Date: Fri, 3 Jan 2014 15:45:34 -0500 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> To: Roger Pau Monne <roger.pau@citrix.com> Cc: jhb@freebsd.org, julien.grall@citrix.com, freebsd-xen@freebsd.org, freebsd-current@freebsd.org, kib@freebsd.org, xen-devel@lists.xenproject.org, gibbs@freebsd.org Subject: Re: [Xen-devel] [PATCH RFC 03/13] xen: mask event channels while changing affinity Message-ID: <20140103204534.GA2732@phenom.dumpdata.com> In-Reply-To: <1387884062-41154-4-git-send-email-roger.pau@citrix.com> References: <1387884062-41154-1-git-send-email-roger.pau@citrix.com> <1387884062-41154-4-git-send-email-roger.pau@citrix.com>
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On Tue, Dec 24, 2013 at 12:20:52PM +0100, Roger Pau Monne wrote:
> Event channels should be masked while chaning affinity, or else we
changing
> might get spurious/lost interrupts.
> ---
> sys/x86/xen/xen_intr.c | 15 ++++++++++++---
> 1 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/sys/x86/xen/xen_intr.c b/sys/x86/xen/xen_intr.c
> index fd36e68..bc0781e 100644
> --- a/sys/x86/xen/xen_intr.c
> +++ b/sys/x86/xen/xen_intr.c
> @@ -797,7 +797,7 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
> struct evtchn_bind_vcpu bind_vcpu;
> struct xenisrc *isrc;
> u_int to_cpu, vcpu_id;
> - int error;
> + int error, masked;
>
> #ifdef XENHVM
> if (xen_vector_callback_enabled == 0)
> @@ -815,6 +815,12 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
> return (EINVAL);
> }
>
> + /*
> + * Mask the event channel port so we don't receive spurious events
> + * while changing affinity.
> + */
> + masked = evtchn_test_and_set_mask(isrc->xi_port);
> +
> if ((isrc->xi_type == EVTCHN_TYPE_VIRQ) ||
> (isrc->xi_type == EVTCHN_TYPE_IPI)) {
> /*
> @@ -825,8 +831,7 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
> evtchn_cpu_mask_port(isrc->xi_cpu, isrc->xi_port);
> isrc->xi_cpu = to_cpu;
> evtchn_cpu_unmask_port(isrc->xi_cpu, isrc->xi_port);
> - mtx_unlock(&xen_intr_isrc_lock);
> - return (0);
> + goto out;
> }
>
> bind_vcpu.port = isrc->xi_port;
> @@ -848,6 +853,10 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
> evtchn_cpu_mask_port(to_cpu, isrc->xi_port);
> }
> }
> +
> +out:
> + if (!masked)
> + evtchn_unmask_port(isrc->xi_port);
> mtx_unlock(&xen_intr_isrc_lock);
> return (0);
> #else
> --
> 1.7.7.5 (Apple Git-26)
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
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