From: "Jan Beulich" <JBeulich@suse.com>
To: Razvan Cojocaru <rcojocaru@bitdefender.com>
Cc: andrew.cooper3@citrix.com, keir@xen.org, tamas@tklengyel.com,
"wei.liu2@citrix.com" <Wei.Liu2@citrix.com>,
xen-devel@lists.xen.org
Subject: Re: [PATCH V3] x86/monitor: Disallow setting mem_access_emulate_each_rep when vm_event is NULL
Date: Tue, 03 May 2016 02:14:05 -0600 [thread overview]
Message-ID: <572879ED02000078000E7E19@prv-mh.provo.novell.com> (raw)
In-Reply-To: <3a451eea-47b8-42f0-fa73-132c0fe4e39a@bitdefender.com>
>>> On 29.04.16 at 18:12, <rcojocaru@bitdefender.com> wrote:
> 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,
>
> 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.
Even if - without the pending ./MAINTAINERS adjustment - not
formally required, I don't understand why you didn't Cc Tamas on
this patch. I don't think this should go in without his ack.
Jan
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next prev parent reply other threads:[~2016-05-03 8:14 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
2016-05-02 10:26 ` Wei Liu
2016-05-03 8:14 ` Jan Beulich [this message]
2016-05-03 8:18 ` Razvan Cojocaru
2016-05-03 18:28 ` Tamas K Lengyel
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