Re: [PATCH v3 03/70] x86/pv-shim: Don't modify the hypercall table

From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Juergen Gross <jgross@suse.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH v3 03/70] x86/pv-shim: Don't modify the hypercall table
Date: Tue, 22 Feb 2022 17:24:57 +0100	[thread overview]
Message-ID: <c8c6be89-d880-f5d4-b382-0d8e06a7de0e@suse.com> (raw)
In-Reply-To: <20220222152645.8844-3-andrew.cooper3@citrix.com>

On 22.02.2022 16:26, Andrew Cooper wrote:
> From: Juergen Gross <jgross@suse.com>
> 
> When running as pv-shim the hypercall is modified today in order to
> replace the functions for __HYPERVISOR_event_channel_op and
> __HYPERVISOR_grant_table_op hypercalls.
> 
> Change this to call the related functions from the normal handlers
> instead when running as shim. The performance implications are not
> really relevant, as a normal production hypervisor will not be
> configured to support shim mode, so the related calls will be dropped
> due to optimisation of the compiler.
> 
> Note that for the CONFIG_PV_SHIM_EXCLUSIVE case there is a dummy
> wrapper do_grant_table_op() needed, as in this case grant_table.c
> isn't being built.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> [Split out of series.  Make compile in isolation]
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

As said, somewhat hesitantly
Reviewed-by: Jan Beulich <jbeulich@suse.com>

"Make compile in isolation", while describing the changes which weren't
in Jürgen's original patch, is quite terse. But anyway.

Jan