From: Krister Johansen <kjlx@templeofstupid.com>
To: xen-devel@lists.xenproject.org
Cc: "Jan Beulich" <jbeulich@suse.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
"Juergen Gross" <jgross@suse.com>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"David Reaver" <me@davidreaver.com>
Subject: [PATCH v2] xen/x86: public: add TSC defines for cpuid leaf 4
Date: Wed, 25 Jan 2023 10:33:37 -0800 [thread overview]
Message-ID: <20230125183337.GC1963@templeofstupid.com> (raw)
In-Reply-To: <20230124223531.GB1962@templeofstupid.com>
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>
---
v2:
- Fix whitespace between comment and #defines (feedback from Jan Beulich)
- Add tsc mode 3: no emulate TSC_AUX (feedback from Jan Beulich)
---
xen/include/public/arch-x86/cpuid.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/xen/include/public/arch-x86/cpuid.h b/xen/include/public/arch-x86/cpuid.h
index 7ecd16ae05..090f7f0034 100644
--- a/xen/include/public/arch-x86/cpuid.h
+++ b/xen/include/public/arch-x86/cpuid.h
@@ -72,6 +72,14 @@
* 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)
+#define XEN_CPUID_TSC_MODE_NOEMULATE_TSC_AUX (3u)
+
/*
* Leaf 5 (0x40000x04)
* HVM-specific features
--
2.25.1
next prev parent reply other threads:[~2023-01-25 18:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 22:35 [PATCH] perf/util: Symbol lookup can fail if multiple segmets match stext Krister Johansen
2023-01-25 7:29 ` Adrian Hunter
2023-01-25 7:37 ` Adrian Hunter
2023-01-25 18:32 ` Krister Johansen
2023-01-25 18:33 ` Krister Johansen [this message]
2023-01-25 18:34 ` [PATCH v2] perf/util: Symbol lookup with kcore can fail if multiple segments " Krister Johansen
2023-01-30 13:29 ` Adrian Hunter
2023-02-02 1:00 ` Arnaldo Carvalho de Melo
2023-02-20 17:16 ` Krister Johansen
-- strict thread matches above, loose matches on Subject: below --
2023-01-24 22:35 [PATCH] xen/x86: public: add TSC defines for cpuid leaf 4 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
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