Messages in this thread Patch in this message | | | From | Tony Luck <> | Subject | [PATCH v2 2/6] x86/sgx: Add infrastructure to identify SGX EPC pages | Date | Mon, 19 Jul 2021 11:20:05 -0700 |
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X86 machine check architecture reports a physical address when there is a memory error. Handling that error requires a method to determine whether the physical address reported is in any of the areas reserved for EPC pages by BIOS.
Add an end_phys_addr field to the sgx_epc_section structure and a new function sgx_paddr_to_page() that searches all such structures and returns the struct sgx_epc_page pointer if the address is an EPC page. This function is only intended for use within SGX code.
Export a function sgx_is_epc_page() that simply reports whether an address is an EPC page for use elsewhere in the kernel.
Signed-off-by: Tony Luck <tony.luck@intel.com> --- arch/x86/kernel/cpu/sgx/main.c | 24 ++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 1 + 2 files changed, 25 insertions(+)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index d61bc1f635a1..41753f81a071 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -654,6 +654,7 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, } section->phys_addr = phys_addr; + section->end_phys_addr = phys_addr + size - 1; for (i = 0; i < nr_pages; i++) { section->pages[i].section = index; @@ -665,6 +666,29 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size, return true; } +static struct sgx_epc_page *sgx_paddr_to_page(u64 paddr) +{ + struct sgx_epc_section *section; + int i; + + for (i = 0; i < ARRAY_SIZE(sgx_epc_sections); i++) { + section = &sgx_epc_sections[i]; + + if (paddr < section->phys_addr || paddr > section->end_phys_addr) + continue; + + return §ion->pages[PFN_DOWN(paddr - section->phys_addr)]; + } + + return NULL; +} + +bool sgx_is_epc_page(u64 paddr) +{ + return !!sgx_paddr_to_page(paddr); +} +EXPORT_SYMBOL_GPL(sgx_is_epc_page); + /** * A section metric is concatenated in a way that @low bits 12-31 define the * bits 12-31 of the metric and @high bits 0-19 define the bits 32-51 of the diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 4e1a410b8a62..226b081a4d05 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -50,6 +50,7 @@ struct sgx_numa_node { */ struct sgx_epc_section { unsigned long phys_addr; + unsigned long end_phys_addr; void *virt_addr; struct sgx_epc_page *pages; struct sgx_numa_node *node; -- 2.29.2
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