Re: [Xen-devel] [PATCH v2 16/16] ARM64: XEN: Initialize Xen specific UEFI runtime services

From: Shannon Zhao
Date: Tue Jan 19 2016 - 08:13:06 EST




On 2016/1/19 1:03, Stefano Stabellini wrote:
On Fri, 15 Jan 2016, Shannon Zhao wrote:
From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

When running on Xen hypervisor, runtime services are supported through
hypercall. So call Xen specific function to initialize runtime services.

Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

Thanks Shannon, much much better! Just a couple of questions.


arch/arm/xen/enlighten.c | 5 +++++
arch/arm64/xen/Makefile | 1 +
arch/arm64/xen/efi.c | 36 ++++++++++++++++++++++++++++++++++++
drivers/xen/Kconfig | 2 +-
include/xen/xen-ops.h | 1 +
5 files changed, 44 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/xen/efi.c

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 485e117..84f27ec 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -414,6 +414,11 @@ static int __init xen_guest_init(void)
if (xen_initial_domain())
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);

+ if (IS_ENABLED(CONFIG_XEN_EFI)) {
+ if (efi_enabled(EFI_PARAVIRT))
+ xen_efi_runtime_setup();
+ }
+
return 0;
}
early_initcall(xen_guest_init);
diff --git a/arch/arm64/xen/Makefile b/arch/arm64/xen/Makefile
index 74a8d87..62e6fe2 100644
--- a/arch/arm64/xen/Makefile
+++ b/arch/arm64/xen/Makefile
@@ -1,2 +1,3 @@
xen-arm-y += $(addprefix ../../arm/xen/, enlighten.o grant-table.o p2m.o mm.o)
obj-y := xen-arm.o hypercall.o
+obj-$(CONFIG_XEN_EFI) += efi.o
diff --git a/arch/arm64/xen/efi.c b/arch/arm64/xen/efi.c
new file mode 100644
index 0000000..33046b0
--- /dev/null
+++ b/arch/arm64/xen/efi.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2015, Linaro Limited, Shannon Zhao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/efi.h>
+#include <xen/xen-ops.h>
+
+void __init xen_efi_runtime_setup(void)
+{
+ efi.get_time = xen_efi_get_time;
+ efi.set_time = xen_efi_set_time;
+ efi.get_wakeup_time = xen_efi_get_wakeup_time;
+ efi.set_wakeup_time = xen_efi_set_wakeup_time;
+ efi.get_variable = xen_efi_get_variable;
+ efi.get_next_variable = xen_efi_get_next_variable;
+ efi.set_variable = xen_efi_set_variable;
+ efi.query_variable_info = xen_efi_query_variable_info;
+ efi.update_capsule = xen_efi_update_capsule;
+ efi.query_capsule_caps = xen_efi_query_capsule_caps;
+ efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
+ efi.reset_system = NULL;
+}
+EXPORT_SYMBOL_GPL(xen_efi_runtime_setup);

This looks very similar to struct efi efi_xen previously in
drivers/xen/efi.c. Maybe it makes sense to leave struct efi efi_xen in
drivers/xen/efi.c, export it in include/xen/xen-ops.h, then here just:

efi = efi_xen;

Would that improve code readability?

Ok.

Correct me if I am wrong, but on ARM64 (differently from x86) it is not
necessary to set efi.systab because it is not used, right? If so, it
would be best to add a comment here to remember.

Not set efi.systab here because it gets the system table through fdt and set efi.systab there. See uefi_init() in arch/arm64/kernel.efi.c

efi.systab = early_memremap(efi_system_table,
sizeof(efi_system_table_t));

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 73708ac..27d216a 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -268,7 +268,7 @@ config XEN_HAVE_PVMMU

config XEN_EFI
def_bool y
- depends on X86_64 && EFI
+ depends on (ARM64 || X86_64) && EFI

config XEN_AUTO_XLATE
def_bool y
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index c83a338..36ff8e4 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -107,6 +107,7 @@ efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules,
efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules,
unsigned long count, u64 *max_size,
int *reset_type);
+void xen_efi_runtime_setup(void);

xen_efi_runtime_setup is not defined on x86, but this header is not arch
specific.


--
Shannon