From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org, x86@kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Stephen Hemminger" <sthemmin@microsoft.com>,
"Andy Lutomirski" <luto@kernel.org>,
linux-kernel@vger.kernel.org, devel@linuxdriverproject.org
Subject: [PATCH RFC 2/6] x86/hyper-v: add a function to read both TSC and TSC page value simulateneously
Date: Fri, 1 Dec 2017 14:13:17 +0100 [thread overview]
Message-ID: <20171201131321.918-3-vkuznets@redhat.com> (raw)
In-Reply-To: <20171201131321.918-1-vkuznets@redhat.com>
This is going to be used from KVM code were we need to get both
TSC and TSC page value.
When Hyper-V code is compiled out just return rdtsc(), this will allow us
to avoid ugly ifdefs in non-Hyper-V code.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/include/asm/mshyperv.h | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 5400add2885b..2611d2c49f27 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -323,9 +323,10 @@ static inline void hyperv_setup_mmu_ops(void) {}
#ifdef CONFIG_HYPERV_TSCPAGE
struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
-static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
{
- u64 scale, offset, cur_tsc;
+ u64 scale, offset;
u32 sequence;
/*
@@ -356,7 +357,7 @@ static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
scale = READ_ONCE(tsc_pg->tsc_scale);
offset = READ_ONCE(tsc_pg->tsc_offset);
- cur_tsc = rdtsc_ordered();
+ *cur_tsc = rdtsc_ordered();
/*
* Make sure we read sequence after we read all other values
@@ -366,7 +367,14 @@ static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
} while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
- return mul_u64_u64_shr(cur_tsc, scale, 64) + offset;
+ return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
+}
+
+static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+{
+ u64 cur_tsc;
+
+ return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
}
#else
@@ -374,5 +382,13 @@ static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
return NULL;
}
+
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ *cur_tsc = rdtsc();
+
+ return cur_tsc;
+}
#endif
#endif
--
2.14.3
next prev parent reply other threads:[~2017-12-01 13:16 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-01 13:13 [PATCH RFC 0/6] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V Vitaly Kuznetsov
2017-12-01 13:13 ` [PATCH RFC 1/6] x86/hyper-v: check for required priviliges in hyperv_init() Vitaly Kuznetsov
2017-12-01 13:13 ` Vitaly Kuznetsov [this message]
2017-12-01 17:29 ` [PATCH RFC 2/6] x86/hyper-v: add a function to read both TSC and TSC page value simulateneously Stephen Hemminger
2017-12-01 17:52 ` Paolo Bonzini
2017-12-04 9:08 ` Vitaly Kuznetsov
2017-12-01 13:13 ` [PATCH RFC 3/6] x86/hyper-v: reenlightenment notifications support Vitaly Kuznetsov
2017-12-01 13:13 ` [PATCH RFC 4/6] x86/hyper-v: redirect reenlightment notifications on CPU offlining Vitaly Kuznetsov
2017-12-01 13:13 ` [PATCH RFC 5/6] x86/kvm: pass stable clocksource to guests when running nested on Hyper-V Vitaly Kuznetsov
2017-12-01 17:45 ` Radim Krčmář
2017-12-01 13:13 ` [PATCH RFC 6/6] x86/kvm: support Hyper-V reenlightenment Vitaly Kuznetsov
2017-12-01 16:11 ` [PATCH RFC 0/6] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V Paolo Bonzini
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