On 2024/6/24 16:17, Jan Beulich wrote:
> On 21.06.2024 10:20, Chen, Jiqian wrote:
>> On 2024/6/20 18:42, Jan Beulich wrote:
>>> On 20.06.2024 11:40, Chen, Jiqian wrote:
>>>> On 2024/6/18 17:23, Jan Beulich wrote:
>>>>> On 18.06.2024 10:23, Chen, Jiqian wrote:
>>>>>> On 2024/6/17 23:32, Jan Beulich wrote:
>>>>>>> On 17.06.2024 11:00, Jiqian Chen wrote:
>>>>>>>> @@ -1516,14 +1519,39 @@ static void pci_add_dm_done(libxl__egc *egc,
>>>>>>>> rc = ERROR_FAIL;
>>>>>>>> goto out;
>>>>>>>> }
>>>>>>>> - r = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
>>>>>>>> +#ifdef CONFIG_X86
>>>>>>>> + /* If dom0 doesn't have PIRQs, need to use
>>>>>>>> xc_domain_gsi_permission */
>>>>>>>> + r = xc_domain_getinfo_single(ctx->xch, 0, &info);
>>>>>>>
>>>>>>> Hard-coded 0 is imposing limitations. Ideally you would use DOMID_SELF,
>>>>>>> but
>>>>>>> I didn't check if that can be used with the underlying hypercall(s).
>>>>>>> Otherwise
>>>> From the commit 10ef7a91b5a8cb8c58903c60e2dd16ed490b3bcf, DOMID_SELF is
>>>> not allowed for XEN_DOMCTL_getdomaininfo.
>>>> And now XEN_DOMCTL_getdomaininfo gets domain through rcu_lock_domain_by_id.
>>>>
>>>>>>> you want to pass the actual domid of the local domain here.
>>>> What is the local domain here?
>>>
>>> The domain your code is running in.
>>>
>>>> What is method for me to get its domid?
>>>
>>> I hope there's an available function in one of the libraries to do that.
>> I didn't find relate function.
>> Hi Anthony, do you know?
>>
>>> But I wouldn't even know what to look for; that's a question to (primarily)
>>> Anthony then, who sadly continues to be our only tool stack maintainer.
>>>
>>> Alternatively we could maybe enable XEN_DOMCTL_getdomaininfo to permit
>>> DOMID_SELF.
>> It didn't permit DOMID_SELF since below commit. Does it still have the same
>> problem if permit DOMID_SELF?
>
> To answer this, all respective callers would need auditing. However, ...
>
>> commit 10ef7a91b5a8cb8c58903c60e2dd16ed490b3bcf
>> Author: kfraser@localhost.localdomain <kfraser@localhost.localdomain>
>> Date: Tue Aug 14 09:56:46 2007 +0100
>>
>> xen: Do not accept DOMID_SELF as input to DOMCTL_getdomaininfo.
>> This was screwing up callers that loop on getdomaininfo(), if there
>> was a domain with domid DOMID_FIRST_RESERVED-1 (== DOMID_SELF-1).
>> They would see DOMID_SELF-1, then look up DOMID_SELF, which has domid
>> 0 of course, and then start their domain-finding loop all over again!
>> Found by Kouya Shimura <ko...@jp.fujitsu.com>. Thanks!
>> Signed-off-by: Keir Fraser <k...@xensource.com>
>
> ... I view this as a pretty odd justification for the change, when imo the
> bogus loops should instead have been adjusted.
Yes, you are right.
And Anthony suggested to use LIBXL_TOOLSTACK_DOMID to replace 0 domid.
It seems there is no need to change hypercall DOMCTL_getdomaininfo for now?
>
> Jan
>
>> diff --git a/xen/common/domctl.c b/xen/common/domctl.c
>> index 09a1e84d98e0..5d29667b7c3d 100644
>> --- a/xen/common/domctl.c
>> +++ b/xen/common/domctl.c
>> @@ -463,19 +463,13 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domctl_t) u_domctl)
>> case XEN_DOMCTL_getdomaininfo:
>> {
>> struct domain *d;
>> - domid_t dom;
>> -
>> - dom = op->domain;
>> - if ( dom == DOMID_SELF )
>> - dom = current->domain->domain_id;
>> + domid_t dom = op->domain;
>>
>> rcu_read_lock(&domlist_read_lock);
>>
>> for_each_domain ( d )
>> - {
>> if ( d->domain_id >= dom )
>> break;
>> - }
>>
>> if ( d == NULL )
>> {
>
--
Best regards,
Jiqian Chen.
