From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Juergen Gross <jgross@suse.com>, xen-devel@lists.xen.org
Cc: sstabellini@kernel.org, wei.liu2@citrix.com,
George.Dunlap@eu.citrix.com, tim@xen.org,
ian.jackson@eu.citrix.com, julien.grall@arm.com,
jbeulich@suse.com
Subject: Re: [PATCH 2/2] xen: add update indicator to vcpu_runstate_info
Date: Fri, 20 May 2016 14:34:35 +0100 [thread overview]
Message-ID: <573F126B.2050608@citrix.com> (raw)
In-Reply-To: <1463750562-20549-3-git-send-email-jgross@suse.com>
On 20/05/16 14:22, Juergen Gross wrote:
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index 1365b4a..91f256b 100644
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -239,10 +239,32 @@ static void ctxt_switch_to(struct vcpu *n)
> /* Update per-VCPU guest runstate shared memory area (if registered). */
> static void update_runstate_area(struct vcpu *v)
> {
> + bool_t update_flag;
> + void __user *guest_handle = NULL;
> + unsigned off = 0;
> +
> if ( guest_handle_is_null(runstate_guest(v)) )
> return;
>
> + update_flag = VM_ASSIST(v->domain, runstate_update_flag);
> + if ( update_flag )
> + {
> + off = offsetof(struct vcpu_runstate_info, state_entry_time) + 7;
> + guest_handle = v->runstate_guest.p;
> + guest_handle += off;
> + v->runstate.state_entry_time |= XEN_RUNSTATE_UPDATE;
> + __raw_copy_to_guest(guest_handle, (void *)&v->runstate + off, 1);
> + wmb();
smp_wmb(), throughout.
A whole lot of code gets this wrong in Xen, and plan to clean it all up
in 4.8
~Andrew
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next prev parent reply other threads:[~2016-05-20 13:34 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 13:22 [PATCH 0/2] Support consistent reads of mapped vcpu_runstate_info Juergen Gross
2016-05-20 13:22 ` [PATCH 1/2] xen/arm: add support for vm_assist hypercall Juergen Gross
2016-05-20 13:58 ` Julien Grall
2016-05-20 14:34 ` Jan Beulich
[not found] ` <573F3C9702000078000ED477@suse.com>
2016-05-20 14:42 ` Juergen Gross
2016-05-20 14:51 ` Jan Beulich
[not found] ` <573F409702000078000ED4C9@suse.com>
2016-05-20 15:08 ` Juergen Gross
2016-05-20 15:33 ` Jan Beulich
[not found] ` <573F4A7302000078000ED510@suse.com>
2016-05-20 16:02 ` Juergen Gross
2016-05-21 13:27 ` Stefano Stabellini
2016-05-21 13:59 ` Julien Grall
2016-05-21 14:03 ` Stefano Stabellini
2016-05-20 13:22 ` [PATCH 2/2] xen: add update indicator to vcpu_runstate_info Juergen Gross
2016-05-20 13:34 ` Andrew Cooper [this message]
2016-05-20 13:38 ` Juergen Gross
2016-05-20 14:49 ` Jan Beulich
[not found] ` <573F402602000078000ED4AD@suse.com>
2016-05-20 15:04 ` Juergen Gross
2016-05-20 15:36 ` Jan Beulich
[not found] ` <573F4B2F02000078000ED513@suse.com>
2016-05-20 15:54 ` Juergen Gross
2016-05-20 16:16 ` Jan Beulich
2016-05-21 14:00 ` Stefano Stabellini
[not found] ` <573F549602000078000ED57C@suse.com>
2016-05-21 4:50 ` Juergen Gross
2016-05-20 14:10 ` [PATCH 0/2] Support consistent reads of mapped vcpu_runstate_info Julien Grall
2016-05-20 14:19 ` Juergen Gross
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