| Message ID | f1393ef80c8d1f1bdd3e34baf60c0286f77a8aa1.1638381245.git.reinette.chatre@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/sgx and selftests/sgx: Support SGX2 | expand |
On Wed, Dec 01, 2021 at 11:23:07AM -0800, Reinette Chatre wrote: > SGX2 functions are not allowed on all page types. For example, > ENCLS[EMODPR] is only allowed on regular SGX enclave pages and > ENCLS[EMODPT] is only allowed on TCS and regular pages. If these > functions are attempted on another type of page the hardware would > trigger a fault. > > Keep a record of the SGX page type so that there is more > certainty whether an SGX2 instruction can succeed and faults > can be treated as real failures. > > The page type is made to be a property of struct sgx_encl_page > and thus does not cover the VA page type. VA pages are maintained > in separate structures and thus their type can be determined in > a different way. The SGX2 instructions being supported do not > operate on VA pages and this is thus not a scenario needing to > be covered at this time. > > With the protection bits consuming 16 bits of the unsigned long > there is room available in the bitfield to include the page type > information without increasing the space consumed by the struct. > > Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> I think this is needed for any formation of these patches, and I cannot forsee it done by any other way, so Acked-by: Jarkko Sakkinen <jarkko@kernel.org> /Jarkko
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index ebae2a153c66..8b6cbedada96 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -221,6 +221,9 @@ struct sgx_pageinfo { * %SGX_PAGE_TYPE_REG: a regular page * %SGX_PAGE_TYPE_VA: a VA page * %SGX_PAGE_TYPE_TRIM: a page in trimmed state + * + * Make sure when making changes to this enum that its values can still fit + * in the bitfield within &struct sgx_encl_page */ enum sgx_page_type { SGX_PAGE_TYPE_SECS, diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 82e21088e68b..cb9f16d457ac 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -29,6 +29,7 @@ struct sgx_encl_page { unsigned long desc; unsigned long vm_max_prot_bits:8; unsigned long vm_run_prot_bits:8; + enum sgx_page_type type:16; struct sgx_epc_page *epc_page; struct sgx_encl *encl; struct sgx_va_page *va_page; diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 7e0819a89532..491d2700a54d 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -107,6 +107,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) set_bit(SGX_ENCL_DEBUG, &encl->flags); encl->secs.encl = encl; + encl->secs.type = SGX_PAGE_TYPE_SECS; encl->base = secs->base; encl->size = secs->size; encl->attributes = secs->attributes; @@ -350,6 +351,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, */ encl_page->encl = encl; encl_page->epc_page = epc_page; + encl_page->type = (secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK) >> 8; encl->secs_child_cnt++; if (flags & SGX_PAGE_MEASURE) {
SGX2 functions are not allowed on all page types. For example, ENCLS[EMODPR] is only allowed on regular SGX enclave pages and ENCLS[EMODPT] is only allowed on TCS and regular pages. If these functions are attempted on another type of page the hardware would trigger a fault. Keep a record of the SGX page type so that there is more certainty whether an SGX2 instruction can succeed and faults can be treated as real failures. The page type is made to be a property of struct sgx_encl_page and thus does not cover the VA page type. VA pages are maintained in separate structures and thus their type can be determined in a different way. The SGX2 instructions being supported do not operate on VA pages and this is thus not a scenario needing to be covered at this time. With the protection bits consuming 16 bits of the unsigned long there is room available in the bitfield to include the page type information without increasing the space consumed by the struct. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> --- arch/x86/include/asm/sgx.h | 3 +++ arch/x86/kernel/cpu/sgx/encl.h | 1 + arch/x86/kernel/cpu/sgx/ioctl.c | 2 ++ 3 files changed, 6 insertions(+)