From 75d090fd167acab4d7eda7e2b65729e877c0fd64 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Tue, 6 Jun 2023 17:26:37 +0300
Subject: x86/tdx: Add unaccepted memory support
Hookup TDX-specific code to accept memory.
Accepting the memory is done with ACCEPT_PAGE module call on every page
in the range. MAP_GPA hypercall is not required as the unaccepted memory
is considered private already.
Extract the part of tdx_enc_status_changed() that does memory acceptance
in a new helper. Move the helper tdx-shared.c. It is going to be used by
both main kernel and decompressor.
[ bp: Fix the INTEL_TDX_GUEST=y, KVM_GUEST=n build. ]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230606142637.5171-10-kirill.shutemov@linux.intel.com
---
arch/x86/coco/tdx/Makefile | 2 +-
arch/x86/coco/tdx/tdx-shared.c | 71 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/coco/tdx/tdx.c | 70 ++---------------------------------------
3 files changed, 75 insertions(+), 68 deletions(-)
create mode 100644 arch/x86/coco/tdx/tdx-shared.c
(limited to 'arch/x86/coco/tdx')
diff --git a/arch/x86/coco/tdx/Makefile b/arch/x86/coco/tdx/Makefile
index 46c55998557d..2c7dcbf1458b 100644
--- a/arch/x86/coco/tdx/Makefile
+++ b/arch/x86/coco/tdx/Makefile
@@ -1,3 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
-obj-y += tdx.o tdcall.o
+obj-y += tdx.o tdx-shared.o tdcall.o
diff --git a/arch/x86/coco/tdx/tdx-shared.c b/arch/x86/coco/tdx/tdx-shared.c
new file mode 100644
index 000000000000..ef20ddc37b58
--- /dev/null
+++ b/arch/x86/coco/tdx/tdx-shared.c
@@ -0,0 +1,71 @@
+#include <asm/tdx.h>
+#include <asm/pgtable.h>
+
+static unsigned long try_accept_one(phys_addr_t start, unsigned long len,
+ enum pg_level pg_level)
+{
+ unsigned long accept_size = page_level_size(pg_level);
+ u64 tdcall_rcx;
+ u8 page_size;
+
+ if (!IS_ALIGNED(start, accept_size))
+ return 0;
+
+ if (len < accept_size)
+ return 0;
+
+ /*
+ * 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 0;
+ }
+
+ tdcall_rcx = start | page_size;
+ if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL))
+ return 0;
+
+ return accept_size;
+}
+
+bool tdx_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+ /*
+ * For shared->private conversion, accept the page using
+ * TDX_ACCEPT_PAGE TDX module call.
+ */
+ while (start < end) {
+ unsigned long len = end - start;
+ unsigned long accept_size;
+
+ /*
+ * Try larger accepts first. It gives chance to VMM to keep
+ * 1G/2M Secure EPT entries where possible and speeds up
+ * process by cutting number of hypercalls (if successful).
+ */
+
+ accept_size = try_accept_one(start, len, PG_LEVEL_1G);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_2M);
+ if (!accept_size)
+ accept_size = try_accept_one(start, len, PG_LEVEL_4K);
+ if (!accept_size)
+ return false;
+ start += accept_size;
+ }
+
+ return true;
+}
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 0d5fe6e24e45..a9c4ba6c5c5d 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -713,46 +713,6 @@ static bool tdx_cache_flush_required(void)
return true;
}
-static unsigned long try_accept_one(phys_addr_t start, unsigned long len,
- enum pg_level pg_level)
-{
- unsigned long accept_size = page_level_size(pg_level);
- u64 tdcall_rcx;
- u8 page_size;
-
- if (!IS_ALIGNED(start, accept_size))
- return 0;
-
- if (len < accept_size)
- return 0;
-
- /*
- * 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 0;
- }
-
- tdcall_rcx = start | page_size;
- if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL))
- return 0;
-
- return accept_size;
-}
-
/*
* 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
@@ -777,33 +737,9 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
if (_tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0))
return false;
- /* private->shared conversion requires only MapGPA call */
- if (!enc)
- return true;
-
- /*
- * For shared->private conversion, accept the page using
- * TDX_ACCEPT_PAGE TDX module call.
- */
- while (start < end) {
- unsigned long len = end - start;
- unsigned long accept_size;
-
- /*
- * Try larger accepts first. It gives chance to VMM to keep
- * 1G/2M Secure EPT entries where possible and speeds up
- * process by cutting number of hypercalls (if successful).
- */
-
- accept_size = try_accept_one(start, len, PG_LEVEL_1G);
- if (!accept_size)
- accept_size = try_accept_one(start, len, PG_LEVEL_2M);
- if (!accept_size)
- accept_size = try_accept_one(start, len, PG_LEVEL_4K);
- if (!accept_size)
- return false;
- start += accept_size;
- }
+ /* shared->private conversion requires memory to be accepted before use */
+ if (enc)
+ return tdx_accept_memory(start, end);
return true;
}
--
cgit