From: Juergen Gross <jgross@suse.com>
To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>,
jdelvare@suse.com, peterz@infradead.org, hpa@zytor.com,
x86@kernel.org, mingo@redhat.com, david.vrabel@citrix.com,
Douglas_Warzecha@dell.com, pali.rohar@gmail.com,
boris.ostrovsky@oracle.com, tglx@linutronix.de,
linux@roeck-us.net
Subject: [PATCH 6/6] xen: add xen_pin_vcpu() to support calling functions on a dedicated pcpu
Date: Fri, 11 Mar 2016 12:59:34 +0100 [thread overview]
Message-ID: <1457697574-6710-7-git-send-email-jgross__11803.9429224611$1457697665$gmane$org@suse.com> (raw)
In-Reply-To: <1457697574-6710-1-git-send-email-jgross@suse.com>
Some hardware models (e.g. Dell Studio 1555 laptops) require calls to
the firmware to be issued on cpu 0 only. As Dom0 might have to use
these calls, add xen_pin_vcpu() to achieve this functionality.
In case either the domain doesn't have the privilege to make the
related hypercall or the hypervisor isn't supporting it, issue a
warning once and disable further pinning attempts.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
arch/x86/xen/enlighten.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d09e4c9..325e108 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1884,6 +1884,45 @@ static void xen_set_cpu_features(struct cpuinfo_x86 *c)
}
}
+static void xen_pin_vcpu(int cpu)
+{
+ static bool disable_pinning;
+ struct sched_pin_override pin_override;
+ int ret;
+
+ if (disable_pinning)
+ return;
+
+ pin_override.pcpu = cpu;
+ ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override);
+ if (cpu < 0)
+ return;
+
+ switch (ret) {
+ case -ENOSYS:
+ pr_warn("The kernel tried to call a function on physical cpu %d, but Xen isn't\n"
+ "supporting this. In case of problems you might consider vcpu pinning.\n",
+ cpu);
+ disable_pinning = true;
+ break;
+ case -EPERM:
+ WARN(1, "Trying to pin vcpu without having privilege to do so\n");
+ disable_pinning = true;
+ break;
+ case -EINVAL:
+ case -EBUSY:
+ pr_warn("The kernel tried to call a function on physical cpu %d, but this cpu\n"
+ "seems not to be available. Please check your Xen cpu configuration.\n",
+ cpu);
+ break;
+ case 0:
+ break;
+ default:
+ WARN(1, "rc %d while trying to pin vcpu\n", ret);
+ disable_pinning = true;
+ }
+}
+
const struct hypervisor_x86 x86_hyper_xen = {
.name = "Xen",
.detect = xen_platform,
@@ -1892,6 +1931,7 @@ const struct hypervisor_x86 x86_hyper_xen = {
#endif
.x2apic_available = xen_x2apic_para_available,
.set_cpu_features = xen_set_cpu_features,
+ .pin_vcpu = xen_pin_vcpu,
};
EXPORT_SYMBOL(x86_hyper_xen);
--
2.6.2
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-03-11 11:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1457697574-6710-1-git-send-email-jgross@suse.com>
2016-03-11 11:59 ` [PATCH 1/6] xen: sync xen header Juergen Gross
2016-03-11 11:59 ` [PATCH 2/6] sched: add function to execute a function synchronously on a physical cpu Juergen Gross
2016-03-11 11:59 ` [PATCH 3/6] dcdbas: make use of call_sync_on_phys_cpu() Juergen Gross
2016-03-11 11:59 ` [PATCH 4/6] hwmon: use call_sync_on_phys_cpu() for dell-smm i8k Juergen Gross
2016-03-11 11:59 ` [PATCH 5/6] virt, sched: add cpu pinning to call_sync_on_phys_cpu() Juergen Gross
2016-03-11 11:59 ` Juergen Gross [this message]
[not found] ` <1457697574-6710-3-git-send-email-jgross@suse.com>
2016-03-11 12:19 ` [PATCH 2/6] sched: add function to execute a function synchronously on a physical cpu Peter Zijlstra
[not found] ` <20160311121950.GZ6344@twins.programming.kicks-ass.net>
2016-03-11 12:42 ` Peter Zijlstra
2016-03-11 12:43 ` Juergen Gross
[not found] ` <56E2BD89.4020400@suse.com>
2016-03-11 12:45 ` Peter Zijlstra
[not found] ` <20160311124238.GN6375@twins.programming.kicks-ass.net>
2016-03-11 12:48 ` Juergen Gross
[not found] ` <56E2BE8C.9030309@suse.com>
2016-03-11 12:57 ` Peter Zijlstra
[not found] ` <20160311125706.GC6344@twins.programming.kicks-ass.net>
2016-03-11 13:07 ` Juergen Gross
2016-03-11 12:25 ` [PATCH 0/6] Support calling functions on dedicated " Peter Zijlstra
[not found] ` <20160311122514.GA6344@twins.programming.kicks-ass.net>
2016-03-11 12:28 ` Pali Rohár
2016-03-11 13:15 ` One Thousand Gnomes
2016-03-11 13:19 ` Peter Zijlstra
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