| Message ID | 20220425033934.68551-11-kirill.shutemov@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PATCHv5,01/12] x86/boot/: Centralize __pa()/__va() definitions | expand |
On Mon, Apr 25, 2022 at 06:39:32AM +0300, Kirill A. Shutemov wrote: > Subject: [PATCHv5 10/12] x86/tdx: Unaccepted memory support Patch subject needs a verb: "Add ... " > All preparations are complete. Drop this sentence. > Hookup TDX-specific code to accept memory. > > Accepting the memory is the same process as converting memory from > shared to private: kernel notifies VMM with MAP_GPA hypercall and then > accept pages with ACCEPT_PAGE module call. > > The implementation in core kernel uses tdx_enc_status_changed(). It > already used for converting memory to shared and back for I/O > transactions. > > Boot stub provides own implementation of tdx_accept_memory(). It is > similar in structure to tdx_enc_status_changed(), but only cares about > converting memory to private. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > arch/x86/Kconfig | 1 + > arch/x86/boot/compressed/mem.c | 24 ++++++++- > arch/x86/boot/compressed/tdx.c | 85 +++++++++++++++++++++++++++++++ > arch/x86/coco/tdx/tdx.c | 31 +++++++---- > arch/x86/include/asm/shared/tdx.h | 2 + > arch/x86/mm/unaccepted_memory.c | 9 +++- > 6 files changed, 141 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 7021ec725dd3..e4c31dbea6d7 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -885,6 +885,7 @@ config INTEL_TDX_GUEST > select ARCH_HAS_CC_PLATFORM > select X86_MEM_ENCRYPT > select X86_MCE > + select UNACCEPTED_MEMORY WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] Selected by [y]: - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] Selected by [y]: - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] > diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c > index b5058c975d26..539fff27de49 100644 > --- a/arch/x86/boot/compressed/mem.c > +++ b/arch/x86/boot/compressed/mem.c > @@ -5,6 +5,8 @@ > #include "error.h" > #include "find.h" > #include "math.h" > +#include "tdx.h" > +#include <asm/shared/tdx.h> > > #define PMD_SHIFT 21 > #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) > @@ -12,10 +14,30 @@ > > extern struct boot_params *boot_params; > > +static bool is_tdx_guest(void) There is arch/x86/boot/compressed/tdx.c which already looks at that leaf and detects crap. Why is that hastily slapped here too? > +{ > + static bool once; > + static bool is_tdx; > + > + if (!once) { > + u32 eax, sig[3]; > + > + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, > + &sig[0], &sig[2], &sig[1]); > + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); > + once = true; > + } > + > + return is_tdx; > +} > + > static inline void __accept_memory(phys_addr_t start, phys_addr_t end) > { > /* Platform-specific memory-acceptance call goes here */ > - error("Cannot accept memory"); > + if (is_tdx_guest()) > + tdx_accept_memory(start, end); > + else > + error("Cannot accept memory"); What is that supposed to catch? > diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c > index 918a7606f53c..57fd2bf28484 100644 > --- a/arch/x86/boot/compressed/tdx.c > +++ b/arch/x86/boot/compressed/tdx.c > @@ -3,12 +3,14 @@ > #include "../cpuflags.h" > #include "../string.h" > #include "../io.h" > +#include "align.h" > #include "error.h" > > #include <vdso/limits.h> > #include <uapi/asm/vmx.h> > > #include <asm/shared/tdx.h> > +#include <asm/page_types.h> > > /* Called from __tdx_hypercall() for unrecoverable failure */ > void __tdx_hypercall_failed(void) > @@ -75,3 +77,86 @@ void early_tdx_detect(void) > pio_ops.f_outb = tdx_outb; > pio_ops.f_outw = tdx_outw; > } > + > +enum pg_level { > + PG_LEVEL_4K, > + PG_LEVEL_2M, > + PG_LEVEL_1G, > +}; > + > +#define PTE_SHIFT 9 At least stick those in a header. > +static bool try_accept_one(phys_addr_t *start, unsigned long len, > + enum pg_level pg_level) No need to break that line. Also, it doesn't need to be bool - you can simply return accept_size on success and 0 on error so that you don't have an I/O argument. Ditto for the copy in coco/tdx/tdx.c > +{ > + unsigned long accept_size = PAGE_SIZE << (pg_level * PTE_SHIFT); > + 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; > +} > + > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) > +{ > + /* > + * Notify the VMM about page mapping conversion. More info about ABI > + * can be found in TDX Guest-Host-Communication Interface (GHCI), > + * section "TDG.VP.VMCALL<MapGPA>" > + */ > + if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) > + error("Accepting memory failed\n"); > + /* > + * 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 "SEPT"? > + * 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)) > + error("Accepting memory failed\n"); > + } > +} > diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c > index ddb60a87b426..ab4deb897942 100644 > --- a/arch/x86/coco/tdx/tdx.c > +++ b/arch/x86/coco/tdx/tdx.c > @@ -580,16 +580,9 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len, > 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 > - * of the page in response. > - */ > -static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > +static bool tdx_enc_status_changed_phys(phys_addr_t start, phys_addr_t end, Why? is tdx_enc_status_changed_virt() coming too? > + bool enc) > { > - phys_addr_t start = __pa(vaddr); > - phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); > - > if (!enc) { > /* Set the shared (decrypted) bits: */ > start |= cc_mkdec(0); > @@ -634,6 +627,25 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > return true; > } > > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) > +{ > + if (!tdx_enc_status_changed_phys(start, end, true)) > + panic("Accepting memory failed\n"); > +} > + > +/* > + * 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 > + * of the page in response. > + */ > +static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > +{ > + phys_addr_t start = __pa(vaddr); > + phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); > + > + return tdx_enc_status_changed_phys(start, end, enc); > +} > + > void __init tdx_early_init(void) > { > u64 cc_mask; > @@ -645,6 +657,7 @@ void __init tdx_early_init(void) > return; > > setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); > + setup_clear_cpu_cap(X86_FEATURE_MCE); What, no comment? Why does TDX need to disable MCE? > cc_set_vendor(CC_VENDOR_INTEL); > cc_mask = get_cc_mask(); > diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h > index 956ced04c3be..97534c334473 100644 > --- a/arch/x86/include/asm/shared/tdx.h > +++ b/arch/x86/include/asm/shared/tdx.h > @@ -81,5 +81,7 @@ struct tdx_module_output { > u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, > struct tdx_module_output *out); > > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end); > + > #endif /* !__ASSEMBLY__ */ > #endif /* _ASM_X86_SHARED_TDX_H */ > diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c > index 1327f64d5205..de0790af1824 100644 > --- a/arch/x86/mm/unaccepted_memory.c > +++ b/arch/x86/mm/unaccepted_memory.c > @@ -6,6 +6,7 @@ > > #include <asm/io.h> > #include <asm/setup.h> > +#include <asm/shared/tdx.h> > #include <asm/unaccepted_memory.h> > > /* Protects unaccepted memory bitmap */ > @@ -29,7 +30,13 @@ void accept_memory(phys_addr_t start, phys_addr_t end) > unsigned long len = range_end - range_start; > > /* Platform-specific memory-acceptance call goes here */ > - panic("Cannot accept memory"); > + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { > + tdx_accept_memory(range_start * PMD_SIZE, > + range_end * PMD_SIZE); > + } else { > + panic("Cannot accept memory"); Why panic here? A WARN_ONCE() should suffice, methinks.
On Thu, May 05, 2022 at 12:12:52PM +0200, Borislav Petkov wrote: > On Mon, Apr 25, 2022 at 06:39:32AM +0300, Kirill A. Shutemov wrote: > > Subject: [PATCHv5 10/12] x86/tdx: Unaccepted memory support > > Patch subject needs a verb: > > "Add ... " > > > All preparations are complete. > > Drop this sentence. > > > Hookup TDX-specific code to accept memory. > > > > Accepting the memory is the same process as converting memory from > > shared to private: kernel notifies VMM with MAP_GPA hypercall and then > > accept pages with ACCEPT_PAGE module call. > > > > The implementation in core kernel uses tdx_enc_status_changed(). It > > already used for converting memory to shared and back for I/O > > transactions. > > > > Boot stub provides own implementation of tdx_accept_memory(). It is > > similar in structure to tdx_enc_status_changed(), but only cares about > > converting memory to private. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > --- > > arch/x86/Kconfig | 1 + > > arch/x86/boot/compressed/mem.c | 24 ++++++++- > > arch/x86/boot/compressed/tdx.c | 85 +++++++++++++++++++++++++++++++ > > arch/x86/coco/tdx/tdx.c | 31 +++++++---- > > arch/x86/include/asm/shared/tdx.h | 2 + > > arch/x86/mm/unaccepted_memory.c | 9 +++- > > 6 files changed, 141 insertions(+), 11 deletions(-) > > > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > index 7021ec725dd3..e4c31dbea6d7 100644 > > --- a/arch/x86/Kconfig > > +++ b/arch/x86/Kconfig > > @@ -885,6 +885,7 @@ config INTEL_TDX_GUEST > > select ARCH_HAS_CC_PLATFORM > > select X86_MEM_ENCRYPT > > select X86_MCE > > + select UNACCEPTED_MEMORY > > WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY > Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] > Selected by [y]: > - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] > > WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY > Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] > Selected by [y]: > - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] Ughh. Any ideas how to get around it? (Except for implementing kexec support right away?) > > > > diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c > > index b5058c975d26..539fff27de49 100644 > > --- a/arch/x86/boot/compressed/mem.c > > +++ b/arch/x86/boot/compressed/mem.c > > @@ -5,6 +5,8 @@ > > #include "error.h" > > #include "find.h" > > #include "math.h" > > +#include "tdx.h" > > +#include <asm/shared/tdx.h> > > > > #define PMD_SHIFT 21 > > #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) > > @@ -12,10 +14,30 @@ > > > > extern struct boot_params *boot_params; > > > > +static bool is_tdx_guest(void) > > There is arch/x86/boot/compressed/tdx.c which already looks at that leaf > and detects crap. Why is that hastily slapped here too? I'm not happhy with this too. process_unaccepted_memory() called form EFI stub that called before decompression code. I'm not sure how to structure code that it makes sense. Call early_tdx_detect() from efi_main() in libstub/x86-stub.c? It would require to include tdx.h from decompression code there which is non-sense. I would appreciate an idea. > > +{ > > + static bool once; > > + static bool is_tdx; > > + > > + if (!once) { > > + u32 eax, sig[3]; > > + > > + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, > > + &sig[0], &sig[2], &sig[1]); > > + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); > > + once = true; > > + } > > + > > + return is_tdx; > > +} > > + > > static inline void __accept_memory(phys_addr_t start, phys_addr_t end) > > { > > /* Platform-specific memory-acceptance call goes here */ > > - error("Cannot accept memory"); > > + if (is_tdx_guest()) > > + tdx_accept_memory(start, end); > > + else > > + error("Cannot accept memory"); > > What is that supposed to catch? Booting on a platform that uses unaccepted memory, but kernel doesn't not support it. > > diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c > > index 918a7606f53c..57fd2bf28484 100644 > > --- a/arch/x86/boot/compressed/tdx.c > > +++ b/arch/x86/boot/compressed/tdx.c > > @@ -3,12 +3,14 @@ > > #include "../cpuflags.h" > > #include "../string.h" > > #include "../io.h" > > +#include "align.h" > > #include "error.h" > > > > #include <vdso/limits.h> > > #include <uapi/asm/vmx.h> > > > > #include <asm/shared/tdx.h> > > +#include <asm/page_types.h> > > > > /* Called from __tdx_hypercall() for unrecoverable failure */ > > void __tdx_hypercall_failed(void) > > @@ -75,3 +77,86 @@ void early_tdx_detect(void) > > pio_ops.f_outb = tdx_outb; > > pio_ops.f_outw = tdx_outw; > > } > > + > > +enum pg_level { > > + PG_LEVEL_4K, > > + PG_LEVEL_2M, > > + PG_LEVEL_1G, > > +}; > > + > > +#define PTE_SHIFT 9 > > At least stick those in a header. > > > +static bool try_accept_one(phys_addr_t *start, unsigned long len, > > + enum pg_level pg_level) > > No need to break that line. > > Also, it doesn't need to be bool - you can simply return accept_size on > success and 0 on error so that you don't have an I/O argument. So on the calling side it would look like: accepted = try_accept_one(start, len, PG_LEVEL_1G) if (accepted) { start += accepted; continue; } And the similar for other levels. Is it really better? > > Ditto for the copy in coco/tdx/tdx.c > > > +{ > > + unsigned long accept_size = PAGE_SIZE << (pg_level * PTE_SHIFT); > > + 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; > > +} > > + > > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) > > +{ > > + /* > > + * Notify the VMM about page mapping conversion. More info about ABI > > + * can be found in TDX Guest-Host-Communication Interface (GHCI), > > + * section "TDG.VP.VMCALL<MapGPA>" > > + */ > > + if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) > > + error("Accepting memory failed\n"); > > + /* > > + * 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 > > "SEPT"? Secure EPT. EPT for private memory in TDX. > > + * 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)) > > + error("Accepting memory failed\n"); > > + } > > +} > > diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c > > index ddb60a87b426..ab4deb897942 100644 > > --- a/arch/x86/coco/tdx/tdx.c > > +++ b/arch/x86/coco/tdx/tdx.c > > @@ -580,16 +580,9 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len, > > 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 > > - * of the page in response. > > - */ > > -static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > > +static bool tdx_enc_status_changed_phys(phys_addr_t start, phys_addr_t end, > > Why? is tdx_enc_status_changed_virt() coming too? tdx_enc_status_changed() deals with virtual addresses. > > + bool enc) > > { > > - phys_addr_t start = __pa(vaddr); > > - phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); > > - > > if (!enc) { > > /* Set the shared (decrypted) bits: */ > > start |= cc_mkdec(0); > > @@ -634,6 +627,25 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > > return true; > > } > > > > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) > > +{ > > + if (!tdx_enc_status_changed_phys(start, end, true)) > > + panic("Accepting memory failed\n"); > > +} > > + > > +/* > > + * 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 > > + * of the page in response. > > + */ > > +static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) > > +{ > > + phys_addr_t start = __pa(vaddr); > > + phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); > > + > > + return tdx_enc_status_changed_phys(start, end, enc); > > +} > > + > > void __init tdx_early_init(void) > > { > > u64 cc_mask; > > @@ -645,6 +657,7 @@ void __init tdx_early_init(void) > > return; > > > > setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); > > + setup_clear_cpu_cap(X86_FEATURE_MCE); > > What, no comment? Why does TDX need to disable MCE? It doesn't not suppose to be here. Sorry. > > > cc_set_vendor(CC_VENDOR_INTEL); > > cc_mask = get_cc_mask(); > > diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h > > index 956ced04c3be..97534c334473 100644 > > --- a/arch/x86/include/asm/shared/tdx.h > > +++ b/arch/x86/include/asm/shared/tdx.h > > @@ -81,5 +81,7 @@ struct tdx_module_output { > > u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, > > struct tdx_module_output *out); > > > > +void tdx_accept_memory(phys_addr_t start, phys_addr_t end); > > + > > #endif /* !__ASSEMBLY__ */ > > #endif /* _ASM_X86_SHARED_TDX_H */ > > diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c > > index 1327f64d5205..de0790af1824 100644 > > --- a/arch/x86/mm/unaccepted_memory.c > > +++ b/arch/x86/mm/unaccepted_memory.c > > @@ -6,6 +6,7 @@ > > > > #include <asm/io.h> > > #include <asm/setup.h> > > +#include <asm/shared/tdx.h> > > #include <asm/unaccepted_memory.h> > > > > /* Protects unaccepted memory bitmap */ > > @@ -29,7 +30,13 @@ void accept_memory(phys_addr_t start, phys_addr_t end) > > unsigned long len = range_end - range_start; > > > > /* Platform-specific memory-acceptance call goes here */ > > - panic("Cannot accept memory"); > > + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { > > + tdx_accept_memory(range_start * PMD_SIZE, > > + range_end * PMD_SIZE); > > + } else { > > + panic("Cannot accept memory"); > > Why panic here? A WARN_ONCE() should suffice, methinks. As I said before, memory accept failure is fatal.
On Fri, May 06, 2022 at 11:44:23PM +0300, Kirill A. Shutemov wrote: > > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > > > index 7021ec725dd3..e4c31dbea6d7 100644 > > > --- a/arch/x86/Kconfig > > > +++ b/arch/x86/Kconfig > > > @@ -885,6 +885,7 @@ config INTEL_TDX_GUEST > > > select ARCH_HAS_CC_PLATFORM > > > select X86_MEM_ENCRYPT > > > select X86_MCE > > > + select UNACCEPTED_MEMORY > > > > WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY > > Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] > > Selected by [y]: > > - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] > > > > WARNING: unmet direct dependencies detected for UNACCEPTED_MEMORY > > Depends on [n]: EFI [=y] && EFI_STUB [=y] && !KEXEC_CORE [=y] > > Selected by [y]: > > - INTEL_TDX_GUEST [=y] && HYPERVISOR_GUEST [=y] && X86_64 [=y] && CPU_SUP_INTEL [=y] && X86_X2APIC [=y] > > Ughh. Any ideas how to get around it? (Except for implementing kexec > support right away?) I reworked this to boot-time kexec disable. > > Also, it doesn't need to be bool - you can simply return accept_size on > > success and 0 on error so that you don't have an I/O argument. > > So on the calling side it would look like: > > accepted = try_accept_one(start, len, PG_LEVEL_1G) > if (accepted) { > start += accepted; > continue; > } > > And the similar for other levels. Is it really better? JFYI, I've reworked it as accepted = try_accept_one(start, len, PG_LEVEL_1G); if (!accepted) accepted = try_accept_one(start, len, PG_LEVEL_2M); if (!accepted) accepted = try_accept_one(start, len, PG_LEVEL_4K); if (!accepted) return false; start += accepted; looks good to me.
On Wed, May 11, 2022 at 04:19:06AM +0300, Kirill A. Shutemov wrote: > JFYI, I've reworked it as > > accepted = try_accept_one(start, len, PG_LEVEL_1G); > if (!accepted) > accepted = try_accept_one(start, len, PG_LEVEL_2M); > if (!accepted) > accepted = try_accept_one(start, len, PG_LEVEL_4K); > if (!accepted) > return false; > start += accepted; s/accepted/accpt_size/ and then it is perfectly clear what that variable contains. But it seems you're preparing a new version so I'll continue looking at there.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7021ec725dd3..e4c31dbea6d7 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -885,6 +885,7 @@ config INTEL_TDX_GUEST select ARCH_HAS_CC_PLATFORM select X86_MEM_ENCRYPT select X86_MCE + select UNACCEPTED_MEMORY help Support running as a guest under Intel TDX. Without this support, the guest kernel can not boot or run under TDX. diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c index b5058c975d26..539fff27de49 100644 --- a/arch/x86/boot/compressed/mem.c +++ b/arch/x86/boot/compressed/mem.c @@ -5,6 +5,8 @@ #include "error.h" #include "find.h" #include "math.h" +#include "tdx.h" +#include <asm/shared/tdx.h> #define PMD_SHIFT 21 #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) @@ -12,10 +14,30 @@ extern struct boot_params *boot_params; +static bool is_tdx_guest(void) +{ + static bool once; + static bool is_tdx; + + if (!once) { + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, + &sig[0], &sig[2], &sig[1]); + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); + once = true; + } + + return is_tdx; +} + static inline void __accept_memory(phys_addr_t start, phys_addr_t end) { /* Platform-specific memory-acceptance call goes here */ - error("Cannot accept memory"); + if (is_tdx_guest()) + tdx_accept_memory(start, end); + else + error("Cannot accept memory"); } /* diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c index 918a7606f53c..57fd2bf28484 100644 --- a/arch/x86/boot/compressed/tdx.c +++ b/arch/x86/boot/compressed/tdx.c @@ -3,12 +3,14 @@ #include "../cpuflags.h" #include "../string.h" #include "../io.h" +#include "align.h" #include "error.h" #include <vdso/limits.h> #include <uapi/asm/vmx.h> #include <asm/shared/tdx.h> +#include <asm/page_types.h> /* Called from __tdx_hypercall() for unrecoverable failure */ void __tdx_hypercall_failed(void) @@ -75,3 +77,86 @@ void early_tdx_detect(void) pio_ops.f_outb = tdx_outb; pio_ops.f_outw = tdx_outw; } + +enum pg_level { + PG_LEVEL_4K, + PG_LEVEL_2M, + PG_LEVEL_1G, +}; + +#define PTE_SHIFT 9 + +static bool try_accept_one(phys_addr_t *start, unsigned long len, + enum pg_level pg_level) +{ + unsigned long accept_size = PAGE_SIZE << (pg_level * PTE_SHIFT); + 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; +} + +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* + * Notify the VMM about page mapping conversion. More info about ABI + * can be found in TDX Guest-Host-Communication Interface (GHCI), + * section "TDG.VP.VMCALL<MapGPA>" + */ + if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0)) + error("Accepting memory failed\n"); + + /* + * 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)) + error("Accepting memory failed\n"); + } +} diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index ddb60a87b426..ab4deb897942 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -580,16 +580,9 @@ static bool try_accept_one(phys_addr_t *start, unsigned long len, 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 - * of the page in response. - */ -static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) +static bool tdx_enc_status_changed_phys(phys_addr_t start, phys_addr_t end, + bool enc) { - phys_addr_t start = __pa(vaddr); - phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); - if (!enc) { /* Set the shared (decrypted) bits: */ start |= cc_mkdec(0); @@ -634,6 +627,25 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) return true; } +void tdx_accept_memory(phys_addr_t start, phys_addr_t end) +{ + if (!tdx_enc_status_changed_phys(start, end, true)) + panic("Accepting memory failed\n"); +} + +/* + * 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 + * of the page in response. + */ +static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) +{ + phys_addr_t start = __pa(vaddr); + phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE); + + return tdx_enc_status_changed_phys(start, end, enc); +} + void __init tdx_early_init(void) { u64 cc_mask; @@ -645,6 +657,7 @@ void __init tdx_early_init(void) return; setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); + setup_clear_cpu_cap(X86_FEATURE_MCE); cc_set_vendor(CC_VENDOR_INTEL); cc_mask = get_cc_mask(); diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index 956ced04c3be..97534c334473 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -81,5 +81,7 @@ struct tdx_module_output { u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, struct tdx_module_output *out); +void tdx_accept_memory(phys_addr_t start, phys_addr_t end); + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_SHARED_TDX_H */ diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c index 1327f64d5205..de0790af1824 100644 --- a/arch/x86/mm/unaccepted_memory.c +++ b/arch/x86/mm/unaccepted_memory.c @@ -6,6 +6,7 @@ #include <asm/io.h> #include <asm/setup.h> +#include <asm/shared/tdx.h> #include <asm/unaccepted_memory.h> /* Protects unaccepted memory bitmap */ @@ -29,7 +30,13 @@ void accept_memory(phys_addr_t start, phys_addr_t end) unsigned long len = range_end - range_start; /* Platform-specific memory-acceptance call goes here */ - panic("Cannot accept memory"); + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { + tdx_accept_memory(range_start * PMD_SIZE, + range_end * PMD_SIZE); + } else { + panic("Cannot accept memory"); + } + bitmap_clear(unaccepted_memory, range_start, len); } spin_unlock_irqrestore(&unaccepted_memory_lock, flags);
All preparations are complete. Hookup TDX-specific code to accept memory. Accepting the memory is the same process as converting memory from shared to private: kernel notifies VMM with MAP_GPA hypercall and then accept pages with ACCEPT_PAGE module call. The implementation in core kernel uses tdx_enc_status_changed(). It already used for converting memory to shared and back for I/O transactions. Boot stub provides own implementation of tdx_accept_memory(). It is similar in structure to tdx_enc_status_changed(), but only cares about converting memory to private. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- arch/x86/Kconfig | 1 + arch/x86/boot/compressed/mem.c | 24 ++++++++- arch/x86/boot/compressed/tdx.c | 85 +++++++++++++++++++++++++++++++ arch/x86/coco/tdx/tdx.c | 31 +++++++---- arch/x86/include/asm/shared/tdx.h | 2 + arch/x86/mm/unaccepted_memory.c | 9 +++- 6 files changed, 141 insertions(+), 11 deletions(-)