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author | 2023-06-26 15:32:39 -0700 | |
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committer | 2023-06-26 15:32:39 -0700 | |
commit | 2c96136a3f8dad6bfe35b003fb8b312f13a107e8 (patch) | |
tree | dcc5713059bf56cf70dfc4ec0d53ef7cbc88bcd1 /arch/x86/coco/tdx/tdx.c | |
parent | Merge tag 'x86_cache_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
parent | virt: sevguest: Add CONFIG_CRYPTO dependency (diff) | |
download | linux-2c96136a3f8dad6bfe35b003fb8b312f13a107e8.tar.gz linux-2c96136a3f8dad6bfe35b003fb8b312f13a107e8.tar.bz2 linux-2c96136a3f8dad6bfe35b003fb8b312f13a107e8.zip |
Merge tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 confidential computing update from Borislav Petkov:
- Add support for unaccepted memory as specified in the UEFI spec v2.9.
The gist of it all is that Intel TDX and AMD SEV-SNP confidential
computing guests define the notion of accepting memory before using
it and thus preventing a whole set of attacks against such guests
like memory replay and the like.
There are a couple of strategies of how memory should be accepted -
the current implementation does an on-demand way of accepting.
* tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt: sevguest: Add CONFIG_CRYPTO dependency
x86/efi: Safely enable unaccepted memory in UEFI
x86/sev: Add SNP-specific unaccepted memory support
x86/sev: Use large PSC requests if applicable
x86/sev: Allow for use of the early boot GHCB for PSC requests
x86/sev: Put PSC struct on the stack in prep for unaccepted memory support
x86/sev: Fix calculation of end address based on number of pages
x86/tdx: Add unaccepted memory support
x86/tdx: Refactor try_accept_one()
x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub
efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory
efi: Add unaccepted memory support
x86/boot/compressed: Handle unaccepted memory
efi/libstub: Implement support for unaccepted memory
efi/x86: Get full memory map in allocate_e820()
mm: Add support for unaccepted memory
Diffstat (limited to 'arch/x86/coco/tdx/tdx.c')
-rw-r--r-- | arch/x86/coco/tdx/tdx.c | 102 |
1 files changed, 3 insertions, 99 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 27ce10c9ff61..fe67c027a27b 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -14,20 +14,6 @@ #include <asm/insn-eval.h> #include <asm/pgtable.h> -/* TDX module Call Leaf IDs */ -#define TDX_GET_INFO 1 -#define TDX_GET_VEINFO 3 -#define TDX_GET_REPORT 4 -#define TDX_ACCEPT_PAGE 6 -#define TDX_WR 8 - -/* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */ -#define TDCS_NOTIFY_ENABLES 0x9100000000000010 - -/* TDX hypercall Leaf IDs */ -#define TDVMCALL_MAP_GPA 0x10001 -#define TDVMCALL_REPORT_FATAL_ERROR 0x10003 - /* MMIO direction */ #define EPT_READ 0 #define EPT_WRITE 1 @@ -51,24 +37,6 @@ #define TDREPORT_SUBTYPE_0 0 -/* - * Wrapper for standard use of __tdx_hypercall with no output aside from - * return code. - */ -static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15) -{ - struct tdx_hypercall_args args = { - .r10 = TDX_HYPERCALL_STANDARD, - .r11 = fn, - .r12 = r12, - .r13 = r13, - .r14 = r14, - .r15 = r15, - }; - - return __tdx_hypercall(&args); -} - /* Called from __tdx_hypercall() for unrecoverable failure */ noinstr void __tdx_hypercall_failed(void) { @@ -745,47 +713,6 @@ static bool tdx_cache_flush_required(void) return true; } -static bool try_accept_one(phys_addr_t *start, unsigned long len, - enum pg_level pg_level) -{ - unsigned long accept_size = page_level_size(pg_level); - u64 tdcall_rcx; - u8 page_size; - - if (!IS_ALIGNED(*start, accept_size)) - return false; - - if (len < accept_size) - return false; - - /* - * Pass the page physical address to the TDX module to accept the - * pending, private page. - * - * Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G. - */ - switch (pg_level) { - case PG_LEVEL_4K: - page_size = 0; - break; - case PG_LEVEL_2M: - page_size = 1; - break; - case PG_LEVEL_1G: - page_size = 2; - break; - default: - return false; - } - - tdcall_rcx = *start | page_size; - if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL)) - return false; - - *start += accept_size; - return true; -} - /* * Inform the VMM of the guest's intent for this physical page: shared with * the VMM or private to the guest. The VMM is expected to change its mapping @@ -810,32 +737,9 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) return false; - /* private->shared conversion requires only MapGPA call */ - if (!enc) - return true; - - /* - * For shared->private conversion, accept the page using - * TDX_ACCEPT_PAGE TDX module call. - */ - while (start < end) { - unsigned long len = end - start; - - /* - * Try larger accepts first. It gives chance to VMM to keep - * 1G/2M SEPT entries where possible and speeds up process by - * cutting number of hypercalls (if successful). - */ - - if (try_accept_one(&start, len, PG_LEVEL_1G)) - continue; - - if (try_accept_one(&start, len, PG_LEVEL_2M)) - continue; - - if (!try_accept_one(&start, len, PG_LEVEL_4K)) - return false; - } + /* shared->private conversion requires memory to be accepted before use */ + if (enc) + return tdx_accept_memory(start, end); return true; } |