[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 05/34] xen: is_hvm_domain should evaluate to 0 when !CONFIG_HVM



Hi Wei,

On 21/08/18 21:08, Wei Liu wrote:
On Tue, Aug 21, 2018 at 11:59:26AM -0700, Stefano Stabellini wrote:
On Tue, 21 Aug 2018, Julien Grall wrote:
On 08/21/2018 07:49 PM, Wei Liu wrote:
On Tue, Aug 21, 2018 at 07:33:56PM +0100, Julien Grall wrote:
Hi Wei,

On 08/21/2018 05:31 PM, Wei Liu wrote:
On Mon, Aug 20, 2018 at 05:51:28AM -0600, Jan Beulich wrote:
On 17.08.18 at 17:12, <wei.liu2@xxxxxxxxxx> wrote:
Since it is defined in common header file, introduce CONFIG_HVM to
Arm to avoid breakage.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
    xen/arch/arm/Kconfig    | 3 +++
    xen/include/xen/sched.h | 6 ++++++
    2 files changed, 9 insertions(+)
,
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 586bc62..c0e969e 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -52,6 +52,9 @@ config HAS_ITS
            prompt "GICv3 ITS MSI controller support" if EXPERT = "y"
            depends on GICV3 && !NEW_VGIC
+config HVM
+        def_bool y

I'm not convinced this is a good idea, but I'll let the ARM
maintainers
judge.

Andrew discovered that hvm flag is not set by toolstack so ARM guests
are PV guests to Xen. I think the addition here can be omitted.

However I would still like to hear from ARM maintainers what guest type
should be set for ARM, because sooner or later I will need to change PV
code as well.

Grepping for is_{hvm,pv}_* in arch/arm yields no result, but then there
is common code that we need to take care of.

Using PV was more a convenience at the time because was not there. The
plan
is to switch to PVH (see RFC [1]).

I will try to find some times this week to rework the patch based on the
comments.

Cheers,

[1] https://lists.xen.org/archives/html/xen-devel/2018-06/msg01537.html

Yes, switching to PVH in toolstack is ideal.

The problem we discuss here is in the hypervisor. Hypervisor only has
HVM and PV. What type should ARM guests be? I think with the move to use
PVH in toolstack, the type in hypervisor should be HVM (as oppose to PV
now)?

Arm guest are much closer to HVM than PV. So the hypervisor should use HVM
here.
+1

OK. In that case, what do you guys think about introducing CONFIG_HVM to
ARM?

I am ok with that. Note, you will need my patch series "tools/libxl: Switch Arm guest type to PVH" [1] to make it work on Arm.

Cheers,

[1] https://lists.xenproject.org/archives/html/xen-devel/2018-08/msg01902.html

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.