diff options
Diffstat (limited to '0020-x86-sgx-Free-up-EPC-pages-directly-to-support-large-.patch')
| -rw-r--r-- | 0020-x86-sgx-Free-up-EPC-pages-directly-to-support-large-.patch | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/0020-x86-sgx-Free-up-EPC-pages-directly-to-support-large-.patch b/0020-x86-sgx-Free-up-EPC-pages-directly-to-support-large-.patch new file mode 100644 index 000000000000..bd86089962d2 --- /dev/null +++ b/0020-x86-sgx-Free-up-EPC-pages-directly-to-support-large-.patch @@ -0,0 +1,101 @@ +From 0ed2b241836b30d344da4f8f73ce87878aea5c87 Mon Sep 17 00:00:00 2001 +From: Reinette Chatre <reinette.chatre@intel.com> +Date: Wed, 13 Apr 2022 14:10:20 -0700 +Subject: [PATCH 20/31] x86/sgx: Free up EPC pages directly to support large + page ranges + +The page reclaimer ensures availability of EPC pages across all +enclaves. In support of this it runs independently from the +individual enclaves in order to take locks from the different +enclaves as it writes pages to swap. + +When needing to load a page from swap an EPC page needs to be +available for its contents to be loaded into. Loading an existing +enclave page from swap does not reclaim EPC pages directly if +none are available, instead the reclaimer is woken when the +available EPC pages are found to be below a watermark. + +When iterating over a large number of pages in an oversubscribed +environment there is a race between the reclaimer woken up and +EPC pages reclaimed fast enough for the page operations to proceed. + +Ensure there are EPC pages available before attempting to load +a page that may potentially be pulled from swap into an available +EPC page. + +Acked-by: Jarkko Sakkinen <jarkko@kernel.org> +Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> +--- + arch/x86/kernel/cpu/sgx/ioctl.c | 6 ++++++ + arch/x86/kernel/cpu/sgx/main.c | 11 +++++++++++ + arch/x86/kernel/cpu/sgx/sgx.h | 1 + + 3 files changed, 18 insertions(+) + +diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c +index f9a1654a49b7..83674d054c13 100644 +--- a/arch/x86/kernel/cpu/sgx/ioctl.c ++++ b/arch/x86/kernel/cpu/sgx/ioctl.c +@@ -745,6 +745,8 @@ sgx_enclave_restrict_permissions(struct sgx_encl *encl, + for (c = 0 ; c < modp->length; c += PAGE_SIZE) { + addr = encl->base + modp->offset + c; + ++ sgx_reclaim_direct(); ++ + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); +@@ -910,6 +912,8 @@ static long sgx_enclave_modify_type(struct sgx_encl *encl, + for (c = 0 ; c < modt->length; c += PAGE_SIZE) { + addr = encl->base + modt->offset + c; + ++ sgx_reclaim_direct(); ++ + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); +@@ -1095,6 +1099,8 @@ static long sgx_encl_remove_pages(struct sgx_encl *encl, + for (c = 0 ; c < params->length; c += PAGE_SIZE) { + addr = encl->base + params->offset + c; + ++ sgx_reclaim_direct(); ++ + mutex_lock(&encl->lock); + + entry = sgx_encl_load_page(encl, addr); +diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c +index 1a3014aec490..c6adb7edebca 100644 +--- a/arch/x86/kernel/cpu/sgx/main.c ++++ b/arch/x86/kernel/cpu/sgx/main.c +@@ -378,6 +378,17 @@ static bool sgx_should_reclaim(unsigned long watermark) + !list_empty(&sgx_active_page_list); + } + ++/* ++ * sgx_reclaim_direct() should be called (without enclave's mutex held) ++ * in locations where SGX memory resources might be low and might be ++ * needed in order to make forward progress. ++ */ ++void sgx_reclaim_direct(void) ++{ ++ if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) ++ sgx_reclaim_pages(); ++} ++ + static int ksgxd(void *p) + { + set_freezable(); +diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h +index b30cee4de903..0f2020653fba 100644 +--- a/arch/x86/kernel/cpu/sgx/sgx.h ++++ b/arch/x86/kernel/cpu/sgx/sgx.h +@@ -86,6 +86,7 @@ static inline void *sgx_get_epc_virt_addr(struct sgx_epc_page *page) + struct sgx_epc_page *__sgx_alloc_epc_page(void); + void sgx_free_epc_page(struct sgx_epc_page *page); + ++void sgx_reclaim_direct(void); + void sgx_mark_page_reclaimable(struct sgx_epc_page *page); + int sgx_unmark_page_reclaimable(struct sgx_epc_page *page); + struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim); +-- +2.35.2 + |