diff --git a/xen/arch/x86/efi/boot.c b/xen/arch/x86/efi/boot.c
index 4005b5e7d6..44bc7b7670 100644
--- a/xen/arch/x86/efi/boot.c
+++ b/xen/arch/x86/efi/boot.c
@@ -234,6 +234,15 @@ static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
     case EFI_VOLUME_FULL:
         mesg = L"Volume is full";
         break;
+    case EFI_SECURITY_VIOLATION:
+        mesg = L"Security violation";
+        break;
+    case EFI_CRC_ERROR:
+        mesg = L"CRC error";
+        break;
+    case EFI_COMPROMISED_DATA:
+        mesg = L"Compromised data";
+        break;
     default:
         PrintErr(L"ErrCode: ");
         DisplayUint(ErrCode, 0);
@@ -1231,6 +1240,23 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     /* Collect PCI ROM contents. */
     setup_efi_pci();
 
+    /* Get snapshot of variable store parameters. */
+    status = efi_rs->QueryVariableInfo(EFI_VARIABLE_NON_VOLATILE |
+                                       EFI_VARIABLE_BOOTSERVICE_ACCESS |
+                                       EFI_VARIABLE_RUNTIME_ACCESS,
+                                       &efi_boot_max_var_store_size,
+                                       &efi_boot_remain_var_store_size,
+                                       &efi_boot_max_var_size);
+    if ( EFI_ERROR(status) )
+    {
+        efi_boot_max_var_store_size = 0;
+        efi_boot_remain_var_store_size = 0;
+        efi_boot_max_var_size = status;
+        PrintStr(L"Warning: Could not query variable store: ");
+        DisplayUint(status, 0);
+        PrintStr(newline);
+    }
+
     /* Allocate space for trampoline (in first Mb). */
     cfg.addr = 0x100000;
     cfg.size = trampoline_end - trampoline_start;
diff --git a/xen/arch/x86/efi/efi.h b/xen/arch/x86/efi/efi.h
index 43dbd1728b..a80d5f1abb 100644
--- a/xen/arch/x86/efi/efi.h
+++ b/xen/arch/x86/efi/efi.h
@@ -32,5 +32,8 @@ extern l4_pgentry_t *efi_l4_pgtable;
 
 extern const struct efi_pci_rom *efi_pci_roms;
 
+extern UINT64 efi_boot_max_var_store_size, efi_boot_remain_var_store_size,
+              efi_boot_max_var_size;
+
 unsigned long efi_rs_enter(void);
 void efi_rs_leave(unsigned long);
diff --git a/xen/arch/x86/efi/runtime.c b/xen/arch/x86/efi/runtime.c
index aafdfebdd8..be3f5376b3 100644
--- a/xen/arch/x86/efi/runtime.c
+++ b/xen/arch/x86/efi/runtime.c
@@ -28,6 +28,10 @@ UINTN __read_mostly efi_memmap_size;
 UINTN __read_mostly efi_mdesc_size;
 void *__read_mostly efi_memmap;
 
+UINT64 __read_mostly efi_boot_max_var_store_size;
+UINT64 __read_mostly efi_boot_remain_var_store_size;
+UINT64 __read_mostly efi_boot_max_var_size;
+
 struct efi __read_mostly efi = {
 	.acpi   = EFI_INVALID_TABLE_ADDR,
 	.acpi20 = EFI_INVALID_TABLE_ADDR,
@@ -464,6 +468,35 @@ int efi_runtime_call(struct xenpf_efi_runtime_call *op)
     break;
 
     case XEN_EFI_query_variable_info:
+        if ( op->misc & ~XEN_EFI_VARINFO_BOOT_SNAPSHOT )
+            return -EINVAL;
+
+        if ( op->misc & XEN_EFI_VARINFO_BOOT_SNAPSHOT )
+        {
+            if ( (op->u.query_variable_info.attr
+                  & ~EFI_VARIABLE_APPEND_WRITE) !=
+                 (EFI_VARIABLE_NON_VOLATILE |
+                  EFI_VARIABLE_BOOTSERVICE_ACCESS |
+                  EFI_VARIABLE_RUNTIME_ACCESS) )
+                return -EINVAL;
+
+            op->u.query_variable_info.max_store_size =
+                efi_boot_max_var_store_size;
+            op->u.query_variable_info.remain_store_size =
+                efi_boot_remain_var_store_size;
+            if ( efi_boot_max_var_store_size )
+            {
+                op->u.query_variable_info.max_size = efi_boot_max_var_size;
+                status = EFI_SUCCESS;
+            }
+            else
+            {
+                op->u.query_variable_info.max_size = 0;
+                status = efi_boot_max_var_size;
+            }
+            break;
+        }
+
         cr3 = efi_rs_enter();
         if ( (efi_rs->Hdr.Revision >> 16) < 2 )
         {
@@ -480,6 +513,9 @@ int efi_runtime_call(struct xenpf_efi_runtime_call *op)
 
     case XEN_EFI_query_capsule_capabilities:
     case XEN_EFI_update_capsule:
+        if ( op->misc )
+            return -EINVAL;
+
         cr3 = efi_rs_enter();
         if ( (efi_rs->Hdr.Revision >> 16) < 2 )
         {
diff --git a/xen/include/efi/efiapi.h b/xen/include/efi/efiapi.h
index 7c276cfc63..a616d1238a 100644
--- a/xen/include/efi/efiapi.h
+++ b/xen/include/efi/efiapi.h
@@ -213,6 +213,10 @@ VOID
 #define EFI_VARIABLE_NON_VOLATILE           0x00000001
 #define EFI_VARIABLE_BOOTSERVICE_ACCESS     0x00000002
 #define EFI_VARIABLE_RUNTIME_ACCESS         0x00000004
+#define EFI_VARIABLE_HARDWARE_ERROR_RECORD  0x00000008
+#define EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS 0x00000010
+#define EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS 0x00000020
+#define EFI_VARIABLE_APPEND_WRITE           0x00000040
 
 // Variable size limitation
 #define EFI_MAXIMUM_VARIABLE_SIZE           1024
diff --git a/xen/include/efi/efierr.h b/xen/include/efi/efierr.h
index 669d7baee7..dfd3d3cf48 100644
--- a/xen/include/efi/efierr.h
+++ b/xen/include/efi/efierr.h
@@ -50,6 +50,13 @@ Revision History
 #define EFI_ICMP_ERROR                  EFIERR(22)
 #define EFI_TFTP_ERROR                  EFIERR(23)
 #define EFI_PROTOCOL_ERROR              EFIERR(24)
+#define EFI_INCOMPATIBLE_VERSION        EFIERR(25)
+#define EFI_SECURITY_VIOLATION          EFIERR(26)
+#define EFI_CRC_ERROR                   EFIERR(27)
+#define EFI_END_OF_MEDIA                EFIERR(28)
+#define EFI_END_OF_FILE                 EFIERR(31)
+#define EFI_INVALID_LANGUAGE            EFIERR(32)
+#define EFI_COMPROMISED_DATA            EFIERR(33)
 
 #define EFI_WARN_UNKOWN_GLYPH           EFIWARN(1)
 #define EFI_WARN_DELETE_FAILURE         EFIWARN(2)
diff --git a/xen/include/public/platform.h b/xen/include/public/platform.h
index d7d2a5bddf..4341f5462c 100644
--- a/xen/include/public/platform.h
+++ b/xen/include/public/platform.h
@@ -184,6 +184,7 @@ struct xenpf_efi_runtime_call {
             struct xenpf_efi_guid vendor_guid;
         } get_next_variable_name;
 
+#define XEN_EFI_VARINFO_BOOT_SNAPSHOT       0x00000001
         struct {
             uint32_t attr;
             uint64_t max_store_size;