RE: [PATCH 1/2] hyperv: implement hv_get_tsc_page()

Stephen Hemminger via Virtualization
2017-02-09T18:24:53Z

The actual code looks fine, but the style police will not like you.
{ should be at start of line on functions.
And #else should be at start of line,

But maybe this was just more of exchange mangling the mail.

-----Original Message-----
From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
Sent: Thursday, February 9, 2017 6:11 AM
To: x86@kernel.org; Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; H. Peter Anvin <hpa@zytor.com>; KY Srinivasan <kys@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>; Stephen Hemminger <sthemmin@microsoft.com>; Dexuan Cui <decui@microsoft.com>; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org; virtualization@lists.linux-foundation.org
Subject: [PATCH 1/2] hyperv: implement hv_get_tsc_page()

To use Hyper-V TSC page clocksource from vDSO we need to make tsc_pg available. Implement hv_get_tsc_page() and add CONFIG_HYPERV_TSCPAGE to make #ifdef-s simple.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/hyperv/hv_init.c | 9 +++++++--
arch/x86/include/asm/mshyperv.h | 8 ++++++++
drivers/hv/Kconfig | 3 +++
3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index b371d0e..0ce8485 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -27,10 +27,15 @@
#include <linux/clockchips.h>

-#ifdef CONFIG_X86_64
+#ifdef CONFIG_HYPERV_TSCPAGE

static struct ms_hyperv_tsc_page *tsc_pg;

+struct ms_hyperv_tsc_page *hv_get_tsc_page(void) {
+ return tsc_pg;
+}
+
static u64 read_hv_clock_tsc(struct clocksource *arg) {
u64 current_tick;
@@ -136,7 +141,7 @@ void hyperv_init(void)
/*
* Register Hyper-V specific clocksource.
*/
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_HYPERV_TSCPAGE
if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
union hv_x64_msr_hypercall_contents tsc_msr;

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index f8dc370..14dd92c 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -173,4 +173,12 @@ void hyperv_report_panic(struct pt_regs *regs); bool hv_is_hypercall_page_setup(void); void hyperv_cleanup(void); #endif
+#ifdef CONFIG_HYPERV_TSCPAGE
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void); #else static inline
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void) {
+ return NULL;
+}
+#endif
#endif
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index 0403b51..c29cd53 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -7,6 +7,9 @@ config HYPERV
Select this option to run Linux as a Hyper-V client operating
system.

+config HYPERV_TSCPAGE
+ def_bool HYPERV && X86_64
+
config HYPERV_UTILS
tristate "Microsoft Hyper-V Utilities driver"
depends on HYPERV && CONNECTOR && NLS
--
2.9.3