[PATCH v5 10/16] efi: create efi_enabled()

From: Daniel Kiper <daniel.kiper@oracle.com>
To: xen-devel@lists.xenproject.org
Cc: jgross@suse.com, sstabellini@kernel.org,
	andrew.cooper3@citrix.com, cardoe@cardoe.com,
	pgnet.dev@gmail.com, ning.sun@intel.com, david.vrabel@citrix.com,
	jbeulich@suse.com, qiaowei.ren@intel.com, gang.wei@intel.com,
	fu.wei@linaro.org
Subject: [PATCH v5 10/16] efi: create efi_enabled()
Date: Sat, 20 Aug 2016 00:43:20 +0200	[thread overview]
Message-ID: <1471646606-28519-11-git-send-email-daniel.kiper@oracle.com> (raw)
In-Reply-To: <1471646606-28519-1-git-send-email-daniel.kiper@oracle.com>

First of all we need to differentiate between legacy BIOS
and EFI platforms during runtime, not during build, because
one image will have legacy and EFI code and can be executed
on both platforms. Additionally, we need more fine grained
knowledge about EFI environment and check for EFI platform
and EFI loader separately to properly support multiboot2
protocol. In general Xen loaded by this protocol uses memory
mappings and loaded modules in similar way to Xen loaded by
multiboot (v1) protocol. Hence, create efi_enabled() which
checks available features in efi_flags. This patch defines
EFI_BOOT, EFI_LOADER and EFI_RS features. EFI_BOOT is equal
to old efi_enabled == 1. EFI_RS ease control on runtime
services usage. EFI_LOADER tells that Xen was loaded
directly from EFI as PE executable.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
---
v5 - suggestions/fixes:
   - squash three patches into one
     (suggested by Jan Beulich),
   - introduce all features at once
     (suggested by Jan Beulich),
   - efi_enabled() returns bool_t
     instead of unsigned int
     (suggested by Jan Beulich),
   - update commit message.

v4 - suggestions/fixes:
   - rename EFI_PLATFORM to EFI_BOOT
     (suggested by Jan Beulich),
   - move EFI_BOOT definition to efi struct definition
     (suggested by Jan Beulich),
   - remove unneeded efi.flags initialization
     (suggested by Jan Beulich),
   - use __set_bit() instead of set_bit() if possible
     (suggested by Jan Beulich),
   - do efi_enabled() cleanup
     (suggested by Jan Beulich),
   - improve comments
     (suggested by Jan Beulich),
   - improve commit message.

v3 - suggestions/fixes:
   - define efi struct in xen/arch/x86/efi/stub.c
     in earlier patch
     (suggested by Jan Beulich),
   - improve comments
     (suggested by Jan Beulich),
   - improve commit message
     (suggested by Jan Beulich).
---
 xen/arch/x86/dmi_scan.c    |    4 ++--
 xen/arch/x86/domain_page.c |    2 +-
 xen/arch/x86/efi/stub.c    |    7 ++++---
 xen/arch/x86/mpparse.c     |    4 ++--
 xen/arch/x86/setup.c       |   14 ++++++++------
 xen/arch/x86/shutdown.c    |    4 ++--
 xen/arch/x86/time.c        |    2 +-
 xen/common/efi/boot.c      |   17 +++++++++++++----
 xen/common/efi/runtime.c   |   15 +++++++++------
 xen/drivers/acpi/osl.c     |    2 +-
 xen/include/xen/efi.h      |    9 +++++++--
 11 files changed, 50 insertions(+), 30 deletions(-)

diff --git a/xen/arch/x86/dmi_scan.c b/xen/arch/x86/dmi_scan.c
index b049e31..8dcb640 100644
--- a/xen/arch/x86/dmi_scan.c
+++ b/xen/arch/x86/dmi_scan.c
@@ -238,7 +238,7 @@ const char *__init dmi_get_table(paddr_t *base, u32 *len)
 {
 	static unsigned int __initdata instance;
 
-	if (efi_enabled) {
+	if (efi_enabled(EFI_BOOT)) {
 		if (efi_smbios3_size && !(instance & 1)) {
 			*base = efi_smbios3_address;
 			*len = efi_smbios3_size;
@@ -696,7 +696,7 @@ static void __init dmi_decode(struct dmi_header *dm)
 
 void __init dmi_scan_machine(void)
 {
-	if ((!efi_enabled ? dmi_iterate(dmi_decode) :
+	if ((!efi_enabled(EFI_BOOT) ? dmi_iterate(dmi_decode) :
 	                    dmi_efi_iterate(dmi_decode)) == 0)
  		dmi_check_system(dmi_blacklist);
 	else
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index d86f8fe..7541b91 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -36,7 +36,7 @@ static inline struct vcpu *mapcache_current_vcpu(void)
      * domain's page tables but current may point at another domain's VCPU.
      * Return NULL as though current is not properly set up yet.
      */
-    if ( efi_enabled && efi_rs_using_pgtables() )
+    if ( efi_enabled(EFI_RS) && efi_rs_using_pgtables() )
         return NULL;
 
     /*
diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c
index 07c2bd0..f087023 100644
--- a/xen/arch/x86/efi/stub.c
+++ b/xen/arch/x86/efi/stub.c
@@ -4,9 +4,10 @@
 #include <xen/lib.h>
 #include <asm/page.h>
 
-#ifndef efi_enabled
-const bool_t efi_enabled = 0;
-#endif
+bool_t efi_enabled(int feature)
+{
+    return false;
+}
 
 void __init efi_init_memory(void) { }
 
diff --git a/xen/arch/x86/mpparse.c b/xen/arch/x86/mpparse.c
index ef6557c..c3d5bdc 100644
--- a/xen/arch/x86/mpparse.c
+++ b/xen/arch/x86/mpparse.c
@@ -564,7 +564,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 
 static __init void efi_unmap_mpf(void)
 {
-	if (efi_enabled)
+	if (efi_enabled(EFI_BOOT))
 		clear_fixmap(FIX_EFI_MPF);
 }
 
@@ -722,7 +722,7 @@ void __init find_smp_config (void)
 {
 	unsigned int address;
 
-	if (efi_enabled) {
+	if (efi_enabled(EFI_BOOT)) {
 		efi_check_config();
 		return;
 	}
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 8ae897a..360ca59 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -439,8 +439,8 @@ static void __init parse_video_info(void)
 {
     struct boot_video_info *bvi = &bootsym(boot_vid_info);
 
-    /* The EFI loader fills vga_console_info directly. */
-    if ( efi_enabled )
+    /* vga_console_info is filled directly on EFI platform. */
+    if ( efi_enabled(EFI_BOOT) )
         return;
 
     if ( (bvi->orig_video_isVGA == 1) && (bvi->orig_video_mode == 3) )
@@ -726,7 +726,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     if ( !(mbi->flags & MBI_MODULES) || (mbi->mods_count == 0) )
         panic("dom0 kernel not specified. Check bootloader configuration.");
 
-    if ( efi_enabled )
+    if ( efi_enabled(EFI_LOADER) )
     {
         set_pdx_range(xen_phys_start >> PAGE_SHIFT,
                       (xen_phys_start + BOOTSTRAP_MAP_BASE) >> PAGE_SHIFT);
@@ -739,8 +739,10 @@ void __init noreturn __start_xen(unsigned long mbi_p)
         l3_bootmap[l3_table_offset(BOOTSTRAP_MAP_BASE)] =
             l3e_from_paddr(__pa(l2_bootmap), __PAGE_HYPERVISOR);
 
-        memmap_type = loader;
+        memmap_type = "EFI";
     }
+    else if ( efi_enabled(EFI_BOOT) )
+        memmap_type = "EFI";
     else if ( e820_raw_nr != 0 )
     {
         memmap_type = "Xen-e820";
@@ -837,7 +839,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
      * we can relocate the dom0 kernel and other multiboot modules. Also, on
      * x86/64, we relocate Xen to higher memory.
      */
-    for ( i = 0; !efi_enabled && i < mbi->mods_count; i++ )
+    for ( i = 0; !efi_enabled(EFI_LOADER) && i < mbi->mods_count; i++ )
     {
         if ( mod[i].mod_start & (PAGE_SIZE - 1) )
             panic("Bootloader didn't honor module alignment request.");
@@ -1078,7 +1080,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     if ( !xen_phys_start )
         panic("Not enough memory to relocate Xen.");
-    reserve_e820_ram(&boot_e820, efi_enabled ? mbi->mem_upper : __pa(&_start),
+    reserve_e820_ram(&boot_e820, efi_enabled(EFI_BOOT) ? mbi->mem_upper : __pa(&_start),
                      __pa(&_end));
 
     /* Late kexec reservation (dynamic start address). */
diff --git a/xen/arch/x86/shutdown.c b/xen/arch/x86/shutdown.c
index 972e20b..b429fd0 100644
--- a/xen/arch/x86/shutdown.c
+++ b/xen/arch/x86/shutdown.c
@@ -81,7 +81,7 @@ static void __init set_reboot_type(char *str)
         str++;
     }
 
-    if ( reboot_type == BOOT_EFI && !efi_enabled )
+    if ( reboot_type == BOOT_EFI && !efi_enabled(EFI_RS) )
         reboot_type = BOOT_INVALID;
 }
 custom_param("reboot", set_reboot_type);
@@ -119,7 +119,7 @@ void machine_halt(void)
 static void default_reboot_type(void)
 {
     if ( reboot_type == BOOT_INVALID )
-        reboot_type = efi_enabled ? BOOT_EFI
+        reboot_type = efi_enabled(EFI_RS) ? BOOT_EFI
                                   : acpi_disabled ? BOOT_KBD
                                                   : BOOT_ACPI;
 }
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index b316f23..34f82cb 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -727,7 +727,7 @@ static unsigned long get_cmos_time(void)
     static bool_t __read_mostly cmos_rtc_probe;
     boolean_param("cmos-rtc-probe", cmos_rtc_probe);
 
-    if ( efi_enabled )
+    if ( efi_enabled(EFI_RS) )
     {
         res = efi_get_time();
         if ( res )
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 125c9ce..d7c484e 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -934,6 +934,13 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     char *option_str;
     bool_t use_cfg_file;
 
+    __set_bit(EFI_BOOT, &efi_flags);
+    __set_bit(EFI_LOADER, &efi_flags);
+
+#ifndef CONFIG_ARM /* Disabled until runtime services implemented. */
+    __set_bit(EFI_RS, &efi_flags);
+#endif
+
     efi_init(ImageHandle, SystemTable);
 
     use_cfg_file = efi_arch_use_config_file(SystemTable);
@@ -1153,7 +1160,6 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 
 #ifndef CONFIG_ARM /* TODO - runtime service support */
 
-static bool_t __initdata efi_rs_enable = 1;
 static bool_t __initdata efi_map_uc;
 
 static void __init parse_efi_param(char *s)
@@ -1171,7 +1177,10 @@ static void __init parse_efi_param(char *s)
             *ss = '\0';
 
         if ( !strcmp(s, "rs") )
-            efi_rs_enable = val;
+        {
+            if ( !val )
+                __clear_bit(EFI_RS, &efi_flags);
+        }
         else if ( !strcmp(s, "attr=uc") )
             efi_map_uc = val;
 
@@ -1254,7 +1263,7 @@ void __init efi_init_memory(void)
                desc->PhysicalStart, desc->PhysicalStart + len - 1,
                desc->Type, desc->Attribute);
 
-        if ( !efi_rs_enable ||
+        if ( !efi_enabled(EFI_RS) ||
              (!(desc->Attribute & EFI_MEMORY_RUNTIME) &&
               (!map_bs ||
                (desc->Type != EfiBootServicesCode &&
@@ -1328,7 +1337,7 @@ void __init efi_init_memory(void)
         }
     }
 
-    if ( !efi_rs_enable )
+    if ( !efi_enabled(EFI_RS) )
     {
         efi_fw_vendor = NULL;
         return;
diff --git a/xen/common/efi/runtime.c b/xen/common/efi/runtime.c
index c256814..6bffda0 100644
--- a/xen/common/efi/runtime.c
+++ b/xen/common/efi/runtime.c
@@ -10,12 +10,6 @@ DEFINE_XEN_GUEST_HANDLE(CHAR16);
 
 #ifndef COMPAT
 
-/*
- * Currently runtime services are not implemented on ARM. To boot Xen with ACPI,
- * set efi_enabled to 1, so that Xen can get the ACPI root pointer from EFI.
- */
-const bool_t efi_enabled = 1;
-
 #ifndef CONFIG_ARM
 # include <asm/i387.h>
 # include <asm/xstate.h>
@@ -43,6 +37,9 @@ 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;
 
+/* Bit fields representing available EFI features/properties. */
+unsigned long efi_flags;
+
 struct efi __read_mostly efi = {
 	.acpi   = EFI_INVALID_TABLE_ADDR,
 	.acpi20 = EFI_INVALID_TABLE_ADDR,
@@ -53,6 +50,12 @@ struct efi __read_mostly efi = {
 
 const struct efi_pci_rom *__read_mostly efi_pci_roms;
 
+/* Test whether EFI_* bits are enabled. */
+bool_t efi_enabled(int feature)
+{
+    return test_bit(feature, &efi_flags);
+}
+
 #ifndef CONFIG_ARM /* TODO - disabled until implemented on ARM */
 unsigned long efi_rs_enter(void)
 {
diff --git a/xen/drivers/acpi/osl.c b/xen/drivers/acpi/osl.c
index 9a49029..3616dfd 100644
--- a/xen/drivers/acpi/osl.c
+++ b/xen/drivers/acpi/osl.c
@@ -66,7 +66,7 @@ void __init acpi_os_vprintf(const char *fmt, va_list args)
 
 acpi_physical_address __init acpi_os_get_root_pointer(void)
 {
-	if (efi_enabled) {
+	if (efi_enabled(EFI_BOOT)) {
 		if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
 			return efi.acpi20;
 		else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
diff --git a/xen/include/xen/efi.h b/xen/include/xen/efi.h
index e74dad1..8372ae2 100644
--- a/xen/include/xen/efi.h
+++ b/xen/include/xen/efi.h
@@ -2,13 +2,17 @@
 #define __XEN_EFI_H__
 
 #ifndef __ASSEMBLY__
+#include <xen/bitops.h>
 #include <xen/types.h>
 #endif
 
-extern const bool_t efi_enabled;
-
 #define EFI_INVALID_TABLE_ADDR (~0UL)
 
+extern unsigned long efi_flags;
+#define EFI_BOOT	0	/* Were we booted from EFI? */
+#define EFI_LOADER	1	/* Were we booted directly from EFI loader? */
+#define EFI_RS		2	/* Can we use runtime services? */
+
 /* Add fields here only if they need to be referenced from non-EFI code. */
 struct efi {
     unsigned long mps;          /* MPS table */
@@ -28,6 +32,7 @@ union compat_pf_efi_info;
 struct xenpf_efi_runtime_call;
 struct compat_pf_efi_runtime_call;
 
+bool_t efi_enabled(int feature);
 void efi_init_memory(void);
 bool_t efi_rs_using_pgtables(void);
 unsigned long efi_get_time(void);
-- 
1.7.10.4


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