[PATCH 1/2] x86: sgx_vepc: extract sgx_vepc_remove_page

Paolo Bonzini
2021-09-13T13:12:01Z

Windows expects all pages to be in uninitialized state on startup.
In order to implement this, we will need a ioctl that performs
EREMOVE on all pages mapped by a /dev/sgx_vepc file descriptor:
other possibilities, such as closing and reopening the device,
are racy.

Start the implementation by pulling the EREMOVE into a separate
function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kernel/cpu/sgx/virt.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
index 64511c4a5200..59b9c13121cd 100644
--- a/arch/x86/kernel/cpu/sgx/virt.c
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -111,7 +111,7 @@ static int sgx_vepc_mmap(struct file *file, struct vm_area_struct *vma)
return 0;
}

-static int sgx_vepc_free_page(struct sgx_epc_page *epc_page)
+static int sgx_vepc_remove_page(struct sgx_epc_page *epc_page)
{
int ret;

@@ -140,11 +140,17 @@ static int sgx_vepc_free_page(struct sgx_epc_page *epc_page)
*/
WARN_ONCE(ret != SGX_CHILD_PRESENT, EREMOVE_ERROR_MESSAGE,
ret, ret);
- return ret;
}
+ return ret;
+}

- sgx_free_epc_page(epc_page);
+static int sgx_vepc_free_page(struct sgx_epc_page *epc_page)
+{
+ int ret = sgx_vepc_remove_page(epc_page);
+ if (ret)
+ return ret;

+ sgx_free_epc_page(epc_page);
return 0;
}

--
2.27.0