From: Razvan Cojocaru <rcojocaru@bitdefender.com>
To: xen-devel@lists.xen.org
Cc: andrew.cooper3@citrix.com, keir@xen.org,
"wei.liu2@citrix.com" <Wei.Liu2@citrix.com>,
jbeulich@suse.com
Subject: Re: [PATCH V3] x86/monitor: Disallow setting mem_access_emulate_each_rep when vm_event is NULL
Date: Fri, 29 Apr 2016 19:12:47 +0300 [thread overview]
Message-ID: <3a451eea-47b8-42f0-fa73-132c0fe4e39a@bitdefender.com> (raw)
In-Reply-To: <1460181249-13651-1-git-send-email-rcojocaru@bitdefender.com>
On 04/09/16 08:54, Razvan Cojocaru wrote:
> It is meaningless (and potentially dangerous - see hvmemul_virtual_to_linear())
> to set mem_access_emulate_each_rep before xc_monitor_enable() (which allocates
> vcpu->arch.vm_event) has been called, so return an error from the
> XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP hypercall when that is the case.
>
> Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
> Reviewed-by: Andrew Cooper <andrew.cooper3@citirx.com>
>
> ---
> Changes since V2:
> - Updated the if() condition as recommended by Andrew Cooper.
> - Added Andrew Cooper's Reviewed-by.
> ---
> xen/include/asm-x86/monitor.h | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/xen/include/asm-x86/monitor.h b/xen/include/asm-x86/monitor.h
> index 0954b59..d367099 100644
> --- a/xen/include/asm-x86/monitor.h
> +++ b/xen/include/asm-x86/monitor.h
> @@ -32,19 +32,29 @@
> static inline
> int arch_monitor_domctl_op(struct domain *d, struct xen_domctl_monitor_op *mop)
> {
> + int rc = 0;
> +
> switch ( mop->op )
> {
> case XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP:
> domain_pause(d);
> - d->arch.mem_access_emulate_each_rep = !!mop->event;
> + /*
> + * Enabling mem_access_emulate_each_rep without a vm_event subscriber
> + * is meaningless.
> + */
> + if ( d->max_vcpus && d->vcpu[0] && d->vcpu[0]->arch.vm_event )
> + d->arch.mem_access_emulate_each_rep = !!mop->event;
> + else
> + rc = -EINVAL;
> +
> domain_unpause(d);
> break;
>
> default:
> - return -EOPNOTSUPP;
> + rc = -EOPNOTSUPP;
> }
>
> - return 0;
> + return rc;
> }
>
> int arch_monitor_domctl_event(struct domain *d,
Hello,
According to the previous list discussion with Andrew Cooper, this fix
might be considered for the 4.7 release, so CC-ing Wei for a release
ack, as suggested.
Thanks,
Razvan
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next prev parent reply other threads:[~2016-04-29 16:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-09 5:54 [PATCH V3] x86/monitor: Disallow setting mem_access_emulate_each_rep when vm_event is NULL Razvan Cojocaru
2016-04-29 16:12 ` Razvan Cojocaru [this message]
2016-05-02 10:26 ` Wei Liu
2016-05-03 8:14 ` Jan Beulich
2016-05-03 8:18 ` Razvan Cojocaru
2016-05-03 18:28 ` Tamas K Lengyel
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