory regions managed by memblock and
> add them to a global list of "TDX-usable" memory regions, which is a
> fixed list after the module initialization (or empty if initialization
> fails). To reject non-TDX-memory in memory hotplug, add an additional
> check in arch_add_memory() to check whether the new region is covered by
> any region in the "TDX-usable" memory region list.
>
> Note this requires all memory regions in memblock are TDX convertible
> memory when initializing the TDX module. This is true in practice if no
> new memory has been hot-added before initializing the TDX module, since
> in practice all boot-time present DIMM is TDX convertible memory. If
> any new memory has been hot-added, then initializing the TDX module will
> fail due to that memory region is not covered by CMR.
>
> This can be enhanced in the future, i.e. by allowing adding non-TDX
> memory to a separate NUMA node. In this case, the "TDX-capable" nodes
> and the "non-TDX-capable" nodes can co-exist, but the kernel/userspace
> needs to guarantee memory pages for TDX guests are always allocated from
> the "TDX-capable" nodes.
>
> Note TDX assumes convertible memory is always physically present during
> machine's runtime. A non-buggy BIOS should never support hot-removal of
> any convertible memory. This implementation doesn't handle ACPI memory
> removal but depends on the BIOS to behave correctly.
>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---
>
> v6 -> v7:
> - Changed to use all system memory in memblock at the time of
> initializing the TDX module as TDX memory
> - Added memory hotplug support
>
> ---
> arch/x86/Kconfig | 1 +
> arch/x86/include/asm/tdx.h | 3 +
> arch/x86/mm/init_64.c | 10 ++
> arch/x86/virt/vmx/tdx/tdx.c | 183 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 197 insertions(+)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index dd333b46fafb..b36129183035 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1959,6 +1959,7 @@ config INTEL_TDX_HOST
> depends on X86_64
> depends on KVM_INTEL
> depends on X86_X2APIC
> + select ARCH_KEEP_MEMBLOCK
> help
> Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
> host and certain physical attacks. This option enables necessary TDX
> diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
> index d688228f3151..71169ecefabf 100644
> --- a/arch/x86/include/asm/tdx.h
> +++ b/arch/x86/include/asm/tdx.h
> @@ -111,9 +111,12 @@ static inline long tdx_kvm_hypercall(unsigned int nr, unsigned long p1,
> #ifdef CONFIG_INTEL_TDX_HOST
> bool platform_tdx_enabled(void);
> int tdx_enable(void);
> +bool tdx_cc_memory_compatible(unsigned long start_pfn, unsigned long end_pfn);
> #else /* !CONFIG_INTEL_TDX_HOST */
> static inline bool platform_tdx_enabled(void) { return false; }
> static inline int tdx_enable(void) { return -ENODEV; }
> +static inline bool tdx_cc_memory_compatible(unsigned long start_pfn,
> + unsigned long end_pfn) { return true; }
> #endif /* CONFIG_INTEL_TDX_HOST */
>
> #endif /* !__ASSEMBLY__ */
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index 3f040c6e5d13..900341333d7e 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -55,6 +55,7 @@
> #include <asm/uv/uv.h>
> #include <asm/setup.h>
> #include <asm/ftrace.h>
> +#include <asm/tdx.h>
>
> #include "mm_internal.h"
>
> @@ -968,6 +969,15 @@ int arch_add_memory(int nid, u64 start, u64 size,
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
>
> + /*
> + * For now if TDX is enabled, all pages in the page allocator
> + * must be TDX memory, which is a fixed set of memory regions
> + * that are passed to the TDX module. Reject the new region
> + * if it is not TDX memory to guarantee above is true.
> + */
> + if (!tdx_cc_memory_compatible(start_pfn, start_pfn + nr_pages))
> + return -EINVAL;
arch_add_memory() does not add memory to the page allocator. For
example, memremap_pages() uses arch_add_memory() and explicitly does not
release the memory to the page allocator. This check belongs in
add_memory_resource() to prevent new memory that violates TDX from being
onlined. Hopefully there is also an option to disable TDX from the
kernel boot command line to recover memory-hotplug without needing to
boot into the BIOS to toggle TDX.
next prev parent reply other threads:[~2022-11-24 1:50 UTC|newest]
Thread overview: 163+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-21 0:26 [PATCH v7 00/20] TDX host kernel support Kai Huang
2022-11-21 0:26 ` [PATCH v7 01/20] x86/tdx: Define TDX supported page sizes as macros Kai Huang
2022-11-21 2:52 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:15 ` Huang, Kai
2022-11-21 17:23 ` Sathyanarayanan Kuppuswamy
2022-11-21 18:12 ` Dave Hansen
2022-11-21 23:48 ` Dave Hansen
2022-11-22 0:01 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 02/20] x86/virt/tdx: Detect TDX during kernel boot Kai Huang
2022-11-21 3:07 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:37 ` Huang, Kai
2022-11-21 23:57 ` Sathyanarayanan Kuppuswamy
2022-11-22 0:10 ` Dave Hansen
2022-11-22 11:28 ` Huang, Kai
2022-11-22 16:50 ` Dave Hansen
2022-11-22 23:21 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 03/20] x86/virt/tdx: Disable TDX if X2APIC is not enabled Kai Huang
2022-11-21 3:51 ` Sathyanarayanan Kuppuswamy
2022-11-21 9:44 ` Huang, Kai
2022-11-21 22:00 ` Sathyanarayanan Kuppuswamy
2022-11-21 23:40 ` Huang, Kai
2022-11-21 23:46 ` Dave Hansen
2022-11-22 0:30 ` Huang, Kai
2022-11-22 0:44 ` Dave Hansen
2022-11-22 0:58 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 04/20] x86/virt/tdx: Add skeleton to initialize TDX on demand Kai Huang
2022-11-22 9:02 ` Peter Zijlstra
2022-11-22 10:31 ` Thomas Gleixner
2022-11-22 15:35 ` Dave Hansen
2022-11-22 20:03 ` Thomas Gleixner
2022-11-22 20:11 ` Sean Christopherson
2022-11-23 0:30 ` Huang, Kai
2022-11-23 1:12 ` Huang, Kai
2022-11-23 11:05 ` Thomas Gleixner
2022-11-23 12:22 ` Huang, Kai
2022-11-22 18:05 ` Dave Hansen
2022-11-23 10:18 ` Huang, Kai
2022-11-23 16:58 ` Dave Hansen
2022-11-23 21:58 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 05/20] x86/virt/tdx: Implement functions to make SEAMCALL Kai Huang
2022-11-22 9:06 ` Peter Zijlstra
2022-11-23 8:53 ` Huang, Kai
2022-11-22 18:20 ` Dave Hansen
2022-11-23 10:43 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 06/20] x86/virt/tdx: Shut down TDX module in case of error Kai Huang
2022-11-22 9:10 ` Peter Zijlstra
2022-11-22 9:13 ` Peter Zijlstra
2022-11-22 15:14 ` Dave Hansen
2022-11-22 19:13 ` Peter Zijlstra
2022-11-22 19:24 ` Dave Hansen
2022-11-22 19:33 ` Peter Zijlstra
2022-11-23 1:14 ` Huang, Kai
2022-11-29 21:40 ` Dave Hansen
2022-11-30 11:09 ` Thomas Gleixner
2022-11-23 0:58 ` Huang, Kai
2022-11-23 1:04 ` Dave Hansen
2022-11-23 1:22 ` Huang, Kai
2022-11-23 16:20 ` Sean Christopherson
2022-11-23 16:41 ` Dave Hansen
2022-11-23 17:37 ` Sean Christopherson
2022-11-23 18:18 ` Dave Hansen
2022-11-23 19:03 ` Sean Christopherson
2022-11-22 9:20 ` Peter Zijlstra
2022-11-22 15:06 ` Thomas Gleixner
2022-11-22 19:06 ` Peter Zijlstra
2022-11-22 19:31 ` Sean Christopherson
2022-11-23 9:39 ` Huang, Kai
2022-11-22 15:20 ` Dave Hansen
2022-11-22 16:52 ` Thomas Gleixner
2022-11-22 18:57 ` Dave Hansen
2022-11-22 19:14 ` Peter Zijlstra
2022-11-23 1:24 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 07/20] x86/virt/tdx: Do TDX module global initialization Kai Huang
2022-11-22 19:14 ` Dave Hansen
2022-11-23 11:45 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 08/20] x86/virt/tdx: Do logical-cpu scope TDX module initialization Kai Huang
2022-11-21 0:26 ` [PATCH v7 09/20] x86/virt/tdx: Get information about TDX module and TDX-capable memory Kai Huang
2022-11-22 23:39 ` Dave Hansen
2022-11-23 11:40 ` Huang, Kai
2022-11-23 16:44 ` Dave Hansen
2022-11-23 22:53 ` Huang, Kai
2022-12-02 11:19 ` Huang, Kai
2022-12-02 17:25 ` Dave Hansen
2022-12-02 21:57 ` Huang, Kai
2022-12-02 11:11 ` Huang, Kai
2022-12-02 17:06 ` Dave Hansen
2022-12-02 21:56 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 10/20] x86/virt/tdx: Use all system memory when initializing TDX module as TDX memory Kai Huang
2022-11-21 5:37 ` Huang, Ying
2022-11-21 9:09 ` Huang, Kai
2022-11-22 1:54 ` Huang, Ying
2022-11-22 9:16 ` Huang, Kai
2022-11-24 0:47 ` Huang, Ying
2022-11-22 10:10 ` Peter Zijlstra
2022-11-22 11:40 ` Huang, Kai
2022-11-23 0:21 ` Dave Hansen
2022-11-23 9:29 ` Peter Zijlstra
2022-11-24 1:04 ` Huang, Kai
2022-11-24 1:22 ` Dave Hansen
2022-11-24 2:27 ` Huang, Kai
2022-11-24 1:50 ` Dan Williams [this message]
2022-11-24 9:06 ` Huang, Kai
2022-11-25 9:28 ` David Hildenbrand
2022-11-28 8:38 ` Huang, Kai
2022-11-28 8:43 ` David Hildenbrand
2022-11-28 9:21 ` Huang, Kai
2022-11-28 9:26 ` David Hildenbrand
2022-11-28 9:50 ` Huang, Kai
2022-11-24 9:26 ` Peter Zijlstra
2022-11-24 10:02 ` Huang, Kai
2022-11-30 22:26 ` Dave Hansen
2022-11-21 0:26 ` [PATCH v7 11/20] x86/virt/tdx: Add placeholder to construct TDMRs to cover all TDX memory regions Kai Huang
2022-11-23 22:17 ` Dave Hansen
2022-11-24 9:51 ` Huang, Kai
2022-11-24 12:02 ` Huang, Kai
2022-11-28 15:59 ` Dave Hansen
2022-11-28 22:13 ` Huang, Kai
2022-11-28 22:19 ` Dave Hansen
2022-11-28 22:50 ` Huang, Kai
2022-12-07 11:47 ` Huang, Kai
2022-12-08 12:56 ` Huang, Kai
2022-12-08 14:58 ` Dave Hansen
2022-12-08 23:29 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 12/20] x86/virt/tdx: Create " Kai Huang
2022-11-23 22:41 ` Dave Hansen
2022-11-24 11:29 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 13/20] x86/virt/tdx: Allocate and set up PAMTs for TDMRs Kai Huang
2022-11-23 22:57 ` Dave Hansen
2022-11-24 11:46 ` Huang, Kai
2022-11-28 16:39 ` Dave Hansen
2022-11-28 22:48 ` Huang, Kai
2022-11-28 22:56 ` Dave Hansen
2022-11-28 23:14 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 14/20] x86/virt/tdx: Set up reserved areas for all TDMRs Kai Huang
2022-11-23 23:39 ` Dave Hansen
2022-11-28 9:14 ` Huang, Kai
2022-11-28 13:18 ` Dave Hansen
2022-11-28 22:24 ` Huang, Kai
2022-11-28 22:58 ` Dave Hansen
2022-11-28 23:10 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 15/20] x86/virt/tdx: Reserve TDX module global KeyID Kai Huang
2022-11-23 23:40 ` Dave Hansen
2022-11-24 22:39 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 16/20] x86/virt/tdx: Configure TDX module with TDMRs and " Kai Huang
2022-11-23 23:56 ` Dave Hansen
2022-11-25 0:59 ` Huang, Kai
2022-11-25 1:18 ` Dave Hansen
2022-11-25 1:44 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 17/20] x86/virt/tdx: Configure global KeyID on all packages Kai Huang
2022-11-24 0:28 ` Dave Hansen
2022-11-24 22:28 ` Huang, Kai
2022-11-25 0:08 ` Huang, Kai
2022-11-30 3:35 ` Binbin Wu
2022-11-30 8:34 ` Huang, Kai
2022-11-30 14:04 ` kirill.shutemov
2022-11-30 15:13 ` Dave Hansen
2022-11-30 20:17 ` Huang, Kai
2022-11-30 17:37 ` Dave Hansen
2022-11-21 0:26 ` [PATCH v7 18/20] x86/virt/tdx: Initialize all TDMRs Kai Huang
2022-11-24 0:42 ` Dave Hansen
2022-11-25 2:27 ` Huang, Kai
2022-11-21 0:26 ` [PATCH v7 19/20] x86/virt/tdx: Flush cache in kexec() when TDX is enabled Kai Huang
2022-11-21 0:26 ` [PATCH v7 20/20] Documentation/x86: Add documentation for TDX host support Kai Huang
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