TDVF supports partial memory accept to optimize boot time and
leaves remaining memory accept to OS.
Accept remaining memory of EFI_UNACCEPTED_MEMORY type at bootup.
Try 2M page accept first even though hugepage memory isn't used
in qemu command line currently.
Export below functions so they can be used by TDX specific
sub-test in the future.
tdx_shared_mask()
tdx_hcall_gpa_intent()
tdx_accept_memory()
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
Reviewed-by: Yu Zhang <yu.c.zhang@xxxxxxxxx>
---
lib/asm-generic/page.h | 7 ++-
lib/linux/efi.h | 23 ++++++-
lib/x86/setup.c | 2 +-
lib/x86/tdx.c | 139 ++++++++++++++++++++++++++++++++++++++++-
lib/x86/tdx.h | 20 +++++-
5 files changed, 185 insertions(+), 6 deletions(-)
diff --git a/lib/asm-generic/page.h b/lib/asm-generic/page.h
index 5ed086129657..56f539ac45eb 100644
--- a/lib/asm-generic/page.h
+++ b/lib/asm-generic/page.h
@@ -12,8 +12,11 @@
#include <linux/const.h>
#define PAGE_SHIFT 12
-#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
-#define PAGE_MASK (~(PAGE_SIZE-1))
+#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
+#define PAGE_MASK (~(PAGE_SIZE - 1))
+#define PMD_SHIFT 21
+#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
+#define PMD_MASK (~(PMD_SIZE - 1))
#ifndef __ASSEMBLY__
diff --git a/lib/linux/efi.h b/lib/linux/efi.h
index 455625aa155d..df9fa7974d87 100644
--- a/lib/linux/efi.h
+++ b/lib/linux/efi.h
@@ -96,7 +96,8 @@ typedef struct {
#define EFI_MEMORY_MAPPED_IO_PORT_SPACE 12
#define EFI_PAL_CODE 13
#define EFI_PERSISTENT_MEMORY 14
-#define EFI_MAX_MEMORY_TYPE 15
+#define EFI_UNACCEPTED_MEMORY 15
+#define EFI_MAX_MEMORY_TYPE 16
/* Attribute values: */
#define EFI_MEMORY_UC ((u64)0x0000000000000001ULL) /* uncached */
@@ -416,6 +417,26 @@ struct efi_boot_memmap {
unsigned long *buff_size;
};
+/*
+ * efi_memdesc_ptr - get the n-th EFI memmap descriptor
+ * @map: the start of efi memmap
+ * @desc_size: the size of space for each EFI memmap descriptor
+ * @n: the index of efi memmap descriptor
+ *
+ * EFI boot service provides the GetMemoryMap() function to get a copy of the
+ * current memory map which is an array of memory descriptors, each of
+ * which describes a contiguous block of memory. It also gets the size of the
+ * map, and the size of each descriptor, etc.
+ *
+ * Note that per section 6.2 of UEFI Spec 2.6 Errata A, the returned size of
+ * each descriptor might not be equal to sizeof(efi_memory_memdesc_t),
+ * since efi_memory_memdesc_t may be extended in the future. Thus the OS
+ * MUST use the returned size of the descriptor to find the start of each
+ * efi_memory_memdesc_t in the memory map array.
+ */
+#define efi_memdesc_ptr(map, desc_size, n) \
+ ((efi_memory_desc_t *)((void *)(map) + ((n) * (desc_size))))
+
#define efi_bs_call(func, ...) efi_system_table->boottime->func(__VA_ARGS__)
#define efi_rs_call(func, ...) efi_system_table->runtime->func(__VA_ARGS__)
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index e834fdfd290c..29202478ae0d 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c
@@ -288,7 +288,7 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
* TDVF support partial memory accept, accept remaining memory
* early so memory allocator can use it.
*/
- status = setup_tdx();
+ status = setup_tdx(efi_bootinfo);
if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) {
printf("INTEL TDX setup failed, error = 0x%lx\n", status);
return status;
diff --git a/lib/x86/tdx.c b/lib/x86/tdx.c
index 2b2e3164be33..b74c697353d9 100644
--- a/lib/x86/tdx.c
+++ b/lib/x86/tdx.c
@@ -10,9 +10,11 @@
*/
#include "tdx.h"
+#include "errno.h"
#include "bitops.h"
#include "x86/processor.h"
#include "x86/smp.h"
+#include "asm/page.h"
#define VE_IS_IO_OUT(exit_qual) (((exit_qual) & 8) ? 0 : 1)
#define VE_GET_IO_SIZE(exit_qual) (((exit_qual) & 7) + 1)
@@ -124,6 +126,42 @@ done:
return !!tdx_guest;
}
+static struct {
+ unsigned int gpa_width;
+ unsigned long attributes;
+} td_info;
+
+/* The highest bit of a guest physical address is the "sharing" bit */
+phys_addr_t tdx_shared_mask(void)
+{
+ return 1ULL << (td_info.gpa_width - 1);
+}
+
+static void tdx_get_info(void)
+{
+ struct tdx_module_output out;
+ u64 ret;
+
+ /*
+ * TDINFO TDX Module call is used to get the TD
+ * execution environment information like GPA
+ * width, number of available vcpus, debug mode
+ * information, etc. More details about the ABI
+ * can be found in TDX Guest-Host-Communication
+ * Interface (GHCI), sec 2.4.2 TDCALL [TDG.VP.INFO].
+ */
+ ret = __tdx_module_call(TDX_GET_INFO, 0, 0, 0, 0, &out);
+
+ /*
+ * Non zero return means buggy TDX module (which is
+ * fatal). So raise a BUG().
+ */
+ BUG_ON(ret);
+
+ td_info.gpa_width = out.rcx & GENMASK(5, 0);
+ td_info.attributes = out.rdx;
+}
+
/*
* Wrapper for standard use of __tdx_hypercall with BUG_ON() check
* for TDCALL error.
@@ -393,11 +431,110 @@ static void tdx_handle_ve(struct ex_regs *regs)
tdx_handle_virtualization_exception(regs, &ve);
}
-efi_status_t setup_tdx(void)
+static u64 tdx_accept_page(phys_addr_t gpa, bool page_2mb)
+{
+ /*
+ * Pass the page physical address and size (4KB|2MB) to the
+ * TDX module to accept the pending, private page. More info
+ * about ABI can be found in TDX Guest-Host-Communication
+ * Interface (GHCI), sec 2.4.7.
+ */
+
+ if (page_2mb)
+ gpa |= 1;
+
+ return __tdx_module_call(TDX_ACCEPT_PAGE, gpa, 0, 0, 0, NULL);
+}
+
+/*
+ * 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 of the page in response.
+ */
+int tdx_hcall_gpa_intent(phys_addr_t start, phys_addr_t end,
+ enum tdx_map_type map_type)
+{
+ u64 ret = 0;
+
+ if (map_type == TDX_MAP_SHARED) {
+ start |= tdx_shared_mask();
+ end |= tdx_shared_mask();
+ }
+
+ /*
+ * Notify VMM about page mapping conversion. More info
+ * about ABI can be found in TDX Guest-Host-Communication
+ * Interface (GHCI), sec 3.2.
+ */
+ ret = _tdx_hypercall(TDVMCALL_MAP_GPA, start, end - start, 0, 0,
+ NULL);
+ if (ret)
+ ret = -EIO;
+
+ if (ret || map_type == TDX_MAP_SHARED)
+ return ret;
+ /*
+ * For shared->private conversion, accept the page using
+ * TDX_ACCEPT_PAGE TDX module call.
+ */
+ while (start < end) {
+ /* Try 2M page accept first if possible */
+ if (!(start & ~PMD_MASK) && end - start >= PMD_SIZE &&
+ !tdx_accept_page(start, true)) {
+ start += PMD_SIZE;
+ continue;
+ }
+
+ if (tdx_accept_page(start, false))
+ return -EIO;
+ start += PAGE_SIZE;
+ }
+
+ return 0;
+}
+
+bool tdx_accept_memory(phys_addr_t start, phys_addr_t end)
+{
+ if (tdx_hcall_gpa_intent(start, end, TDX_MAP_PRIVATE)) {
+ tdx_printf("Accepting memory failed\n");
+ return false;
+ }
+ return true;
+}
+
+static bool tdx_accept_memory_regions(struct efi_boot_memmap *mem_map)
+{
+ unsigned long i, nr_desc = *mem_map->map_size / *mem_map->desc_size;
+ efi_memory_desc_t *d;
+
+ for (i = 0; i < nr_desc; i++) {
+ d = efi_memdesc_ptr(*mem_map->map, *mem_map->desc_size, i);
+
+ if (d->type == EFI_UNACCEPTED_MEMORY) {
+ if (d->phys_addr & ~PAGE_MASK) {
+ tdx_printf("WARN: EFI: unaligned base %lx\n",
+ d->phys_addr);
+ d->phys_addr &= PAGE_MASK;
+ }
+ if (!tdx_accept_memory(d->phys_addr, d->phys_addr +
+ PAGE_SIZE * d->num_pages))
+ return false;
+
+ d->type = EFI_CONVENTIONAL_MEMORY;
+ }
+ }
+ return true;
+}
+
+efi_status_t setup_tdx(efi_bootinfo_t *efi_bootinfo)
{
if (!is_tdx_guest())
return EFI_UNSUPPORTED;
+ tdx_get_info();
+ if (!tdx_accept_memory_regions(&efi_bootinfo->mem_map))
+ return EFI_OUT_OF_RESOURCES;
+
handle_exception(20, tdx_handle_ve);
printf("Initialized TDX.\n");
diff --git a/lib/x86/tdx.h b/lib/x86/tdx.h
index 68ddc136d1d9..2f938038dc45 100644
--- a/lib/x86/tdx.h
+++ b/lib/x86/tdx.h
@@ -30,7 +30,12 @@
#define EXIT_REASON_MSR_WRITE 32
/* TDX Module call Leaf IDs */
+#define TDX_GET_INFO 1
#define TDX_GET_VEINFO 3
+#define TDX_ACCEPT_PAGE 6
+
+/* TDX hypercall Leaf IDs */
+#define TDVMCALL_MAP_GPA 0x10001
/*
* Used in __tdx_module_call() helper function to gather the
@@ -76,8 +81,21 @@ struct ve_info {
u32 instr_info;
};
+/*
+ * Page mapping type enum. This is software construct not
+ * part of any hardware or VMM ABI.
+ */
+enum tdx_map_type {
+ TDX_MAP_PRIVATE,
+ TDX_MAP_SHARED,
+};
+
bool is_tdx_guest(void);
-efi_status_t setup_tdx(void);
+phys_addr_t tdx_shared_mask(void);
+int tdx_hcall_gpa_intent(phys_addr_t start, phys_addr_t end,
+ enum tdx_map_type map_type);
+bool tdx_accept_memory(phys_addr_t start, phys_addr_t end);
+efi_status_t setup_tdx(efi_bootinfo_t *efi_bootinfo);
/* Helper function used to communicate with the TDX module */
u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9,
--
2.25.1
