From: Krister Johansen <kjlx@templeofstupid.com>
To: "Jan Beulich" <jbeulich@suse.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>
Cc: xen-devel@lists.xenproject.org, Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
David Reaver <me@davidreaver.com>
Subject: [PATCH] xen/x86: public: add TSC defines for cpuid leaf 4
Date: Tue, 24 Jan 2023 14:35:16 -0800 [thread overview]
Message-ID: <20230124223516.GA1962@templeofstupid.com> (raw)
Cpuid leaf 4 contains information about how the state of the tsc, its
mode, and some additional information. A commit that is queued for
linux would like to use this to determine whether the tsc mode has been
set to 'no emulation' in order to make some decisions about which
clocksource is more reliable.
Expose this information in the public API headers so that they can
subsequently be imported into linux and used there.
Link: https://lore.kernel.org/xen-devel/eda8d9f2-3013-1b68-0df8-64d7f13ee35e@suse.com/
Link: https://lore.kernel.org/xen-devel/0835453d-9617-48d5-b2dc-77a2ac298bad@oracle.com/
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
---
xen/include/public/arch-x86/cpuid.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/xen/include/public/arch-x86/cpuid.h b/xen/include/public/arch-x86/cpuid.h
index 7ecd16ae05..97dc970417 100644
--- a/xen/include/public/arch-x86/cpuid.h
+++ b/xen/include/public/arch-x86/cpuid.h
@@ -71,6 +71,12 @@
* EDX: shift amount for tsc->ns conversion
* Sub-leaf 2: EAX: host tsc frequency in kHz
*/
+#define XEN_CPUID_TSC_EMULATED (1u << 0)
+#define XEN_CPUID_HOST_TSC_RELIABLE (1u << 1)
+#define XEN_CPUID_RDTSCP_INSTR_AVAIL (1u << 2)
+#define XEN_CPUID_TSC_MODE_DEFAULT (0)
+#define XEN_CPUID_TSC_MODE_EMULATE (1u)
+#define XEN_CPUID_TSC_MODE_NOEMULATE (2u)
/*
* Leaf 5 (0x40000x04)
--
2.25.1
next reply other threads:[~2023-01-24 22:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 22:35 Krister Johansen [this message]
2023-01-25 6:57 ` [PATCH] xen/x86: public: add TSC defines for cpuid leaf 4 Jan Beulich
2023-01-25 18:31 ` Krister Johansen
2023-01-25 18:45 ` [PATCH v2] " Krister Johansen
2023-01-26 8:57 ` Jan Beulich
2023-01-26 17:54 ` Krister Johansen
2023-01-26 9:57 ` Jan Beulich
2023-01-26 18:02 ` Krister Johansen
2023-01-27 7:16 ` Jan Beulich
2023-01-27 18:37 ` Krister Johansen
2023-01-27 18:51 ` [PATCH v3] " Krister Johansen
2023-01-30 8:22 ` Jan Beulich
2023-01-30 17:43 ` Krister Johansen
2023-01-30 17:44 ` [PATCH v4] " Krister Johansen
2023-01-31 8:42 ` Jan Beulich
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